Added the JsonFormatWriter/Reader

src/ProtoBench/Program.cs

@@ -39,6 +39,7 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 using System.Threading;
+using Google.ProtocolBuffers.Serialization;
 using Google.ProtocolBuffers.TestProtos;
 
 namespace Google.ProtocolBuffers.ProtoBench
@@ -127,12 +128,25 @@ namespace Google.ProtocolBuffers.ProtoBench
                 inputData = inputData ?? File.ReadAllBytes(file);
                 MemoryStream inputStream = new MemoryStream(inputData);
                 ByteString inputString = ByteString.CopyFrom(inputData);
-                IMessage sampleMessage =
+                IMessage sampleMessage = defaultMessage.WeakCreateBuilderForType().WeakMergeFrom(inputString, registry).WeakBuild();
-                    defaultMessage.WeakCreateBuilderForType().WeakMergeFrom(inputString, registry).WeakBuild();
+                
+                StringWriter temp = new StringWriter();
+                new XmlFormatWriter(temp).WriteMessage(sampleMessage);
+                string xmlMessageText = temp.ToString();
+                temp = new StringWriter();
+                new JsonFormatWriter(temp).WriteMessage(sampleMessage);
+                string jsonMessageText = temp.ToString();
+
+                //Serializers
                 if(!FastTest) RunBenchmark("Serialize to byte string", inputData.Length, () => sampleMessage.ToByteString());
                 RunBenchmark("Serialize to byte array", inputData.Length, () => sampleMessage.ToByteArray());
                 if (!FastTest) RunBenchmark("Serialize to memory stream", inputData.Length,
                           () => sampleMessage.WriteTo(new MemoryStream()));
+
+                RunBenchmark("Serialize to xml", xmlMessageText.Length, () => new XmlFormatWriter(new StringWriter()).WriteMessage(sampleMessage));
+                RunBenchmark("Serialize to json", jsonMessageText.Length, () => new JsonFormatWriter(new StringWriter()).WriteMessage(sampleMessage));
+
+                //Deserializers
                 if (!FastTest) RunBenchmark("Deserialize from byte string", inputData.Length,
                           () => defaultMessage.WeakCreateBuilderForType()
                                     .WeakMergeFrom(inputString, registry)
@@ -151,6 +165,10 @@ namespace Google.ProtocolBuffers.ProtoBench
                               CodedInputStream.CreateInstance(inputStream), registry)
                           .WeakBuild();
                   });
+
+                RunBenchmark("Deserialize from xml", xmlMessageText.Length, () => new XmlFormatReader(xmlMessageText).Merge(defaultMessage.WeakCreateBuilderForType()).WeakBuild());
+                RunBenchmark("Deserialize from json", jsonMessageText.Length, () => new JsonFormatReader(jsonMessageText).Merge(defaultMessage.WeakCreateBuilderForType()).WeakBuild());
+
                 Console.WriteLine();
                 return true;
             }

src/ProtocolBuffers.Test/CompatTests/JsonCompatibilityTests.cs

@@ -0,0 +1,26 @@
+using System.IO;
+using System.Text;
+using Google.ProtocolBuffers.Serialization;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers.CompatTests
+{
+    [TestFixture]
+    public class JsonCompatibilityTests : CompatibilityTests
+    {
+        protected override object SerializeMessage<TMessage, TBuilder>(TMessage message)
+        {
+            StringWriter sw = new StringWriter();
+            new JsonFormatWriter(sw)
+                .Formatted()
+                .WriteMessage(message);
+            return sw.ToString();
+        }
+
+        protected override TBuilder DeerializeMessage<TMessage, TBuilder>(object message, TBuilder builder, ExtensionRegistry registry)
+        {
+            new JsonFormatReader((string)message).Merge(builder);
+            return builder;
+        }
+    }
+}

src/ProtocolBuffers.Test/ProtocolBuffers.Test.csproj

@@ -77,6 +77,7 @@
     <Compile Include="Collections\PopsicleListTest.cs" />
     <Compile Include="CompatTests\BinaryCompatibilityTests.cs" />
     <Compile Include="CompatTests\CompatibilityTests.cs" />
+    <Compile Include="CompatTests\JsonCompatibilityTests.cs" />
     <Compile Include="CompatTests\TestResources.Designer.cs">
       <AutoGen>True</AutoGen>
       <DesignTime>True</DesignTime>
@@ -115,6 +116,7 @@
     <Compile Include="TestProtos\UnitTestXmlSerializerTestProtoFile.cs" />
     <Compile Include="TestRpcGenerator.cs" />
     <Compile Include="TestUtil.cs" />
+    <Compile Include="TestWriterFormatJson.cs" />
     <Compile Include="TestWriterFormatXml.cs" />
     <Compile Include="TextFormatTest.cs" />
     <Compile Include="UnknownFieldSetTest.cs" />

src/ProtocolBuffers.Test/ProtocolBuffers.Test.csproj.user

@@ -0,0 +1,5 @@
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ProjectView>ProjectFiles</ProjectView>
+  </PropertyGroup>
+</Project>

