Benchmarking, dumping and munging

.gitignore

@@ -6,10 +6,16 @@ src/ProtocolBuffers/bin/
 src/ProtocolBuffers/obj/
 src/ProtocolBuffers.Test/bin/
 src/ProtocolBuffers.Test/obj/
+src/ProtoBench/bin/
+src/ProtoBench/obj/
+src/ProtoDump/bin/
+src/ProtoDump/obj/
 src/ProtoGen/bin/
 src/ProtoGen/obj/
 src/ProtoGen.Test/bin/
 src/ProtoGen.Test/obj/
+src/ProtoMunge/bin/
+src/ProtoMunge/obj/
 tmp/
 dist/
 *.user

ProtocolBuffers.build

@@ -72,6 +72,7 @@
           workingdir="${tmp-dir}">
       <arg value="--proto_path=${protos-dir}" />
       <arg value="--descriptor_set_out=compiled.pb" />
+      <arg file="${protos-dir}/google/protobuf/benchmark.proto" />
       <arg file="${protos-dir}/google/protobuf/descriptor.proto" />
       <arg file="${protos-dir}/google/protobuf/csharp_options.proto" />
       <arg file="${protos-dir}/google/protobuf/unittest.proto" />
@@ -114,6 +115,12 @@
         <include name="AddressBookProtos.cs" />
       </fileset>
     </copy>
+
+    <copy todir="${src}/ProtoBench">
+      <fileset basedir="${tmp-dir}">
+        <include name="BenchmarkProtoFile.cs" />
+      </fileset>
+    </copy>
   </target>
       
   <target name="build"
@@ -147,6 +154,9 @@
       <fileset basedir="${src}">
         <include name="ProtocolBuffers/bin/${build-configuration}/Google.ProtocolBuffers.dll" />
         <include name="ProtoGen/bin/${build-configuration}/ProtoGen.exe" />
+        <include name="ProtoMunge/bin/${build-configuration}/ProtoMunge.exe" />
+        <include name="ProtoDump/bin/${build-configuration}/ProtoDump.exe" />
+        <include name="ProtoBench/bin/${build-configuration}/ProtoBench.exe" />
       </fileset>
     </copy>
     

