MessagePack for C# (.NET, .NET Core, Unity, Xamarin)

The extremely fast MessagePack serializer for C#. It is 10x faster than MsgPack-Cli and outperforms other C# serializers. MessagePack for C# also ships with built-in support for LZ4 compression - an extremely fast compression algorithm. Performance is important, particularly in applications like game development, distributed computing, microservice architecture, and caching.

MessagePack has compact binary size and full set of general purpose expression. Please see the comparison with JSON, protobuf, ZeroFormatter section. Learn why MessagePack C# is fastest.

Installation

This library is distributed via NuGet package and with special support for Unity.

NuGet packages

We target .NET Standard 2.0 with special optimizations for .NET Core 2.1+.

Install-Package MessagePack

Install the optional C# analyzer to get warnings for coding mistakes and code fixes to save you time:

Install-Package MessagePackAnalyzer

Extension Packages (learn more in our extensions section):

Install-Package MessagePack.ImmutableCollection
Install-Package MessagePack.ReactiveProperty
Install-Package MessagePack.UnityShims
Install-Package MessagePack.AspNetCoreMvcFormatter

Unity

For Unity, download from releases page, providing .unitypackage. Unity IL2CPP or Xamarin AOT Environment, check the pre-code generation section.

Quick Start

Define the class to be serialized and attribute the class with [MessagePackObject]. Attribute public members (property or field) with [Key].

[MessagePackObject]
public class MyClass
{
    // Key is serialization index, it is important for versioning.
    [Key(0)]
    public int Age { get; set; }

    [Key(1)]
    public string FirstName { get; set; }

    [Key(2)]
    public string LastName { get; set; }

    // public members and does not serialize target, mark IgnoreMemberttribute
    [IgnoreMember]
    public string FullName { get { return FirstName + LastName; } }
}

Call MessagePackSerializer.Serialize<T>/Deserialize<T> to serialize/deserialize your object graph. You can also use the ConvertToJson method to see a human readable representation of the msgpack that was written.

class Program
{
    static void Main(string[] args)
    {
        var mc = new MyClass
        {
            Age = 99,
            FirstName = "hoge",
            LastName = "huga",
        };

        // call Serialize/Deserialize, that's all.
        byte[] bytes = MessagePackSerializer.Serialize(mc);
        MyClass mc2 = MessagePackSerializer.Deserialize<MyClass>(bytes);

        // you can dump msgpack binary to human readable json.
        // In default, MeesagePack for C# reduce property name information.
        // [99,"hoge","huga"]
        var json = MessagePackSerializer.ConvertToJson(bytes);
        Console.WriteLine(json);
    }
}

By default the attribute is required. Optionally it can be unnecessary, see Object Serialization section and Formatter Resolver section for details.

Analyzer

The MessagePackAnalyzer helps to:

1. Automate defining your serializable objects.
2. Produces compiler warnings due to incorrect attribute use, accessibility, and more.

If you want to allow a specific type (for example, when registering a custom type), put MessagePackAnalyzer.json at the project root and make the Build Action to AdditionalFiles.

This is a sample of the contents of MessagePackAnalyzer.json:

[ "MyNamespace.FooClass", "MyNameSpace.BarStruct" ]

Built-in support types

These types can serialize by default.

Primitives(int, string, etc...), Enum, Nullable<>, TimeSpan, DateTime, DateTimeOffset, Nil, Guid, Uri, Version, StringBuilder, BitArray, ArraySegment<>, BigInteger, Complext, Task, Array[], Array[,], Array[,,], Array[,,,], KeyValuePair<,>, Tuple<,...>, ValueTuple<,...>, List<>, LinkedList<>, Queue<>, Stack<>, HashSet<>, ReadOnlyCollection<>, IList<>, ICollection<>, IEnumerable<>, Dictionary<,>, IDictionary<,>, SortedDictionary<,>, SortedList<,>, ILookup<,>, IGrouping<,>, ObservableCollection<>, ReadOnlyOnservableCollection<>, IReadOnlyList<>, IReadOnlyCollection<>, ISet<>, ConcurrentBag<>, ConcurrentQueue<>, ConcurrentStack<>, ReadOnlyDictionary<,>, IReadOnlyDictionary<,>, ConcurrentDictionary<,>, Lazy<>, Task<>, custom inherited ICollection<> or IDictionary<,> with paramterless constructor, IList, IDictionary and custom inherited ICollection or IDictionary with paramterless constructor(includes ArrayList and Hashtable).