src/ProtocolBuffers.Test/TestWriterFormatJson.cs

@@ -0,0 +1,342 @@
+using System;
+using System.IO;
+using Google.ProtocolBuffers.Serialization;
+using NUnit.Framework;
+using Google.ProtocolBuffers.TestProtos;
+
+namespace Google.ProtocolBuffers
+{
+    [TestFixture]
+    public class TestWriterFormatJson
+    {
+        protected string Content;
+        [System.Diagnostics.DebuggerNonUserCode]
+        protected void FormatterAssert<TMessage>(TMessage message, params string[] expecting) where TMessage : IMessageLite
+        {
+            StringWriter sw = new StringWriter();
+            new JsonFormatWriter(sw).WriteMessage(message);
+            
+            Content = sw.ToString();
+
+            ExtensionRegistry registry = ExtensionRegistry.CreateInstance();
+            UnitTestXmlSerializerTestProtoFile.RegisterAllExtensions(registry);
+
+            IMessageLite copy = 
+                new JsonFormatReader(Content)
+                .Merge(message.WeakCreateBuilderForType(), registry).WeakBuild();
+
+            Assert.AreEqual(typeof(TMessage), copy.GetType());
+            Assert.AreEqual(message, copy);
+            foreach (string expect in expecting)
+                Assert.IsTrue(Content.IndexOf(expect) >= 0, "Expected to find content '{0}' in: \r\n{1}", expect, Content);
+        }
+
+        [Test]
+        public void TestJsonFormatted()
+        {
+            TestXmlMessage message = TestXmlMessage.CreateBuilder()
+                .SetValid(true)
+                .SetNumber(0x1010)
+                .AddChildren(TestXmlMessage.Types.Children.CreateBuilder())
+                .AddChildren(TestXmlMessage.Types.Children.CreateBuilder().AddOptions(EnumOptions.ONE))
+                .AddChildren(TestXmlMessage.Types.Children.CreateBuilder().AddOptions(EnumOptions.ONE).AddOptions(EnumOptions.TWO))
+                .AddChildren(TestXmlMessage.Types.Children.CreateBuilder().SetBinary(ByteString.CopyFromUtf8("abc")))
+                .Build();
+
+            StringWriter sw = new StringWriter();
+            new JsonFormatWriter(sw).Formatted()
+                .WriteMessage(message);
+
+            string json = sw.ToString();
+
+            TestXmlMessage copy = new JsonFormatReader(json)
+                .Merge(TestXmlMessage.CreateBuilder()).Build();
+            Assert.AreEqual(message, copy);
+        }
+
+        [Test]
+        public void TestEmptyMessage()
+        {
+            FormatterAssert(
+                TestXmlChild.CreateBuilder()
+                .Build(),
+                @"{}"
+                );
+        }
+        [Test]
+        public void TestRepeatedField()
+        {
+            FormatterAssert(
+                TestXmlChild.CreateBuilder()
+                .AddOptions(EnumOptions.ONE)
+                .AddOptions(EnumOptions.TWO)
+                .Build(),
+                @"{""options"":[""ONE"",""TWO""]}"
+                );
+        }
+        [Test]
+        public void TestNestedEmptyMessage()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetChild(TestXmlChild.CreateBuilder().Build())
+                .Build(),
+                @"{""child"":{}}"
+                );
+        }
+        [Test]
+        public void TestNestedMessage()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetChild(TestXmlChild.CreateBuilder().AddOptions(EnumOptions.TWO).Build())
+                .Build(),
+                @"{""child"":{""options"":[""TWO""]}}"
+                );
+        }
+        [Test]
+        public void TestBooleanTypes()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetValid(true)
+                .Build(),
+                @"{""valid"":true}"
+                );
+        }
+        [Test]
+        public void TestFullMessage()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetValid(true)
+                .SetText("text")
+                .AddTextlines("a")
+                .AddTextlines("b")
+                .AddTextlines("c")
+                .SetNumber(0x1010101010)
+                .AddNumbers(1)
+                .AddNumbers(2)
+                .AddNumbers(3)
+                .SetChild(TestXmlChild.CreateBuilder().AddOptions(EnumOptions.ONE).SetBinary(ByteString.CopyFrom(new byte[1])))
+                .AddChildren(TestXmlMessage.Types.Children.CreateBuilder().AddOptions(EnumOptions.TWO).SetBinary(ByteString.CopyFrom(new byte[2])))
+                .AddChildren(TestXmlMessage.Types.Children.CreateBuilder().AddOptions(EnumOptions.THREE).SetBinary(ByteString.CopyFrom(new byte[3])))
+                .Build(),
+                @"""text"":""text""",
+                @"[""a"",""b"",""c""]",
+                @"[1,2,3]",
+                @"""child"":{",
+                @"""children"":[{",
+                @"AA==",
+                @"AAA=",
+                @"AAAA",
+                0x1010101010L.ToString()
+                );
+        }
+        [Test]
+        public void TestMessageWithXmlText()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetText("<text></text>")
+                .Build(),
+                @"{""text"":""<text><\/text>""}"
+                );
+        }
+        [Test]
+        public void TestWithEscapeChars()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetText(" \t <- \"leading space and trailing\" -> \\ \xef54 \x0000 \xFF \xFFFF \b \f \r \n \t ")
+                .Build(),
+                "{\"text\":\" \\t <- \\\"leading space and trailing\\\" -> \\\\ \\uef54 \\u0000 \\u00ff \\uffff \\b \\f \\r \\n \\t \"}"
+                );
+        }
+        [Test]
+        public void TestWithExtensionText()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetValid(false)
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionText, " extension text value ! ")
+                .Build(),
+                @"{""valid"":false,""extension_text"":"" extension text value ! ""}"
+                );
+        }
+        [Test]
+        public void TestWithExtensionNumber()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionMessage,
+                new TestXmlExtension.Builder().SetNumber(42).Build())
+                .Build(),
+                @"{""number"":42}"
+                );
+        }
+        [Test]
+        public void TestWithExtensionArray()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 100)
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 101)
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 102)
+                .Build(),
+                @"{""extension_number"":[100,101,102]}"
+                );
+        }
+        [Test]
