am 216c9e86: Merge "Nano protobufs."

* commit '216c9e8681b9426e84c9e2222da5c0dd669261b2':
  Nano protobufs.

Android.mk

@@ -106,6 +106,15 @@ COMPILER_SRC_FILES :=  \
     src/google/protobuf/compiler/javamicro/javamicro_message.cc \
     src/google/protobuf/compiler/javamicro/javamicro_message_field.cc \
     src/google/protobuf/compiler/javamicro/javamicro_primitive_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_enum.cc \
+    src/google/protobuf/compiler/javanano/javanano_enum_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_file.cc \
+    src/google/protobuf/compiler/javanano/javanano_generator.cc \
+    src/google/protobuf/compiler/javanano/javanano_helpers.cc \
+    src/google/protobuf/compiler/javanano/javanano_message.cc \
+    src/google/protobuf/compiler/javanano/javanano_message_field.cc \
+    src/google/protobuf/compiler/javanano/javanano_primitive_field.cc \
     src/google/protobuf/compiler/python/python_generator.cc \
     src/google/protobuf/io/coded_stream.cc \
     src/google/protobuf/io/gzip_stream.cc \
@@ -121,6 +130,29 @@ COMPILER_SRC_FILES :=  \
     src/google/protobuf/stubs/strutil.cc \
     src/google/protobuf/stubs/substitute.cc
 
+# Java nano library (for device-side users)
+# =======================================================
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := libprotobuf-java-2.3.0-nano
+LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 8
+
+LOCAL_SRC_FILES := $(call all-java-files-under, java/src/main/java/com/google/protobuf/nano)
+
+include $(BUILD_STATIC_JAVA_LIBRARY)
+
+# Java nano library (for host-side users)
+# =======================================================
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := host-libprotobuf-java-2.3.0-nano
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SRC_FILES := $(call all-java-files-under, java/src/main/java/com/google/protobuf/nano)
+
+include $(BUILD_HOST_JAVA_LIBRARY)
+
 # Java micro library (for device-side users)
 # =======================================================
 include $(CLEAR_VARS)

java/README.txt

@@ -260,6 +260,57 @@ This could be compiled using:
 With the result will be com/example/TestMessages.java
 
 
+Nano version
+============================
+
+Nano is even smaller than micro, especially in the number of generated
+functions. It is like micro except:
+
+- No setter/getter/hazzer functions.
+- Has state is not available. Outputs all fields not equal to their
+  default. (See important implications below.)
+- CodedInputStreamMicro is renamed to CodedInputByteBufferNano and can
+  only take byte[] (not InputStream).
+- Similar rename from CodedOutputStreamMicro to
+  CodedOutputByteBufferNano.
+- Repeated fields are in arrays, not ArrayList or Vector.
+- Unset messages/groups are null, not an immutable empty default
+  instance.
+- Required fields are always serialized.
+- toByteArray(...) and mergeFrom(...) are now static functions of
+  MessageNano.
+- "bytes" are of java type byte[].
+
+IMPORTANT: If you have fields with defaults
+
+How fields with defaults are serialized has changed. Because we don't
+keep "has" state, any field equal to its default is assumed to be not
+set and therefore is not serialized. Consider the situation where we
+change the default value of a field. Senders compiled against an older
+version of the proto continue to match against the old default, and
+don't send values to the receiver even though the receiver assumes the
+new default value. Therefore, think carefully about the implications
+of changing the default value.
+
+IMPORTANT: If you have "bytes" fields with non-empty defaults
+
+Because the byte buffer is now of mutable type byte[], the default
+static final cannot be exposed through a public field. Each time a
+message's constructor or clear() function is called, the default value
+(kept in a private byte[]) is cloned. This causes a small memory
+penalty. This is not a problem if the field has no default or is an
+empty default.
+
+
+To use nano protobufs:
+
+- Link with the generated jar file
+  <protobuf-root>java/target/protobuf-java-2.3.0-nano.jar.
+- Invoke with --javanano_out, e.g.:
+
+../src/protoc '--javanano_out=java_package=src/test/proto/simple-data.proto|my_package,java_outer_classname=src/test/proto/simple-data.proto|OuterName:.' src/test/proto/simple-data.proto
+
+
 Usage
 =====
 

java/src/main/java/com/google/protobuf/nano/CodedInputByteBufferNano.java

@@ -0,0 +1,624 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf.nano;
+
+import java.io.IOException;
+
+/**
+ * Reads and decodes protocol message fields.
+ *
+ * This class contains two kinds of methods:  methods that read specific
+ * protocol message constructs and field types (e.g. {@link #readTag()} and
+ * {@link #readInt32()}) and methods that read low-level values (e.g.
+ * {@link #readRawVarint32()} and {@link #readRawBytes}).  If you are reading
+ * encoded protocol messages, you should use the former methods, but if you are
+ * reading some other format of your own design, use the latter.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public final class CodedInputByteBufferNano {
+  /**
+   * Create a new CodedInputStream wrapping the given byte array.
+   */
+  public static CodedInputByteBufferNano newInstance(final byte[] buf) {
+    return newInstance(buf, 0, buf.length);
+  }
+
+  /**
+   * Create a new CodedInputStream wrapping the given byte array slice.
+   */
+  public static CodedInputByteBufferNano newInstance(final byte[] buf, final int off,
+                                             final int len) {
+    return new CodedInputByteBufferNano(buf, off, len);
+  }
+
+  // -----------------------------------------------------------------
+
+  /**
+   * Attempt to read a field tag, returning zero if we have reached EOF.
+   * Protocol message parsers use this to read tags, since a protocol message
+   * may legally end wherever a tag occurs, and zero is not a valid tag number.
+   */
+  public int readTag() throws IOException {
+    if (isAtEnd()) {
+      lastTag = 0;
+      return 0;
+    }
+
+    lastTag = readRawVarint32();
+    if (lastTag == 0) {
+      // If we actually read zero, that's not a valid tag.
+      throw InvalidProtocolBufferNanoException.invalidTag();
+    }
+    return lastTag;
+  }
+
+  /**
+   * Verifies that the last call to readTag() returned the given tag value.
+   * This is used to verify that a nested group ended with the correct
+   * end tag.
+   *
+   * @throws InvalidProtocolBufferNanoException {@code value} does not match the
+   *                                        last tag.
+   */
+  public void checkLastTagWas(final int value)
+                              throws InvalidProtocolBufferNanoException {
+    if (lastTag != value) {
+      throw InvalidProtocolBufferNanoException.invalidEndTag();
+    }
+  }
+
+  /**
+   * Reads and discards a single field, given its tag value.
+   *
+   * @return {@code false} if the tag is an endgroup tag, in which case
+   *         nothing is skipped.  Otherwise, returns {@code true}.
+   */
+  public boolean skipField(final int tag) throws IOException {
+    switch (WireFormatNano.getTagWireType(tag)) {
+      case WireFormatNano.WIRETYPE_VARINT:
+        readInt32();
+        return true;
+      case WireFormatNano.WIRETYPE_FIXED64:
+        readRawLittleEndian64();
+        return true;
+      case WireFormatNano.WIRETYPE_LENGTH_DELIMITED:
+        skipRawBytes(readRawVarint32());
+        return true;
+      case WireFormatNano.WIRETYPE_START_GROUP:
+        skipMessage();
+        checkLastTagWas(
+          WireFormatNano.makeTag(WireFormatNano.getTagFieldNumber(tag),
+                             WireFormatNano.WIRETYPE_END_GROUP));
+        return true;
+      case WireFormatNano.WIRETYPE_END_GROUP:
+        return false;
+      case WireFormatNano.WIRETYPE_FIXED32:
+        readRawLittleEndian32();
+        return true;
+      default:
+        throw InvalidProtocolBufferNanoException.invalidWireType();
+    }
+  }
+
+  /**
+   * Reads and discards an entire message.  This will read either until EOF
+   * or until an endgroup tag, whichever comes first.
+   */
+  public void skipMessage() throws IOException {
+    while (true) {
+      final int tag = readTag();
+      if (tag == 0 || !skipField(tag)) {
+        return;
+      }
+    }
+  }
+
+  // -----------------------------------------------------------------
+
+  /** Read a {@code double} field value from the stream. */
+  public double readDouble() throws IOException {
+    return Double.longBitsToDouble(readRawLittleEndian64());
+  }
+
+  /** Read a {@code float} field value from the stream. */
+  public float readFloat() throws IOException {
+    return Float.intBitsToFloat(readRawLittleEndian32());
+  }
+
+  /** Read a {@code uint64} field value from the stream. */
+  public long readUInt64() throws IOException {
+    return readRawVarint64();
+  }
+
+  /** Read an {@code int64} field value from the stream. */
+  public long readInt64() throws IOException {
+    return readRawVarint64();
+  }
+
+  /** Read an {@code int32} field value from the stream. */
+  public int readInt32() throws IOException {
+    return readRawVarint32();
+  }
+
+  /** Read a {@code fixed64} field value from the stream. */
+  public long readFixed64() throws IOException {
+    return readRawLittleEndian64();
+  }
+
+  /** Read a {@code fixed32} field value from the stream. */
+  public int readFixed32() throws IOException {
+    return readRawLittleEndian32();
+  }
+
+  /** Read a {@code bool} field value from the stream. */
+  public boolean readBool() throws IOException {
+    return readRawVarint32() != 0;
+  }
+
+  /** Read a {@code string} field value from the stream. */
+  public String readString() throws IOException {
+    final int size = readRawVarint32();
+    if (size <= (bufferSize - bufferPos) && size > 0) {
+      // Fast path:  We already have the bytes in a contiguous buffer, so
+      //   just copy directly from it.
+      final String result = new String(buffer, bufferPos, size, "UTF-8");
+      bufferPos += size;
+      return result;
+    } else {
+      // Slow path:  Build a byte array first then copy it.
+      return new String(readRawBytes(size), "UTF-8");
+    }
+  }
+
+  /** Read a {@code group} field value from the stream. */
+  public void readGroup(final MessageNano msg, final int fieldNumber)
+      throws IOException {
+    if (recursionDepth >= recursionLimit) {
+      throw InvalidProtocolBufferNanoException.recursionLimitExceeded();
+    }
+    ++recursionDepth;
+    msg.mergeFrom(this);
+    checkLastTagWas(
+      WireFormatNano.makeTag(fieldNumber, WireFormatNano.WIRETYPE_END_GROUP));
+    --recursionDepth;
+  }
+
+  public void readMessage(final MessageNano msg)
+      throws IOException {
+    final int length = readRawVarint32();
+    if (recursionDepth >= recursionLimit) {
+      throw InvalidProtocolBufferNanoException.recursionLimitExceeded();
+    }
+    final int oldLimit = pushLimit(length);
+    ++recursionDepth;
+    msg.mergeFrom(this);
+    checkLastTagWas(0);
+    --recursionDepth;
+    popLimit(oldLimit);
+  }
+
+  /** Read a {@code bytes} field value from the stream. */
+  public byte[] readBytes() throws IOException {
+    final int size = readRawVarint32();
+    if (size <= (bufferSize - bufferPos) && size > 0) {
+      // Fast path:  We already have the bytes in a contiguous buffer, so
+      //   just copy directly from it.
+      final byte[] result = new byte[size];
+      System.arraycopy(buffer, bufferPos, result, 0, size);
+      bufferPos += size;
+      return result;
+    } else {
+      // Slow path:  Build a byte array first then copy it.
+      return readRawBytes(size);
+    }
+  }
+
+  /** Read a {@code uint32} field value from the stream. */
+  public int readUInt32() throws IOException {
+    return readRawVarint32();
+  }
+
+  /**
+   * Read an enum field value from the stream.  Caller is responsible
+   * for converting the numeric value to an actual enum.
+   */
+  public int readEnum() throws IOException {
+    return readRawVarint32();
+  }
+
+  /** Read an {@code sfixed32} field value from the stream. */
+  public int readSFixed32() throws IOException {
+    return readRawLittleEndian32();
+  }
+
+  /** Read an {@code sfixed64} field value from the stream. */
+  public long readSFixed64() throws IOException {
+    return readRawLittleEndian64();
+  }
+
+  /** Read an {@code sint32} field value from the stream. */
+  public int readSInt32() throws IOException {
+    return decodeZigZag32(readRawVarint32());
+  }
+
+  /** Read an {@code sint64} field value from the stream. */
+  public long readSInt64() throws IOException {
+    return decodeZigZag64(readRawVarint64());
+  }
+
+  // =================================================================
+
+  /**
+   * Read a raw Varint from the stream.  If larger than 32 bits, discard the
+   * upper bits.
+   */
+  public int readRawVarint32() throws IOException {
+    byte tmp = readRawByte();
+    if (tmp >= 0) {
+      return tmp;
+    }
+    int result = tmp & 0x7f;
+    if ((tmp = readRawByte()) >= 0) {
+      result |= tmp << 7;
+    } else {
+      result |= (tmp & 0x7f) << 7;
+      if ((tmp = readRawByte()) >= 0) {
+        result |= tmp << 14;
+      } else {
+        result |= (tmp & 0x7f) << 14;
+        if ((tmp = readRawByte()) >= 0) {
+          result |= tmp << 21;
+        } else {
+          result |= (tmp & 0x7f) << 21;
+          result |= (tmp = readRawByte()) << 28;
+          if (tmp < 0) {
+            // Discard upper 32 bits.
+            for (int i = 0; i < 5; i++) {
+              if (readRawByte() >= 0) {
+                return result;
+              }
+            }
+            throw InvalidProtocolBufferNanoException.malformedVarint();
+          }
+        }
+      }
+    }
+    return result;
+  }
+
+  /** Read a raw Varint from the stream. */
+  public long readRawVarint64() throws IOException {
+    int shift = 0;
+    long result = 0;
+    while (shift < 64) {
+      final byte b = readRawByte();
+      result |= (long)(b & 0x7F) << shift;
+      if ((b & 0x80) == 0) {
+        return result;
+      }
+      shift += 7;
+    }
+    throw InvalidProtocolBufferNanoException.malformedVarint();
+  }
+
+  /** Read a 32-bit little-endian integer from the stream. */
+  public int readRawLittleEndian32() throws IOException {
+    final byte b1 = readRawByte();
+    final byte b2 = readRawByte();
+    final byte b3 = readRawByte();
+    final byte b4 = readRawByte();
+    return ((b1 & 0xff)      ) |
+           ((b2 & 0xff) <<  8) |
+           ((b3 & 0xff) << 16) |
+           ((b4 & 0xff) << 24);
+  }
+
+  /** Read a 64-bit little-endian integer from the stream. */
+  public long readRawLittleEndian64() throws IOException {
+    final byte b1 = readRawByte();
+    final byte b2 = readRawByte();
+    final byte b3 = readRawByte();
+    final byte b4 = readRawByte();
+    final byte b5 = readRawByte();
+    final byte b6 = readRawByte();
+    final byte b7 = readRawByte();
+    final byte b8 = readRawByte();
+    return (((long)b1 & 0xff)      ) |
+           (((long)b2 & 0xff) <<  8) |
+           (((long)b3 & 0xff) << 16) |
+           (((long)b4 & 0xff) << 24) |
+           (((long)b5 & 0xff) << 32) |
+           (((long)b6 & 0xff) << 40) |
+           (((long)b7 & 0xff) << 48) |
+           (((long)b8 & 0xff) << 56);
+  }
+
+  /**
+   * Decode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n An unsigned 32-bit integer, stored in a signed int because
+   *          Java has no explicit unsigned support.
+   * @return A signed 32-bit integer.
+   */
+  public static int decodeZigZag32(final int n) {
+    return (n >>> 1) ^ -(n & 1);
+  }
+
+  /**
+   * Decode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n An unsigned 64-bit integer, stored in a signed int because
+   *          Java has no explicit unsigned support.
+   * @return A signed 64-bit integer.
+   */
+  public static long decodeZigZag64(final long n) {
+    return (n >>> 1) ^ -(n & 1);
+  }
+
+  // -----------------------------------------------------------------
+
+  private final byte[] buffer;
+  private int bufferStart;
+  private int bufferSize;
+  private int bufferSizeAfterLimit;
+  private int bufferPos;
+  private int lastTag;
+
+  /** The absolute position of the end of the current message. */
+  private int currentLimit = Integer.MAX_VALUE;
+
+  /** See setRecursionLimit() */
+  private int recursionDepth;
+  private int recursionLimit = DEFAULT_RECURSION_LIMIT;
+
+  /** See setSizeLimit() */
+  private int sizeLimit = DEFAULT_SIZE_LIMIT;
+
+  private static final int DEFAULT_RECURSION_LIMIT = 64;
+  private static final int DEFAULT_SIZE_LIMIT = 64 << 20;  // 64MB
+
+  private CodedInputByteBufferNano(final byte[] buffer, final int off, final int len) {
+    this.buffer = buffer;
+    bufferStart = off;
+    bufferSize = off + len;
+    bufferPos = off;
+  }
+
+  /**
+   * Set the maximum message recursion depth.  In order to prevent malicious
+   * messages from causing stack overflows, {@code CodedInputStream} limits
+   * how deeply messages may be nested.  The default limit is 64.
+   *
+   * @return the old limit.
+   */
+  public int setRecursionLimit(final int limit) {
+    if (limit < 0) {
+      throw new IllegalArgumentException(
+        "Recursion limit cannot be negative: " + limit);
+    }
+    final int oldLimit = recursionLimit;
+    recursionLimit = limit;
+    return oldLimit;
+  }
+
+  /**
+   * Set the maximum message size.  In order to prevent malicious
+   * messages from exhausting memory or causing integer overflows,
+   * {@code CodedInputStream} limits how large a message may be.
+   * The default limit is 64MB.  You should set this limit as small
+   * as you can without harming your app's functionality.  Note that
+   * size limits only apply when reading from an {@code InputStream}, not
+   * when constructed around a raw byte array.
+   * <p>
+   * If you want to read several messages from a single CodedInputStream, you
+   * could call {@link #resetSizeCounter()} after each one to avoid hitting the
+   * size limit.
+   *
+   * @return the old limit.
+   */
+  public int setSizeLimit(final int limit) {
+    if (limit < 0) {
+      throw new IllegalArgumentException(
+        "Size limit cannot be negative: " + limit);
+    }
+    final int oldLimit = sizeLimit;
+    sizeLimit = limit;
+    return oldLimit;
+  }
+
+  /**
+   * Resets the current size counter to zero (see {@link #setSizeLimit(int)}).
+   */
+  public void resetSizeCounter() {
+  }
+
+  /**
+   * Sets {@code currentLimit} to (current position) + {@code byteLimit}.  This
+   * is called when descending into a length-delimited embedded message.
+   *
+   * @return the old limit.
+   */
+  public int pushLimit(int byteLimit) throws InvalidProtocolBufferNanoException {
+    if (byteLimit < 0) {
+      throw InvalidProtocolBufferNanoException.negativeSize();
+    }
+    byteLimit += bufferPos;
+    final int oldLimit = currentLimit;
+    if (byteLimit > oldLimit) {
+      throw InvalidProtocolBufferNanoException.truncatedMessage();
+    }
+    currentLimit = byteLimit;
+
+    recomputeBufferSizeAfterLimit();
+
+    return oldLimit;
+  }
+
+  private void recomputeBufferSizeAfterLimit() {
+    bufferSize += bufferSizeAfterLimit;
+    final int bufferEnd = bufferSize;
+    if (bufferEnd > currentLimit) {
+      // Limit is in current buffer.
+      bufferSizeAfterLimit = bufferEnd - currentLimit;
+      bufferSize -= bufferSizeAfterLimit;
+    } else {
+      bufferSizeAfterLimit = 0;
+    }
+  }
+
+  /**
+   * Discards the current limit, returning to the previous limit.
+   *
+   * @param oldLimit The old limit, as returned by {@code pushLimit}.
+   */
+  public void popLimit(final int oldLimit) {
+    currentLimit = oldLimit;
+    recomputeBufferSizeAfterLimit();
+  }
+
+  /**
+   * Returns the number of bytes to be read before the current limit.
+   * If no limit is set, returns -1.
+   */
+  public int getBytesUntilLimit() {
+    if (currentLimit == Integer.MAX_VALUE) {
+      return -1;
+    }
+
+    final int currentAbsolutePosition = bufferPos;
+    return currentLimit - currentAbsolutePosition;
+  }
+
+  /**
+   * Returns true if the stream has reached the end of the input.  This is the
+   * case if either the end of the underlying input source has been reached or
+   * if the stream has reached a limit created using {@link #pushLimit(int)}.
+   */
+  public boolean isAtEnd() {
+    return bufferPos == bufferSize;
+  }
+
+  /**
+   * Get current position in buffer relative to beginning offset.
+   */
+  public int getPosition() {
+    return bufferPos - bufferStart;
+  }
+
+  /**
+   * Rewind to previous position. Cannot go forward.
+   */
+  public void rewindToPosition(int position) {
+    if (position > bufferPos - bufferStart) {
+      throw new IllegalArgumentException(
+              "Position " + position + " is beyond current " + (bufferPos - bufferStart));
+    }
+    if (position < 0) {
+      throw new IllegalArgumentException("Bad position " + position);
+    }
+    bufferPos = bufferStart + position;
+  }
+
+  /**
+   * Read one byte from the input.
+   *
+   * @throws InvalidProtocolBufferNanoException The end of the stream or the current
+   *                                        limit was reached.
+   */
+  public byte readRawByte() throws IOException {
+    if (bufferPos == bufferSize) {
+      throw InvalidProtocolBufferNanoException.truncatedMessage();
+    }
+    return buffer[bufferPos++];
+  }
+
+  /**
+   * Read a fixed size of bytes from the input.
+   *
+   * @throws InvalidProtocolBufferNanoException The end of the stream or the current
+   *                                        limit was reached.
+   */
+  public byte[] readRawBytes(final int size) throws IOException {
+    if (size < 0) {
+      throw InvalidProtocolBufferNanoException.negativeSize();
+    }
+
+    if (bufferPos + size > currentLimit) {
+      // Read to the end of the stream anyway.
+      skipRawBytes(currentLimit - bufferPos);
+      // Then fail.
+      throw InvalidProtocolBufferNanoException.truncatedMessage();
+    }
+
+    if (size <= bufferSize - bufferPos) {
+      // We have all the bytes we need already.
+      final byte[] bytes = new byte[size];
+      System.arraycopy(buffer, bufferPos, bytes, 0, size);
+      bufferPos += size;
+      return bytes;
+    } else {
+      throw InvalidProtocolBufferNanoException.truncatedMessage();
+    }
+  }
+
+  /**
+   * Reads and discards {@code size} bytes.
+   *
+   * @throws InvalidProtocolBufferNanoException The end of the stream or the current
+   *                                        limit was reached.
+   */
+  public void skipRawBytes(final int size) throws IOException {
+    if (size < 0) {
+      throw InvalidProtocolBufferNanoException.negativeSize();
+    }
+
+    if (bufferPos + size > currentLimit) {
+      // Read to the end of the stream anyway.
+      skipRawBytes(currentLimit - bufferPos);
+      // Then fail.
+      throw InvalidProtocolBufferNanoException.truncatedMessage();
+    }
+
+    if (size <= bufferSize - bufferPos) {
+      // We have all the bytes we need already.
+      bufferPos += size;
+    } else {
+      throw InvalidProtocolBufferNanoException.truncatedMessage();
+    }
+  }
+}