You can add custom type support and has some official/third-party extension package. for ImmutableCollections(ImmutableList<>, etc), for ReactiveProperty and for Unity(Vector3, Quaternion, etc...), for F#(Record, FsList, Discriminated Unions, etc...). Please see extensions section.

MessagePack.Nil is built-in null/void/unit representation type of MessagePack for C#.

Object Serialization

MessagePack for C# can serialize your own public Class or Struct. Serialization target must marks [MessagePackObject] and [Key]. Key type can choose int or string. If key type is int, serialized format is used array. If key type is string, serialized format is used map. If you define [MessagePackObject(keyAsPropertyName: true)], does not require KeyAttribute.

[MessagePackObject]
public class Sample1
{
    [Key(0)]
    public int Foo { get; set; }
    [Key(1)]
    public int Bar { get; set; }
}

[MessagePackObject]
public class Sample2
{
    [Key("foo")]
    public int Foo { get; set; }
    [Key("bar")]
    public int Bar { get; set; }
}

[MessagePackObject(keyAsPropertyName: true)]
public class Sample3
{
    // no needs KeyAttribute
    public int Foo { get; set; }

    // If ignore public member, you can use IgnoreMemberAttribute
    [IgnoreMember]
    public int Bar { get; set; }
}

// [10,20]
Console.WriteLine(MessagePackSerializer.ToJson(new Sample1 { Foo = 10, Bar = 20 }));

// {"foo":10,"bar":20}
Console.WriteLine(MessagePackSerializer.ToJson(new Sample2 { Foo = 10, Bar = 20 }));

// {"Foo":10}
Console.WriteLine(MessagePackSerializer.ToJson(new Sample3 { Foo = 10, Bar = 20 }));

All patterns serialization target are public instance member(field or property). If you want to avoid serialization target, you can add [IgnoreMember] to target member.

target class must be public, does not allows private, internal class.

Which should uses int key or string key? I recommend use int key because faster and compact than string key. But string key has key name information, it is useful for debugging.

MessagePackSerializer requests target must put attribute is for robustness. If class is grown, you need to be conscious of versioning. MessagePackSerializer uses default value if key does not exists. If uses int key, should be start from 0 and should be sequential. If unnecessary properties come out, please make a missing number. Reuse is bad. Also, if Int Key's jump number is too large, it affects binary size.

[MessagePackObject]
public class IntKeySample
{
    [Key(3)]
    public int A { get; set; }
    [Key(10)]
    public int B { get; set; }
}

// [null,null,null,0,null,null,null,null,null,null,0]
Console.WriteLine(MessagePackSerializer.ToJson(new IntKeySample()));

I want to use like JSON.NET! I don't want to put attribute! If you think that way, you can use a contractless resolver.

public class ContractlessSample
{
    public int MyProperty1 { get; set; }
    public int MyProperty2 { get; set; }
}

var data = new ContractlessSample { MyProperty1 = 99, MyProperty2 = 9999 };
var bin = MessagePackSerializer.Serialize(data, MessagePack.Resolvers.ContractlessStandardResolver.Instance);

// {"MyProperty1":99,"MyProperty2":9999}
Console.WriteLine(MessagePackSerializer.ToJson(bin));

// You can set ContractlessStandardResolver as default.
MessagePackSerializer.SetDefaultResolver(MessagePack.Resolvers.ContractlessStandardResolver.Instance);

// serializable.
var bin2 = MessagePackSerializer.Serialize(data);

I want to serialize private member! In default, can not serialize/deserialize private members. But you can use allow-private resolver.