+        public void TestWithExtensionEnum()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionEnum, EnumOptions.ONE)
+                .Build(),
+                @"{""extension_enum"":""ONE""}"
+                );
+        }
+        [Test]
+        public void TestMessageWithExtensions()
+        {
+            FormatterAssert(
+                TestXmlMessage.CreateBuilder()
+                .SetValid(true)
+                .SetText("text")
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionText, "extension text")
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionMessage, new TestXmlExtension.Builder().SetNumber(42).Build())
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 100)
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 101)
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 102)
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionEnum, EnumOptions.ONE)
+                .Build(),
+                @"""text"":""text""",
+                @"""valid"":true",
+                @"""extension_enum"":""ONE""",
+                @"""extension_text"":""extension text""",
+                @"""extension_number"":[100,101,102]",
+                @"""extension_message"":{""number"":42}"
+                );
+        }
+        [Test]
+        public void TestMessageMissingExtensions()
+        {
+            TestXmlMessage original = TestXmlMessage.CreateBuilder()
+                .SetValid(true)
+                .SetText("text")
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionText, " extension text value ! ")
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionMessage, new TestXmlExtension.Builder().SetNumber(42).Build())
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 100)
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 101)
+                .AddExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber, 102)
+                .SetExtension(UnitTestXmlSerializerTestProtoFile.ExtensionEnum, EnumOptions.ONE)
+                .Build();
+
+            TestXmlMessage message = original.ToBuilder()
+                .ClearExtension(UnitTestXmlSerializerTestProtoFile.ExtensionText)
+                .ClearExtension(UnitTestXmlSerializerTestProtoFile.ExtensionMessage)
+                .ClearExtension(UnitTestXmlSerializerTestProtoFile.ExtensionNumber)
+                .ClearExtension(UnitTestXmlSerializerTestProtoFile.ExtensionEnum)
+                .Build();
+
+            JsonFormatWriter writer = new JsonFormatWriter();
+            writer.WriteMessage(original);
+            Content = writer.ToString();
+
+            IMessageLite copy = new JsonFormatReader(Content)
+                .Merge(message.CreateBuilderForType()).Build();
+
+            Assert.AreNotEqual(original, message);
+            Assert.AreNotEqual(original, copy);
+            Assert.AreEqual(message, copy);
+        }
+        [Test]
+        public void TestMergeFields()
+        {
+            TestXmlMessage.Builder builder = TestXmlMessage.CreateBuilder();
+            builder.MergeFrom(new JsonFormatReader("\"valid\": true"));
+            builder.MergeFrom(new JsonFormatReader("\"text\": \"text\", \"number\": \"411\""));
+            Assert.AreEqual(true, builder.Valid);
+            Assert.AreEqual("text", builder.Text);
+            Assert.AreEqual(411, builder.Number);
+        }
+        [Test]
+        public void TestMessageArray()
+        {
+            JsonFormatWriter writer = new JsonFormatWriter().Formatted();
+            using (writer.StartArray())
+            {
+                writer.WriteMessage(TestXmlMessage.CreateBuilder().SetNumber(1).AddTextlines("a").Build());
+                writer.WriteMessage(TestXmlMessage.CreateBuilder().SetNumber(2).AddTextlines("b").Build());
+                writer.WriteMessage(TestXmlMessage.CreateBuilder().SetNumber(3).AddTextlines("c").Build());
+            }
+            string json = writer.ToString();
+            JsonFormatReader reader = new JsonFormatReader(json);
+            
+            TestXmlMessage.Builder builder = TestXmlMessage.CreateBuilder();
+            int ordinal = 0;
+
+            foreach (JsonFormatReader r in reader.EnumerateArray())
+            {
+                r.Merge(builder);
+                Assert.AreEqual(++ordinal, builder.Number);
+            }
+            Assert.AreEqual(3, ordinal);
+            Assert.AreEqual(3, builder.TextlinesCount);
+        }
+        [Test]
+        public void TestNestedMessageArray()
+        {
+            JsonFormatWriter writer = new JsonFormatWriter();
+            using (writer.StartArray())
+            {
+                using (writer.StartArray())
+                {
+                    writer.WriteMessage(TestXmlMessage.CreateBuilder().SetNumber(1).AddTextlines("a").Build());
+                    writer.WriteMessage(TestXmlMessage.CreateBuilder().SetNumber(2).AddTextlines("b").Build());
+                } 
+                using (writer.StartArray())
+                    writer.WriteMessage(TestXmlMessage.CreateBuilder().SetNumber(3).AddTextlines("c").Build());
+            }
+            string json = writer.ToString();
+            JsonFormatReader reader = new JsonFormatReader(json);
+
+            TestXmlMessage.Builder builder = TestXmlMessage.CreateBuilder();
+            int ordinal = 0;
+
+            foreach (JsonFormatReader r in reader.EnumerateArray())
+                foreach (JsonFormatReader r2 in r.EnumerateArray())
+                {
+                    r2.Merge(builder);
+                    Assert.AreEqual(++ordinal, builder.Number);
+                }
+            Assert.AreEqual(3, ordinal);
+            Assert.AreEqual(3, builder.TextlinesCount);
+        }
+        [Test, ExpectedException(typeof(FormatException))]
+        public void FailWithEmptyText()
+        {
+            new JsonFormatReader("")
+                .Merge(TestXmlMessage.CreateBuilder());
+        }
+        [Test, ExpectedException(typeof(FormatException))]
+        public void FailWithUnexpectedValue()
+        {
+            new JsonFormatReader("{{}}")
+                .Merge(TestXmlMessage.CreateBuilder());
+        }
+        [Test, ExpectedException(typeof(FormatException))]
+        public void FailWithUnQuotedName()
+        {
+            new JsonFormatReader("{name:{}}")
+                .Merge(TestXmlMessage.CreateBuilder());
+        }
+        [Test, ExpectedException(typeof(FormatException))]
+        public void FailWithUnexpectedType()
+        {
+            new JsonFormatReader("{\"valid\":{}}")
+                .Merge(TestXmlMessage.CreateBuilder());
+        }
+    }
+}