java/src/main/java/com/google/protobuf/nano/CodedOutputByteBufferNano.java

@@ -0,0 +1,910 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf.nano;
+
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+
+/**
+ * Encodes and writes protocol message fields.
+ *
+ * <p>This class contains two kinds of methods:  methods that write specific
+ * protocol message constructs and field types (e.g. {@link #writeTag} and
+ * {@link #writeInt32}) and methods that write low-level values (e.g.
+ * {@link #writeRawVarint32} and {@link #writeRawBytes}).  If you are
+ * writing encoded protocol messages, you should use the former methods, but if
+ * you are writing some other format of your own design, use the latter.
+ *
+ * <p>This class is totally unsynchronized.
+ *
+ * @author kneton@google.com Kenton Varda
+ */
+public final class CodedOutputByteBufferNano {
+  private final byte[] buffer;
+  private final int limit;
+  private int position;
+
+  private CodedOutputByteBufferNano(final byte[] buffer, final int offset,
+                            final int length) {
+    this.buffer = buffer;
+    position = offset;
+    limit = offset + length;
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes directly to the given
+   * byte array.  If more bytes are written than fit in the array,
+   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
+   * array is faster than writing to an {@code OutputStream}.
+   */
+  public static CodedOutputByteBufferNano newInstance(final byte[] flatArray) {
+    return newInstance(flatArray, 0, flatArray.length);
+  }
+
+  /**
+   * Create a new {@code CodedOutputStream} that writes directly to the given
+   * byte array slice.  If more bytes are written than fit in the slice,
+   * {@link OutOfSpaceException} will be thrown.  Writing directly to a flat
+   * array is faster than writing to an {@code OutputStream}.
+   */
+  public static CodedOutputByteBufferNano newInstance(final byte[] flatArray,
+                                              final int offset,
+                                              final int length) {
+    return new CodedOutputByteBufferNano(flatArray, offset, length);
+  }
+
+  // -----------------------------------------------------------------
+
+  /** Write a {@code double} field, including tag, to the stream. */
+  public void writeDouble(final int fieldNumber, final double value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_FIXED64);
+    writeDoubleNoTag(value);
+  }
+
+  /** Write a {@code float} field, including tag, to the stream. */
+  public void writeFloat(final int fieldNumber, final float value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_FIXED32);
+    writeFloatNoTag(value);
+  }
+
+  /** Write a {@code uint64} field, including tag, to the stream. */
+  public void writeUInt64(final int fieldNumber, final long value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeUInt64NoTag(value);
+  }
+
+  /** Write an {@code int64} field, including tag, to the stream. */
+  public void writeInt64(final int fieldNumber, final long value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeInt64NoTag(value);
+  }
+
+  /** Write an {@code int32} field, including tag, to the stream. */
+  public void writeInt32(final int fieldNumber, final int value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeInt32NoTag(value);
+  }
+
+  /** Write a {@code fixed64} field, including tag, to the stream. */
+  public void writeFixed64(final int fieldNumber, final long value)
+                           throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_FIXED64);
+    writeFixed64NoTag(value);
+  }
+
+  /** Write a {@code fixed32} field, including tag, to the stream. */
+  public void writeFixed32(final int fieldNumber, final int value)
+                           throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_FIXED32);
+    writeFixed32NoTag(value);
+  }
+
+  /** Write a {@code bool} field, including tag, to the stream. */
+  public void writeBool(final int fieldNumber, final boolean value)
+                        throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeBoolNoTag(value);
+  }
+
+  /** Write a {@code string} field, including tag, to the stream. */
+  public void writeString(final int fieldNumber, final String value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_LENGTH_DELIMITED);
+    writeStringNoTag(value);
+  }
+
+  /** Write a {@code group} field, including tag, to the stream. */
+  public void writeGroup(final int fieldNumber, final MessageNano value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_START_GROUP);
+    writeGroupNoTag(value);
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_END_GROUP);
+  }
+
+  /** Write an embedded message field, including tag, to the stream. */
+  public void writeMessage(final int fieldNumber, final MessageNano value)
+                           throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_LENGTH_DELIMITED);
+    writeMessageNoTag(value);
+  }
+
+  /** Write a {@code bytes} field, including tag, to the stream. */
+  public void writeBytes(final int fieldNumber, final byte[] value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_LENGTH_DELIMITED);
+    writeBytesNoTag(value);
+  }
+
+  /** Write a {@code byte} field, including tag, to the stream. */
+  public void writeByteArray(final int fieldNumber, final byte[] value)
+                         throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_LENGTH_DELIMITED);
+    writeByteArrayNoTag(value);
+  }
+
+
+  /** Write a {@code uint32} field, including tag, to the stream. */
+  public void writeUInt32(final int fieldNumber, final int value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeUInt32NoTag(value);
+  }
+
+  /**
+   * Write an enum field, including tag, to the stream.  Caller is responsible
+   * for converting the enum value to its numeric value.
+   */
+  public void writeEnum(final int fieldNumber, final int value)
+                        throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeEnumNoTag(value);
+  }
+
+  /** Write an {@code sfixed32} field, including tag, to the stream. */
+  public void writeSFixed32(final int fieldNumber, final int value)
+                            throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_FIXED32);
+    writeSFixed32NoTag(value);
+  }
+
+  /** Write an {@code sfixed64} field, including tag, to the stream. */
+  public void writeSFixed64(final int fieldNumber, final long value)
+                            throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_FIXED64);
+    writeSFixed64NoTag(value);
+  }
+
+  /** Write an {@code sint32} field, including tag, to the stream. */
+  public void writeSInt32(final int fieldNumber, final int value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeSInt32NoTag(value);
+  }
+
+  /** Write an {@code sint64} field, including tag, to the stream. */
+  public void writeSInt64(final int fieldNumber, final long value)
+                          throws IOException {
+    writeTag(fieldNumber, WireFormatNano.WIRETYPE_VARINT);
+    writeSInt64NoTag(value);
+  }
+
+  /**
+   * Write a MessageSet extension field to the stream.  For historical reasons,
+   * the wire format differs from normal fields.
+   */
+//  public void writeMessageSetExtension(final int fieldNumber,
+//                                       final MessageMicro value)
+//                                       throws IOException {
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_START_GROUP);
+//    writeUInt32(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber);
+//    writeMessage(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_END_GROUP);
+//  }
+
+  /**
+   * Write an unparsed MessageSet extension field to the stream.  For
+   * historical reasons, the wire format differs from normal fields.
+   */
+//  public void writeRawMessageSetExtension(final int fieldNumber,
+//                                          final ByteStringMicro value)
+//                                          throws IOException {
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_START_GROUP);
+//    writeUInt32(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber);
+//    writeBytes(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//    writeTag(WireFormatMicro.MESSAGE_SET_ITEM, WireFormatMicro.WIRETYPE_END_GROUP);
+//  }
+
+  // -----------------------------------------------------------------
+
+  /** Write a {@code double} field to the stream. */
+  public void writeDoubleNoTag(final double value) throws IOException {
+    writeRawLittleEndian64(Double.doubleToLongBits(value));
+  }
+
+  /** Write a {@code float} field to the stream. */
+  public void writeFloatNoTag(final float value) throws IOException {
+    writeRawLittleEndian32(Float.floatToIntBits(value));
+  }
+
+  /** Write a {@code uint64} field to the stream. */
+  public void writeUInt64NoTag(final long value) throws IOException {
+    writeRawVarint64(value);
+  }
+
+  /** Write an {@code int64} field to the stream. */
+  public void writeInt64NoTag(final long value) throws IOException {
+    writeRawVarint64(value);
+  }
+
+  /** Write an {@code int32} field to the stream. */
+  public void writeInt32NoTag(final int value) throws IOException {
+    if (value >= 0) {
+      writeRawVarint32(value);
+    } else {
+      // Must sign-extend.
+      writeRawVarint64(value);
+    }
+  }
+
+  /** Write a {@code fixed64} field to the stream. */
+  public void writeFixed64NoTag(final long value) throws IOException {
+    writeRawLittleEndian64(value);
+  }
+
+  /** Write a {@code fixed32} field to the stream. */
+  public void writeFixed32NoTag(final int value) throws IOException {
+    writeRawLittleEndian32(value);
+  }
+
+  /** Write a {@code bool} field to the stream. */
+  public void writeBoolNoTag(final boolean value) throws IOException {
+    writeRawByte(value ? 1 : 0);
+  }
+
+  /** Write a {@code string} field to the stream. */
+  public void writeStringNoTag(final String value) throws IOException {
+    // Unfortunately there does not appear to be any way to tell Java to encode
+    // UTF-8 directly into our buffer, so we have to let it create its own byte
+    // array and then copy.
+    final byte[] bytes = value.getBytes("UTF-8");
+    writeRawVarint32(bytes.length);
+    writeRawBytes(bytes);
+  }
+
+  /** Write a {@code group} field to the stream. */
+  public void writeGroupNoTag(final MessageNano value) throws IOException {
+    value.writeTo(this);
+  }
+
+  /** Write an embedded message field to the stream. */
+  public void writeMessageNoTag(final MessageNano value) throws IOException {
+    writeRawVarint32(value.getCachedSize());
+    value.writeTo(this);
+  }
+
+  /** Write a {@code bytes} field to the stream. */
+  public void writeBytesNoTag(final byte[] value) throws IOException {
+    writeRawVarint32(value.length);
+    writeRawBytes(value);
+  }
+
+  /** Write a {@code byte[]} field to the stream. */
+  public void writeByteArrayNoTag(final byte [] value) throws IOException {
+    writeRawVarint32(value.length);
+    writeRawBytes(value);
+  }
+
+  /** Write a {@code uint32} field to the stream. */
+  public void writeUInt32NoTag(final int value) throws IOException {
+    writeRawVarint32(value);
+  }
+
+  /**
+   * Write an enum field to the stream.  Caller is responsible
+   * for converting the enum value to its numeric value.
+   */
+  public void writeEnumNoTag(final int value) throws IOException {
+    writeRawVarint32(value);
+  }
+
+  /** Write an {@code sfixed32} field to the stream. */
+  public void writeSFixed32NoTag(final int value) throws IOException {
+    writeRawLittleEndian32(value);
+  }
+
+  /** Write an {@code sfixed64} field to the stream. */
+  public void writeSFixed64NoTag(final long value) throws IOException {
+    writeRawLittleEndian64(value);
+  }
+
+  /** Write an {@code sint32} field to the stream. */
+  public void writeSInt32NoTag(final int value) throws IOException {
+    writeRawVarint32(encodeZigZag32(value));
+  }
+
+  /** Write an {@code sint64} field to the stream. */
+  public void writeSInt64NoTag(final long value) throws IOException {
+    writeRawVarint64(encodeZigZag64(value));
+  }
+
+  // =================================================================
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code double} field, including tag.
+   */
+  public static int computeDoubleSize(final int fieldNumber,
+                                      final double value) {
+    return computeTagSize(fieldNumber) + computeDoubleSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code float} field, including tag.
+   */
+  public static int computeFloatSize(final int fieldNumber, final float value) {
+    return computeTagSize(fieldNumber) + computeFloatSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint64} field, including tag.
+   */
+  public static int computeUInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeUInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int64} field, including tag.
+   */
+  public static int computeInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int32} field, including tag.
+   */
+  public static int computeInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed64} field, including tag.
+   */
+  public static int computeFixed64Size(final int fieldNumber,
+                                       final long value) {
+    return computeTagSize(fieldNumber) + computeFixed64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed32} field, including tag.
+   */
+  public static int computeFixed32Size(final int fieldNumber,
+                                       final int value) {
+    return computeTagSize(fieldNumber) + computeFixed32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bool} field, including tag.
+   */
+  public static int computeBoolSize(final int fieldNumber,
+                                    final boolean value) {
+    return computeTagSize(fieldNumber) + computeBoolSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code string} field, including tag.
+   */
+  public static int computeStringSize(final int fieldNumber,
+                                      final String value) {
+    return computeTagSize(fieldNumber) + computeStringSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code group} field, including tag.
+   */
+  public static int computeGroupSize(final int fieldNumber,
+                                     final MessageNano value) {
+    return computeTagSize(fieldNumber) * 2 + computeGroupSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * embedded message field, including tag.
+   */
+  public static int computeMessageSize(final int fieldNumber,
+                                       final MessageNano value) {
+    return computeTagSize(fieldNumber) + computeMessageSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field, including tag.
+   */
+  public static int computeBytesSize(final int fieldNumber,
+                                     final byte[] value) {
+    return computeTagSize(fieldNumber) + computeBytesSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code byte[]} field, including tag.
+   */
+  public static int computeByteArraySize(final int fieldNumber,
+                                     final byte[] value) {
+    return computeTagSize(fieldNumber) + computeByteArraySizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint32} field, including tag.
+   */
+  public static int computeUInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeUInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * enum field, including tag.  Caller is responsible for converting the
+   * enum value to its numeric value.
+   */
+  public static int computeEnumSize(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeEnumSizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed32} field, including tag.
+   */
+  public static int computeSFixed32Size(final int fieldNumber,
+                                        final int value) {
+    return computeTagSize(fieldNumber) + computeSFixed32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed64} field, including tag.
+   */
+  public static int computeSFixed64Size(final int fieldNumber,
+                                        final long value) {
+    return computeTagSize(fieldNumber) + computeSFixed64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint32} field, including tag.
+   */
+  public static int computeSInt32Size(final int fieldNumber, final int value) {
+    return computeTagSize(fieldNumber) + computeSInt32SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint64} field, including tag.
+   */
+  public static int computeSInt64Size(final int fieldNumber, final long value) {
+    return computeTagSize(fieldNumber) + computeSInt64SizeNoTag(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * MessageSet extension to the stream.  For historical reasons,
+   * the wire format differs from normal fields.
+   */
+//  public static int computeMessageSetExtensionSize(
+//      final int fieldNumber, final MessageMicro value) {
+//    return computeTagSize(WireFormatMicro.MESSAGE_SET_ITEM) * 2 +
+//           computeUInt32Size(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber) +
+//           computeMessageSize(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * unparsed MessageSet extension field to the stream.  For
+   * historical reasons, the wire format differs from normal fields.
+   */
+//  public static int computeRawMessageSetExtensionSize(
+//      final int fieldNumber, final ByteStringMicro value) {
+//    return computeTagSize(WireFormatMicro.MESSAGE_SET_ITEM) * 2 +
+//           computeUInt32Size(WireFormatMicro.MESSAGE_SET_TYPE_ID, fieldNumber) +
+//           computeBytesSize(WireFormatMicro.MESSAGE_SET_MESSAGE, value);
+//  }
+
+  // -----------------------------------------------------------------
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code double} field, including tag.
+   */
+  public static int computeDoubleSizeNoTag(final double value) {
+    return LITTLE_ENDIAN_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code float} field, including tag.
+   */
+  public static int computeFloatSizeNoTag(final float value) {
+    return LITTLE_ENDIAN_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint64} field, including tag.
+   */
+  public static int computeUInt64SizeNoTag(final long value) {
+    return computeRawVarint64Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int64} field, including tag.
+   */
+  public static int computeInt64SizeNoTag(final long value) {
+    return computeRawVarint64Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code int32} field, including tag.
+   */
+  public static int computeInt32SizeNoTag(final int value) {
+    if (value >= 0) {
+      return computeRawVarint32Size(value);
+    } else {
+      // Must sign-extend.
+      return 10;
+    }
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed64} field.
+   */
+  public static int computeFixed64SizeNoTag(final long value) {
+    return LITTLE_ENDIAN_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code fixed32} field.
+   */
+  public static int computeFixed32SizeNoTag(final int value) {
+    return LITTLE_ENDIAN_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bool} field.
+   */
+  public static int computeBoolSizeNoTag(final boolean value) {
+    return 1;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code string} field.
+   */
+  public static int computeStringSizeNoTag(final String value) {
+    try {
+      final byte[] bytes = value.getBytes("UTF-8");
+      return computeRawVarint32Size(bytes.length) +
+             bytes.length;
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported.");
+    }
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code group} field.
+   */
+  public static int computeGroupSizeNoTag(final MessageNano value) {
+    return value.getSerializedSize();
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an embedded
+   * message field.
+   */
+  public static int computeMessageSizeNoTag(final MessageNano value) {
+    final int size = value.getSerializedSize();
+    return computeRawVarint32Size(size) + size;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code bytes} field.
+   */
+  public static int computeBytesSizeNoTag(final byte[] value) {
+    return computeRawVarint32Size(value.length) + value.length;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code byte[]} field.
+   */
+  public static int computeByteArraySizeNoTag(final byte[] value) {
+    return computeRawVarint32Size(value.length) + value.length;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a
+   * {@code uint32} field.
+   */
+  public static int computeUInt32SizeNoTag(final int value) {
+    return computeRawVarint32Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an enum field.
+   * Caller is responsible for converting the enum value to its numeric value.
+   */
+  public static int computeEnumSizeNoTag(final int value) {
+    return computeRawVarint32Size(value);
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed32} field.
+   */
+  public static int computeSFixed32SizeNoTag(final int value) {
+    return LITTLE_ENDIAN_32_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sfixed64} field.
+   */
+  public static int computeSFixed64SizeNoTag(final long value) {
+    return LITTLE_ENDIAN_64_SIZE;
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint32} field.
+   */
+  public static int computeSInt32SizeNoTag(final int value) {
+    return computeRawVarint32Size(encodeZigZag32(value));
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode an
+   * {@code sint64} field.
+   */
+  public static int computeSInt64SizeNoTag(final long value) {
+    return computeRawVarint64Size(encodeZigZag64(value));
+  }
+
+  // =================================================================
+
+  /**
+   * If writing to a flat array, return the space left in the array.
+   * Otherwise, throws {@code UnsupportedOperationException}.
+   */
+  public int spaceLeft() {
+    return limit - position;
+  }
+
+  /**
+   * Verifies that {@link #spaceLeft()} returns zero.  It's common to create
+   * a byte array that is exactly big enough to hold a message, then write to
+   * it with a {@code CodedOutputStream}.  Calling {@code checkNoSpaceLeft()}
+   * after writing verifies that the message was actually as big as expected,
+   * which can help catch bugs.
+   */
+  public void checkNoSpaceLeft() {
+    if (spaceLeft() != 0) {
+      throw new IllegalStateException(
+        "Did not write as much data as expected.");
+    }
+  }
+
+  /**
+   * If you create a CodedOutputStream around a simple flat array, you must
+   * not attempt to write more bytes than the array has space.  Otherwise,
+   * this exception will be thrown.
+   */
+  public static class OutOfSpaceException extends IOException {
+    private static final long serialVersionUID = -6947486886997889499L;
+
+    OutOfSpaceException(int position, int limit) {
+      super("CodedOutputStream was writing to a flat byte array and ran " +
+            "out of space (pos " + position + " limit " + limit + ").");
+    }
+  }
+
+  /** Write a single byte. */
+  public void writeRawByte(final byte value) throws IOException {
+    if (position == limit) {
+      // We're writing to a single buffer.
+      throw new OutOfSpaceException(position, limit);
+    }
+
+    buffer[position++] = value;
+  }
+
+  /** Write a single byte, represented by an integer value. */
+  public void writeRawByte(final int value) throws IOException {
+    writeRawByte((byte) value);
+  }
+
+  /** Write an array of bytes. */
+  public void writeRawBytes(final byte[] value) throws IOException {
+    writeRawBytes(value, 0, value.length);
+  }
+
+  /** Write part of an array of bytes. */
+  public void writeRawBytes(final byte[] value, int offset, int length)
+                            throws IOException {
+    if (limit - position >= length) {
+      // We have room in the current buffer.
+      System.arraycopy(value, offset, buffer, position, length);
+      position += length;
+    } else {
+      // We're writing to a single buffer.
+      throw new OutOfSpaceException(position, limit);
+    }
+  }
+
+  /** Encode and write a tag. */
+  public void writeTag(final int fieldNumber, final int wireType)
+                       throws IOException {
+    writeRawVarint32(WireFormatNano.makeTag(fieldNumber, wireType));
+  }
+
+  /** Compute the number of bytes that would be needed to encode a tag. */
+  public static int computeTagSize(final int fieldNumber) {
+    return computeRawVarint32Size(WireFormatNano.makeTag(fieldNumber, 0));
+  }
+
+  /**
+   * Encode and write a varint.  {@code value} is treated as
+   * unsigned, so it won't be sign-extended if negative.
+   */
+  public void writeRawVarint32(int value) throws IOException {
+    while (true) {
+      if ((value & ~0x7F) == 0) {
+        writeRawByte(value);
+        return;
+      } else {
+        writeRawByte((value & 0x7F) | 0x80);
+        value >>>= 7;
+      }
+    }
+  }
+
+  /**
+   * Compute the number of bytes that would be needed to encode a varint.
+   * {@code value} is treated as unsigned, so it won't be sign-extended if
+   * negative.
+   */
+  public static int computeRawVarint32Size(final int value) {
+    if ((value & (0xffffffff <<  7)) == 0) return 1;
+    if ((value & (0xffffffff << 14)) == 0) return 2;
+    if ((value & (0xffffffff << 21)) == 0) return 3;
+    if ((value & (0xffffffff << 28)) == 0) return 4;
+    return 5;
+  }
+
+  /** Encode and write a varint. */
+  public void writeRawVarint64(long value) throws IOException {
+    while (true) {
+      if ((value & ~0x7FL) == 0) {
+        writeRawByte((int)value);
+        return;
+      } else {
+        writeRawByte(((int)value & 0x7F) | 0x80);
+        value >>>= 7;
+      }
+    }
+  }
+
+  /** Compute the number of bytes that would be needed to encode a varint. */
+  public static int computeRawVarint64Size(final long value) {
+    if ((value & (0xffffffffffffffffL <<  7)) == 0) return 1;
+    if ((value & (0xffffffffffffffffL << 14)) == 0) return 2;
+    if ((value & (0xffffffffffffffffL << 21)) == 0) return 3;
+    if ((value & (0xffffffffffffffffL << 28)) == 0) return 4;
+    if ((value & (0xffffffffffffffffL << 35)) == 0) return 5;
+    if ((value & (0xffffffffffffffffL << 42)) == 0) return 6;
+    if ((value & (0xffffffffffffffffL << 49)) == 0) return 7;
+    if ((value & (0xffffffffffffffffL << 56)) == 0) return 8;
+    if ((value & (0xffffffffffffffffL << 63)) == 0) return 9;
+    return 10;
+  }
+
+  /** Write a little-endian 32-bit integer. */
+  public void writeRawLittleEndian32(final int value) throws IOException {
+    writeRawByte((value      ) & 0xFF);
+    writeRawByte((value >>  8) & 0xFF);
+    writeRawByte((value >> 16) & 0xFF);
+    writeRawByte((value >> 24) & 0xFF);
+  }
+
+  public static final int LITTLE_ENDIAN_32_SIZE = 4;
+
+  /** Write a little-endian 64-bit integer. */
+  public void writeRawLittleEndian64(final long value) throws IOException {
+    writeRawByte((int)(value      ) & 0xFF);
+    writeRawByte((int)(value >>  8) & 0xFF);
+    writeRawByte((int)(value >> 16) & 0xFF);
+    writeRawByte((int)(value >> 24) & 0xFF);
+    writeRawByte((int)(value >> 32) & 0xFF);
+    writeRawByte((int)(value >> 40) & 0xFF);
+    writeRawByte((int)(value >> 48) & 0xFF);
+    writeRawByte((int)(value >> 56) & 0xFF);
+  }
+
+  public static final int LITTLE_ENDIAN_64_SIZE = 8;
+
+  /**
+   * Encode a ZigZag-encoded 32-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 32-bit integer.
+   * @return An unsigned 32-bit integer, stored in a signed int because
+   *         Java has no explicit unsigned support.
+   */
+  public static int encodeZigZag32(final int n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 31);
+  }
+
+  /**
+   * Encode a ZigZag-encoded 64-bit value.  ZigZag encodes signed integers
+   * into values that can be efficiently encoded with varint.  (Otherwise,
+   * negative values must be sign-extended to 64 bits to be varint encoded,
+   * thus always taking 10 bytes on the wire.)
+   *
+   * @param n A signed 64-bit integer.
+   * @return An unsigned 64-bit integer, stored in a signed int because
+   *         Java has no explicit unsigned support.
+   */
+  public static long encodeZigZag64(final long n) {
+    // Note:  the right-shift must be arithmetic
+    return (n << 1) ^ (n >> 63);
+  }
+}

