Write/Read delimited messages

src/AddressBook/AddressBookProtos.cs

@@ -174,6 +174,12 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
         public static PhoneNumber ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static PhoneNumber ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static PhoneNumber ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static PhoneNumber ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -217,6 +223,9 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
           }
           
           public override PhoneNumber BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             PhoneNumber returnMe = result;
             result = null;
             return returnMe;
@@ -446,6 +455,12 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
     public static Person ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static Person ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static Person ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static Person ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -489,6 +504,9 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
       }
       
       public override Person BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.phone_.MakeReadOnly();
         Person returnMe = result;
         result = null;
@@ -753,6 +771,12 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
     public static AddressBook ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static AddressBook ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static AddressBook ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static AddressBook ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -796,6 +820,9 @@ namespace Google.ProtocolBuffers.Examples.AddressBook {
       }
       
       public override AddressBook BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.person_.MakeReadOnly();
         AddressBook returnMe = result;
         result = null;

src/ProtoGen/MessageGenerator.cs

@@ -218,6 +218,12 @@ namespace Google.ProtocolBuffers.ProtoGen {
       writer.WriteLine("public static {0} ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {{", ClassName);
       writer.WriteLine("  return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();");
       writer.WriteLine("}");
+      writer.WriteLine("public static {0} ParseDelimitedFrom(global::System.IO.Stream input) {{", ClassName);
+      writer.WriteLine("  return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();");
+      writer.WriteLine("}");
+      writer.WriteLine("public static {0} ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {{", ClassName);
+      writer.WriteLine("  return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();");
+      writer.WriteLine("}");
       writer.WriteLine("public static {0} ParseFrom(pb::CodedInputStream input) {{", ClassName);
       writer.WriteLine("  return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();");
       writer.WriteLine("}");
@@ -325,6 +331,9 @@ namespace Google.ProtocolBuffers.ProtoGen {
     
       writer.WriteLine("public override {0} BuildPartial() {{", ClassName);
       writer.Indent();
+      writer.WriteLine("if (result == null) {");
+      writer.WriteLine("  throw new global::System.InvalidOperationException(\"build() has already been called on this Builder\");");
+      writer.WriteLine("}");
       foreach (FieldDescriptor field in Descriptor.Fields) {
         SourceGenerators.CreateFieldGenerator(field).GenerateBuildingCode(writer);
       }

src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs

@@ -141,6 +141,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestEmbedOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestEmbedOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestEmbedOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestEmbedOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -184,6 +190,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestEmbedOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.repeatedMessage_.MakeReadOnly();
         TestEmbedOptimizedForSize returnMe = result;
         result = null;

src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs

@@ -123,6 +123,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static ImportMessage ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static ImportMessage ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static ImportMessage ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static ImportMessage ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -166,6 +172,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override ImportMessage BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         ImportMessage returnMe = result;
         result = null;
         return returnMe;

src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs

@@ -136,6 +136,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSet ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSet ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSet ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSet ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -179,6 +185,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSet BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSet returnMe = result;
         result = null;
         return returnMe;
@@ -314,6 +323,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSetContainer ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSetContainer ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSetContainer ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSetContainer ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -357,6 +372,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSetContainer BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSetContainer returnMe = result;
         result = null;
         return returnMe;
@@ -542,6 +560,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSetExtension1 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSetExtension1 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSetExtension1 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSetExtension1 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -585,6 +609,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSetExtension1 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSetExtension1 returnMe = result;
         result = null;
         return returnMe;
@@ -747,6 +774,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestMessageSetExtension2 ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestMessageSetExtension2 ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestMessageSetExtension2 ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestMessageSetExtension2 ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -790,6 +823,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestMessageSetExtension2 BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestMessageSetExtension2 returnMe = result;
         result = null;
         return returnMe;
@@ -992,6 +1028,12 @@ namespace Google.ProtocolBuffers.TestProtos {
         public static Item ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
           return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
         }
+        public static Item ParseDelimitedFrom(global::System.IO.Stream input) {
+          return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+        }
+        public static Item ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+          return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+        }
         public static Item ParseFrom(pb::CodedInputStream input) {
           return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
         }
@@ -1035,6 +1077,9 @@ namespace Google.ProtocolBuffers.TestProtos {
           }
           