src/ProtocolBuffers/ProtocolBuffers.csproj

@@ -184,6 +184,9 @@
     <Compile Include="Serialization\AbstractTextReader.cs" />
     <Compile Include="Serialization\AbstractTextWriter.cs" />
     <Compile Include="Serialization\AbstractWriter.cs" />
+    <Compile Include="Serialization\JsonFormatReader.cs" />
+    <Compile Include="Serialization\JsonFormatWriter.cs" />
+    <Compile Include="Serialization\JsonTextCursor.cs" />
     <Compile Include="Serialization\XmlFormatReader.cs" />
     <Compile Include="Serialization\XmlFormatWriter.cs" />
     <Compile Include="Serialization\XmlReaderOptions.cs" />

src/ProtocolBuffers/Serialization/JsonFormatReader.cs

@@ -0,0 +1,181 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Xml;
+
+namespace Google.ProtocolBuffers.Serialization
+{
+    /// <summary>
+    /// JsonFormatReader is used to parse Json into a message or an array of messages
+    /// </summary>
+    public class JsonFormatReader : AbstractTextReader
+    {
+        private readonly JsonTextCursor _input;
+        private readonly Stack<int> _stopChar;
+
+        enum ReaderState { Start, BeginValue, EndValue, BeginObject, BeginArray }
+        string _current;
+        ReaderState _state;
+
+        /// <summary>
+        /// Constructs a JsonFormatReader to parse Json into a message
+        /// </summary>
+        public JsonFormatReader(string jsonText)
+        {
+            _input = new JsonTextCursor(jsonText.ToCharArray());
+            _stopChar = new Stack<int>();
+            _stopChar.Push(-1);
+            _state = ReaderState.Start;
+        }
+        /// <summary>
+        /// Constructs a JsonFormatReader to parse Json into a message
+        /// </summary>
+        public JsonFormatReader(TextReader input)
+        {
+            _input = new JsonTextCursor(input);
+            _stopChar = new Stack<int>();
+            _stopChar.Push(-1);
+            _state = ReaderState.Start;
+        }
+
+        /// <summary>
+        /// Returns true if the reader is currently on an array element
+        /// </summary>
+        public bool IsArrayMessage { get { return _input.NextChar == '['; } }
+
+        /// <summary>
+        /// Returns an enumerator that is used to cursor over an array of messages
+        /// </summary>
+        /// <remarks>
+        /// This is generally used when receiving an array of messages rather than a single root message
+        /// </remarks>
+        public IEnumerable<JsonFormatReader> EnumerateArray()
+        {
+            foreach (string ignored in ForeachArrayItem(_current))
+                yield return this;
+        }
+
+        /// <summary>
+        /// Merges the contents of stream into the provided message builder
+        /// </summary>
+        public override TBuilder Merge<TBuilder>(TBuilder builder, ExtensionRegistry registry)
+        {
+            _input.Consume('{');
+            _stopChar.Push('}');
+
+            _state = ReaderState.BeginObject;
+            builder.WeakMergeFrom(this, registry);
+            _input.Consume((char)_stopChar.Pop());
+            _state = ReaderState.EndValue;
+            return builder;
+        }
+
+        /// <summary>
+        /// Causes the reader to skip past this field
+        /// </summary>
+        protected override void Skip()
+        {
+            object temp;
+            _input.ReadVariant(out temp);
+            _state = ReaderState.EndValue;
+        }
+
+        /// <summary>
+        /// Peeks at the next field in the input stream and returns what information is available.
+        /// </summary>
+        /// <remarks>
+        /// This may be called multiple times without actually reading the field.  Only after the field
+        /// is either read, or skipped, should PeekNext return a different value.
+        /// </remarks>
+        protected override bool PeekNext(out string field)
+        {
+            field = _current;
+            if(_state == ReaderState.BeginValue)
+                return true;
+
+            int next = _input.NextChar;
+            if (next == _stopChar.Peek())
+                return false;
+
+            _input.Assert(next != -1, "Unexpected end of file.");
+
+            //not sure about this yet, it will allow {, "a":true }
+            if (_state == ReaderState.EndValue && !_input.TryConsume(','))
+                return false;
+
+            field = _current = _input.ReadString();
+            _input.Consume(':');
+            _state = ReaderState.BeginValue;
+            return true;
+        }
+
+        /// <summary>
+        /// Returns true if it was able to read a String from the input
+        /// </summary>
+        protected override bool ReadAsText(ref string value, Type typeInfo)
+        {
+            object temp;
+            JsonTextCursor.JsType type = _input.ReadVariant(out temp);
+            _state = ReaderState.EndValue;
+
+            _input.Assert(type != JsonTextCursor.JsType.Array && type != JsonTextCursor.JsType.Object, "Encountered {0} while expecting {1}", type, typeInfo);
+            if (type == JsonTextCursor.JsType.Null)
+                return false;
+            if (type == JsonTextCursor.JsType.True) value = "1";
+            else if (type == JsonTextCursor.JsType.False) value = "0";
+            else value = temp as string;
+
+            //exponent representation of integer number:
+            if (value != null && type == JsonTextCursor.JsType.Number &&
+                (typeInfo != typeof(double) && typeInfo != typeof(float)) &&
+                value.IndexOf("e", StringComparison.OrdinalIgnoreCase) > 0)
+            {
+                value = XmlConvert.ToString((long)Math.Round(XmlConvert.ToDouble(value), 0));
+            }
+            return value != null;
+        }
+
+        /// <summary>
+        /// Returns true if it was able to read a ByteString from the input
+        /// </summary>
+        protected override bool Read(ref ByteString value)
+        {
+            string bytes = null;
+            if (Read(ref bytes))
+            {
+                value = ByteString.FromBase64(bytes);
+                return true;
+            }
+            return false;
+        }
+
+        /// <summary>
+        /// Cursors through the array elements and stops at the end of the array
+        /// </summary>
+        protected override IEnumerable<string> ForeachArrayItem(string field)
+        {
+            _input.Consume('[');
+            _stopChar.Push(']');
+            _state = ReaderState.BeginArray;
+            while (_input.NextChar != ']')
+            {
+                _current = field;
+                yield return field;
+                if(!_input.TryConsume(','))
+                    break;
+            }
+            _input.Consume((char)_stopChar.Pop());
+            _state = ReaderState.EndValue;
+        }
+
+        /// <summary>
+        /// Merges the input stream into the provided IBuilderLite 
+        /// </summary>
+        protected override bool ReadMessage(IBuilderLite builder, ExtensionRegistry registry)
+        {
+            Merge(builder, registry);
+            return true;
+        }
+
+    }
+}