[MessagePackObject]
public class PrivateSample
{
    [Key(0)]
    int x;

    public void SetX(int v)
    {
        x = v;
    }

    public int GetX()
    {
        return x;
    }
}

var data = new PrivateSample();
data.SetX(9999);

// You can choose StandardResolverAllowPrivate or  ContractlessStandardResolverAllowPrivate
var bin = MessagePackSerializer.Serialize(data, MessagePack.Resolvers.DynamicObjectResolverAllowPrivate.Instance);

I don't need type, I want to use like BinaryFormatter! You can use as typeless resolver and helpers. Please see Typeless section.

Resolver is key customize point of MessagePack for C#. Details, please see extension point.

DataContract compatibility

You can use [DataContract] instead of [MessagePackObject]. If type is marked DataContract, you can use [DataMember] instead of [Key] and [IgnoreDataMember] instead of [IgnoreMember].

[DataMember(Order = int)] is same as [Key(int)], [DataMember(Name = string)] is same as [Key(string)]. If use [DataMember], same as [Key(nameof(propertyname)].

Using DataContract makes it a shared class library and you do not have to refer to MessagePack for C#. However, it is not included in analysis by Analyzer or code generation by mpc.exe. Also, functions like UnionAttribute, MessagePackFormatterAttribute, SerializationConstructorAttribute etc can not be used. For this reason, I recommend that you use the MessagePack for C# attribute basically.

Serialize ImmutableObject (SerializationConstructor)

MessagePack for C# supports deserialize immutable object. For example, this struct can serialize/deserialize naturally.

[MessagePackObject]
public struct Point
{
    [Key(0)]
    public readonly int X;
    [Key(1)]
    public readonly int Y;

    public Point(int x, int y)
    {
        this.X = x;
        this.Y = y;
    }
}

var data = new Point(99, 9999);
var bin = MessagePackSerializer.Serialize(data);

// Okay to deserialize immutable obejct
var point = MessagePackSerializer.Deserialize<Point>(bin);

MessagePackSerializer choose constructor with the most matched argument, match index if key in integer or match name(ignore case) if key is string. If encounts MessagePackDynamicObjectResolverException: can't find matched constructor parameter you should check about this.

If can not match automatically, you can specify to use constructor manually by [SerializationConstructorAttribute].

[MessagePackObject]
public struct Point
{
    [Key(0)]
    public readonly int X;
    [Key(1)]
    public readonly int Y;

    [SerializationConstructor]
    public Point(int x)
    {
        this.X = x;
        this.Y = -1;
    }

    // If not marked attribute, used this(most matched argument)
    public Point(int x, int y)
    {
        this.X = x;
        this.Y = y;
    }
}

Serialization Callback

If object implements IMessagePackSerializationCallbackReceiver, received OnBeforeSerialize and OnAfterDeserialize on serilization process.

[MessagePackObject]
public class SampleCallback : IMessagePackSerializationCallbackReceiver
{
    [Key(0)]
    public int Key { get; set; }

    public void OnBeforeSerialize()
    {
        Console.WriteLine("OnBefore");
    }

    public void OnAfterDeserialize()
    {
        Console.WriteLine("OnAfter");
    }
}

Union

MessagePack for C# supports serialize interface. It is like XmlInclude or ProtoInclude. MessagePack for C# there called Union. UnionAttribute can only attach to interface or abstract class. It requires discriminated integer key and sub-type.

// mark inheritance types
[MessagePack.Union(0, typeof(FooClass))]
[MessagePack.Union(1, typeof(BarClass))]
public interface IUnionSample
{
}

[MessagePackObject]
public class FooClass : IUnionSample
{
    [Key(0)]
    public int XYZ { get; set; }
}

[MessagePackObject]
public class BarClass : IUnionSample
{
    [Key(0)]
    public string OPQ { get; set; }
}

// ---

IUnionSample data = new FooClass() { XYZ = 999 };

// serialize interface.
var bin = MessagePackSerializer.Serialize(data);

// deserialize interface.
var reData = MessagePackSerializer.Deserialize<IUnionSample>(bin);

// use type-switch of C# 7.0
switch (reData)
{
    case FooClass x:
        Console.WriteLine(x.XYZ);
        break;
    case BarClass x:
        Console.WriteLine(x.OPQ);
        break;
    default:
        break;
}

C# 7.0 type-switch is best match for Union. Union is serialized to two-length array.