protos/google/protobuf/benchmark.proto

+import "google/protobuf/csharp_options.proto";
+import "google/protobuf/descriptor.proto";
+option (google.protobuf.csharp_file_options).namespace = "Google.ProtocolBuffers.BenchmarkProtos";
+option (google.protobuf.csharp_file_options).umbrella_classname = "BenchmarkProtoFile";
+
+package proto2.benchmark.v2_api;
+
+option optimize_for = SPEED;
+
+message Message1 {
+  required string field1 = 1;
+  optional string field9 = 9;
+  optional string field18 = 18;
+  optional bool field80 = 80 [default=false];
+  optional bool field81 = 81 [default=true];
+  required int32 field2 = 2;
+  required int32 field3 = 3;
+  optional int32 field280 = 280;
+  optional int32 field6 = 6 [default=0];
+  optional int64 field22 = 22;
+  optional string field4 = 4;
+  repeated fixed64 field5 = 5;
+  optional bool field59 = 59 [default=false];
+  optional string field7 = 7;
+  optional int32 field16 = 16;
+  optional int32 field130 = 130 [default=0];
+  optional bool field12 = 12 [default=true];
+  optional bool field17 = 17 [default=true];
+  optional bool field13 = 13 [default=true];
+  optional bool field14 = 14 [default=true];
+  optional int32 field104 = 104 [default=0];
+  optional int32 field100 = 100 [default=0];
+  optional int32 field101 = 101 [default=0];
+  optional string field102 = 102;
+  optional string field103 = 103;
+  optional int32 field29 = 29 [default=0];
+  optional bool field30 = 30 [default=false];
+  optional int32 field60 = 60 [default=-1];
+  optional int32 field271 = 271 [default=-1];
+  optional int32 field272 = 272 [default=-1];
+  optional int32 field150 = 150;
+  optional int32 field23 = 23 [default=0];
+  optional bool field24 = 24 [default=false];
+  optional int32 field25 = 25 [default=0];
+  optional Message2 field15 = 15;
+  optional bool field78 = 78;
+  optional int32 field67 = 67 [default=0];
+  optional int32 field68 = 68;
+  optional int32 field128 = 128 [default=0];
+  optional string field129 = 129 [default="xxxxxxxxxxxxxxxxxxxxx"];
+  optional int32 field131 = 131 [default=0];
+}
+
+message Message2 {
+  optional int32 field1 = 1 [default=0];
+  optional int32 field2 = 2 [default=0];
+  optional int32 field3 = 3 [default=0];
+  optional string field15 = 15;
+  optional bool field12 = 12 [default=true];
+  optional int64 field13 = 13;
+  optional int64 field14 = 14;
+  optional int32 field16 = 16;
+  optional int32 field19 = 19 [default=2];
+  optional bool field20  = 20 [default=true];
+  optional bool field28 = 28 [default=true];
+  optional fixed64 field21 = 21;
+  optional int32 field22 = 22;
+  optional bool field23 = 23 [ default=false ];
+  optional bool field206 = 206 [default=false];
+  optional fixed32 field203 = 203;
+  optional int32 field204 = 204;
+  optional string field205 = 205;
+  optional uint64 field207 = 207;
+  optional uint64 field300 = 300;
+}
+
+message Message3 {
+  optional string field1 = 1;
+  optional int64 field3 = 3;
+  optional int64 field4 = 4;
+  optional int64 field30 = 30;
+  optional bool field75  = 75 [default=false];
+  optional string field6 = 6;
+  optional bytes field2 = 2;
+  optional int32 field21 = 21 [default=0];
+  optional int32 field71 = 71;
+  optional float field25 = 25;
+  optional int32 field109 = 109 [default=0];
+  optional int32 field210 = 210 [default=0];
+  optional int32 field211 = 211 [default=0];
+  optional int32 field212 = 212 [default=0];
+  optional int32 field213 = 213 [default=0];
+  optional int32 field216 = 216 [default=0];
+  optional int32 field217 = 217 [default=0];
+  optional int32 field218 = 218 [default=0];
+  optional int32 field220 = 220 [default=0];
+  optional int32 field221 = 221 [default=0];
+  optional float field222 = 222 [default=0.0];
+  optional int32 field63 = 63;
+
+  repeated group Group1 = 10 {
+    required float field11 = 11;
+    optional float field26 = 26;
+    optional string field12 = 12;
+    optional string field13 = 13;
+    repeated string field14 = 14;
+    required uint64 field15 = 15;
+    optional int32 field5 = 5;
+    optional string field27 = 27;
+    optional int32 field28 = 28;
+    optional string field29 = 29;
+    optional string field16 = 16;
+    repeated string field22 = 22;
+    repeated int32 field73 = 73;
+    optional int32 field20 = 20 [default=0];
+    optional string field24 = 24;
+    optional Message4 field31 = 31;
+  }
+  repeated string field128 = 128;
+  optional int64 field131 = 131;
+  repeated string field127 = 127;
+  optional int32 field129 = 129;
+  repeated int64 field130 = 130;
+  optional bool field205 = 205 [default=false];
+  optional bool field206 = 206 [default=false];
+}
+
+message Message4 {
+  optional float field1 = 1;
+  optional float field2 = 2;
+  optional float field3 = 3 [default=0.0];
+  optional bool field4 = 4;
+  optional bool field5 = 5;
+  optional bool field6 = 6 [default=true];
+  optional bool field7 = 7 [default=false];
+  optional float field8 = 8;
+  optional bool field9 = 9;
+  optional float field10 = 10;
+  optional int64 field11 = 11;
+}