src/ProtocolBuffers/Serialization/JsonFormatWriter.cs

@@ -0,0 +1,329 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers.Serialization
+{
+    /// <summary>
+    /// JsonFormatWriter is a .NET 2.0 friendly json formatter for proto buffer messages.  For .NET 3.5
+    /// you may also use the XmlFormatWriter with an XmlWriter created by the
+    /// <see cref="System.Runtime.Serialization.Json.JsonReaderWriterFactory">JsonReaderWriterFactory</see>.
+    /// </summary>
+    public class JsonFormatWriter : AbstractTextWriter
+    {
+        private readonly char[] _buffer;
+        private readonly TextWriter _output;
+        private readonly List<int> _counter;
+        private bool _isArray;
+        int _bufferPos;
+        /// <summary>
+        /// Constructs a JsonFormatWriter to output to a new instance of a StringWriter, use
+        /// the ToString() member to extract the final Json on completion.
+        /// </summary>
+        public JsonFormatWriter() : this(new StringWriter()) { }
+        /// <summary>
+        /// Constructs a JsonFormatWriter to output to the given text writer
+        /// </summary>
+        public JsonFormatWriter(TextWriter output)
+        {
+            _buffer = new char[4096];
+            _bufferPos = 0;
+            _output = output;
+            _counter = new List<int>();
+            _counter.Add(0);
+        }
+
+
+        private void WriteToOutput(string format, params object[] args)
+        { WriteToOutput(String.Format(format, args)); }
+
+        private void WriteToOutput(string text)
+        { WriteToOutput(text.ToCharArray(), 0, text.Length); }
+
+        private void WriteToOutput(char[] chars, int offset, int len)
+        {
+            if (_bufferPos + len >= _buffer.Length)
+                Flush();
+            if (len < _buffer.Length)
+            {
+                if (len <= 12)
+                {
+                    int stop = offset + len;
+                    for (int i = offset; i < stop; i++)
+                        _buffer[_bufferPos++] = chars[i];
+                }
+                else
+                {
+                    Buffer.BlockCopy(chars, offset << 1, _buffer, _bufferPos << 1, len << 1);
+                    _bufferPos += len;
+                }
+            }
+            else
+                _output.Write(chars, offset, len);
+        }
+
+        private void WriteToOutput(char ch)
+        {
+            if (_bufferPos >= _buffer.Length)
+                Flush();
+            _buffer[_bufferPos++] = ch;
+        }
+
+        public override void Flush()
+        {
+            if (_bufferPos > 0)
+            {
+                _output.Write(_buffer, 0, _bufferPos);
+                _bufferPos = 0;
+            }
+            base.Flush();
+        }
+
+        /// <summary>
+        /// Returns the output of TextWriter.ToString() where TextWriter is the ctor argument.
+        /// </summary>
+        public override string ToString()
+        { Flush(); return _output.ToString(); }
+
+        /// <summary> Sets the output formatting to use Environment.NewLine with 4-character indentions </summary>
+        public JsonFormatWriter Formatted()
+        {
+            NewLine = Environment.NewLine;
+            Indent = "    ";
+            Whitespace = " ";
+            return this;
+        }
+
+        /// <summary> Gets or sets the characters to use for the new-line, default = empty </summary>
+        public string NewLine { get; set; }
+        /// <summary> Gets or sets the text to use for indenting, default = empty </summary>
+        public string Indent { get; set; }
+        /// <summary> Gets or sets the whitespace to use to separate the text, default = empty </summary>
+        public string Whitespace { get; set; }
+
+        private void Seperator()
+        {
+            if (_counter.Count == 0)
+                throw new InvalidOperationException("Missmatched open/close in Json writer.");
+
+            int index = _counter.Count - 1;
+            if (_counter[index] > 0)
+                WriteToOutput(',');
+
+            WriteLine(String.Empty);
+            _counter[index] = _counter[index] + 1;
+        }
+
+        private void WriteLine(string content)
+        {
+            if (!String.IsNullOrEmpty(NewLine))
+            {
+                WriteToOutput(NewLine);
+                for (int i = 1; i < _counter.Count; i++)
+                    WriteToOutput(Indent);
+            }
+            else if(!String.IsNullOrEmpty(Whitespace))
+                WriteToOutput(Whitespace);
+
+            WriteToOutput(content);
+        }
+
+        private void WriteName(string field)
+        {
+            Seperator();
+            if (!String.IsNullOrEmpty(field))
+            {
+                WriteToOutput('"');
+                WriteToOutput(field);
+                WriteToOutput('"');
+                WriteToOutput(':');
+                if (!String.IsNullOrEmpty(Whitespace))
+                    WriteToOutput(Whitespace);
+            }
+        }
+
+        private void EncodeText(string value)
+        {
+            char[] text = value.ToCharArray();
+            int len = text.Length;
+            int pos = 0;
+
+            while (pos < len)
+            {
+                int next = pos;
+                while (next < len && text[next] >= 32 && text[next] < 127 && text[next] != '\\' && text[next] != '/' && text[next] != '"')
+                    next++;
+                WriteToOutput(text, pos, next - pos);
+                if (next < len)
+                {
+                    switch (text[next])
+                    {
+                        case '"': WriteToOutput(@"\"""); break;
+                        case '\\': WriteToOutput(@"\\"); break;
+                        //odd at best to escape '/', most Json implementations don't, but it is defined in the rfc-4627