           public override Item BuildPartial() {
+            if (result == null) {
+              throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+            }
             Item returnMe = result;
             result = null;
             return returnMe;
@@ -1203,6 +1248,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static RawMessageSet ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static RawMessageSet ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static RawMessageSet ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static RawMessageSet ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -1246,6 +1297,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override RawMessageSet BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         result.item_.MakeReadOnly();
         RawMessageSet returnMe = result;
         result = null;

src/ProtocolBuffers.Test/TestProtos/UnitTestOptimizeForProtoFile.cs

@@ -119,6 +119,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -162,6 +168,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestOptimizedForSize returnMe = result;
         result = null;
         return returnMe;
@@ -274,6 +283,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestRequiredOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestRequiredOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestRequiredOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestRequiredOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -317,6 +332,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestRequiredOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestRequiredOptimizedForSize returnMe = result;
         result = null;
         return returnMe;
@@ -393,6 +411,12 @@ namespace Google.ProtocolBuffers.TestProtos {
     public static TestOptionalOptimizedForSize ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static TestOptionalOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static TestOptionalOptimizedForSize ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static TestOptionalOptimizedForSize ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -436,6 +460,9 @@ namespace Google.ProtocolBuffers.TestProtos {
       }
       
       public override TestOptionalOptimizedForSize BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         TestOptionalOptimizedForSize returnMe = result;
         result = null;
         return returnMe;

src/ProtocolBuffers.Test/WireFormatTest.cs

@@ -29,6 +29,7 @@
 // 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.
+using System.IO;
 using System.Reflection;
 using Google.ProtocolBuffers.Descriptors;
 using Google.ProtocolBuffers.TestProtos;
@@ -98,6 +99,23 @@ namespace Google.ProtocolBuffers {
       Assert.AreEqual(rawBytes, rawBytes2);
     }
 
+    [Test]
+    public void SerializeDelimited() {
+      MemoryStream stream = new MemoryStream();
+      TestUtil.GetAllSet().WriteDelimitedTo(stream);
+      stream.WriteByte(12);
+      TestUtil.GetPackedSet().WriteDelimitedTo(stream);
+      stream.WriteByte(34);
+
+      stream.Position = 0;
+
+      TestUtil.AssertAllFieldsSet(TestAllTypes.ParseDelimitedFrom(stream));
+      Assert.AreEqual(12, stream.ReadByte());
+      TestUtil.AssertPackedFieldsSet(TestPackedTypes.ParseDelimitedFrom(stream));
+      Assert.AreEqual(34, stream.ReadByte());
+      Assert.AreEqual(-1, stream.ReadByte());
+    }
+
     [Test]
     public void ParseExtensions() {
       // TestAllTypes and TestAllExtensions should have compatible wire formats,
@@ -133,7 +151,7 @@ namespace Google.ProtocolBuffers {
       Assert.AreEqual(TestUtil.GetAllSet().SerializedSize, TestUtil.GetAllExtensionsSet().SerializedSize);
     }
 
-    private void AssertFieldsInOrder(ByteString data) {
+    private static void AssertFieldsInOrder(ByteString data) {
       CodedInputStream input = data.CreateCodedInput();
       uint previousTag = 0;
 

src/ProtocolBuffers/AbstractBuilder.cs

@@ -225,6 +225,16 @@ namespace Google.ProtocolBuffers {
       return ThisBuilder;
     }
 