src/ProtoBench/Program.cs

+using System;
+using System.Diagnostics;
+using System.IO;
+using Google.ProtocolBuffers;
+
+namespace ProtoBench {
+  /// <summary>
+  /// Simple benchmarking of arbitrary messages.
+  /// </summary>
+  public sealed class Program {
+
+    private static readonly TimeSpan MinSampleTime = TimeSpan.FromSeconds(2);
+    private static readonly TimeSpan TargetTime = TimeSpan.FromSeconds(30);
+
+    // Avoid a .NET 3.5 dependency
+    delegate void Action();
+
+    public static int Main(string[] args) {
+      if (args.Length != 2) {
+        Console.Error.WriteLine("Usage: ProtoBecnh <descriptor type name> <input data>");
+        Console.Error.WriteLine("The descriptor type name is the fully-qualified message name,");
+        Console.Error.WriteLine("including assembly - e.g. Google.ProtocolBuffers.BenchmarkProtos.Message1,ProtoBench");
+        return 1;
+      }
+      IMessage defaultMessage;
+      try {
+        defaultMessage = MessageUtil.GetDefaultMessage(args[0]);
+      } catch (ArgumentException e) {
+        Console.Error.WriteLine(e.Message);
+        return 1;
+      }
+      try {
+        IBuilder builder = defaultMessage.WeakCreateBuilderForType();
+        byte[] inputData = File.ReadAllBytes(args[1]);
+        ByteString inputString = ByteString.CopyFrom(inputData);
+        IMessage sampleMessage = defaultMessage.WeakCreateBuilderForType().WeakMergeFrom(inputString).WeakBuild();
+        sampleMessage.ToByteString();
+        Console.WriteLine("Benchmarking {0} with file {1}", sampleMessage.GetType().Name, args[1]);
+        Benchmark("Serialize to byte string", inputData.Length, () => sampleMessage.ToByteString());
+        Benchmark("Serialize to byte array", inputData.Length, () => sampleMessage.ToByteArray());
+        Benchmark("Serialize to memory stream", inputData.Length, () => sampleMessage.WriteTo(new MemoryStream()));
+        Benchmark("Deserialize from byte array", inputData.Length, () =>
+          defaultMessage.WeakCreateBuilderForType()
+              .WeakMergeFrom(CodedInputStream.CreateInstance(inputData))
+              .WeakBuild()
+        );
+        Benchmark("Deserialize from byte array", inputData.Length, () =>
+          defaultMessage.WeakCreateBuilderForType()
+              .WeakMergeFrom(inputString)
+              .WeakBuild()
+        );
+        return 0;
+      } catch (Exception e) {
+        Console.Error.WriteLine("Error: {0}", e.Message);
+        Console.Error.WriteLine();
+        Console.Error.WriteLine("Detailed exception information: {0}", e);
+        return 1;
+      }
+    }
+
+    private static void Benchmark(string name, int dataSize, Action action) {
+      // Make sure it's JITted
+      action();
+      // Run it progressively more times until we've got a reasonable sample
+
+      int iterations = 1;
+      TimeSpan elapsed = TimeAction(action, iterations);
+      while (elapsed < MinSampleTime) {
+        iterations *= 2;
+        elapsed = TimeAction(action, iterations);
+      }
+      // Upscale the sample to the target time. Do this in floating point arithmetic
+      // to avoid overflow issues.
+      iterations = (int) ((TargetTime.Ticks / (double)elapsed.Ticks) * iterations);
+      elapsed = TimeAction(action, iterations);
+      Console.WriteLine("{0}: {1} iterations in {2:f3}s; {3:f3}MB/s",
+        name, iterations, elapsed.TotalSeconds,
+        (iterations * dataSize) / (elapsed.TotalSeconds * 1024 * 1024));
+    }
+
+    private static TimeSpan TimeAction(Action action, int iterations) {
+      Stopwatch sw = Stopwatch.StartNew();
+      for (int i = 0; i < iterations; i++) {
+        action();
+      }
+      sw.Stop();
+      return sw.Elapsed;
+    }
+  }
+}

src/ProtoBench/Properties/AssemblyInfo.cs

+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ProtoBench")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ProtoBench")]
+[assembly: AssemblyCopyright("Copyright ©  2009")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("0f515d09-9a6c-49ec-8500-14a5303ebadf")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

src/ProtoBench/ProtoBench.csproj

+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>9.0.30729</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{C7A4A435-2813-41C8-AA87-BD914BA5223D}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Google.ProtocolBuffers.ProtoBench</RootNamespace>
+    <AssemblyName>ProtoBench</AssemblyName>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <TargetFrameworkSubset>
+    </TargetFrameworkSubset>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="BenchmarkProtoFile.cs" />
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\ProtocolBuffers\ProtocolBuffers.csproj">
+      <Project>{6908BDCE-D925-43F3-94AC-A531E6DF2591}</Project>
+      <Name>ProtocolBuffers</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="app.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>
\ No newline at end of file

src/ProtoBench/app.config

+<?xml version="1.0"?>
+<configuration>
+<startup><supportedRuntime version="v2.0.50727"/></startup></configuration>