+                        case '/': WriteToOutput(@"\/"); break; 
+                        case '\b': WriteToOutput(@"\b"); break;
+                        case '\f': WriteToOutput(@"\f"); break;
+                        case '\n': WriteToOutput(@"\n"); break;
+                        case '\r': WriteToOutput(@"\r"); break;
+                        case '\t': WriteToOutput(@"\t"); break;
+                        default: WriteToOutput(@"\u{0:x4}", (int)text[next]); break;
+                    }
+                    next++;
+                }
+                pos = next;
+            }
+        }
+
+        /// <summary>
+        /// Writes a String value
+        /// </summary>
+        protected override void WriteAsText(string field, string textValue, object typedValue)
+        {
+            WriteName(field);
+            if(typedValue is bool || typedValue is int || typedValue is uint || typedValue is long || typedValue is ulong || typedValue is double || typedValue is float)
+                WriteToOutput(textValue);
+            else
+            {
+                WriteToOutput('"');
+                if (typedValue is string)
+                    EncodeText(textValue);
+                else
+                    WriteToOutput(textValue);
+                WriteToOutput('"');
+            }
+        }
+
+        /// <summary>
+        /// Writes a Double value
+        /// </summary>
+        protected override void Write(string field, double value)
+        {
+            if (double.IsNaN(value) || double.IsNegativeInfinity(value) || double.IsPositiveInfinity(value))
+                throw new InvalidOperationException("This format does not support NaN, Infinity, or -Infinity");
+            base.Write(field, value);
+        }
+
+        /// <summary>
+        /// Writes a Single value
+        /// </summary>
+        protected override void Write(string field, float value)
+        {
+            if (float.IsNaN(value) || float.IsNegativeInfinity(value) || float.IsPositiveInfinity(value))
+                throw new InvalidOperationException("This format does not support NaN, Infinity, or -Infinity");
+            base.Write(field, value);
+        }
+
+        // Treat enum as string
+        protected override void WriteEnum(string field, int number, string name)
+        {
+            Write(field, name);
+        }
+
+        /// <summary>
+        /// Writes an array of field values
+        /// </summary>
+        protected override void WriteArray(FieldType type, string field, System.Collections.IEnumerable items)
+        {
+            System.Collections.IEnumerator enumerator = items.GetEnumerator();
+            try { if (!enumerator.MoveNext()) return; }
+            finally { if (enumerator is IDisposable) ((IDisposable)enumerator).Dispose(); }
+
+            WriteName(field);
+            WriteToOutput("[");
+            _counter.Add(0);
+
+            base.WriteArray(type, String.Empty, items);
+
+            _counter.RemoveAt(_counter.Count - 1);
+            WriteLine("]");
+        }
+
+        /// <summary>
+        /// Writes a message
+        /// </summary>
+        protected override void WriteMessageOrGroup(string field, IMessageLite message)
+        {
+            WriteName(field);
+            WriteMessage(message);
+        }
+
+        /// <summary>
+        /// Writes the message to the the formatted stream.
+        /// </summary>
+        public override void WriteMessage(IMessageLite message)
+        {
+            if (_isArray) Seperator();
+            WriteToOutput("{");
+            _counter.Add(0);
+            message.WriteTo(this);
+            _counter.RemoveAt(_counter.Count - 1);
+            WriteLine("}");
+            Flush();
+        }
+
+        /// <summary>
+        /// Writes a message
+        /// </summary>
+        [System.ComponentModel.Browsable(false)]
+        [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
+        public override void WriteMessage(string field, IMessageLite message)
+        {
+            WriteMessage(message);
+        }
+
+        /// <summary>
+        /// Used in streaming arrays of objects to the writer
+        /// </summary>
+        /// <example>
+        /// <code>
+        /// using(writer.StartArray())
+        ///     foreach(IMessageLite m in messages)
+        ///         writer.WriteMessage(m);
+        /// </code>
+        /// </example>
+        public sealed class JsonArray : IDisposable 
+        {
+            JsonFormatWriter _writer;
+            internal JsonArray(JsonFormatWriter writer)
+            {
+                _writer = writer;
+                _writer.WriteToOutput("[");
+                _writer._counter.Add(0);
+            }
+
+            /// <summary>
+            /// Causes the end of the array character to be written.
+            /// </summary>
+            void EndArray() 
+            {
+                if (_writer != null)
+                {
+                    _writer._counter.RemoveAt(_writer._counter.Count - 1);
+                    _writer.WriteLine("]");
+                    _writer.Flush();
+                }
+                _writer = null; 
+            }
+            void IDisposable.Dispose() { EndArray(); }
+        }
+
+        /// <summary>
+        /// Used to write an array of messages as the output rather than a single message.
+        /// </summary>
+        /// <example>
+        /// <code>
+        /// using(writer.StartArray())
+        ///     foreach(IMessageLite m in messages)
+        ///         writer.WriteMessage(m);
+        /// </code>
+        /// </example>
+        public JsonArray StartArray()
+        {
+            if (_isArray) Seperator();
+            _isArray = true;
+            return new JsonArray(this);
+        }
+    }
+}