java/src/main/java/com/google/protobuf/nano/InternalNano.java

@@ -0,0 +1,113 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf.nano;
+
+import java.io.UnsupportedEncodingException;
+
+/**
+ * The classes contained within are used internally by the Protocol Buffer
+ * library and generated message implementations. They are public only because
+ * those generated messages do not reside in the {@code protobuf} package.
+ * Others should not use this class directly.
+ *
+ * @author kenton@google.com (Kenton Varda)
+ */
+public class InternalNano {
+  /**
+   * Helper called by generated code to construct default values for string
+   * fields.
+   * <p>
+   * The protocol compiler does not actually contain a UTF-8 decoder -- it
+   * just pushes UTF-8-encoded text around without touching it.  The one place
+   * where this presents a problem is when generating Java string literals.
+   * Unicode characters in the string literal would normally need to be encoded
+   * using a Unicode escape sequence, which would require decoding them.
+   * To get around this, protoc instead embeds the UTF-8 bytes into the
+   * generated code and leaves it to the runtime library to decode them.
+   * <p>
+   * It gets worse, though.  If protoc just generated a byte array, like:
+   *   new byte[] {0x12, 0x34, 0x56, 0x78}
+   * Java actually generates *code* which allocates an array and then fills
+   * in each value.  This is much less efficient than just embedding the bytes
+   * directly into the bytecode.  To get around this, we need another
+   * work-around.  String literals are embedded directly, so protoc actually
+   * generates a string literal corresponding to the bytes.  The easiest way
+   * to do this is to use the ISO-8859-1 character set, which corresponds to
+   * the first 256 characters of the Unicode range.  Protoc can then use
+   * good old CEscape to generate the string.
+   * <p>
+   * So we have a string literal which represents a set of bytes which
+   * represents another string.  This function -- stringDefaultValue --
+   * converts from the generated string to the string we actually want.  The
+   * generated code calls this automatically.
+   */
+  public static final String stringDefaultValue(String bytes) {
+    try {
+      return new String(bytes.getBytes("ISO-8859-1"), "UTF-8");
+    } catch (UnsupportedEncodingException e) {
+      // This should never happen since all JVMs are required to implement
+      // both of the above character sets.
+      throw new IllegalStateException(
+          "Java VM does not support a standard character set.", e);
+    }
+  }
+
+  /**
+   * Helper called by generated code to construct default values for bytes
+   * fields.
+   * <p>
+   * This is a lot like {@link #stringDefaultValue}, but for bytes fields.
+   * In this case we only need the second of the two hacks -- allowing us to
+   * embed raw bytes as a string literal with ISO-8859-1 encoding.
+   */
+  public static final byte[] bytesDefaultValue(String bytes) {
+    try {
+      return bytes.getBytes("ISO-8859-1");
+    } catch (UnsupportedEncodingException e) {
+      // This should never happen since all JVMs are required to implement
+      // ISO-8859-1.
+      throw new IllegalStateException(
+          "Java VM does not support a standard character set.", e);
+    }
+  }
+
+  /**
+   * Helper function to convert a string into UTF-8 while turning the
+   * UnsupportedEncodingException to a RuntimeException.
+   */
+  public static final byte[] copyFromUtf8(final String text) {
+    try {
+      return text.getBytes("UTF-8");
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("UTF-8 not supported?");
+    }
+  }
+}

java/src/main/java/com/google/protobuf/nano/InvalidProtocolBufferNanoException.java

@@ -0,0 +1,93 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf.nano;
+
+import java.io.IOException;
+
+/**
+ * Thrown when a protocol message being parsed is invalid in some way,
+ * e.g. it contains a malformed varint or a negative byte length.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public class InvalidProtocolBufferNanoException extends IOException {
+  private static final long serialVersionUID = -1616151763072450476L;
+
+  public InvalidProtocolBufferNanoException(final String description) {
+    super(description);
+  }
+
+  static InvalidProtocolBufferNanoException truncatedMessage() {
+    return new InvalidProtocolBufferNanoException(
+      "While parsing a protocol message, the input ended unexpectedly " +
+      "in the middle of a field.  This could mean either than the " +
+      "input has been truncated or that an embedded message " +
+      "misreported its own length.");
+  }
+
+  static InvalidProtocolBufferNanoException negativeSize() {
+    return new InvalidProtocolBufferNanoException(
+      "CodedInputStream encountered an embedded string or message " +
+      "which claimed to have negative size.");
+  }
+
+  static InvalidProtocolBufferNanoException malformedVarint() {
+    return new InvalidProtocolBufferNanoException(
+      "CodedInputStream encountered a malformed varint.");
+  }
+
+  static InvalidProtocolBufferNanoException invalidTag() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message contained an invalid tag (zero).");
+  }
+
+  static InvalidProtocolBufferNanoException invalidEndTag() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message end-group tag did not match expected tag.");
+  }
+
+  static InvalidProtocolBufferNanoException invalidWireType() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message tag had invalid wire type.");
+  }
+
+  static InvalidProtocolBufferNanoException recursionLimitExceeded() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message had too many levels of nesting.  May be malicious.  " +
+      "Use CodedInputStream.setRecursionLimit() to increase the depth limit.");
+  }
+
+  static InvalidProtocolBufferNanoException sizeLimitExceeded() {
+    return new InvalidProtocolBufferNanoException(
+      "Protocol message was too large.  May be malicious.  " +
+      "Use CodedInputStream.setSizeLimit() to increase the size limit.");
+  }
+}

java/src/main/java/com/google/protobuf/nano/MessageNano.java

@@ -0,0 +1,128 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf.nano;
+
+import java.io.IOException;
+
+/**
+ * Abstract interface implemented by Protocol Message objects.
+ *
+ * @author wink@google.com Wink Saville
+ */
+public abstract class MessageNano {
+    /**
+     * Get the number of bytes required to encode this message.
+     * Returns the cached size or calls getSerializedSize which
+     * sets the cached size. This is used internally when serializing
+     * so the size is only computed once. If a member is modified
+     * then this could be stale call getSerializedSize if in doubt.
+     */
+    abstract public int getCachedSize();
+
+    /**
+     * Computes the number of bytes required to encode this message.
+     * The size is cached and the cached result can be retrieved
+     * using getCachedSize().
+     */
+    abstract public int getSerializedSize();
+
+    /**
+     * Serializes the message and writes it to {@code output}.  This does not
+     * flush or close the stream.
+     */
+    abstract public void writeTo(CodedOutputByteBufferNano output) throws java.io.IOException;
+
+    /**
+     * Parse {@code input} as a message of this type and merge it with the
+     * message being built.
+     */
+    abstract public MessageNano mergeFrom(final CodedInputByteBufferNano input) throws IOException;
+
+    /**
+     * Serialize to a byte array.
+     * @return byte array with the serialized data.
+     */
+    public static final byte[] toByteArray(MessageNano msg) {
+        final byte[] result = new byte[msg.getSerializedSize()];
+        toByteArray(msg, result, 0, result.length);
+        return result;
+    }
+
+    /**
+     * Serialize to a byte array starting at offset through length. The
+     * method getSerializedSize must have been called prior to calling
+     * this method so the proper length is know.  If an attempt to
+     * write more than length bytes OutOfSpaceException will be thrown
+     * and if length bytes are not written then IllegalStateException
+     * is thrown.
+     * @return byte array with the serialized data.
+     */
+    public static final void toByteArray(MessageNano msg, byte [] data, int offset, int length) {
+        try {
+            final CodedOutputByteBufferNano output =
+                CodedOutputByteBufferNano.newInstance(data, offset, length);
+            msg.writeTo(output);
+            output.checkNoSpaceLeft();
+        } catch (IOException e) {
+            throw new RuntimeException("Serializing to a byte array threw an IOException "
+                    + "(should never happen).");
+        }
+    }
+
+    /**
+     * Parse {@code data} as a message of this type and merge it with the
+     * message being built.
+     */
+    public static final MessageNano mergeFrom(MessageNano msg, final byte[] data)
+        throws InvalidProtocolBufferNanoException {
+        return mergeFrom(msg, data, 0, data.length);
+    }
+
+    /**
+     * Parse {@code data} as a message of this type and merge it with the
+     * message being built.
+     */
+    public static final MessageNano mergeFrom(MessageNano msg, final byte[] data, final int off,
+        final int len) throws InvalidProtocolBufferNanoException {
+        try {
+            final CodedInputByteBufferNano input =
+                CodedInputByteBufferNano.newInstance(data, off, len);
+            msg.mergeFrom(input);
+            input.checkLastTagWas(0);
+            return msg;
+        } catch (InvalidProtocolBufferNanoException e) {
+            throw e;
+        } catch (IOException e) {
+            throw new RuntimeException("Reading from a byte array threw an IOException (should "
+                    + "never happen).");
+        }
+    }
+}