src/ProtoDump/Program.cs

+using System;
+using System.IO;
+using System.Reflection;
+using Google.ProtocolBuffers;
+
+namespace ProtoDump {
+  /// <summary>
+  /// Small utility to load a binary message and dump it in text form
+  /// </summary>
+  class Program {
+    static int Main(string[] args) {
+      if (args.Length != 2) {
+        Console.Error.WriteLine("Usage: ProtoDump <descriptor type name> <input data>");
+        Console.Error.WriteLine("The descriptor type name is the fully-qualified message name,");
+        Console.Error.WriteLine("including assembly e.g. ProjectNamespace.Message,Company.Project");
+        return 1;
+      }
+      IMessage defaultMessage;
+      try {
+        defaultMessage = MessageUtil.GetDefaultMessage(args[0]);
+      } catch (ArgumentException e) {
+        Console.Error.WriteLine(e.Message);
+        return 1;
+      }
+      try {
+        IBuilder builder = defaultMessage.WeakCreateBuilderForType();
+        if (builder == null) {
+          Console.Error.WriteLine("Unable to create builder");
+          return 1;
+        }
+        byte[] inputData = File.ReadAllBytes(args[1]);
+        builder.WeakMergeFrom(ByteString.CopyFrom(inputData));
+        Console.WriteLine(TextFormat.PrintToString(builder.WeakBuild()));
+        return 0;
+      } catch (Exception e) {
+        Console.Error.WriteLine("Error: {0}", e.Message);
+        Console.Error.WriteLine();
+        Console.Error.WriteLine("Detailed exception information: {0}", e);
+        return 1;
+      }
+    }
+  }
+}

src/ProtoDump/Properties/AssemblyInfo.cs

+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ProtoDump")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ProtoDump")]
+[assembly: AssemblyCopyright("Copyright ©  2009")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("fed7572b-d747-4704-a6da-6c3c61088346")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

src/ProtoDump/ProtoDump.csproj

+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>9.0.30729</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{D7282E99-2DC3-405B-946F-177DB2FD2AE2}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Google.ProtocolBuffers.ProtoDump</RootNamespace>
+    <AssemblyName>ProtoDump</AssemblyName>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <TargetFrameworkSubset>
+    </TargetFrameworkSubset>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\ProtocolBuffers\ProtocolBuffers.csproj">
+      <Project>{6908BDCE-D925-43F3-94AC-A531E6DF2591}</Project>
+      <Name>ProtocolBuffers</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="app.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>
\ No newline at end of file

src/ProtoDump/app.config

+<?xml version="1.0"?>
+<configuration>
+<startup><supportedRuntime version="v2.0.50727"/></startup></configuration>

src/ProtoGen.Test/DependencyResolutionTest.cs

-using System;
 using System.Collections.Generic;
-using System.Text;
+using Google.ProtocolBuffers.DescriptorProtos;
 using Google.ProtocolBuffers.Descriptors;
 using NUnit.Framework;
-using Google.ProtocolBuffers.DescriptorProtos;
-using Google.ProtocolBuffers.ProtoGen;
 
 namespace Google.ProtocolBuffers.ProtoGen {
   /// <summary>

src/ProtoGen.Test/GeneratorTest.cs

-using Google.ProtocolBuffers.DescriptorProtos;
-using NUnit.Framework;
-using Google.ProtocolBuffers.Descriptors;
-
-namespace Google.ProtocolBuffers.ProtoGen {
-  [TestFixture]
-  public class GeneratorTest {
-
-  }
-}
\ No newline at end of file

src/ProtoGen.Test/ProtoGen.Test.csproj

@@ -45,7 +45,6 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="DependencyResolutionTest.cs" />
-    <Compile Include="GeneratorTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>

src/ProtoGen/Program.cs

@@ -23,8 +23,6 @@ namespace Google.ProtocolBuffers.ProtoGen {
 
         Generator generator = Generator.CreateGenerator(options);
         generator.Generate();
-
-
         return 0;
       } catch (Exception e) {
         Console.Error.WriteLine("Error: {0}", e.Message);