IUnionSample data = new BarClass { OPQ = "FooBar" };

var bin = MessagePackSerializer.Serialize(data);

// Union is serialized to two-length array, [key, object]
// [1,["FooBar"]]
Console.WriteLine(MessagePackSerializer.ToJson(bin));

Using Union in Abstract Class, you can use same of interface.

[Union(0, typeof(SubUnionType1))]
[Union(1, typeof(SubUnionType2))]
[MessagePackObject]
public abstract class ParentUnionType
{
    [Key(0)]
    public int MyProperty { get; set; }
}

[MessagePackObject]
public class SubUnionType1 : ParentUnionType
{
    [Key(1)]
    public int MyProperty1 { get; set; }
}

[MessagePackObject]
public class SubUnionType2 : ParentUnionType
{
    [Key(1)]
    public int MyProperty2 { get; set; }
}

Serialization of inherited type, flatten in array(or map), be carefult to integer key, it cannot duplicate parent and all childrens.

Dynamic (Untyped) Deserialization

If use MessagePackSerializer.Deserialize<object> or MessagePackSerializer.Deserialize<dynamic>, convert messagepack binary to primitive values that convert from msgpack-primitive to bool, char, sbyte, byte, short, int, long, ushort, uint, ulong, float, double, DateTime, string, byte[], object[], IDictionary<object, object>.

// sample binary.
var model = new DynamicModel { Name = "foobar", Items = new[] { 1, 10, 100, 1000 } };
var bin = MessagePackSerializer.Serialize(model, ContractlessStandardResolver.Instance);

// dynamic, untyped
var dynamicModel = MessagePackSerializer.Deserialize<dynamic>(bin, ContractlessStandardResolver.Instance);

Console.WriteLine(dynamicModel["Name"]); // foobar
Console.WriteLine(dynamicModel["Items"][2]); // 100

So you can access indexer for msgpack map and array.

Object Type Serialization

StandardResolver and ContractlessStandardResolver can serialize object type as concrete type by DynamicObjectTypeFallbackResolver.

var objects = new object[] { 1, "aaa", new ObjectFieldType { Anything = 9999 } };
var bin = MessagePackSerializer.Serialize(objects);

// [1,"aaa",[9999]]
Console.WriteLine(MessagePackSerializer.ToJson(bin));

// Support Anonymous Type Serialize
var anonType = new { Foo = 100, Bar = "foobar" };
var bin2 = MessagePackSerializer.Serialize(anonType, MessagePack.Resolvers.ContractlessStandardResolver.Instance);

// {"Foo":100,"Bar":"foobar"}
Console.WriteLine(MessagePackSerializer.ToJson(bin2));

Unity supports is limited.

When deserializing, same as Dynamic(Untyped) Deserialization.

Typeless

Typeless API is like BinaryFormatter, embed type information to binary so no needs type to deserialize.

object mc = new Sandbox.MyClass()
{
    Age = 10,
    FirstName = "hoge",
    LastName = "huga"
};

// serialize to typeless
var bin = MessagePackSerializer.Typeless.Serialize(mc);

// binary data is embeded type-assembly information.
// ["Sandbox.MyClass, Sandbox",10,"hoge","huga"]
Console.WriteLine(MessagePackSerializer.ToJson(bin));

// can deserialize to MyClass with typeless
var objModel = MessagePackSerializer.Typeless.Deserialize(bin) as MyClass;

Type information is serialized by mspgack ext format, typecode is 100.

MessagePackSerializer.Typeless is shortcut of Serialize/Deserialize<object>(TypelessContractlessStandardResolver.Instance). If you want to configure default typeless resolver, you can set by MessagePackSerializer.Typeless.RegisterDefaultResolver.

