All Languages
* Repeated fields of primitive types (types other that string, group, and
nested messages) may now use the option [packed = true] to get a more
efficient encoding. In the new encoding, the entire list is written
as a single byte blob using the "length-delimited" wire type. Within
this blob, the individual values are encoded the same way they would
be normally except without a tag before each value (thus, they are
tightly "packed").
C++
* UnknownFieldSet now supports STL-like iteration.
* Message interface has method ParseFromBoundedZeroCopyStream() which parses
a limited number of bytes from an input stream rather than parsing until
EOF.
Java
* Fixed bug where Message.mergeFrom(Message) failed to merge extensions.
* Message interface has new method toBuilder() which is equivalent to
newBuilderForType().mergeFrom(this).
* All enums now implement the ProtocolMessageEnum interface.
* Setting a field to null now throws NullPointerException.
* Fixed tendency for TextFormat's parsing to overflow the stack when
parsing large string values. The underlying problem is with Java's
regex implementation (which unfortunately uses recursive backtracking
rather than building an NFA). Worked around by making use of possesive
quantifiers.
Python
* Updated RPC interfaces to allow for blocking operation. A client may
now pass None for a callback when making an RPC, in which case the
call will block until the response is received, and the response
object will be returned directly to the caller. This interface change
cannot be used in practice until RPC implementations are updated to
implement it.
protoc
* Enum values may now have custom options, using syntax similar to field
options.
* Fixed bug where .proto files which use custom options but don't actually
define them (i.e. they import another .proto file defining the options)
had to explicitly import descriptor.proto.
* Adjacent string literals in .proto files will now be concatenated, like in
C.
C++
* Generated message classes now have a Swap() method which efficiently swaps
the contents of two objects.
* All message classes now have a SpaceUsed() method which returns an estimate
of the number of bytes of allocated memory currently owned by the object.
This is particularly useful when you are reusing a single message object
to improve performance but want to make sure it doesn't bloat up too large.
* New method Message::SerializeAsString() returns a string containing the
serialized data. May be more convenient than calling
SerializeToString(string*).
* In debug mode, log error messages when string-type fields are found to
contain bytes that are not valid UTF-8.
* Fixed bug where a message with multiple extension ranges couldn't parse
extensions.
* Fixed bug where MergeFrom(const Message&) didn't do anything if invoked on
a message that contained no fields (but possibly contained extensions).
* Fixed ShortDebugString() to not be O(n^2). Durr.
* Fixed crash in TextFormat parsing if the first token in the input caused a
tokenization error.
Java
* New overload of mergeFrom() which parses a slice of a byte array instead
of the whole thing.
* New method ByteString.asReadOnlyByteBuffer() does what it sounds like.
* Improved performance of isInitialized() when optimizing for code size.
Python
* Corrected ListFields() signature in Message base class to match what
subclasses actually implement.
* Some minor refactoring.
General
* License changed from Apache 2.0 to New BSD.
* It is now possible to define custom "options", which are basically
annotations which may be placed on definitions in a .proto file.
For example, you might define a field option called "foo" like so:
import "google/protobuf/descriptor.proto"
extend google.protobuf.FieldOptions {
optional string foo = 12345;
}
Then you annotate a field using the "foo" option:
message MyMessage {
optional int32 some_field = 1 [(foo) = "bar"]
}
The value of this option is then visible via the message's
Descriptor:
const FieldDescriptor* field =
MyMessage::descriptor()->FindFieldByName("some_field");
assert(field->options().GetExtension(foo) == "bar");
This feature has been implemented and tested in C++ and Java.
Other languages may or may not need to do extra work to support
custom options, depending on how they construct descriptors.
C++
* Fixed some GCC warnings that only occur when using -pedantic.
* Improved static initialization code, making ordering more
predictable among other things.
* TextFormat will no longer accept messages which contain multiple
instances of a singular field. Previously, the latter instance
would overwrite the former.
* Now works on systems that don't have hash_map.
Python
* Strings now use the "unicode" type rather than the "str" type.
String fields may still be assigned ASCII "str" values; they will
automatically be converted.
* Adding a property to an object representing a repeated field now
raises an exception. For example:
# No longer works (and never should have).
message.some_repeated_field.foo = 1
xiaofeng@google.com
liujisi@google.com
kenton@google.com
pesho.petrov
Jon Skeet