src/ProtoMunge/Program.cs

+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers.ProtoMunge
+{
+  /// <summary>
+  /// Utility console application which takes a message descriptor and a corresponding message,
+  /// and produces a new message with similar but random data. The data is the same length
+  /// as the original, but with random values within appropriate bands. (For instance, a compressed
+  /// integer in the range 0-127 will end up as another integer in the same range, to keep the length
+  /// the same.)
+  /// TODO(jonskeet): Potentially refactor to use an instance instead, making it simpler to
+  /// be thread-safe for external use.
+  /// </summary>
+  public sealed class Program {
+
+    static readonly Random rng = new Random();
+
+    static int Main(string[] args) {
+      if (args.Length != 3) {
+        Console.Error.WriteLine("Usage: ProtoMunge <descriptor type name> <input data> <output file>");
+        Console.Error.WriteLine("The descriptor type name is the fully-qualified message name, including assembly.");
+        Console.Error.WriteLine("(At a future date it may be possible to do this without building the .NET assembly at all.)");
+        return 1;
+      }
+      IMessage defaultMessage;
+      try {
+        defaultMessage = MessageUtil.GetDefaultMessage(args[0]);
+      } catch (ArgumentException e) {
+        Console.Error.WriteLine(e.Message);
+        return 1;
+      }
+      try {
+        IBuilder builder = defaultMessage.WeakCreateBuilderForType();
+        byte[] inputData = File.ReadAllBytes(args[1]);
+        builder.WeakMergeFrom(ByteString.CopyFrom(inputData));
+        IMessage original = builder.WeakBuild();
+        IMessage munged = Munge(original);
+        if (original.SerializedSize != munged.SerializedSize) {
+          throw new Exception("Serialized sizes don't match");
+        }
+        File.WriteAllBytes(args[2], munged.ToByteArray());
+        return 0;
+      } catch (Exception e) {
+        Console.Error.WriteLine("Error: {0}", e.Message);
+        Console.Error.WriteLine();
+        Console.Error.WriteLine("Detailed exception information: {0}", e);
+        return 1;
+      }
+    }
+
+    /// <summary>
+    /// Munges a message recursively.
+    /// </summary>
+    /// <returns>A new message of the same type as the original message,
+    /// but munged so that all the data is desensitised.</returns>
+    private static IMessage Munge(IMessage message) {
+      IBuilder builder = message.WeakCreateBuilderForType();
+      foreach (var pair in message.AllFields) {
+        if (pair.Key.IsRepeated) {
+          foreach (object singleValue in (IEnumerable)pair.Value) {
+            builder.WeakAddRepeatedField(pair.Key, CheckedMungeValue(pair.Key, singleValue));
+          }
+        } else {
+          builder[pair.Key] = CheckedMungeValue(pair.Key, pair.Value);
+        }
+      }
+      IMessage munged = builder.WeakBuild();
+      if (message.SerializedSize != munged.SerializedSize) {
+        Console.WriteLine("Sub message sizes: {0}/{1}", message.SerializedSize, munged.SerializedSize);
+      }
+      return munged;
+    }
+
+    /// <summary>
+    /// Munges a single value and checks that the length ends up the same as it was before.
+    /// </summary>
+    private static object CheckedMungeValue(FieldDescriptor fieldDescriptor, object value) {
+      int currentSize = CodedOutputStream.ComputeFieldSize(fieldDescriptor.FieldType, fieldDescriptor.FieldNumber, value);
+      object mungedValue = MungeValue(fieldDescriptor, value);
+      int mungedSize = CodedOutputStream.ComputeFieldSize(fieldDescriptor.FieldType, fieldDescriptor.FieldNumber, mungedValue);
+      // Exceptions log more easily than assertions
+      if (currentSize != mungedSize) {
+        throw new Exception("Munged value had wrong size. Field type: " + fieldDescriptor.FieldType
+            + "; old value: " + value + "; new value: " + mungedValue);
+      }
+      return mungedValue;
+    }
+
+    /// <summary>
+    /// Munges a single value of the specified field descriptor. (i.e. if the field is
+    /// actually a repeated int, this method receives a single int value to munge, and
+    /// is called multiple times).
+    /// </summary>
+    private static object MungeValue(FieldDescriptor fieldDescriptor, object value) {
+      switch (fieldDescriptor.FieldType) {
+        case FieldType.SInt64:
+        case FieldType.Int64:
+          return (long) MungeVarint64((ulong) (long)value);
+        case FieldType.UInt64:
+          return MungeVarint64((ulong)value);
+        case FieldType.SInt32:
+          return (int)MungeVarint32((uint)(int)value);
+        case FieldType.Int32:
+          return MungeInt32((int) value);