src/ProtocolBuffers/Serialization/JsonTextCursor.cs

@@ -0,0 +1,270 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Text;
+
+namespace Google.ProtocolBuffers.Serialization
+{
+    /// <summary>
+    /// JSon Tokenizer used by JsonFormatReader
+    /// </summary>
+    class JsonTextCursor
+    {
+        public enum JsType { String, Number, Object, Array, True, False, Null }
+
+        private readonly char[] _buffer;
+        private int _bufferPos;
+        private readonly TextReader _input;
+        private int _lineNo, _linePos;
+
+        public JsonTextCursor(char[] input)
+        {
+            _input = null;
+            _buffer = input;
+            _bufferPos = 0;
+            _next = Peek();
+            _lineNo = 1;
+        }
+
+        public JsonTextCursor(TextReader input)
+        {
+            _input = input;
+            _next = Peek();
+            _lineNo = 1;
+        }
+
+        private int Peek()
+        {
+            if (_input != null)
+                return _input.Peek();
+            else if (_bufferPos < _buffer.Length)
+                return _buffer[_bufferPos];
+            else
+                return -1;
+        }
+
+        private int Read()
+        {
+            if (_input != null)
+                return _input.Read();
+            else if (_bufferPos < _buffer.Length)
+                return _buffer[_bufferPos++];
+            else
+                return -1;
+        }
+
+        int _next;
+        public Char NextChar { get { SkipWhitespace(); return (char)_next; } }
+
+        #region Assert(...)
+        [System.Diagnostics.DebuggerNonUserCode]
+        private string CharDisplay(int ch)
+        {
+            return ch == -1 ? "EOF" :
+                                        (ch > 32 && ch < 127) ? String.Format("'{0}'", (char)ch) :
+                                                                                                     String.Format("'\\u{0:x4}'", ch);
+        }
+        [System.Diagnostics.DebuggerNonUserCode]
+        private void Assert(bool cond, char expected)
+        {
+            if (!cond)
+            {
+                throw new FormatException(
+                    String.Format(CultureInfo.InvariantCulture,
+                                  "({0}:{1}) error: Unexpected token {2}, expected: {3}.",
+                                  _lineNo, _linePos, 
+                                  CharDisplay(_next),
+                                  CharDisplay(expected)
+                        ));
+            }
+        }
+        [System.Diagnostics.DebuggerNonUserCode]
+        public void Assert(bool cond, string message)
+        {
+            if (!cond)
+            {
+                throw new FormatException(
+                    String.Format(CultureInfo.InvariantCulture,
+                                  "({0},{1}) error: {2}", _lineNo, _linePos, message));
+            }
+        }
+        [System.Diagnostics.DebuggerNonUserCode]
+        public void Assert(bool cond, string format, params object[] args)
+        {
+            if (!cond)
+            {
+                if (args != null && args.Length > 0)
+                    format = String.Format(format, args);
+                throw new FormatException(
+                    String.Format(CultureInfo.InvariantCulture,
+                                  "({0},{1}) error: {2}", _lineNo, _linePos, format));
+            }
+        }
+        #endregion
+
+        private char ReadChar()
+        {
+            int ch = Read();
+            Assert(ch != -1, "Unexpected end of file.");
+            if (ch == '\n')
+            {
+                _lineNo++;
+                _linePos = 0;
+            }
+            else if (ch != '\r')
+            {
+                _linePos++;
+            }
+            _next = Peek();
+            return (char)ch;
+        }
+
+        public void Consume(char ch) { Assert(TryConsume(ch), ch); }
+        public bool TryConsume(char ch)
+        {
+            SkipWhitespace();
+            if (_next == ch)
+            {
+                ReadChar();
+                return true;
+            }
+            return false;
+        }
+
+        public void Consume(string sequence)
+        {
+            SkipWhitespace();
+
+            foreach (char ch in sequence)
+                Assert(ch == ReadChar(), "Expected token '{0}'.", sequence);
+        }
+
+        public void SkipWhitespace()
+        {
+            int chnext = _next;
+            while (chnext != -1)
+            {
+                if (!Char.IsWhiteSpace((char)chnext))
+                    break;
+                ReadChar();