+    public TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry) {
+      int size = CodedInputStream.ReadRawVarint32(input);
+      Stream limitedStream = new LimitedInputStream(input, size);
+      return MergeFrom(limitedStream, extensionRegistry);
+    }
+
+    public TBuilder MergeDelimitedFrom(Stream input) {
+      return MergeDelimitedFrom(input, ExtensionRegistry.Empty);
+    }
+
     public virtual IBuilder SetField(FieldDescriptor field, object value) {
       this[field] = value;
       return ThisBuilder;
@@ -234,5 +244,70 @@ namespace Google.ProtocolBuffers {
       this[field, index] = value;
       return ThisBuilder;
     }
+
+    /// <summary>
+    /// Stream implementation which proxies another stream, only allowing a certain amount
+    /// of data to be read. Note that this is only used to read delimited streams, so it
+    /// doesn't attempt to implement everything.
+    /// </summary>
+    private class LimitedInputStream : Stream {
+
+      private readonly Stream proxied;
+      private int bytesLeft;
+
+      internal LimitedInputStream(Stream proxied, int size) {
+        this.proxied = proxied;
+        bytesLeft = size;
+      }
+
+      public override bool CanRead {
+        get { return true; }
+      }
+
+      public override bool CanSeek {
+        get { return false; }
+      }
+
+      public override bool CanWrite {
+        get { return false; }
+      }
+
+      public override void Flush() {
+      }
+
+      public override long Length {
+        get { throw new NotImplementedException(); }
+      }
+
+      public override long Position {
+        get {
+          throw new NotImplementedException();
+        }
+        set {
+          throw new NotImplementedException();
+        }
+      }
+
+      public override int Read(byte[] buffer, int offset, int count) {
+        if (bytesLeft > 0) {
+          int bytesRead = proxied.Read(buffer, offset, Math.Min(bytesLeft, count));
+          bytesLeft -= bytesRead;
+          return bytesRead;
+        }
+        return 0;
+      }
+
+      public override long Seek(long offset, SeekOrigin origin) {
+        throw new NotImplementedException();
+      }
+
+      public override void SetLength(long value) {
+        throw new NotImplementedException();
+      }
+
+      public override void Write(byte[] buffer, int offset, int count) {
+        throw new NotImplementedException();
+      }
+    }
   }
 }

src/ProtocolBuffers/AbstractMessage.cs

@@ -205,6 +205,13 @@ namespace Google.ProtocolBuffers {
       codedOutput.Flush();
     }
 
+    public void WriteDelimitedTo(Stream output) {
+      CodedOutputStream codedOutput = CodedOutputStream.CreateInstance(output);
+      codedOutput.WriteRawVarint32((uint) SerializedSize);
+      WriteTo(codedOutput);
+      codedOutput.Flush();
+    }
+
     public override bool Equals(object other) {
       if (other == this) {
         return true;

src/ProtocolBuffers/CodedInputStream.cs

@@ -141,7 +141,7 @@ namespace Google.ProtocolBuffers {
     /// zero is not a valid tag number.
     /// </summary>
     public uint ReadTag() {
-      if (bufferPos == bufferSize && !RefillBuffer(false)) {
+      if (IsAtEnd) {
         lastTag = 0;
         return 0;
       }
@@ -457,6 +457,41 @@ namespace Google.ProtocolBuffers {
       return (uint)result;
     }
 
+    /// <summary>
+    /// Reads a varint from the input one byte at a time, so that it does not
+    /// read any bytes after the end of the varint. If you simply wrapped the
+    /// stream in a CodedInputStream and used ReadRawVarint32(Stream)}
+    /// then you would probably end up reading past the end of the varint since
+    /// CodedInputStream buffers its input.
+    /// </summary>
+    /// <param name="input"></param>
+    /// <returns></returns>
+    internal static int ReadRawVarint32(Stream input) {
+      int result = 0;
+      int offset = 0;
+      for (; offset < 32; offset += 7) {
+        int b = input.ReadByte();
+        if (b == -1) {
+          throw InvalidProtocolBufferException.TruncatedMessage();
+        }
+        result |= (b & 0x7f) << offset;
+        if ((b & 0x80) == 0) {
+          return result;
+        }
+      }
+      // Keep reading up to 64 bits.
+      for (; offset < 64; offset += 7) {
+        int b = input.ReadByte();
+        if (b == -1) {
+          throw InvalidProtocolBufferException.TruncatedMessage();
+        }
+        if ((b & 0x80) == 0) {
+          return result;
+        }
+      }
+      throw InvalidProtocolBufferException.MalformedVarint();
+    }
+
     /// <summary>
     /// Read a raw varint from the stream.
     /// </summary>
@@ -555,6 +590,9 @@ namespace Google.ProtocolBuffers {
     /// as you can without harming your app's functionality.  Note that
     /// size limits only apply when reading from an InputStream, not
     /// when constructed around a raw byte array (nor with ByteString.NewCodedInput).
+    /// If you want to read several messages from a single CodedInputStream, you
+    /// can call ResetSizeCounter() after each message to avoid hitting the
+    /// size limit.
     /// </remarks>
     public int SetSizeLimit(int limit) {
       if (limit < 0) {
@@ -566,6 +604,13 @@ namespace Google.ProtocolBuffers {
     }
 