+        case FieldType.UInt32:
+          return MungeVarint32((uint)value);
+        case FieldType.Double:
+          return rng.NextDouble();
+        case FieldType.Float:
+          return (float)rng.NextDouble();
+        case FieldType.Fixed64: {
+          byte[] data = new byte[8];
+          rng.NextBytes(data);
+          return BitConverter.ToUInt64(data, 0);
+        }
+        case FieldType.Fixed32:  {
+          byte[] data = new byte[4];
+          rng.NextBytes(data);
+          return BitConverter.ToUInt32(data, 0);
+        }
+        case FieldType.Bool:
+          return rng.Next(2) == 1;
+        case FieldType.String:
+          return MungeString((string)value);
+        case FieldType.Group:
+        case FieldType.Message:
+          return Munge((IMessage)value);
+        case FieldType.Bytes:
+          return MungeByteString((ByteString)value);
+        case FieldType.SFixed64: {
+            byte[] data = new byte[8];
+            rng.NextBytes(data);
+            return BitConverter.ToInt64(data, 0);
+          }
+        case FieldType.SFixed32: {
+            byte[] data = new byte[4];
+            rng.NextBytes(data);
+            return BitConverter.ToInt32(data, 0);
+          }
+        case FieldType.Enum:
+          return MungeEnum(fieldDescriptor, (int) value);
+        default:
+          // TODO(jonskeet): Different exception?
+          throw new ArgumentException("Invalid field descriptor");
+      }
+    }
+
+    private static object MungeString(string original) {
+      foreach (char c in original) {
+        if (c > 127) {
+          throw new ArgumentException("Can't handle non-ascii yet");
+        }
+      }
+      char[] chars = new char[original.Length];
+      // Convert to pure ASCII - no control characters.
+      for (int i = 0; i < chars.Length; i++) {
+        chars[i] = (char) rng.Next(32, 127);
+      }
+      return new string(chars);
+    }
+
+    /// <summary>
+    /// Int32 fields are slightly strange - we need to keep the sign the same way it is:
+    /// negative numbers can munge to any other negative number (it'll always take
+    /// 10 bytes) but positive numbers have to stay positive, so we can't use the
+    /// full range of 32 bits.
+    /// </summary>
+    private static int MungeInt32(int value) {
+      if (value < 0) {
+        return rng.Next(int.MinValue, 0);
+      }
+      int length = CodedOutputStream.ComputeRawVarint32Size((uint) value);
+      uint min = length == 1 ? 0 : 1U << ((length - 1) * 7);
+      uint max = length == 5 ? int.MaxValue : (1U << (length * 7)) - 1;
+      return (int) NextRandomUInt64(min, max);
+    }
+
+    private static uint MungeVarint32(uint original) {
+      int length = CodedOutputStream.ComputeRawVarint32Size(original);
+      uint min = length == 1 ? 0 : 1U << ((length - 1) * 7);
+      uint max = length == 5 ? uint.MaxValue : (1U << (length * 7)) - 1;
+      return (uint)NextRandomUInt64(min, max);
+    }
+
+    private static ulong MungeVarint64(ulong original) {
+      int length = CodedOutputStream.ComputeRawVarint64Size(original);
+      ulong min = length == 1 ? 0 : 1UL << ((length - 1) * 7);
+      ulong max = length == 10 ? ulong.MaxValue : (1UL<< (length * 7)) - 1;
+      return NextRandomUInt64(min, max);
+    }
+
+    /// <summary>
+    /// Returns a random number in the range [min, max] (both inclusive).
+    /// </summary>    
+    private static ulong NextRandomUInt64(ulong min, ulong max) {
+      if (min > max) {
+        throw new ArgumentException("min must be <= max; min=" + min + "; max = " + max);
+      }
+      ulong range = max - min;
+      // This isn't actually terribly good at very large ranges - but it doesn't really matter for the sake
+      // of this program.
+      return min + (ulong)(range * rng.NextDouble());
+    }
+
+    private static object MungeEnum(FieldDescriptor fieldDescriptor, int original) {
+      // Find all the values which get encoded to the same size as the current value, and pick one at random
+      int originalSize = CodedOutputStream.ComputeRawVarint32Size((uint)original);
+      List<EnumValueDescriptor> sameSizeValues = new List<EnumValueDescriptor> ();
+      foreach (EnumValueDescriptor candidate in fieldDescriptor.EnumType.Values) {
+        if (CodedOutputStream.ComputeRawVarint32Size((uint)candidate.Number) == originalSize) {
+          sameSizeValues.Add(candidate);
+        }
+      }
+      return sameSizeValues[rng.Next(sameSizeValues.Count)].Number;
+    }
+
+    private static object MungeByteString(ByteString byteString) {
+      byte[] data = new byte[byteString.Length];
+      rng.NextBytes(data);
+      return ByteString.CopyFrom(data);
+    }
+  }
+}
\ No newline at end of file