java/src/main/java/com/google/protobuf/nano/WireFormatNano.java

@@ -0,0 +1,138 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2013 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package com.google.protobuf.nano;
+
+import java.io.IOException;
+
+/**
+ * This class is used internally by the Protocol Buffer library and generated
+ * message implementations.  It is public only because those generated messages
+ * do not reside in the {@code protobuf} package.  Others should not use this
+ * class directly.
+ *
+ * This class contains constants and helper functions useful for dealing with
+ * the Protocol Buffer wire format.
+ *
+ * @author kenton@google.com Kenton Varda
+ */
+public final class WireFormatNano {
+  // Do not allow instantiation.
+  private WireFormatNano() {}
+
+  static final int WIRETYPE_VARINT           = 0;
+  static final int WIRETYPE_FIXED64          = 1;
+  static final int WIRETYPE_LENGTH_DELIMITED = 2;
+  static final int WIRETYPE_START_GROUP      = 3;
+  static final int WIRETYPE_END_GROUP        = 4;
+  static final int WIRETYPE_FIXED32          = 5;
+
+  static final int TAG_TYPE_BITS = 3;
+  static final int TAG_TYPE_MASK = (1 << TAG_TYPE_BITS) - 1;
+
+  /** Given a tag value, determines the wire type (the lower 3 bits). */
+  static int getTagWireType(final int tag) {
+    return tag & TAG_TYPE_MASK;
+  }
+
+  /** Given a tag value, determines the field number (the upper 29 bits). */
+  public static int getTagFieldNumber(final int tag) {
+    return tag >>> TAG_TYPE_BITS;
+  }
+
+  /** Makes a tag value given a field number and wire type. */
+  static int makeTag(final int fieldNumber, final int wireType) {
+    return (fieldNumber << TAG_TYPE_BITS) | wireType;
+  }
+
+  // Field numbers for feilds in MessageSet wire format.
+  static final int MESSAGE_SET_ITEM    = 1;
+  static final int MESSAGE_SET_TYPE_ID = 2;
+  static final int MESSAGE_SET_MESSAGE = 3;
+
+  // Tag numbers.
+  static final int MESSAGE_SET_ITEM_TAG =
+    makeTag(MESSAGE_SET_ITEM, WIRETYPE_START_GROUP);
+  static final int MESSAGE_SET_ITEM_END_TAG =
+    makeTag(MESSAGE_SET_ITEM, WIRETYPE_END_GROUP);
+  static final int MESSAGE_SET_TYPE_ID_TAG =
+    makeTag(MESSAGE_SET_TYPE_ID, WIRETYPE_VARINT);
+  static final int MESSAGE_SET_MESSAGE_TAG =
+    makeTag(MESSAGE_SET_MESSAGE, WIRETYPE_LENGTH_DELIMITED);
+
+  public static final int EMPTY_INT_ARRAY[] = {};
+  public static final long EMPTY_LONG_ARRAY[] = {};
+  public static final float EMPTY_FLOAT_ARRAY[] = {};
+  public static final double EMPTY_DOUBLE_ARRAY[] = {};
+  public static final boolean EMPTY_BOOLEAN_ARRAY[] = {};
+  public static final String EMPTY_STRING_ARRAY[] = {};
+  public static final byte[] EMPTY_BYTES_ARRAY[] = {};
+  public static final byte[] EMPTY_BYTES = {};
+
+  /**
+   * Called by subclasses to parse an unknown field.
+   * @return {@code true} unless the tag is an end-group tag.
+   */
+  public static boolean parseUnknownField(
+      final CodedInputByteBufferNano input,
+      final int tag) throws IOException {
+    return input.skipField(tag);
+  }
+
+  /**
+   * Computes the array length of a repeated field. We assume that in the common case repeated
+   * fields are contiguously serialized but we still correctly handle interspersed values of a
+   * repeated field (but with extra allocations).
+   *
+   * Rewinds to current input position before returning.
+   *
+   * @param input stream input, pointing to the byte after the first tag
+   * @param tag repeated field tag just read
+   * @return length of array
+   * @throws IOException
+   */
+  public static final int getRepeatedFieldArrayLength(
+      final CodedInputByteBufferNano input,
+      final int tag) throws IOException {
+    int arrayLength = 1;
+    int startPos = input.getPosition();
+    input.skipField(tag);
+    while (input.getBytesUntilLimit() > 0) {
+      int thisTag = input.readTag();
+      if (thisTag != tag) {
+        break;
+      }
+      input.skipField(tag);
+      arrayLength++;
+    }
+    input.rewindToPosition(startPos);
+    return arrayLength;
+  }
+}

src/google/protobuf/compiler/javanano/javanano_enum.cc

@@ -0,0 +1,96 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/compiler/javanano/javanano_enum.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+EnumGenerator::EnumGenerator(const EnumDescriptor* descriptor, const Params& params)
+  : params_(params), descriptor_(descriptor) {
+  for (int i = 0; i < descriptor_->value_count(); i++) {
+    const EnumValueDescriptor* value = descriptor_->value(i);
+    const EnumValueDescriptor* canonical_value =
+      descriptor_->FindValueByNumber(value->number());
+
+    if (value == canonical_value) {
+      canonical_values_.push_back(value);
+    } else {
+      Alias alias;
+      alias.value = value;
+      alias.canonical_value = canonical_value;
+      aliases_.push_back(alias);
+    }
+  }
+}
+
+EnumGenerator::~EnumGenerator() {}
+
+void EnumGenerator::Generate(io::Printer* printer) {
+  printer->Print("// enum $classname$\n", "classname", descriptor_->name());
+  for (int i = 0; i < canonical_values_.size(); i++) {
+    map<string, string> vars;
+    vars["name"] = canonical_values_[i]->name();
+    vars["canonical_value"] = SimpleItoa(canonical_values_[i]->number());
+    printer->Print(vars,
+      "public static final int $name$ = $canonical_value$;\n");
+  }
+
+  // -----------------------------------------------------------------
+
+  for (int i = 0; i < aliases_.size(); i++) {
+    map<string, string> vars;
+    vars["name"] = aliases_[i].value->name();
+    vars["canonical_name"] = aliases_[i].canonical_value->name();
+    printer->Print(vars,
+      "public static final int $name$ = $canonical_name$;\n");
+  }
+
+  printer->Print("\n");
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_enum.h

@@ -0,0 +1,87 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_H__
+
+#include <string>
+#include <vector>
+
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/descriptor.h>
+
+namespace google {
+namespace protobuf {
+  namespace io {
+    class Printer;             // printer.h
+  }
+}
+
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class EnumGenerator {
+ public:
+  explicit EnumGenerator(const EnumDescriptor* descriptor, const Params& params);
+  ~EnumGenerator();
+
+  void Generate(io::Printer* printer);
+
+ private:
+  const Params& params_;
+  const EnumDescriptor* descriptor_;
+
+  // The proto language allows multiple enum constants to have the same numeric
+  // value.  Java, however, does not allow multiple enum constants to be
+  // considered equivalent.  We treat the first defined constant for any
+  // given numeric value as "canonical" and the rest as aliases of that
+  // canonical value.
+  vector<const EnumValueDescriptor*> canonical_values_;
+
+  struct Alias {
+    const EnumValueDescriptor* value;
+    const EnumValueDescriptor* canonical_value;
+  };
+  vector<Alias> aliases_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_H__

src/google/protobuf/compiler/javanano/javanano_enum_field.cc

@@ -0,0 +1,266 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/compiler/javanano/javanano_enum_field.h>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/wire_format.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+namespace {
+
+// TODO(kenton):  Factor out a "SetCommonFieldVariables()" to get rid of
+//   repeat code between this and the other field types.
+void SetEnumVariables(const Params& params,
+    const FieldDescriptor* descriptor, map<string, string>* variables) {
+  (*variables)["name"] =
+    UnderscoresToCamelCase(descriptor);
+  (*variables)["capitalized_name"] =
+    UnderscoresToCapitalizedCamelCase(descriptor);
+  (*variables)["number"] = SimpleItoa(descriptor->number());
+  (*variables)["type"] = "int";
+  (*variables)["default"] = DefaultValue(params, descriptor);
+  (*variables)["tag"] = SimpleItoa(internal::WireFormat::MakeTag(descriptor));
+  (*variables)["tag_size"] = SimpleItoa(
+      internal::WireFormat::TagSize(descriptor->number(), descriptor->type()));
+  (*variables)["message_name"] = descriptor->containing_type()->name();
+}
+
+}  // namespace
+
+// ===================================================================
+
+EnumFieldGenerator::
+EnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetEnumVariables(params, descriptor, &variables_);
+}
+
+EnumFieldGenerator::~EnumFieldGenerator() {}
+
+void EnumFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+    "public int $name$ = $default$;\n");
+}
+
+void EnumFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_, "$name$ = other.$name$;\n");
+}
+
+void EnumFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "  $name$ = input.readInt32();\n");
+}
+
+void EnumFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  if (descriptor_->is_required()) {
+    printer->Print(variables_,
+      "output.writeInt32($number$, $name$);\n");
+  } else {
+    printer->Print(variables_,
+      "if ($name$ != $default$) {\n"
+      "  output.writeInt32($number$, $name$);\n"
+      "}\n");
+  }
+}
+
+void EnumFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  if (descriptor_->is_required()) {
+    printer->Print(variables_,
+      "size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "  .computeInt32Size($number$, $name$);\n");
+  } else {
+    printer->Print(variables_,
+      "if ($name$ != $default$) {\n"
+      "  size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "    .computeInt32Size($number$, $name$);\n"
+      "}\n");
+  }
+}
+
+string EnumFieldGenerator::GetBoxedType() const {
+  return ClassName(params_, descriptor_->enum_type());
+}
+
+// ===================================================================
+
+RepeatedEnumFieldGenerator::
+RepeatedEnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetEnumVariables(params, descriptor, &variables_);
+}
+
+RepeatedEnumFieldGenerator::~RepeatedEnumFieldGenerator() {}
+
+void RepeatedEnumFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+    "public int[] $name$ = com.google.protobuf.nano.WireFormatNano.EMPTY_INT_ARRAY;\n");
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "private int $name$MemoizedSerializedSize;\n");
+  }
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if (other.$name$.length > 0) {\n"
+    "  int[] merged = java.util.Arrays.copyOf(result.$name$, result.$name$.length + other.$name$.length);\n"
+    "  java.lang.System.arraycopy(other.$name$, 0, merged, results.$name$.length, other.$name$.length);\n"
+    "  result.$name$ = merged;\n"
+    "}\n");
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  // First, figure out the length of the array, then parse.
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "int length = input.readRawVarint32();\n"
+      "int limit = input.pushLimit(length);\n"
+      "// First pass to compute array length.\n"
+      "int arrayLength = 0;\n"
+      "int startPos = input.getPosition();\n"
+      "while (input.getBytesUntilLimit() > 0) {\n"
+      "  input.readInt32();\n"
+      "  arrayLength++;\n"
+      "}\n"
+      "input.rewindToPosition(startPos);\n"
+      "$name$ = new $type$[arrayLength];\n"
+      "for (int i = 0; i < arrayLength; i++) {\n"
+      "  $name$[i] = input.readInt32();\n"
+      "}\n"
+      "input.popLimit(limit);\n");
+  } else {
+    printer->Print(variables_,
+      "int arrayLength = com.google.protobuf.nano.WireFormatNano.getRepeatedFieldArrayLength(input, $tag$);\n"
+      "int i = $name$.length;\n"
+      "$name$ = java.util.Arrays.copyOf($name$, $name$.length + arrayLength);\n"
+      "for (; i < $name$.length - 1; i++) {\n"
+      "  $name$[i] = input.readInt32();\n"
+      "  input.readTag();\n"
+      "}\n"
+      "// Last one without readTag.\n"
+      "$name$[i] = input.readInt32();\n");
+  }
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if ($name$.length > 0) {\n");
+  printer->Indent();
+
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "output.writeRawVarint32($tag$);\n"
+      "output.writeRawVarint32($name$MemoizedSerializedSize);\n"
+      "for (int element : $name$) {\n"
+      "  output.writeRawVarint32(element);\n"
+      "}\n");
+  } else {
+    printer->Print(variables_,
+      "for (int element : $name$) {\n"
+      "  output.writeInt32($number$, element);\n"
+      "}\n");
+  }
+  printer->Outdent();
+  printer->Print(variables_,
+    "}\n");
+}
+
+void RepeatedEnumFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if ($name$.length > 0) {\n");
+  printer->Indent();
+
+  printer->Print(variables_,
+    "int dataSize = 0;\n"
+    "for (int element : $name$) {\n"
+    "  dataSize += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+    "    .computeInt32SizeNoTag(element);\n"
+    "}\n");
+
+  printer->Print(
+    "size += dataSize;\n");
+  if (descriptor_->options().packed()) {
+    // cache the data size for packed fields.
+    printer->Print(variables_,
+      "size += $tag_size$;\n"
+      "size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "  .computeRawVarint32Size(dataSize);\n"
+      "$name$MemoizedSerializedSize = dataSize;\n");
+  } else {
+    printer->Print(variables_,
+        "size += $tag_size$ * $name$.length;\n");
+  }
+
+  printer->Outdent();
+
+  // set cached size to 0 for empty packed fields.
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "} else {\n"
+      "  $name$MemoizedSerializedSize = 0;\n"
+      "}\n");
+  } else {
+    printer->Print(
+      "}\n");
+  }
+}
+
+string RepeatedEnumFieldGenerator::GetBoxedType() const {
+  return ClassName(params_, descriptor_->enum_type());
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_enum_field.h

@@ -0,0 +1,94 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_FIELD_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_FIELD_H__
+
+#include <map>
+#include <string>
+#include <google/protobuf/compiler/javanano/javanano_field.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class EnumFieldGenerator : public FieldGenerator {
+ public:
+  explicit EnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params);
+  ~EnumFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumFieldGenerator);
+};
+
+class RepeatedEnumFieldGenerator : public FieldGenerator {
+ public:
+  explicit RepeatedEnumFieldGenerator(const FieldDescriptor* descriptor, const Params& params);
+  ~RepeatedEnumFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedEnumFieldGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_ENUM_FIELD_H__

src/google/protobuf/compiler/javanano/javanano_field.cc

@@ -0,0 +1,102 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <google/protobuf/compiler/javanano/javanano_field.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/compiler/javanano/javanano_primitive_field.h>
+#include <google/protobuf/compiler/javanano/javanano_enum_field.h>
+#include <google/protobuf/compiler/javanano/javanano_message_field.h>
+#include <google/protobuf/stubs/common.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+FieldGenerator::~FieldGenerator() {}
+
+FieldGeneratorMap::FieldGeneratorMap(const Descriptor* descriptor, const Params &params)
+  : descriptor_(descriptor),
+    field_generators_(
+      new scoped_ptr<FieldGenerator>[descriptor->field_count()]),
+    extension_generators_(
+      new scoped_ptr<FieldGenerator>[descriptor->extension_count()]) {
+
+  // Construct all the FieldGenerators.
+  for (int i = 0; i < descriptor->field_count(); i++) {
+    field_generators_[i].reset(MakeGenerator(descriptor->field(i), params));
+  }
+  for (int i = 0; i < descriptor->extension_count(); i++) {
+    extension_generators_[i].reset(MakeGenerator(descriptor->extension(i), params));
+  }
+}
+
+FieldGenerator* FieldGeneratorMap::MakeGenerator(const FieldDescriptor* field, const Params &params) {
+  if (field->is_repeated()) {
+    switch (GetJavaType(field)) {
+      case JAVATYPE_MESSAGE:
+        return new RepeatedMessageFieldGenerator(field, params);
+      case JAVATYPE_ENUM:
+        return new RepeatedEnumFieldGenerator(field, params);
+      default:
+        return new RepeatedPrimitiveFieldGenerator(field, params);
+    }
+  } else {
+    switch (GetJavaType(field)) {
+      case JAVATYPE_MESSAGE:
+        return new MessageFieldGenerator(field, params);
+      case JAVATYPE_ENUM:
+        return new EnumFieldGenerator(field, params);
+      default:
+        return new PrimitiveFieldGenerator(field, params);
+    }
+  }
+}
+
+FieldGeneratorMap::~FieldGeneratorMap() {}
+
+const FieldGenerator& FieldGeneratorMap::get(
+    const FieldDescriptor* field) const {
+  GOOGLE_CHECK_EQ(field->containing_type(), descriptor_);
+  return *field_generators_[field->index()];
+}
+
+const FieldGenerator& FieldGeneratorMap::get_extension(int index) const {
+  return *extension_generators_[index];
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_field.h

@@ -0,0 +1,98 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_FIELD_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_FIELD_H__
+
+#include <string>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/descriptor.h>
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+
+namespace google {
+namespace protobuf {
+  namespace io {
+    class Printer;             // printer.h
+  }
+}
+
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class FieldGenerator {
+ public:
+  //FieldGenerator() {}
+  FieldGenerator(const Params& params) : params_(params) {}
+  virtual ~FieldGenerator();
+
+  virtual void GenerateMembers(io::Printer* printer) const = 0;
+  virtual void GenerateMergingCode(io::Printer* printer) const = 0;
+  virtual void GenerateParsingCode(io::Printer* printer) const = 0;
+  virtual void GenerateSerializationCode(io::Printer* printer) const = 0;
+  virtual void GenerateSerializedSizeCode(io::Printer* printer) const = 0;
+
+  virtual string GetBoxedType() const = 0;
+
+ protected:
+  const Params& params_;
+ private:
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGenerator);
+};
+
+// Convenience class which constructs FieldGenerators for a Descriptor.
+class FieldGeneratorMap {
+ public:
+  explicit FieldGeneratorMap(const Descriptor* descriptor, const Params &params);
+  ~FieldGeneratorMap();
+
+  const FieldGenerator& get(const FieldDescriptor* field) const;
+  const FieldGenerator& get_extension(int index) const;
+
+ private:
+  const Descriptor* descriptor_;
+  scoped_array<scoped_ptr<FieldGenerator> > field_generators_;
+  scoped_array<scoped_ptr<FieldGenerator> > extension_generators_;
+
+  static FieldGenerator* MakeGenerator(const FieldDescriptor* field, const Params &params);
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FieldGeneratorMap);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_FIELD_H__