     #region Internal reading and buffer management
+    /// <summary>
+    /// Resets the current size counter to zero (see SetSizeLimit).
+    /// </summary>
+    public void ResetSizeCounter() {
+      totalBytesRetired = 0;
+    }
+
     /// <summary>
     /// Sets currentLimit to (current position) + byteLimit. This is called
     /// when descending into a length-delimited embedded message. The previous
@@ -622,6 +667,17 @@ namespace Google.ProtocolBuffers {
       }
     }
 
+    /// <summary>
+    /// 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
+    /// the stream has reached a limit created using PushLimit.
+    /// </summary>
+    public bool IsAtEnd {
+      get {
+        return bufferPos == bufferSize && !RefillBuffer(false);
+      }
+    }
+    
     /// <summary>
     /// Called when buffer is empty to read more bytes from the
     /// input.  If <paramref name="mustSucceed"/> is true, RefillBuffer() gurantees that
@@ -649,6 +705,9 @@ namespace Google.ProtocolBuffers {
 
       bufferPos = 0;
       bufferSize = (input == null) ? 0 : input.Read(buffer, 0, buffer.Length);
+      if (bufferSize < 0) {
+        throw new InvalidOperationException("Stream.Read returned a negative count");
+      }
       if (bufferSize == 0) {
         if (mustSucceed) {
           throw InvalidProtocolBufferException.TruncatedMessage();
@@ -847,7 +906,7 @@ namespace Google.ProtocolBuffers {
         throw InvalidProtocolBufferException.TruncatedMessage();
       }
 
-      if (size < bufferSize - bufferPos) {
+      if (size <= bufferSize - bufferPos) {
         // We have all the bytes we need already.
         bufferPos += size;
       } else {
@@ -863,8 +922,9 @@ namespace Google.ProtocolBuffers {
           if (input == null) {
             throw InvalidProtocolBufferException.TruncatedMessage();
           }
-          input.Seek(size - pos, SeekOrigin.Current);
-          if (input.Position > input.Length) {
+          long previousPosition = input.Position;
+          input.Position += size - pos;
+          if (input.Position != previousPosition + size - pos) {
             throw InvalidProtocolBufferException.TruncatedMessage();
           }
           totalBytesRetired += size - pos;

src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs

@@ -143,6 +143,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static CSharpFileOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CSharpFileOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CSharpFileOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CSharpFileOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -186,6 +192,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override CSharpFileOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CSharpFileOptions returnMe = result;
         result = null;
         return returnMe;
@@ -336,6 +345,12 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
     public static CSharpFieldOptions ParseFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
       return ((Builder) CreateBuilder().MergeFrom(input, extensionRegistry)).BuildParsed();
     }
+    public static CSharpFieldOptions ParseDelimitedFrom(global::System.IO.Stream input) {
+      return CreateBuilder().MergeDelimitedFrom(input).BuildParsed();
+    }
+    public static CSharpFieldOptions ParseDelimitedFrom(global::System.IO.Stream input, pb::ExtensionRegistry extensionRegistry) {
+      return CreateBuilder().MergeDelimitedFrom(input, extensionRegistry).BuildParsed();
+    }
     public static CSharpFieldOptions ParseFrom(pb::CodedInputStream input) {
       return ((Builder) CreateBuilder().MergeFrom(input)).BuildParsed();
     }
@@ -379,6 +394,9 @@ namespace Google.ProtocolBuffers.DescriptorProtos {
       }
       