src/ProtoMunge/Properties/AssemblyInfo.cs

+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ProtoMunge")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ProtoMunge")]
+[assembly: AssemblyCopyright("Copyright ©  2008")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("4d26ed0e-a6ca-4df9-bb87-59429d49b676")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

src/ProtoMunge/ProtoMunge.csproj

+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>9.0.30729</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{8F09AF72-3327-4FA7-BC09-070B80221AB9}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Google.ProtocolBuffers.ProtoMunge</RootNamespace>
+    <AssemblyName>ProtoMunge</AssemblyName>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <TargetFrameworkSubset>
+    </TargetFrameworkSubset>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\ProtocolBuffers\ProtocolBuffers.csproj">
+      <Project>{6908BDCE-D925-43F3-94AC-A531E6DF2591}</Project>
+      <Name>ProtocolBuffers</Name>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="app.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>
\ No newline at end of file

src/ProtoMunge/app.config

+<?xml version="1.0"?>
+<configuration>
+<startup><supportedRuntime version="v2.0.50727"/></startup></configuration>

src/ProtocolBuffers.Test/MessageUtilTest.cs

+using System;
+using System.Collections.Generic;
+using System.Text;
+using Google.ProtocolBuffers.TestProtos;
+using NUnit.Framework;
+
+namespace Google.ProtocolBuffers {
+  [TestFixture]
+  public class MessageUtilTest {
+
+    [Test]
+    [ExpectedException(typeof(ArgumentNullException))]
+    public void NullTypeName() {
+      MessageUtil.GetDefaultMessage((string)null);
+    }
+
+    [Test]
+    [ExpectedException(typeof(ArgumentException))]
+    public void InvalidTypeName() {
+      MessageUtil.GetDefaultMessage("invalidtypename");
+    }
+
+    [Test]
+    public void ValidTypeName() {
+      Assert.AreSame(TestAllTypes.DefaultInstance, MessageUtil.GetDefaultMessage(typeof(TestAllTypes).AssemblyQualifiedName));
+    }
+
+    [Test]
+    [ExpectedException(typeof(ArgumentNullException))]
+    public void NullType() {
+      MessageUtil.GetDefaultMessage((Type)null);
+    }
+
+    [Test]
+    [ExpectedException(typeof(ArgumentException))]
+    public void NonMessageType() {
+      MessageUtil.GetDefaultMessage(typeof(string));
+    }
+
+    [Test]
+    public void ValidType() {
+      Assert.AreSame(TestAllTypes.DefaultInstance, MessageUtil.GetDefaultMessage(typeof(TestAllTypes)));
+    }
+  }
+}

src/ProtocolBuffers.Test/ProtocolBuffers.Test.csproj

@@ -58,6 +58,7 @@
     <Compile Include="MessageStreamIteratorTest.cs" />
     <Compile Include="MessageStreamWriterTest.cs" />
     <Compile Include="MessageTest.cs" />
+    <Compile Include="MessageUtilTest.cs" />
     <Compile Include="NameHelpersTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ReflectionTester.cs" />

src/ProtocolBuffers.sln

@@ -11,6 +11,12 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtoGen.Test", "ProtoGen.T
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AddressBook", "AddressBook\AddressBook.csproj", "{A31F5FB2-4FF3-432A-B35B-5CD203606311}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtoMunge", "ProtoMunge\ProtoMunge.csproj", "{8F09AF72-3327-4FA7-BC09-070B80221AB9}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtoBench", "ProtoBench\ProtoBench.csproj", "{C7A4A435-2813-41C8-AA87-BD914BA5223D}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ProtoDump", "ProtoDump\ProtoDump.csproj", "{D7282E99-2DC3-405B-946F-177DB2FD2AE2}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -37,6 +43,18 @@ Global
 		{A31F5FB2-4FF3-432A-B35B-5CD203606311}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{A31F5FB2-4FF3-432A-B35B-5CD203606311}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{A31F5FB2-4FF3-432A-B35B-5CD203606311}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8F09AF72-3327-4FA7-BC09-070B80221AB9}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8F09AF72-3327-4FA7-BC09-070B80221AB9}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8F09AF72-3327-4FA7-BC09-070B80221AB9}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8F09AF72-3327-4FA7-BC09-070B80221AB9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{C7A4A435-2813-41C8-AA87-BD914BA5223D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C7A4A435-2813-41C8-AA87-BD914BA5223D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C7A4A435-2813-41C8-AA87-BD914BA5223D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C7A4A435-2813-41C8-AA87-BD914BA5223D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D7282E99-2DC3-405B-946F-177DB2FD2AE2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D7282E99-2DC3-405B-946F-177DB2FD2AE2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D7282E99-2DC3-405B-946F-177DB2FD2AE2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D7282E99-2DC3-405B-946F-177DB2FD2AE2}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/ProtocolBuffers/ByteString.cs