src/google/protobuf/compiler/javanano/javanano_file.cc

@@ -0,0 +1,251 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <google/protobuf/compiler/javanano/javanano_file.h>
+#include <google/protobuf/compiler/javanano/javanano_enum.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/compiler/javanano/javanano_message.h>
+#include <google/protobuf/compiler/code_generator.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/io/zero_copy_stream.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+namespace {
+
+// Recursively searches the given message to see if it contains any extensions.
+bool UsesExtensions(const Message& message) {
+  const Reflection* reflection = message.GetReflection();
+
+  // We conservatively assume that unknown fields are extensions.
+  if (reflection->GetUnknownFields(message).field_count() > 0) return true;
+
+  vector<const FieldDescriptor*> fields;
+  reflection->ListFields(message, &fields);
+
+  for (int i = 0; i < fields.size(); i++) {
+    if (fields[i]->is_extension()) return true;
+
+    if (fields[i]->cpp_type() == FieldDescriptor::CPPTYPE_MESSAGE) {
+      if (fields[i]->is_repeated()) {
+        int size = reflection->FieldSize(message, fields[i]);
+        for (int j = 0; j < size; j++) {
+          const Message& sub_message =
+            reflection->GetRepeatedMessage(message, fields[i], j);
+          if (UsesExtensions(sub_message)) return true;
+        }
+      } else {
+        const Message& sub_message = reflection->GetMessage(message, fields[i]);
+        if (UsesExtensions(sub_message)) return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+}  // namespace
+
+FileGenerator::FileGenerator(const FileDescriptor* file, const Params& params)
+  : file_(file),
+    params_(params),
+    java_package_(FileJavaPackage(params, file)),
+    classname_(FileClassName(params, file)) {}
+
+FileGenerator::~FileGenerator() {}
+
+bool FileGenerator::Validate(string* error) {
+  // Check for extensions
+  FileDescriptorProto file_proto;
+  file_->CopyTo(&file_proto);
+  if (UsesExtensions(file_proto)) {
+    error->assign(file_->name());
+    error->append(
+      ": Java NANO_RUNTIME does not support extensions\"");
+    return false;
+  }
+
+  // If there is no outer class name then there must be only
+  // message and no enums defined in the file scope.
+  if (!params_.has_java_outer_classname(file_->name())) {
+    if (file_->message_type_count() != 1) {
+      error->assign(file_->name());
+      error->append(
+        ": Java NANO_RUNTIME may only have 1 message if there is no 'option java_outer_classname'\"");
+      return false;
+    }
+
+    if (file_->enum_type_count() != 0) {
+      error->assign(file_->name());
+      error->append(
+        ": Java NANO_RUNTIME must have an 'option java_outer_classname' if file scope enums are present\"");
+      return false;
+    }
+  }
+
+  // Check that no class name matches the file's class name.  This is a common
+  // problem that leads to Java compile errors that can be hard to understand.
+  // It's especially bad when using the java_multiple_files, since we would
+  // end up overwriting the outer class with one of the inner ones.
+  int found_fileName = 0;
+  for (int i = 0; i < file_->enum_type_count(); i++) {
+    if (file_->enum_type(i)->name() == classname_) {
+      found_fileName += 1;
+    }
+  }
+  for (int i = 0; i < file_->message_type_count(); i++) {
+    if (file_->message_type(i)->name() == classname_) {
+      found_fileName += 1;
+    }
+  }
+  if (file_->service_count() != 0) {
+    error->assign(file_->name());
+    error->append(
+      ": Java NANO_RUNTIME does not support services\"");
+    return false;
+  }
+
+  if (found_fileName > 1) {
+    error->assign(file_->name());
+    error->append(
+      ": Cannot generate Java output because there is more than one class name, \"");
+    error->append(classname_);
+    error->append(
+      "\", matches the name of one of the types declared inside it.  "
+      "Please either rename the type or use the java_outer_classname "
+      "option to specify a different outer class name for the .proto file."
+      " -- FIX THIS MESSAGE");
+    return false;
+  }
+  return true;
+}
+
+void FileGenerator::Generate(io::Printer* printer) {
+  // We don't import anything because we refer to all classes by their
+  // fully-qualified names in the generated source.
+  printer->Print(
+    "// Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
+    "\n");
+  if (!java_package_.empty()) {
+    printer->Print(
+      "package $package$;\n"
+      "\n",
+      "package", java_package_);
+  }
+
+  if (params_.has_java_outer_classname(file_->name())) {
+    printer->Print(
+      "public final class $classname$ {\n"
+      "  private $classname$() {}\n",
+      "classname", classname_);
+    printer->Indent();
+  }
+
+  // -----------------------------------------------------------------
+
+  if (!params_.java_multiple_files()) {
+    for (int i = 0; i < file_->enum_type_count(); i++) {
+      EnumGenerator(file_->enum_type(i), params_).Generate(printer);
+    }
+    for (int i = 0; i < file_->message_type_count(); i++) {
+      MessageGenerator(file_->message_type(i), params_).Generate(printer);
+    }
+  }
+
+  // Static variables.
+  for (int i = 0; i < file_->message_type_count(); i++) {
+    // TODO(kenton):  Reuse MessageGenerator objects?
+    MessageGenerator(file_->message_type(i), params_).GenerateStaticVariables(printer);
+  }
+
+  if (params_.has_java_outer_classname(file_->name())) {
+    printer->Outdent();
+    printer->Print(
+      "}\n");
+  }
+}
+
+template<typename GeneratorClass, typename DescriptorClass>
+static void GenerateSibling(const string& package_dir,
+                            const string& java_package,
+                            const DescriptorClass* descriptor,
+                            OutputDirectory* output_directory,
+                            vector<string>* file_list,
+                            const Params& params) {
+  string filename = package_dir + descriptor->name() + ".java";
+  file_list->push_back(filename);
+
+  scoped_ptr<io::ZeroCopyOutputStream> output(
+    output_directory->Open(filename));
+  io::Printer printer(output.get(), '$');
+
+  printer.Print(
+    "// Generated by the protocol buffer compiler.  DO NOT EDIT!\n"
+    "\n");
+  if (!java_package.empty()) {
+    printer.Print(
+      "package $package$;\n"
+      "\n",
+      "package", java_package);
+  }
+
+  GeneratorClass(descriptor, params).Generate(&printer);
+}
+
+void FileGenerator::GenerateSiblings(const string& package_dir,
+                                     OutputDirectory* output_directory,
+                                     vector<string>* file_list) {
+  if (params_.java_multiple_files()) {
+    for (int i = 0; i < file_->enum_type_count(); i++) {
+      GenerateSibling<EnumGenerator>(package_dir, java_package_,
+                                     file_->enum_type(i),
+                                     output_directory, file_list, params_);
+    }
+    for (int i = 0; i < file_->message_type_count(); i++) {
+      GenerateSibling<MessageGenerator>(package_dir, java_package_,
+                                        file_->message_type(i),
+                                        output_directory, file_list, params_);
+    }
+  }
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_file.h

@@ -0,0 +1,94 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_FILE_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_FILE_H__
+
+#include <string>
+#include <vector>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+
+namespace google {
+namespace protobuf {
+  class FileDescriptor;        // descriptor.h
+  namespace io {
+    class Printer;             // printer.h
+  }
+  namespace compiler {
+    class OutputDirectory;     // code_generator.h
+  }
+}
+
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class FileGenerator {
+ public:
+  explicit FileGenerator(const FileDescriptor* file, const Params& params);
+  ~FileGenerator();
+
+  // Checks for problems that would otherwise lead to cryptic compile errors.
+  // Returns true if there are no problems, or writes an error description to
+  // the given string and returns false otherwise.
+  bool Validate(string* error);
+
+  void Generate(io::Printer* printer);
+
+  // If we aren't putting everything into one file, this will write all the
+  // files other than the outer file (i.e. one for each message, enum, and
+  // service type).
+  void GenerateSiblings(const string& package_dir,
+                        OutputDirectory* output_directory,
+                        vector<string>* file_list);
+
+  const string& java_package() { return java_package_; }
+  const string& classname()    { return classname_;    }
+
+ private:
+  const FileDescriptor* file_;
+  const Params& params_;
+  string java_package_;
+  string classname_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(FileGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_FILE_H__

src/google/protobuf/compiler/javanano/javanano_generator.cc

@@ -0,0 +1,170 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/compiler/javanano/javanano_generator.h>
+#include <google/protobuf/compiler/javanano/javanano_file.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/io/zero_copy_stream.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+void UpdateParamsRecursively(Params& params,
+    const FileDescriptor* file) {
+  // Add any parameters for this file
+  if (file->options().has_java_outer_classname()) {
+    params.set_java_outer_classname(
+      file->name(), file->options().java_outer_classname());
+  }
+  if (file->options().has_java_package()) {
+    params.set_java_package(
+      file->name(), file->options().java_package());
+  }
+
+  // Loop through all dependent files recursively
+  // adding dep
+  for (int i = 0; i < file->dependency_count(); i++) {
+    UpdateParamsRecursively(params, file->dependency(i));
+  }
+}
+
+JavaNanoGenerator::JavaNanoGenerator() {}
+JavaNanoGenerator::~JavaNanoGenerator() {}
+
+bool JavaNanoGenerator::Generate(const FileDescriptor* file,
+                             const string& parameter,
+                             OutputDirectory* output_directory,
+                             string* error) const {
+  vector<pair<string, string> > options;
+
+  ParseGeneratorParameter(parameter, &options);
+
+  // -----------------------------------------------------------------
+  // parse generator options
+
+  // Name a file where we will write a list of generated file names, one
+  // per line.
+  string output_list_file;
+  Params params(file->name());
+
+  // Get options from the proto file
+  if (file->options().has_java_multiple_files()) {
+    params.set_java_multiple_files(file->options().java_multiple_files());
+  }
+
+  // Update per file params
+  UpdateParamsRecursively(params, file);
+
+  // Replace any existing options with ones from command line
+  for (int i = 0; i < options.size(); i++) {
+    if (options[i].first == "output_list_file") {
+      output_list_file = options[i].second;
+    } else if (options[i].first == "java_package") {
+        vector<string> parts;
+        SplitStringUsing(options[i].second, "|", &parts);
+        if (parts.size() != 2) {
+          *error = "Bad java_package, expecting filename|PackageName found '"
+            + options[i].second + "'";
+          return false;
+        }
+        params.set_java_package(parts[0], parts[1]);
+    } else if (options[i].first == "java_outer_classname") {
+        vector<string> parts;
+        SplitStringUsing(options[i].second, "|", &parts);
+        if (parts.size() != 2) {
+          *error = "Bad java_outer_classname, "
+                   "expecting filename|ClassName found '"
+                   + options[i].second + "'";
+          return false;
+        }
+        params.set_java_outer_classname(parts[0], parts[1]);
+    } else if (options[i].first == "java_multiple_files") {
+        params.set_java_multiple_files(options[i].second == "true");
+    } else {
+      *error = "Ignore unknown javanano generator option: " + options[i].first;
+    }
+  }
+
+  // -----------------------------------------------------------------
+
+  FileGenerator file_generator(file, params);
+  if (!file_generator.Validate(error)) {
+    return false;
+  }
+
+  string package_dir =
+    StringReplace(file_generator.java_package(), ".", "/", true);
+  if (!package_dir.empty()) package_dir += "/";
+
+  vector<string> all_files;
+
+  string java_filename = package_dir;
+  java_filename += file_generator.classname();
+  java_filename += ".java";
+  all_files.push_back(java_filename);
+
+  // Generate main java file.
+  scoped_ptr<io::ZeroCopyOutputStream> output(
+    output_directory->Open(java_filename));
+  io::Printer printer(output.get(), '$');
+  file_generator.Generate(&printer);
+
+  // Generate sibling files.
+  file_generator.GenerateSiblings(package_dir, output_directory, &all_files);
+
+  // Generate output list if requested.
+  if (!output_list_file.empty()) {
+    // Generate output list.  This is just a simple text file placed in a
+    // deterministic location which lists the .java files being generated.
+    scoped_ptr<io::ZeroCopyOutputStream> srclist_raw_output(
+      output_directory->Open(output_list_file));
+    io::Printer srclist_printer(srclist_raw_output.get(), '$');
+    for (int i = 0; i < all_files.size(); i++) {
+      srclist_printer.Print("$filename$\n", "filename", all_files[i]);
+    }
+  }
+
+  return true;
+}
+
+}  // namespace java
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_generator.h

@@ -0,0 +1,72 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+//
+// Generates Java nano code for a given .proto file.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_NANO_GENERATOR_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_NANO_GENERATOR_H__
+
+#include <string>
+#include <google/protobuf/compiler/code_generator.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+// CodeGenerator implementation which generates Java nano code.  If you create your
+// own protocol compiler binary and you want it to support Java output for the
+// nano runtime, you can do so by registering an instance of this CodeGenerator with
+// the CommandLineInterface in your main() function.
+class LIBPROTOC_EXPORT JavaNanoGenerator : public CodeGenerator {
+ public:
+  JavaNanoGenerator();
+  ~JavaNanoGenerator();
+
+  // implements CodeGenerator ----------------------------------------
+  bool Generate(const FileDescriptor* file,
+                const string& parameter,
+                OutputDirectory* output_directory,
+                string* error) const;
+
+ private:
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(JavaNanoGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_NANO_GENERATOR_H__

src/google/protobuf/compiler/javanano/javanano_helpers.cc

@@ -0,0 +1,404 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <vector>
+
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/stubs/strutil.h>
+#include <google/protobuf/stubs/substitute.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+const char kThickSeparator[] =
+  "// ===================================================================\n";
+const char kThinSeparator[] =
+  "// -------------------------------------------------------------------\n";
+
+namespace {
+
+const char* kDefaultPackage = "";
+
+const string& FieldName(const FieldDescriptor* field) {
+  // Groups are hacky:  The name of the field is just the lower-cased name
+  // of the group type.  In Java, though, we would like to retain the original
+  // capitalization of the type name.
+  if (field->type() == FieldDescriptor::TYPE_GROUP) {
+    return field->message_type()->name();
+  } else {
+    return field->name();
+  }
+}
+
+string UnderscoresToCamelCaseImpl(const string& input, bool cap_next_letter) {
+  string result;
+  // Note:  I distrust ctype.h due to locales.
+  for (int i = 0; i < input.size(); i++) {
+    if ('a' <= input[i] && input[i] <= 'z') {
+      if (cap_next_letter) {
+        result += input[i] + ('A' - 'a');
+      } else {
+        result += input[i];
+      }
+      cap_next_letter = false;
+    } else if ('A' <= input[i] && input[i] <= 'Z') {
+      if (i == 0 && !cap_next_letter) {
+        // Force first letter to lower-case unless explicitly told to
+        // capitalize it.
+        result += input[i] + ('a' - 'A');
+      } else {
+        // Capital letters after the first are left as-is.
+        result += input[i];
+      }
+      cap_next_letter = false;
+    } else if ('0' <= input[i] && input[i] <= '9') {
+      result += input[i];
+      cap_next_letter = true;
+    } else {
+      cap_next_letter = true;
+    }
+  }
+  return result;
+}
+
+}  // namespace
+
+string UnderscoresToCamelCase(const FieldDescriptor* field) {
+  return UnderscoresToCamelCaseImpl(FieldName(field), false);
+}
+
+string UnderscoresToCapitalizedCamelCase(const FieldDescriptor* field) {
+  return UnderscoresToCamelCaseImpl(FieldName(field), true);
+}
+
+string UnderscoresToCamelCase(const MethodDescriptor* method) {
+  return UnderscoresToCamelCaseImpl(method->name(), false);
+}
+
+string StripProto(const string& filename) {
+  if (HasSuffixString(filename, ".protodevel")) {
+    return StripSuffixString(filename, ".protodevel");
+  } else {
+    return StripSuffixString(filename, ".proto");
+  }
+}
+
+string FileClassName(const Params& params, const FileDescriptor* file) {
+  string name;
+
+  if (params.has_java_outer_classname(file->name())) {
+      name = params.java_outer_classname(file->name());
+  } else {
+    if ((file->message_type_count() == 1)
+        || (file->enum_type_count() == 0)) {
+      // If no outer calls and only one message then
+      // use the message name as the file name
+      name = file->message_type(0)->name();
+    } else {
+      // Use the filename it self with underscores removed
+      // and a CamelCase style name.
+      string basename;
+      string::size_type last_slash = file->name().find_last_of('/');
+      if (last_slash == string::npos) {
+        basename = file->name();
+      } else {
+        basename = file->name().substr(last_slash + 1);
+      }
+      name = UnderscoresToCamelCaseImpl(StripProto(basename), true);
+    }
+  }
+
+  return name;
+}
+
+string FileJavaPackage(const Params& params, const FileDescriptor* file) {
+  if (params.has_java_package(file->name())) {
+    return params.java_package(file->name());
+  } else {
+    string result = kDefaultPackage;
+    if (!file->package().empty()) {
+      if (!result.empty()) result += '.';
+      result += file->package();
+    }
+    return result;
+  }
+}
+
+string ToJavaName(const Params& params, const string& full_name,
+    const FileDescriptor* file) {
+  string result;
+  if (params.java_multiple_files()) {
+    result = FileJavaPackage(params, file);
+  } else {
+    result = ClassName(params, file);
+  }
+  if (file->package().empty()) {
+    result += '.';
+    result += full_name;
+  } else {
+    // Strip the proto package from full_name since we've replaced it with
+    // the Java package. If there isn't an outer classname then strip it too.
+    int sizeToSkipPackageName = file->package().size();
+    int sizeToSkipOutClassName;
+    if (params.has_java_outer_classname(file->name())) {
+      sizeToSkipOutClassName = 0;
+    } else {
+      sizeToSkipOutClassName =
+                full_name.find_first_of('.', sizeToSkipPackageName + 1);
+    }
+    int sizeToSkip = sizeToSkipOutClassName > 0 ?
+            sizeToSkipOutClassName : sizeToSkipPackageName;
+    string class_name = full_name.substr(sizeToSkip + 1);
+    if (class_name == FileClassName(params, file)) {
+      // Done class_name is already present.
+    } else {
+      result += '.';
+      result += class_name;
+    }
+  }
+  return result;
+}
+
+string ClassName(const Params& params, const FileDescriptor* descriptor) {
+  string result = FileJavaPackage(params, descriptor);
+  if (!result.empty()) result += '.';
+  result += FileClassName(params, descriptor);
+  return result;
+}
+
+string ClassName(const Params& params, const EnumDescriptor* descriptor) {
+  string result;
+  const FileDescriptor* file = descriptor->file();
+  const string file_name = file->name();
+  const string full_name = descriptor->full_name();
+
+  // Remove enum class name as we use int's for enums
+  string base_name = full_name.substr(0, full_name.find_last_of('.'));
+
+  if (!file->package().empty()) {
+    if (file->package() == base_name.substr(0, file->package().size())) {
+      // Remove package name leaving just the parent class of the enum
+      int offset = file->package().size();
+      if (base_name.size() > offset) {
+        // Remove period between package and class name if there is a classname
+        offset += 1;
+      }
+      base_name = base_name.substr(offset);
+    } else {
+      GOOGLE_LOG(FATAL) << "Expected package name to start an enum";
+    }
+  }
+
+  // Construct the path name from the package and outer class
+
+  // Add the java package name if it exsits
+  if (params.has_java_package(file_name)) {
+    result += params.java_package(file_name);
+  }
+
+  // Add the outer classname if it exists
+  if (params.has_java_outer_classname(file_name)) {
+    if (!result.empty()) {
+      result += ".";
+    }
+    result += params.java_outer_classname(file_name);
+  }
+
+  // Create the full class name from the base and path
+  if (!base_name.empty()) {
+    if (!result.empty()) {
+      result += ".";
+    }
+    result += base_name;
+  }
+  return result;
+}
+
+string FieldConstantName(const FieldDescriptor *field) {
+  string name = field->name() + "_FIELD_NUMBER";
+  UpperString(&name);
+  return name;
+}
+
+string FieldDefaultConstantName(const FieldDescriptor *field) {
+  string name = field->name() + "_DEFAULT";
+  UpperString(&name);
+  return name;
+}
+
+JavaType GetJavaType(FieldDescriptor::Type field_type) {
+  switch (field_type) {
+    case FieldDescriptor::TYPE_INT32:
+    case FieldDescriptor::TYPE_UINT32:
+    case FieldDescriptor::TYPE_SINT32:
+    case FieldDescriptor::TYPE_FIXED32:
+    case FieldDescriptor::TYPE_SFIXED32:
+      return JAVATYPE_INT;
+
+    case FieldDescriptor::TYPE_INT64:
+    case FieldDescriptor::TYPE_UINT64:
+    case FieldDescriptor::TYPE_SINT64:
+    case FieldDescriptor::TYPE_FIXED64:
+    case FieldDescriptor::TYPE_SFIXED64:
+      return JAVATYPE_LONG;
+
+    case FieldDescriptor::TYPE_FLOAT:
+      return JAVATYPE_FLOAT;
+
+    case FieldDescriptor::TYPE_DOUBLE:
+      return JAVATYPE_DOUBLE;
+
+    case FieldDescriptor::TYPE_BOOL:
+      return JAVATYPE_BOOLEAN;
+
+    case FieldDescriptor::TYPE_STRING:
+      return JAVATYPE_STRING;
+
+    case FieldDescriptor::TYPE_BYTES:
+      return JAVATYPE_BYTES;
+
+    case FieldDescriptor::TYPE_ENUM:
+      return JAVATYPE_ENUM;
+
+    case FieldDescriptor::TYPE_GROUP:
+    case FieldDescriptor::TYPE_MESSAGE:
+      return JAVATYPE_MESSAGE;
+
+    // No default because we want the compiler to complain if any new
+    // types are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return JAVATYPE_INT;
+}
+
+const char* BoxedPrimitiveTypeName(JavaType type) {
+  switch (type) {
+    case JAVATYPE_INT    : return "java.lang.Integer";
+    case JAVATYPE_LONG   : return "java.lang.Long";
+    case JAVATYPE_FLOAT  : return "java.lang.Float";
+    case JAVATYPE_DOUBLE : return "java.lang.Double";
+    case JAVATYPE_BOOLEAN: return "java.lang.Boolean";
+    case JAVATYPE_STRING : return "java.lang.String";
+    case JAVATYPE_BYTES  : return "byte[]";
+    case JAVATYPE_ENUM   : return "java.lang.Integer";
+    case JAVATYPE_MESSAGE: return NULL;
+
+    // No default because we want the compiler to complain if any new
+    // JavaTypes are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return NULL;
+}
+
+string EmptyArrayName(const Params& params, const FieldDescriptor* field) {
+  switch (GetJavaType(field)) {
+    case JAVATYPE_INT    : return "com.google.protobuf.nano.WireFormatNano.EMPTY_INT_ARRAY";
+    case JAVATYPE_LONG   : return "com.google.protobuf.nano.WireFormatNano.EMPTY_LONG_ARRAY";
+    case JAVATYPE_FLOAT  : return "com.google.protobuf.nano.WireFormatNano.EMPTY_FLOAT_ARRAY";
+    case JAVATYPE_DOUBLE : return "com.google.protobuf.nano.WireFormatNano.EMPTY_DOUBLE_ARRAY";
+    case JAVATYPE_BOOLEAN: return "com.google.protobuf.nano.WireFormatNano.EMPTY_BOOLEAN_ARRAY";
+    case JAVATYPE_STRING : return "com.google.protobuf.nano.WireFormatNano.EMPTY_STRING_ARRAY";
+    case JAVATYPE_BYTES  : return "com.google.protobuf.nano.WireFormatNano.EMPTY_BYTES_ARRAY";
+    case JAVATYPE_ENUM   : return "com.google.protobuf.nano.WireFormatNano.EMPTY_INT_ARRAY";
+    case JAVATYPE_MESSAGE: return ClassName(params, field->message_type()) + ".EMPTY_ARRAY";
+
+    // No default because we want the compiler to complain if any new
+    // JavaTypes are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return "";
+}
+
+string DefaultValue(const Params& params, const FieldDescriptor* field) {
+  if (field->label() == FieldDescriptor::LABEL_REPEATED) {
+    return EmptyArrayName(params, field);
+  }
+
+  // Switch on cpp_type since we need to know which default_value_* method
+  // of FieldDescriptor to call.
+  switch (field->cpp_type()) {
+    case FieldDescriptor::CPPTYPE_INT32:
+      return SimpleItoa(field->default_value_int32());
+    case FieldDescriptor::CPPTYPE_UINT32:
+      // Need to print as a signed int since Java has no unsigned.
+      return SimpleItoa(static_cast<int32>(field->default_value_uint32()));
+    case FieldDescriptor::CPPTYPE_INT64:
+      return SimpleItoa(field->default_value_int64()) + "L";
+    case FieldDescriptor::CPPTYPE_UINT64:
+      return SimpleItoa(static_cast<int64>(field->default_value_uint64())) +
+             "L";
+    case FieldDescriptor::CPPTYPE_DOUBLE:
+      return SimpleDtoa(field->default_value_double()) + "D";
+    case FieldDescriptor::CPPTYPE_FLOAT:
+      return SimpleFtoa(field->default_value_float()) + "F";
+    case FieldDescriptor::CPPTYPE_BOOL:
+      return field->default_value_bool() ? "true" : "false";
+    case FieldDescriptor::CPPTYPE_STRING:
+      if (!field->default_value_string().empty()) {
+        // Point it to the static final in the generated code.
+        return FieldDefaultConstantName(field);
+      } else {
+        if (field->type() == FieldDescriptor::TYPE_BYTES) {
+          return "com.google.protobuf.nano.WireFormatNano.EMPTY_BYTES";
+        } else {
+          return "\"\"";
+        }
+      }
+
+    case FieldDescriptor::CPPTYPE_ENUM:
+      return ClassName(params, field->enum_type()) + "." +
+             field->default_value_enum()->name();
+
+    case FieldDescriptor::CPPTYPE_MESSAGE:
+      return "null";
+
+    // No default because we want the compiler to complain if any new
+    // types are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return "";
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_helpers.h