       public override CSharpFieldOptions BuildPartial() {
+        if (result == null) {
+          throw new global::System.InvalidOperationException("build() has already been called on this Builder");
+        }
         CSharpFieldOptions returnMe = result;
         result = null;
         return returnMe;

src/ProtocolBuffers/IBuilder.cs

@@ -248,6 +248,20 @@ namespace Google.ProtocolBuffers {
     /// </summary>
     TBuilder MergeUnknownFields(UnknownFieldSet unknownFields);
     
+    /// <summary>
+    /// Like MergeFrom(Stream), but does not read until the end of the file.
+    /// Instead, the size of the message (encoded as a varint) is read first,
+    /// then the message data. Use Message.WriteDelimitedTo(Stream) to
+    /// write messages in this format.
+    /// </summary>
+    /// <param name="input"></param>
+    TBuilder MergeDelimitedFrom(Stream input);
+
+    /// <summary>
+    /// Like MergeDelimitedFrom(Stream) but supporting extensions.
+    /// </summary>
+    TBuilder MergeDelimitedFrom(Stream input, ExtensionRegistry extensionRegistry);
+
     #region Convenience methods
     /// <summary>
     /// Parse <paramref name="data"/> as a message of this type and merge
@@ -283,8 +297,9 @@ namespace Google.ProtocolBuffers {
     /// MergeFrom(CodedInputStream). Note that this method always reads
     /// the entire input (unless it throws an exception). If you want it to
     /// stop earlier, you will need to wrap the input in a wrapper
-    /// stream which limits reading. Despite usually reading the entire
-    /// stream, this method never closes the stream.
+    /// stream which limits reading. Or, use IMessage.WriteDelimitedTo(Stream)
+    /// to write your message and MmergeDelimitedFrom(Stream) to read it.
+    /// Despite usually reading the entire stream, this method never closes the stream. 
     /// </summary>
     TBuilder MergeFrom(Stream input);
 

src/ProtocolBuffers/IMessage.cs

@@ -113,9 +113,26 @@ namespace Google.ProtocolBuffers {
     /// Serializes the message and writes it to the given output stream.
     /// This does not flush or close the stream.
     /// </summary>
-    /// <param name="output"></param>
+    /// <remarks>
+    /// Protocol Buffers are not self-delimiting. Therefore, if you write
+    /// any more data to the stream after the message, you must somehow ensure
+    /// that the parser on the receiving end does not interpret this as being
+    /// part of the protocol message. One way of doing this is by writing the size
+    /// of the message before the data, then making sure you limit the input to
+    /// that size when receiving the data. Alternatively, use WriteDelimitedTo(Stream).
+    /// </remarks>
     void WriteTo(CodedOutputStream output);
 
+    /// <summary>
+    /// Like WriteTo(Stream) but writes the size of the message as a varint before
+    /// writing the data. This allows more data to be written to the stream after the
+    /// message without the need to delimit the message data yourself. Use 
+    /// IBuilder.MergeDelimitedFrom(Stream) or the static method
+    /// YourMessageType.ParseDelimitedFrom(Stream) to parse messages written by this method.
+    /// </summary>
+    /// <param name="output"></param>
+    void WriteDelimitedTo(Stream output);
+
     /// <summary>
     /// Returns the number of bytes required to encode this message.
     /// The result is only computed on the first call and memoized after that.

src/ProtocolBuffers/MessageStreamIterator.cs

 using System;
 using System.Collections.Generic;
-using System.Text;
 using System.Collections;
 using System.IO;
 using System.Reflection;

src/ProtocolBuffers/MessageStreamWriter.cs

-using System;
-using System.Collections.Generic;
-using System.Text;
 using System.IO;
 
 namespace Google.ProtocolBuffers {