+                chnext = _next;
+            }
+        }
+
+        public string ReadString()
+        {
+            SkipWhitespace();
+            Consume('"');
+            StringBuilder sb = new StringBuilder();
+            while (_next != '"')
+            {
+                if (_next == '\\')
+                {
+                    Consume('\\');//skip the escape
+                    char ch = ReadChar();
+                    switch (ch)
+                    {
+                        case 'b': sb.Append('\b'); break;
+                        case 'f': sb.Append('\f'); break;
+                        case 'n': sb.Append('\n'); break;
+                        case 'r': sb.Append('\r'); break;
+                        case 't': sb.Append('\t'); break;
+                        case 'u':
+                            {
+                                string hex = new string(new char[] { ReadChar(), ReadChar(), ReadChar(), ReadChar() });
+                                int result;
+                                Assert(int.TryParse(hex, NumberStyles.AllowHexSpecifier, CultureInfo.InvariantCulture, out result),
+                                       "Expected a 4-character hex specifier.");
+                                sb.Append((char)result);
+                                break;
+                            }
+                        default:
+                            sb.Append(ch); break;
+                    }
+                }
+                else
+                {
+                    Assert(_next != '\n' && _next != '\r' && _next != '\f' && _next != -1, '"');
+                    sb.Append(ReadChar());
+                }
+            }
+            Consume('"');
+            return sb.ToString();
+        }
+
+        public string ReadNumber()
+        {
+            SkipWhitespace();
+
+            StringBuilder sb = new StringBuilder();
+            if (_next == '-')
+                sb.Append(ReadChar());
+            Assert(_next >= '0' && _next <= '9', "Expected a numeric type.");
+            while ((_next >= '0' && _next <= '9') || _next == '.')
+                sb.Append(ReadChar());
+            if (_next == 'e' || _next == 'E')
+            {
+                sb.Append(ReadChar());
+                if (_next == '-' || _next == '+')
+                    sb.Append(ReadChar());
+                Assert(_next >= '0' && _next <= '9', "Expected a numeric type.");
+                while (_next >= '0' && _next <= '9')
+                    sb.Append(ReadChar());
+            }
+            return sb.ToString();
+        }
+
+        public JsType ReadVariant(out object value)
+        {
+            SkipWhitespace();
+            switch (_next)
+            {
+                case 'n': Consume("null"); value = null; return JsType.Null;
+                case 't': Consume("true"); value = true; return JsType.True;
+                case 'f': Consume("false"); value = false; return JsType.False;
+                case '"': value = ReadString(); return JsType.String;
+                case '{':
+                    {
+                        Consume('{');
+                        while (NextChar != '}')
+                        {
+                            ReadString();
+                            Consume(':');
+                            object tmp;
+                            ReadVariant(out tmp);
+                            if (!TryConsume(','))
+                                break;
+                        }
+                        Consume('}');
+                        value = null;
+                        return JsType.Object;
+                    }
+                case '[':
+                    {
+                        Consume('[');
+                        List<object> values = new List<object>();
+                        while (NextChar != ']')
+                        {
+                            object tmp;
+                            ReadVariant(out tmp);
+                            values.Add(tmp);
+                            if (!TryConsume(','))
+                                break;
+                        }
+                        Consume(']');
+                        value = values.ToArray();
+                        return JsType.Array;
+                    }
+                default:
+                    if ((_next >= '0' && _next <= '9') || _next == '-')
+                    {
+                        value = ReadNumber();
+                        return JsType.Number;
+                    }
+                    Assert(false, "Expected a value.");
+                    throw new FormatException();
+            }
+        }
+    }
+}