@@ -0,0 +1,132 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_HELPERS_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_HELPERS_H__
+
+#include <string>
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/descriptor.pb.h>
+#include <google/protobuf/descriptor.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+// Commonly-used separator comments.  Thick is a line of '=', thin is a line
+// of '-'.
+extern const char kThickSeparator[];
+extern const char kThinSeparator[];
+
+// Converts the field's name to camel-case, e.g. "foo_bar_baz" becomes
+// "fooBarBaz" or "FooBarBaz", respectively.
+string UnderscoresToCamelCase(const FieldDescriptor* field);
+string UnderscoresToCapitalizedCamelCase(const FieldDescriptor* field);
+
+// Similar, but for method names.  (Typically, this merely has the effect
+// of lower-casing the first letter of the name.)
+string UnderscoresToCamelCase(const MethodDescriptor* method);
+
+// Strips ".proto" or ".protodevel" from the end of a filename.
+string StripProto(const string& filename);
+
+// Gets the unqualified class name for the file.  Each .proto file becomes a
+// single Java class, with all its contents nested in that class.
+string FileClassName(const Params& params, const FileDescriptor* file);
+
+// Returns the file's Java package name.
+string FileJavaPackage(const Params& params, const FileDescriptor* file);
+
+// Converts the given fully-qualified name in the proto namespace to its
+// fully-qualified name in the Java namespace, given that it is in the given
+// file.
+string ToJavaName(const Params& params, const string& full_name,
+    const FileDescriptor* file);
+
+// These return the fully-qualified class name corresponding to the given
+// descriptor.
+inline string ClassName(const Params& params, const Descriptor* descriptor) {
+  return ToJavaName(params, descriptor->full_name(), descriptor->file());
+}
+string ClassName(const Params& params, const EnumDescriptor* descriptor);
+inline string ClassName(const Params& params,
+    const ServiceDescriptor* descriptor) {
+  return ToJavaName(params, descriptor->full_name(), descriptor->file());
+}
+inline string ExtensionIdentifierName(const Params& params,
+    const FieldDescriptor* descriptor) {
+  return ToJavaName(params, descriptor->full_name(), descriptor->file());
+}
+string ClassName(const Params& params, const FileDescriptor* descriptor);
+
+// Get the unqualified name that should be used for a field's field
+// number constant.
+string FieldConstantName(const FieldDescriptor *field);
+
+string FieldDefaultConstantName(const FieldDescriptor *field);
+
+enum JavaType {
+  JAVATYPE_INT,
+  JAVATYPE_LONG,
+  JAVATYPE_FLOAT,
+  JAVATYPE_DOUBLE,
+  JAVATYPE_BOOLEAN,
+  JAVATYPE_STRING,
+  JAVATYPE_BYTES,
+  JAVATYPE_ENUM,
+  JAVATYPE_MESSAGE
+};
+
+JavaType GetJavaType(FieldDescriptor::Type field_type);
+
+inline JavaType GetJavaType(const FieldDescriptor* field) {
+  return GetJavaType(field->type());
+}
+
+// Get the fully-qualified class name for a boxed primitive type, e.g.
+// "java.lang.Integer" for JAVATYPE_INT.  Returns NULL for enum and message
+// types.
+const char* BoxedPrimitiveTypeName(JavaType type);
+
+string EmptyArrayName(const Params& params, const FieldDescriptor* field);
+
+string DefaultValue(const Params& params, const FieldDescriptor* field);
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_HELPERS_H__

src/google/protobuf/compiler/javanano/javanano_message.cc

@@ -0,0 +1,372 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <algorithm>
+#include <google/protobuf/stubs/hash.h>
+#include <google/protobuf/compiler/javanano/javanano_message.h>
+#include <google/protobuf/compiler/javanano/javanano_enum.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/stubs/strutil.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/io/coded_stream.h>
+#include <google/protobuf/wire_format.h>
+#include <google/protobuf/descriptor.pb.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+using internal::WireFormat;
+using internal::WireFormatLite;
+
+namespace {
+
+void PrintFieldComment(io::Printer* printer, const FieldDescriptor* field) {
+  // Print the field's proto-syntax definition as a comment.  We don't want to
+  // print group bodies so we cut off after the first line.
+  string def = field->DebugString();
+  printer->Print("// $def$\n",
+    "def", def.substr(0, def.find_first_of('\n')));
+}
+
+struct FieldOrderingByNumber {
+  inline bool operator()(const FieldDescriptor* a,
+                         const FieldDescriptor* b) const {
+    return a->number() < b->number();
+  }
+};
+
+// Sort the fields of the given Descriptor by number into a new[]'d array
+// and return it.
+const FieldDescriptor** SortFieldsByNumber(const Descriptor* descriptor) {
+  const FieldDescriptor** fields =
+    new const FieldDescriptor*[descriptor->field_count()];
+  for (int i = 0; i < descriptor->field_count(); i++) {
+    fields[i] = descriptor->field(i);
+  }
+  sort(fields, fields + descriptor->field_count(),
+       FieldOrderingByNumber());
+  return fields;
+}
+
+// Get an identifier that uniquely identifies this type within the file.
+// This is used to declare static variables related to this type at the
+// outermost file scope.
+string UniqueFileScopeIdentifier(const Descriptor* descriptor) {
+  return "static_" + StringReplace(descriptor->full_name(), ".", "_", true);
+}
+
+}  // namespace
+
+// ===================================================================
+
+MessageGenerator::MessageGenerator(const Descriptor* descriptor, const Params& params)
+  : params_(params),
+    descriptor_(descriptor),
+    field_generators_(descriptor, params) {
+}
+
+MessageGenerator::~MessageGenerator() {}
+
+void MessageGenerator::GenerateStaticVariables(io::Printer* printer) {
+  // Generate static members for all nested types.
+  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    // TODO(kenton):  Reuse MessageGenerator objects?
+    MessageGenerator(descriptor_->nested_type(i), params_)
+      .GenerateStaticVariables(printer);
+  }
+}
+
+void MessageGenerator::GenerateStaticVariableInitializers(
+    io::Printer* printer) {
+  // Generate static member initializers for all nested types.
+  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    // TODO(kenton):  Reuse MessageGenerator objects?
+    MessageGenerator(descriptor_->nested_type(i), params_)
+      .GenerateStaticVariableInitializers(printer);
+  }
+
+  if (descriptor_->extension_count() != 0) {
+    GOOGLE_LOG(FATAL) << "Extensions not supported in NANO_RUNTIME\n";
+  }
+}
+
+void MessageGenerator::Generate(io::Printer* printer) {
+  bool is_own_file =
+    params_.java_multiple_files() || ((descriptor_->containing_type() == NULL)
+        && !params_.has_java_outer_classname(descriptor_->file()->name()));
+
+#if 0
+  GOOGLE_LOG(INFO) << "is_own_file=" << is_own_file;
+  GOOGLE_LOG(INFO) << "containing_type()=" << ((descriptor_->containing_type() == NULL) ? "NULL" : "not null");
+  GOOGLE_LOG(INFO) << "java_multiple_files()=" << params_.java_multiple_files();
+  GOOGLE_LOG(INFO) << "has_java_outer_classname()=" << params_.has_java_outer_classname(file_->name());
+#endif
+
+  if ((descriptor_->extension_count() != 0)
+      || (descriptor_->extension_range_count() != 0)) {
+    GOOGLE_LOG(FATAL) << "Extensions not supported in NANO_RUNTIME\n";
+  }
+
+  // Note: Fields (which will be emitted in the loop, below) may have the same names as fields in
+  // the inner or outer class.  This causes Java warnings, but is not fatal, so we suppress those
+  // warnings here in the class declaration.
+  printer->Print(
+    "@SuppressWarnings(\"hiding\")\n"
+    "public $modifiers$ final class $classname$ extends\n"
+    "    com.google.protobuf.nano.MessageNano {\n",
+    "modifiers", is_own_file ? "" : "static",
+    "classname", descriptor_->name());
+  printer->Indent();
+  printer->Print(
+    "public static final $classname$ EMPTY_ARRAY[] = {};\n"
+    "public $classname$() {}\n"
+    "\n",
+    "classname", descriptor_->name());
+
+  // Nested types and extensions
+  for (int i = 0; i < descriptor_->enum_type_count(); i++) {
+    EnumGenerator(descriptor_->enum_type(i), params_).Generate(printer);
+  }
+
+  for (int i = 0; i < descriptor_->nested_type_count(); i++) {
+    MessageGenerator(descriptor_->nested_type(i), params_).Generate(printer);
+  }
+
+  // Fields
+  for (int i = 0; i < descriptor_->field_count(); i++) {
+    PrintFieldComment(printer, descriptor_->field(i));
+    field_generators_.get(descriptor_->field(i)).GenerateMembers(printer);
+    printer->Print("\n");
+  }
+
+  GenerateClear(printer);
+  GenerateMessageSerializationMethods(printer);
+  GenerateMergeFromMethods(printer);
+  GenerateParseFromMethods(printer);
+
+  printer->Outdent();
+  printer->Print("}\n\n");
+}
+
+// ===================================================================
+
+void MessageGenerator::
+GenerateMessageSerializationMethods(io::Printer* printer) {
+  scoped_array<const FieldDescriptor*> sorted_fields(
+    SortFieldsByNumber(descriptor_));
+
+  if (descriptor_->extension_range_count() != 0) {
+    GOOGLE_LOG(FATAL) << "Extensions not supported in NANO_RUNTIME\n";
+  }
+
+  // writeTo only throws an exception if it contains one or more fields to write
+  if (descriptor_->field_count() > 0) {
+    printer->Print(
+      "@Override\n"
+      "public void writeTo(com.google.protobuf.nano.CodedOutputByteBufferNano output)\n"
+      "                    throws java.io.IOException {\n");
+  } else {
+    printer->Print(
+      "@Override\n"
+      "public void writeTo(com.google.protobuf.nano.CodedOutputByteBufferNano output) {\n");
+  }
+  printer->Indent();
+
+  // Output the fields in sorted order
+  for (int i = 0; i < descriptor_->field_count(); i++) {
+      GenerateSerializeOneField(printer, sorted_fields[i]);
+  }
+
+  printer->Outdent();
+  printer->Print(
+    "}\n"
+    "\n"
+    "private int cachedSize = -1;\n"
+    "@Override\n"
+    "public int getCachedSize() {\n"
+    "  if (cachedSize < 0) {\n"
+    "    // getSerializedSize sets cachedSize\n"
+    "    getSerializedSize();\n"
+    "  }\n"
+    "  return cachedSize;\n"
+    "}\n"
+    "\n"
+    "@Override\n"
+    "public int getSerializedSize() {\n"
+    "  int size = 0;\n");
+  printer->Indent();
+
+  for (int i = 0; i < descriptor_->field_count(); i++) {
+    field_generators_.get(sorted_fields[i]).GenerateSerializedSizeCode(printer);
+  }
+
+  printer->Outdent();
+  printer->Print(
+    "  cachedSize = size;\n"
+    "  return size;\n"
+    "}\n"
+    "\n");
+}
+
+void MessageGenerator::GenerateMergeFromMethods(io::Printer* printer) {
+  scoped_array<const FieldDescriptor*> sorted_fields(
+    SortFieldsByNumber(descriptor_));
+
+  printer->Print(
+    "@Override\n"
+    "public $classname$ mergeFrom(\n"
+    "    com.google.protobuf.nano.CodedInputByteBufferNano input)\n"
+    "    throws java.io.IOException {\n",
+    "classname", descriptor_->name());
+
+  printer->Indent();
+
+  printer->Print(
+    "while (true) {\n");
+  printer->Indent();
+
+  printer->Print(
+    "int tag = input.readTag();\n"
+    "switch (tag) {\n");
+  printer->Indent();
+
+  printer->Print(
+    "case 0:\n"          // zero signals EOF / limit reached
+    "  return this;\n"
+    "default: {\n"
+    "  if (!com.google.protobuf.nano.WireFormatNano.parseUnknownField(input, tag)) {\n"
+    "    return this;\n"   // it's an endgroup tag
+    "  }\n"
+    "  break;\n"
+    "}\n");
+
+  for (int i = 0; i < descriptor_->field_count(); i++) {
+    const FieldDescriptor* field = sorted_fields[i];
+    uint32 tag = WireFormatLite::MakeTag(field->number(),
+      WireFormat::WireTypeForField(field));
+
+    printer->Print(
+      "case $tag$: {\n",
+      "tag", SimpleItoa(tag));
+    printer->Indent();
+
+    field_generators_.get(field).GenerateParsingCode(printer);
+
+    printer->Outdent();
+    printer->Print(
+      "  break;\n"
+      "}\n");
+  }
+
+  printer->Outdent();
+  printer->Outdent();
+  printer->Outdent();
+  printer->Print(
+    "    }\n"     // switch (tag)
+    "  }\n"       // while (true)
+    "}\n"
+    "\n");
+}
+
+void MessageGenerator::
+GenerateParseFromMethods(io::Printer* printer) {
+  bool is_own_file =
+    descriptor_->containing_type() == NULL;
+
+  // Note:  These are separate from GenerateMessageSerializationMethods()
+  //   because they need to be generated even for messages that are optimized
+  //   for code size.
+  printer->Print(
+    "public $static$ $classname$ parseFrom(byte[] data)\n"
+    "    throws com.google.protobuf.nano.InvalidProtocolBufferNanoException {\n"
+    "  return ($classname$) com.google.protobuf.nano.MessageNano.mergeFrom(new $classname$(), data);\n"
+    "}\n"
+    "\n"
+    "public $static$ $classname$ parseFrom(\n"
+    "        com.google.protobuf.nano.CodedInputByteBufferNano input)\n"
+    "    throws java.io.IOException {\n"
+    "  return new $classname$().mergeFrom(input);\n"
+    "}\n"
+    "\n",
+    "static", (is_own_file ? "static" : ""),
+    "classname", descriptor_->name());
+}
+
+void MessageGenerator::GenerateSerializeOneField(
+    io::Printer* printer, const FieldDescriptor* field) {
+  field_generators_.get(field).GenerateSerializationCode(printer);
+}
+
+void MessageGenerator::GenerateClear(io::Printer* printer) {
+  printer->Print(
+    "public final $classname$ clear() {\n",
+    "classname", descriptor_->name());
+  printer->Indent();
+
+  // Call clear for all of the fields.
+  for (int i = 0; i < descriptor_->field_count(); i++) {
+    const FieldDescriptor* field = descriptor_->field(i);
+
+    if (field->type() == FieldDescriptor::TYPE_BYTES &&
+        !field->default_value_string().empty()) {
+      // Need to clone the default value because it is of a mutable
+      // type.
+      printer->Print(
+        "$name$ = $default$.clone();\n",
+        "name", UnderscoresToCamelCase(field),
+        "default", DefaultValue(params_, field));
+    } else {
+      printer->Print(
+        "$name$ = $default$;\n",
+        "name", UnderscoresToCamelCase(field),
+        "default", DefaultValue(params_, field));
+    }
+  }
+
+  printer->Outdent();
+  printer->Print(
+    "  cachedSize = -1;\n"
+    "  return this;\n"
+    "}\n"
+    "\n");
+}
+
+// ===================================================================
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_message.h