@@ -184,7 +184,7 @@ namespace Google.ProtocolBuffers {
         output = CodedOutputStream.CreateInstance(buffer);
       }
 
-      public ByteString Build() {
+      internal ByteString Build() {
         output.CheckNoSpaceLeft();
 
         // We can be confident that the CodedOutputStream will not modify the
@@ -193,7 +193,7 @@ namespace Google.ProtocolBuffers {
         return new ByteString(buffer);
       }
 
-      public CodedOutputStream CodedOutput {
+      internal CodedOutputStream CodedOutput {
         get {
           return output;
         }

src/ProtocolBuffers/MessageUtil.cs

+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+
+namespace Google.ProtocolBuffers {
+  /// <summary>
+  /// Utilities for arbitrary messages of an unknown type. This class does not use
+  /// generics precisely because it is designed for dynamically discovered types.
+  /// </summary>
+  public static class MessageUtil {
+
+    /// <summary>
+    /// Returns the default message for the given type. If an exception is thrown
+    /// (directly from this code), the message will be suitable to be displayed to a user.
+    /// </summary>
+    /// <param name="type"></param>
+    /// <exception cref="ArgumentNullException">The type parameter is null.</exception>
+    /// <exception cref="ArgumentException">The type doesn't implement IMessage, or doesn't
+    /// have a static DefaultMessage property of the same type, or is generic or abstract.</exception>
+    /// <returns></returns>
+    public static IMessage GetDefaultMessage(Type type) {
+      if (type == null) {
+        throw new ArgumentNullException("type", "No type specified.");
+      }
+      if (type.IsAbstract || type.IsGenericTypeDefinition) {
+        throw new ArgumentException("Unable to get a default message for an abstract or generic type (" + type.FullName + ")");
+      }
+      if (!typeof(IMessage).IsAssignableFrom(type)) {
+        throw new ArgumentException("Unable to get a default message for non-message type (" + type.FullName + ")");
+      }
+      PropertyInfo property = type.GetProperty("DefaultInstance", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
+      if (property == null) {
+        throw new ArgumentException(type.FullName + " doesn't have a static DefaultInstance property");
+      }
+      if (property.PropertyType != type) {
+        throw new ArgumentException(type.FullName + ".DefaultInstance property is of the wrong type");
+      }
+      return (IMessage) property.GetValue(null, null);
+    }
+
+    /// <summary>
+    /// Returns the default message for the type with the given name. This is just
+    /// a convenience wrapper around calling Type.GetType and then GetDefaultMessage.
+    /// If an exception is thrown, the message will be suitable to be displayed to a user.
+    /// </summary>
+    /// <param name="typeName"></param>
+    /// <exception cref="ArgumentNullException">The typeName parameter is null.</exception>
+    /// <exception cref="ArgumentException">The type doesn't implement IMessage, or doesn't
+    /// have a static DefaultMessage property of the same type, or can't be found.</exception>
+    public static IMessage GetDefaultMessage(string typeName) {
+      if (typeName == null) {
+        throw new ArgumentNullException("typeName", "No type name specified.");
+      }
+      Type type = Type.GetType(typeName);
+      if (type == null) {
+        throw new ArgumentException("Unable to load type " + typeName);
+      }
+      return GetDefaultMessage(type);
+    }
+  }
+}

src/ProtocolBuffers/ProtocolBuffers.csproj

@@ -97,6 +97,7 @@
     <Compile Include="IService.cs" />
     <Compile Include="MessageStreamIterator.cs" />
     <Compile Include="MessageStreamWriter.cs" />
+    <Compile Include="MessageUtil.cs" />
     <Compile Include="NameHelpers.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="RpcUtil.cs" />