@@ -0,0 +1,92 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_MESSAGE_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_MESSAGE_H__
+
+#include <string>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/compiler/javanano/javanano_params.h>
+#include <google/protobuf/compiler/javanano/javanano_field.h>
+
+namespace google {
+namespace protobuf {
+  namespace io {
+    class Printer;             // printer.h
+  }
+}
+
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class MessageGenerator {
+ public:
+  explicit MessageGenerator(const Descriptor* descriptor, const Params& params);
+  ~MessageGenerator();
+
+  // All static variables have to be declared at the top-level of the file
+  // so that we can control initialization order, which is important for
+  // DescriptorProto bootstrapping to work.
+  void GenerateStaticVariables(io::Printer* printer);
+
+  // Output code which initializes the static variables generated by
+  // GenerateStaticVariables().
+  void GenerateStaticVariableInitializers(io::Printer* printer);
+
+  // Generate the class itself.
+  void Generate(io::Printer* printer);
+
+ private:
+  void GenerateMessageSerializationMethods(io::Printer* printer);
+  void GenerateMergeFromMethods(io::Printer* printer);
+  void GenerateParseFromMethods(io::Printer* printer);
+  void GenerateSerializeOneField(io::Printer* printer,
+                                 const FieldDescriptor* field);
+
+  void GenerateClear(io::Printer* printer);
+
+  const Params& params_;
+  const Descriptor* descriptor_;
+  FieldGeneratorMap field_generators_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MessageGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_MESSAGE_H__

src/google/protobuf/compiler/javanano/javanano_message_field.cc

@@ -0,0 +1,216 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/compiler/javanano/javanano_message_field.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/wire_format.h>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+using internal::WireFormat;
+using internal::WireFormatLite;
+
+namespace {
+
+// TODO(kenton):  Factor out a "SetCommonFieldVariables()" to get rid of
+//   repeat code between this and the other field types.
+void SetMessageVariables(const Params& params,
+    const FieldDescriptor* descriptor, map<string, string>* variables) {
+  (*variables)["name"] =
+    UnderscoresToCamelCase(descriptor);
+  (*variables)["capitalized_name"] =
+    UnderscoresToCapitalizedCamelCase(descriptor);
+  (*variables)["number"] = SimpleItoa(descriptor->number());
+  (*variables)["type"] = ClassName(params, descriptor->message_type());
+  (*variables)["group_or_message"] =
+    (descriptor->type() == FieldDescriptor::TYPE_GROUP) ?
+    "Group" : "Message";
+  (*variables)["message_name"] = descriptor->containing_type()->name();
+  //(*variables)["message_type"] = descriptor->message_type()->name();
+  (*variables)["tag"] = SimpleItoa(WireFormat::MakeTag(descriptor));
+}
+
+}  // namespace
+
+// ===================================================================
+
+MessageFieldGenerator::
+MessageFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetMessageVariables(params, descriptor, &variables_);
+}
+
+MessageFieldGenerator::~MessageFieldGenerator() {}
+
+void MessageFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+    "public $type$ $name$ = null;\n");
+}
+
+void MessageFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if (other.$name$ != null) {\n"
+    "  merge$capitalized_name$(other.$name$);\n"
+    "}\n");
+}
+
+void MessageFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "$name$ = new $type$();\n");
+
+  if (descriptor_->type() == FieldDescriptor::TYPE_GROUP) {
+    printer->Print(variables_,
+      "input.readGroup($name$, $number$);\n");
+  } else {
+    printer->Print(variables_,
+      "input.readMessage($name$);\n");
+  }
+}
+
+void MessageFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if ($name$ != null) {\n"
+    "  output.write$group_or_message$($number$, $name$);\n"
+    "}\n");
+}
+
+void MessageFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if ($name$ != null) {\n"
+    "  size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+    "    .compute$group_or_message$Size($number$, $name$);\n"
+    "}\n");
+}
+
+string MessageFieldGenerator::GetBoxedType() const {
+  return ClassName(params_, descriptor_->message_type());
+}
+
+// ===================================================================
+
+RepeatedMessageFieldGenerator::
+RepeatedMessageFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetMessageVariables(params, descriptor, &variables_);
+}
+
+RepeatedMessageFieldGenerator::~RepeatedMessageFieldGenerator() {}
+
+void RepeatedMessageFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+    "public $type$[] $name$ = $type$.EMPTY_ARRAY;\n");
+}
+
+void RepeatedMessageFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if (other.$name$.length > 0) {\n"
+    "  $type$[] merged = java.util.Arrays.copyOf(result.$name$, result.$name$.length + other.$name$.length);\n"
+    "  java.lang.System.arraycopy(other.$name$, 0, merged, results.$name$.length, other.$name$.length);\n"
+    "  result.$name$ = merged;\n"
+    "}\n");
+}
+
+void RepeatedMessageFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  // First, figure out the length of the array, then parse.
+  printer->Print(variables_,
+    "int arrayLength = com.google.protobuf.nano.WireFormatNano.getRepeatedFieldArrayLength(input, $tag$);\n"
+    "int i = $name$.length;\n"
+    "$name$ = java.util.Arrays.copyOf($name$, i + arrayLength);\n"
+    "for (; i < $name$.length - 1; i++) {\n"
+    "  $name$[i] = new $type$();\n");
+
+  if (descriptor_->type() == FieldDescriptor::TYPE_GROUP) {
+    printer->Print(variables_,
+      "  input.readGroup($name$[i], $number$);\n");
+  } else {
+    printer->Print(variables_,
+      "  input.readMessage($name$[i]);\n");
+  }
+
+  printer->Print(variables_,
+    "  input.readTag();\n"
+    "}\n"
+    "// Last one without readTag.\n"
+    "$name$[i] = new $type$();\n");
+
+  if (descriptor_->type() == FieldDescriptor::TYPE_GROUP) {
+    printer->Print(variables_,
+      "input.readGroup($name$[i], $number$);\n");
+  } else {
+    printer->Print(variables_,
+      "input.readMessage($name$[i]);\n");
+  }
+}
+
+void RepeatedMessageFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "for ($type$ element : $name$) {\n"
+    "  output.write$group_or_message$($number$, element);\n"
+    "}\n");
+}
+
+void RepeatedMessageFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "for ($type$ element : $name$) {\n"
+    "  size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+    "    .compute$group_or_message$Size($number$, element);\n"
+    "}\n");
+}
+
+string RepeatedMessageFieldGenerator::GetBoxedType() const {
+  return ClassName(params_, descriptor_->message_type());
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_message_field.h

@@ -0,0 +1,95 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVA_MESSAGE_FIELD_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVA_MESSAGE_FIELD_H__
+
+#include <map>
+#include <string>
+#include <google/protobuf/compiler/javanano/javanano_field.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class MessageFieldGenerator : public FieldGenerator {
+ public:
+  explicit MessageFieldGenerator(const FieldDescriptor* descriptor, const Params& params);
+  ~MessageFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MessageFieldGenerator);
+};
+
+class RepeatedMessageFieldGenerator : public FieldGenerator {
+ public:
+  explicit RepeatedMessageFieldGenerator(const FieldDescriptor* descriptor,
+        const Params& params);
+  ~RepeatedMessageFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedMessageFieldGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVA_MESSAGE_FIELD_H__

src/google/protobuf/compiler/javanano/javanano_params.h

@@ -0,0 +1,123 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2010 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: wink@google.com (Wink Saville)
+
+#ifndef PROTOBUF_COMPILER_JAVANANO_JAVANANO_PARAMS_H_
+#define PROTOBUF_COMPILER_JAVANANO_JAVANANO_PARAMS_H_
+
+#include <map>
+#include <google/protobuf/stubs/strutil.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+// Parameters for used by the generators
+class Params {
+ public:
+  typedef map<string, string> NameMap;
+ private:
+  string empty_;
+  string base_name_;
+  bool java_multiple_files_;
+  NameMap java_packages_;
+  NameMap java_outer_classnames_;
+
+ public:
+  Params(const string & base_name) :
+    empty_(""),
+    base_name_(base_name),
+    java_multiple_files_(false) {
+  }
+
+  const string& base_name() const {
+    return base_name_;
+  }
+
+  bool has_java_package(const string& file_name) const {
+    return java_packages_.find(file_name)
+                        != java_packages_.end();
+  }
+  void set_java_package(const string& file_name,
+      const string& java_package) {
+    java_packages_[file_name] = java_package;
+  }
+  const string& java_package(const string& file_name) const {
+    NameMap::const_iterator itr;
+
+    itr = java_packages_.find(file_name);
+    if  (itr == java_packages_.end()) {
+      return empty_;
+    } else {
+      return itr->second;
+    }
+  }
+  const NameMap& java_packages() {
+    return java_packages_;
+  }
+
+  bool has_java_outer_classname(const string& file_name) const {
+    return java_outer_classnames_.find(file_name)
+                        != java_outer_classnames_.end();
+  }
+  void set_java_outer_classname(const string& file_name,
+      const string& java_outer_classname) {
+    java_outer_classnames_[file_name] = java_outer_classname;
+  }
+  const string& java_outer_classname(const string& file_name) const {
+    NameMap::const_iterator itr;
+
+    itr = java_outer_classnames_.find(file_name);
+    if  (itr == java_outer_classnames_.end()) {
+      return empty_;
+    } else {
+      return itr->second;
+    }
+  }
+  const NameMap& java_outer_classnames() {
+    return java_outer_classnames_;
+  }
+
+  void set_java_multiple_files(bool value) {
+    java_multiple_files_ = value;
+  }
+  bool java_multiple_files() const {
+    return java_multiple_files_;
+  }
+
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google
+#endif  // PROTOBUF_COMPILER_JAVANANO_JAVANANO_PARAMS_H_

src/google/protobuf/compiler/javanano/javanano_primitive_field.cc

@@ -0,0 +1,493 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#include <map>
+#include <string>
+
+#include <google/protobuf/compiler/javanano/javanano_primitive_field.h>
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/compiler/javanano/javanano_helpers.h>
+#include <google/protobuf/io/printer.h>
+#include <google/protobuf/wire_format.h>
+#include <google/protobuf/stubs/strutil.h>
+#include <google/protobuf/stubs/substitute.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+using internal::WireFormat;
+using internal::WireFormatLite;
+
+namespace {
+
+const char* PrimitiveTypeName(JavaType type) {
+  switch (type) {
+    case JAVATYPE_INT    : return "int";
+    case JAVATYPE_LONG   : return "long";
+    case JAVATYPE_FLOAT  : return "float";
+    case JAVATYPE_DOUBLE : return "double";
+    case JAVATYPE_BOOLEAN: return "boolean";
+    case JAVATYPE_STRING : return "java.lang.String";
+    case JAVATYPE_BYTES  : return "byte[]";
+    case JAVATYPE_ENUM   : return NULL;
+    case JAVATYPE_MESSAGE: return NULL;
+
+    // No default because we want the compiler to complain if any new
+    // JavaTypes are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return NULL;
+}
+
+bool IsReferenceType(JavaType type) {
+  switch (type) {
+    case JAVATYPE_INT    : return false;
+    case JAVATYPE_LONG   : return false;
+    case JAVATYPE_FLOAT  : return false;
+    case JAVATYPE_DOUBLE : return false;
+    case JAVATYPE_BOOLEAN: return false;
+    case JAVATYPE_STRING : return true;
+    case JAVATYPE_BYTES  : return true;
+    case JAVATYPE_ENUM   : return false;
+    case JAVATYPE_MESSAGE: return true;
+
+    // No default because we want the compiler to complain if any new
+    // JavaTypes are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return false;
+}
+
+bool IsArrayType(JavaType type) {
+  switch (type) {
+    case JAVATYPE_INT    : return false;
+    case JAVATYPE_LONG   : return false;
+    case JAVATYPE_FLOAT  : return false;
+    case JAVATYPE_DOUBLE : return false;
+    case JAVATYPE_BOOLEAN: return false;
+    case JAVATYPE_STRING : return false;
+    case JAVATYPE_BYTES  : return true;
+    case JAVATYPE_ENUM   : return false;
+    case JAVATYPE_MESSAGE: return false;
+
+    // No default because we want the compiler to complain if any new
+    // JavaTypes are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return false;
+}
+
+const char* GetCapitalizedType(const FieldDescriptor* field) {
+  switch (field->type()) {
+    case FieldDescriptor::TYPE_INT32   : return "Int32"   ;
+    case FieldDescriptor::TYPE_UINT32  : return "UInt32"  ;
+    case FieldDescriptor::TYPE_SINT32  : return "SInt32"  ;
+    case FieldDescriptor::TYPE_FIXED32 : return "Fixed32" ;
+    case FieldDescriptor::TYPE_SFIXED32: return "SFixed32";
+    case FieldDescriptor::TYPE_INT64   : return "Int64"   ;
+    case FieldDescriptor::TYPE_UINT64  : return "UInt64"  ;
+    case FieldDescriptor::TYPE_SINT64  : return "SInt64"  ;
+    case FieldDescriptor::TYPE_FIXED64 : return "Fixed64" ;
+    case FieldDescriptor::TYPE_SFIXED64: return "SFixed64";
+    case FieldDescriptor::TYPE_FLOAT   : return "Float"   ;
+    case FieldDescriptor::TYPE_DOUBLE  : return "Double"  ;
+    case FieldDescriptor::TYPE_BOOL    : return "Bool"    ;
+    case FieldDescriptor::TYPE_STRING  : return "String"  ;
+    case FieldDescriptor::TYPE_BYTES   : return "Bytes"   ;
+    case FieldDescriptor::TYPE_ENUM    : return "Enum"    ;
+    case FieldDescriptor::TYPE_GROUP   : return "Group"   ;
+    case FieldDescriptor::TYPE_MESSAGE : return "Message" ;
+
+    // No default because we want the compiler to complain if any new
+    // types are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return NULL;
+}
+
+// For encodings with fixed sizes, returns that size in bytes.  Otherwise
+// returns -1.
+int FixedSize(FieldDescriptor::Type type) {
+  switch (type) {
+    case FieldDescriptor::TYPE_INT32   : return -1;
+    case FieldDescriptor::TYPE_INT64   : return -1;
+    case FieldDescriptor::TYPE_UINT32  : return -1;
+    case FieldDescriptor::TYPE_UINT64  : return -1;
+    case FieldDescriptor::TYPE_SINT32  : return -1;
+    case FieldDescriptor::TYPE_SINT64  : return -1;
+    case FieldDescriptor::TYPE_FIXED32 : return WireFormatLite::kFixed32Size;
+    case FieldDescriptor::TYPE_FIXED64 : return WireFormatLite::kFixed64Size;
+    case FieldDescriptor::TYPE_SFIXED32: return WireFormatLite::kSFixed32Size;
+    case FieldDescriptor::TYPE_SFIXED64: return WireFormatLite::kSFixed64Size;
+    case FieldDescriptor::TYPE_FLOAT   : return WireFormatLite::kFloatSize;
+    case FieldDescriptor::TYPE_DOUBLE  : return WireFormatLite::kDoubleSize;
+
+    case FieldDescriptor::TYPE_BOOL    : return WireFormatLite::kBoolSize;
+    case FieldDescriptor::TYPE_ENUM    : return -1;
+
+    case FieldDescriptor::TYPE_STRING  : return -1;
+    case FieldDescriptor::TYPE_BYTES   : return -1;
+    case FieldDescriptor::TYPE_GROUP   : return -1;
+    case FieldDescriptor::TYPE_MESSAGE : return -1;
+
+    // No default because we want the compiler to complain if any new
+    // types are added.
+  }
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return -1;
+}
+
+// Return true if the type is a that has variable length
+// for instance String's.
+bool IsVariableLenType(JavaType type) {
+  switch (type) {
+    case JAVATYPE_INT    : return false;
+    case JAVATYPE_LONG   : return false;
+    case JAVATYPE_FLOAT  : return false;
+    case JAVATYPE_DOUBLE : return false;
+    case JAVATYPE_BOOLEAN: return false;
+    case JAVATYPE_STRING : return true;
+    case JAVATYPE_BYTES  : return true;
+    case JAVATYPE_ENUM   : return false;
+    case JAVATYPE_MESSAGE: return true;
+
+    // No default because we want the compiler to complain if any new
+    // JavaTypes are added.
+  }
+
+  GOOGLE_LOG(FATAL) << "Can't get here.";
+  return false;
+}
+
+bool AllAscii(const string& text) {
+  for (int i = 0; i < text.size(); i++) {
+    if ((text[i] & 0x80) != 0) {
+      return false;
+    }
+  }
+  return true;
+}
+
+void SetPrimitiveVariables(const FieldDescriptor* descriptor, const Params params,
+                           map<string, string>* variables) {
+  (*variables)["name"] =
+    UnderscoresToCamelCase(descriptor);
+  (*variables)["capitalized_name"] =
+    UnderscoresToCapitalizedCamelCase(descriptor);
+  (*variables)["number"] = SimpleItoa(descriptor->number());
+  (*variables)["type"] = PrimitiveTypeName(GetJavaType(descriptor));
+  (*variables)["default"] = DefaultValue(params, descriptor);
+  (*variables)["default_constant"] = FieldDefaultConstantName(descriptor);
+  // For C++-string types (string and bytes), we might need to have
+  // the generated code do the unicode decoding (see comments in
+  // InternalNano.java for gory details.). We would like to do this
+  // once into a "private static final" field and re-use that from
+  // then on.
+  if (descriptor->cpp_type() == FieldDescriptor::CPPTYPE_STRING &&
+      !descriptor->default_value_string().empty()) {
+    string default_value;
+    if (descriptor->type() == FieldDescriptor::TYPE_BYTES) {
+      default_value = strings::Substitute(
+          "com.google.protobuf.nano.InternalNano.bytesDefaultValue(\"$0\")",
+          CEscape(descriptor->default_value_string()));
+    } else {
+      if (AllAscii(descriptor->default_value_string())) {
+        // All chars are ASCII.  In this case CEscape() works fine.
+        default_value = "\"" + CEscape(descriptor->default_value_string()) + "\"";
+      } else {
+        default_value = strings::Substitute(
+            "com.google.protobuf.nano.InternalNano.stringDefaultValue(\"$0\")",
+            CEscape(descriptor->default_value_string()));
+      }
+    }
+    (*variables)["default_constant_value"] = default_value;
+  }
+  (*variables)["boxed_type"] = BoxedPrimitiveTypeName(GetJavaType(descriptor));
+  (*variables)["capitalized_type"] = GetCapitalizedType(descriptor);
+  (*variables)["tag"] = SimpleItoa(WireFormat::MakeTag(descriptor));
+  (*variables)["tag_size"] = SimpleItoa(
+      WireFormat::TagSize(descriptor->number(), descriptor->type()));
+  if (IsReferenceType(GetJavaType(descriptor))) {
+    (*variables)["null_check"] =
+        "  if (value == null) {\n"
+        "    throw new NullPointerException();\n"
+        "  }\n";
+  } else {
+    (*variables)["null_check"] = "";
+  }
+  int fixed_size = FixedSize(descriptor->type());
+  if (fixed_size != -1) {
+    (*variables)["fixed_size"] = SimpleItoa(fixed_size);
+  }
+  (*variables)["message_name"] = descriptor->containing_type()->name();
+  (*variables)["empty_array_name"] = EmptyArrayName(params, descriptor);
+}
+}  // namespace
+
+// ===================================================================
+
+PrimitiveFieldGenerator::
+PrimitiveFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetPrimitiveVariables(descriptor, params, &variables_);
+}
+
+PrimitiveFieldGenerator::~PrimitiveFieldGenerator() {}
+
+void PrimitiveFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  if (variables_.find("default_constant_value") != variables_.end()) {
+    // Those primitive types that need a saved default.
+    printer->Print(variables_,
+      "private static final $type$ $default_constant$ = $default_constant_value$;\n");
+    if (descriptor_->type() == FieldDescriptor::TYPE_BYTES) {
+      printer->Print(variables_,
+        "public $type$ $name$ = $default$.clone();\n");
+    } else {
+      printer->Print(variables_,
+        "public $type$ $name$ = $default$;\n");
+    }
+  } else {
+    printer->Print(variables_,
+      "public $type$ $name$ = $default$;\n");
+  }
+}
+
+void PrimitiveFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_, "$name$ = other.$name$;\n");
+}
+
+void PrimitiveFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "$name$ = input.read$capitalized_type$();\n");
+}
+
+void PrimitiveFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  if (descriptor_->is_required()) {
+    printer->Print(variables_,
+      "output.write$capitalized_type$($number$, $name$);\n");
+  } else {
+    if (IsArrayType(GetJavaType(descriptor_))) {
+      printer->Print(variables_,
+        "if (!java.util.Arrays.equals($name$, $default$)) {\n");
+    } else if (IsReferenceType(GetJavaType(descriptor_))) {
+      printer->Print(variables_,
+        "if (!$name$.equals($default$)) {\n");
+    } else {
+      printer->Print(variables_,
+        "if ($name$ != $default$) {\n");
+    }
+
+    printer->Print(variables_,
+      "  output.write$capitalized_type$($number$, $name$);\n"
+      "}\n");
+  }
+}
+
+void PrimitiveFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  if (descriptor_->is_required()) {
+    printer->Print(variables_,
+      "size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "    .compute$capitalized_type$Size($number$, $name$);\n");
+  } else {
+    if (IsArrayType(GetJavaType(descriptor_))) {
+      printer->Print(variables_,
+        "if (!java.util.Arrays.equals($name$, $default$)) {\n");
+    } else  if (IsReferenceType(GetJavaType(descriptor_))) {
+      printer->Print(variables_,
+        "if (!$name$.equals($default$)) {\n");
+    } else {
+      printer->Print(variables_,
+        "if ($name$ != $default$) {\n");
+    }
+
+    printer->Print(variables_,
+      "  size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "      .compute$capitalized_type$Size($number$, $name$);\n"
+      "}\n");
+  }
+}
+
+string PrimitiveFieldGenerator::GetBoxedType() const {
+  return BoxedPrimitiveTypeName(GetJavaType(descriptor_));
+}
+
+// ===================================================================
+
+RepeatedPrimitiveFieldGenerator::
+RepeatedPrimitiveFieldGenerator(const FieldDescriptor* descriptor, const Params& params)
+  : FieldGenerator(params), descriptor_(descriptor) {
+  SetPrimitiveVariables(descriptor, params, &variables_);
+}
+
+RepeatedPrimitiveFieldGenerator::~RepeatedPrimitiveFieldGenerator() {}
+
+void RepeatedPrimitiveFieldGenerator::
+GenerateMembers(io::Printer* printer) const {
+  printer->Print(variables_,
+    "public $type$[] $name$ = $default$;\n");
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "private int $name$MemoizedSerializedSize;\n");
+  }
+}
+
+void RepeatedPrimitiveFieldGenerator::
+GenerateMergingCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if (other.$name$.length > 0) {\n"
+    "  $type$[] merged = java.util.Arrays.copyOf(result.$name$, result.$name$.length + other.$name$.length);\n"
+    "  java.lang.System.arraycopy(other.$name$, 0, merged, results.$name$.length, other.$name$.length);\n"
+    "  result.$name$ = merged;\n"
+    "}\n");
+}
+
+void RepeatedPrimitiveFieldGenerator::
+GenerateParsingCode(io::Printer* printer) const {
+  // First, figure out the length of the array, then parse.
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "int length = input.readRawVarint32();\n"
+      "int limit = input.pushLimit(length);\n"
+      "// First pass to compute array length.\n"
+      "int arrayLength = 0;\n"
+      "int startPos = input.getPosition();\n"
+      "while (input.getBytesUntilLimit() > 0) {\n"
+      "  input.read$capitalized_type$();\n"
+      "  arrayLength++;\n"
+      "}\n"
+      "input.rewindToPosition(startPos);\n"
+      "$name$ = new $type$[arrayLength];\n"
+      "for (int i = 0; i < arrayLength; i++) {\n"
+      "  $name$[i] = input.read$capitalized_type$();\n"
+      "}\n"
+      "input.popLimit(limit);\n");
+  } else {
+    printer->Print(variables_,
+      "int arrayLength = com.google.protobuf.nano.WireFormatNano.getRepeatedFieldArrayLength(input, $tag$);\n"
+      "int i = $name$.length;\n"
+      "$name$ = java.util.Arrays.copyOf($name$, $name$.length + arrayLength);\n"
+      "for (; i < $name$.length - 1; i++) {\n"
+      "  $name$[i] = input.read$capitalized_type$();\n"
+      "  input.readTag();\n"
+      "}\n"
+      "// Last one without readTag.\n"
+      "$name$[i] = input.read$capitalized_type$();\n");
+  }
+}
+
+void RepeatedPrimitiveFieldGenerator::
+GenerateSerializationCode(io::Printer* printer) const {
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "if ($name$.length > 0) {\n"
+      "  output.writeRawVarint32($tag$);\n"
+      "  output.writeRawVarint32($name$MemoizedSerializedSize);\n"
+      "}\n");
+    printer->Print(variables_,
+      "for ($type$ element : $name$) {\n"
+      "  output.write$capitalized_type$NoTag(element);\n"
+      "}\n");
+  } else {
+    printer->Print(variables_,
+      "for ($type$ element : $name$) {\n"
+      "  output.write$capitalized_type$($number$, element);\n"
+      "}\n");
+  }
+}
+
+void RepeatedPrimitiveFieldGenerator::
+GenerateSerializedSizeCode(io::Printer* printer) const {
+  printer->Print(variables_,
+    "if ($name$.length > 0) {\n");
+  printer->Indent();
+
+  if (FixedSize(descriptor_->type()) == -1) {
+    printer->Print(variables_,
+      "int dataSize = 0;\n"
+      "for ($type$ element : $name$) {\n"
+      "  dataSize += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "    .compute$capitalized_type$SizeNoTag(element);\n"
+      "}\n");
+  } else {
+    printer->Print(variables_,
+      "int dataSize = $fixed_size$ * $name$.length;\n");
+  }
+
+  printer->Print(
+    "size += dataSize;\n");
+  if (descriptor_->options().packed()) {
+    // cache the data size for packed fields.
+    printer->Print(variables_,
+      "size += $tag_size$;\n"
+      "size += com.google.protobuf.nano.CodedOutputByteBufferNano\n"
+      "  .computeRawVarint32Size(dataSize);\n"
+      "$name$MemoizedSerializedSize = dataSize;\n");
+  } else {
+    printer->Print(variables_,
+        "size += $tag_size$ * $name$.length;\n");
+  }
+
+  printer->Outdent();
+
+  // set cached size to 0 for empty packed fields.
+  if (descriptor_->options().packed()) {
+    printer->Print(variables_,
+      "} else {\n"
+      "  $name$MemoizedSerializedSize = 0;\n"
+      "}\n");
+  } else {
+    printer->Print(
+      "}\n");
+  }
+}
+
+string RepeatedPrimitiveFieldGenerator::GetBoxedType() const {
+  return BoxedPrimitiveTypeName(GetJavaType(descriptor_));
+}
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google

src/google/protobuf/compiler/javanano/javanano_primitive_field.h

@@ -0,0 +1,94 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+
+#ifndef GOOGLE_PROTOBUF_COMPILER_JAVANANO_PRIMITIVE_FIELD_H__
+#define GOOGLE_PROTOBUF_COMPILER_JAVANANO_PRIMITIVE_FIELD_H__
+
+#include <map>
+#include <string>
+#include <google/protobuf/compiler/javanano/javanano_field.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace javanano {
+
+class PrimitiveFieldGenerator : public FieldGenerator {
+ public:
+  explicit PrimitiveFieldGenerator(const FieldDescriptor* descriptor, const Params &params);
+  ~PrimitiveFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(PrimitiveFieldGenerator);
+};
+
+class RepeatedPrimitiveFieldGenerator : public FieldGenerator {
+ public:
+  explicit RepeatedPrimitiveFieldGenerator(const FieldDescriptor* descriptor, const Params& params);
+  ~RepeatedPrimitiveFieldGenerator();
+
+  // implements FieldGenerator ---------------------------------------
+  void GenerateMembers(io::Printer* printer) const;
+  void GenerateMergingCode(io::Printer* printer) const;
+  void GenerateParsingCode(io::Printer* printer) const;
+  void GenerateSerializationCode(io::Printer* printer) const;
+  void GenerateSerializedSizeCode(io::Printer* printer) const;
+
+  string GetBoxedType() const;
+
+ private:
+  const FieldDescriptor* descriptor_;
+  map<string, string> variables_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(RepeatedPrimitiveFieldGenerator);
+};
+
+}  // namespace javanano
+}  // namespace compiler
+}  // namespace protobuf
+
+}  // namespace google
+#endif  // GOOGLE_PROTOBUF_COMPILER_JAVANANO_PRIMITIVE_FIELD_H__

src/google/protobuf/unittest_import_nano.proto

@@ -0,0 +1,49 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: kenton@google.com (Kenton Varda)
+//
+// This is like unittest_import.proto but with optimize_for = NANO_RUNTIME.
+
+package protobuf_unittest_import;
+
+// java_package and java_outer_classname are specified on the command line.
+//option java_package = "com.google.protobuf.nano";
+//option java_outer_classname = "UnittestImportNano";
+
+message ImportMessageNano {
+  optional int32 d = 1;
+}
+
+enum ImportEnumNano {
+  IMPORT_NANO_FOO = 7;
+  IMPORT_NANO_BAR = 8;
+  IMPORT_NANO_BAZ = 9;
+}

src/google/protobuf/unittest_nano.proto

@@ -0,0 +1,171 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: wink@google.com (Wink Saville)
+
+package protobuf_unittest;
+
+import "google/protobuf/unittest_import_nano.proto";
+
+option java_package = "com.google.protobuf.nano";
+option java_outer_classname = "NanoOuterClass";
+
+// Same as TestAllTypes but with the nano runtime.
+message TestAllTypesNano {
+
+  message NestedMessage {
+    optional int32 bb = 1;
+  }
+
+  enum NestedEnum {
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+  }
+
+  // Singular
+  optional    int32 optional_int32    =  1;
+  optional    int64 optional_int64    =  2;
+  optional   uint32 optional_uint32   =  3;
+  optional   uint64 optional_uint64   =  4;
+  optional   sint32 optional_sint32   =  5;
+  optional   sint64 optional_sint64   =  6;
+  optional  fixed32 optional_fixed32  =  7;
+  optional  fixed64 optional_fixed64  =  8;
+  optional sfixed32 optional_sfixed32 =  9;
+  optional sfixed64 optional_sfixed64 = 10;
+  optional    float optional_float    = 11;
+  optional   double optional_double   = 12;
+  optional     bool optional_bool     = 13;
+  optional   string optional_string   = 14;
+  optional    bytes optional_bytes    = 15;
+
+  optional group OptionalGroup = 16 {
+    optional int32 a = 17;
+  }
+
+  optional NestedMessage      optional_nested_message  = 18;
+  optional ForeignMessageNano optional_foreign_message = 19;
+  optional protobuf_unittest_import.ImportMessageNano
+    optional_import_message = 20;
+
+  optional NestedEnum      optional_nested_enum     = 21;
+  optional ForeignEnumNano optional_foreign_enum    = 22;
+  optional protobuf_unittest_import.ImportEnumNano optional_import_enum = 23;
+
+  optional string optional_string_piece = 24 [ctype=STRING_PIECE];
+  optional string optional_cord = 25 [ctype=CORD];
+
+  // Repeated
+  repeated    int32 repeated_int32    = 31;
+  repeated    int64 repeated_int64    = 32;
+  repeated   uint32 repeated_uint32   = 33;
+  repeated   uint64 repeated_uint64   = 34;
+  repeated   sint32 repeated_sint32   = 35;
+  repeated   sint64 repeated_sint64   = 36;
+  repeated  fixed32 repeated_fixed32  = 37;
+  repeated  fixed64 repeated_fixed64  = 38;
+  repeated sfixed32 repeated_sfixed32 = 39;
+  repeated sfixed64 repeated_sfixed64 = 40;
+  repeated    float repeated_float    = 41;
+  repeated   double repeated_double   = 42;
+  repeated     bool repeated_bool     = 43;
+  repeated   string repeated_string   = 44;
+  repeated    bytes repeated_bytes    = 45;
+
+  repeated group RepeatedGroup = 46 {
+    optional int32 a = 47;
+  }
+
+  repeated NestedMessage      repeated_nested_message  = 48;
+  repeated ForeignMessageNano repeated_foreign_message = 49;
+  repeated protobuf_unittest_import.ImportMessageNano
+    repeated_import_message = 50;
+
+  repeated NestedEnum      repeated_nested_enum  = 51;
+  repeated ForeignEnumNano repeated_foreign_enum = 52;
+  repeated protobuf_unittest_import.ImportEnumNano repeated_import_enum = 53;
+
+  repeated string repeated_string_piece = 54 [ctype=STRING_PIECE];
+  repeated string repeated_cord = 55 [ctype=CORD];
+
+  // Repeated packed
+  repeated    int32 repeated_packed_int32    = 87 [packed=true];
+  repeated sfixed64 repeated_packed_sfixed64 = 88 [packed=true];
+
+  repeated NestedEnum repeated_packed_nested_enum  = 89 [packed=true];
+
+  // Singular with defaults
+  optional    int32 default_int32    = 61 [default =  41    ];
+  optional    int64 default_int64    = 62 [default =  42    ];
+  optional   uint32 default_uint32   = 63 [default =  43    ];
+  optional   uint64 default_uint64   = 64 [default =  44    ];
+  optional   sint32 default_sint32   = 65 [default = -45    ];
+  optional   sint64 default_sint64   = 66 [default =  46    ];
+  optional  fixed32 default_fixed32  = 67 [default =  47    ];
+  optional  fixed64 default_fixed64  = 68 [default =  48    ];
+  optional sfixed32 default_sfixed32 = 69 [default =  49    ];
+  optional sfixed64 default_sfixed64 = 70 [default = -50    ];
+  optional    float default_float    = 71 [default =  51.5  ];
+  optional   double default_double   = 72 [default =  52e3  ];
+  optional     bool default_bool     = 73 [default = true   ];
+  optional   string default_string   = 74 [default = "hello"];
+  optional    bytes default_bytes    = 75 [default = "world"];
+
+  optional string default_string_nonascii = 76 [default = "dünya"];
+  optional  bytes default_bytes_nonascii  = 77 [default = "dünyab"];
+
+  optional NestedEnum default_nested_enum = 81 [default = BAR];
+  optional ForeignEnumNano default_foreign_enum = 82
+      [default = FOREIGN_NANO_BAR];
+  optional protobuf_unittest_import.ImportEnumNano
+      default_import_enum = 83 [default = IMPORT_NANO_BAR];
+
+  optional string default_string_piece = 84 [ctype=STRING_PIECE,default="abc"];
+  optional string default_cord = 85 [ctype=CORD,default="123"];
+
+  required int32 id = 86;
+}
+
+message ForeignMessageNano {
+  optional int32 c = 1;
+}
+
+enum ForeignEnumNano {
+  FOREIGN_NANO_FOO = 4;
+  FOREIGN_NANO_BAR = 5;
+  FOREIGN_NANO_BAZ = 6;
+}
+
+// Test that deprecated fields work.  We only verify that they compile (at one
+// point this failed).
+message TestDeprecatedNano {
+  optional int32 deprecated_field = 1 [deprecated = true];
+}

src/google/protobuf/unittest_recursive_nano.proto

@@ -0,0 +1,47 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: wink@google.com (Wink Saville)
+//
+
+package protobuf_unittest_import;
+
+option java_package = "com.google.protobuf.nano";
+
+message RecursiveMessageNano {
+  message NestedMessage {
+    optional RecursiveMessageNano a = 1;
+  }
+
+  required int32 id = 1;
+  optional NestedMessage nested_message = 2;
+  optional RecursiveMessageNano optional_recursive_message_nano = 3;
+  repeated RecursiveMessageNano repeated_recursive_message_nano = 4;
+}

src/google/protobuf/unittest_simple_nano.proto

@@ -0,0 +1,52 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: wink@google.com (Wink Saville)
+//
+
+package protobuf_unittest_import;
+
+option java_package = "com.google.protobuf.nano";
+
+message SimpleMessageNano {
+  message NestedMessage {
+    optional int32 bb = 1;
+  }
+
+  enum NestedEnum {
+    FOO = 1;
+    BAR = 2;
+    BAZ = 3;
+  }
+
+  optional int32 d = 1 [default = 123];
+  optional NestedMessage nested_msg = 2;
+  optional NestedEnum default_nested_enum = 3 [default = BAZ];
+}

src/google/protobuf/unittest_stringutf8_nano.proto

@@ -0,0 +1,41 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Author: wink@google.com (Wink Saville)
+//
+
+package protobuf_unittest_import;
+
+option java_package = "com.google.protobuf.nano";
+
+message StringUtf8 {
+  optional string id = 1;
+  repeated string rs = 2;
+}