TypelessFormatter can use standalone and combinate with existing resolvers.

// replace `object` uses typeless
MessagePack.Resolvers.CompositeResolver.RegisterAndSetAsDefault(
    new[] { MessagePack.Formatters.TypelessFormatter.Instance },
    new[] { MessagePack.Resolvers.StandardResolver.Instance });

public class Foo
{
    // use Typeless(this field only)
    [MessagePackFormatter(typeof(TypelessFormatter))]
    public object Bar;
}

If type name was changed, can not deserialize. If you need to typename fallback, you can use TypelessFormatter.BindToType.

MessagePack.Formatters.TypelessFormatter.BindToType = typeName =>
{
    if (typeName.StartsWith("SomeNamespace"))
    {
        typeName = typeName.Replace("SomeNamespace", "AnotherNamespace");
    }

    return Type.GetType(typeName, false);
};

Performance

Benchmarks comparing to other serializers run on Windows 10 Pro x64 Intel Core i7-6700K 4.00GHz, 32GB RAM. Benchmark code is here - and there version info, ZeroFormatter and FlatBuffers has infinitely fast deserializer so ignore deserialize performance.

MessagePack for C# uses many techniques for improve performance.

• Serializer uses only IBufferWriter<byte> rather than System.IO.Stream for reduced overhead.
• Buffers are rented from pools to reduce allocations, keeping throughput high through reduced GC pressure.
• Don't create intermediate utility instance(XxxWriter/Reader, XxxContext, etc...)
• Utilize dynamic code generation to avoid boxing value types. Use AOT generation on platforms that prohibit JIT.
• Getting cached generated formatter on static generic field (don't use dictinary-cache because dictionary lookup is overhead). See Resolvers
• Heavily tuned dynamic IL code generation to avoid boxing value types. See DynamicObjectTypeBuilder. Use AOT generation on platforms that prohibit JIT.
• Call PrimitiveAPI directly when il code generation knows target is primitive
• Reduce branch of variable length format when il code generation knows target(integer/string) range
• Don't use IEnumerable<T> abstraction on iterate collection, see:CollectionFormatterBase and inherited collection formatters
• Uses pre generated lookup table to reduce check messagepack type, see: MessagePackBinary
• Uses optimized type key dictionary for non-generic methods, see: ThreadsafeTypeKeyHashTable
• Avoid string key decode for lookup map(string key) key and uses automata based name lookup with il inlining code generation, see: AutomataDictionary
• For string key encode, pre-generated member name bytes and use fixed sized binary copy in IL, see: UnsafeMemory.cs

Before creating this library, I implemented a fast fast serializer with ZeroFormatter#Performance. And this is a further evolved implementation. MessagePack for C# is always fast, optimized for all types(primitive, small struct, large object, any collections).

Deserialize Performance per options

Performance varies depending on options. This is a micro benchamark with BenchmarkDotNet. Target object has 9 members(MyProperty1 ~ MyProperty9), value are zero.

Method	Mean	Error	Scaled	Gen 0	Allocated
IntKey	72.67 ns	NA	1.00	0.0132	56 B
StringKey	217.95 ns	NA	3.00	0.0131	56 B
Typeless_IntKey	176.71 ns	NA	2.43	0.0131	56 B
Typeless_StringKey	378.64 ns	NA	5.21	0.0129	56 B
MsgPackCliMap	1,355.26 ns	NA	18.65	0.1431	608 B
MsgPackCliArray	455.28 ns	NA	6.26	0.0415	176 B
ProtobufNet	265.85 ns	NA	3.66	0.0319	136 B
Hyperion	366.47 ns	NA	5.04	0.0949	400 B
JsonNetString	2,783.39 ns	NA	38.30	0.6790	2864 B
JsonNetStreamReader	3,297.90 ns	NA	45.38	1.4267	6000 B
JilString	553.65 ns	NA	7.62	0.0362	152 B
JilStreamReader	1,408.46 ns	NA	19.38	0.8450	3552 B

IntKey, StringKey, Typeless_IntKey, Typeless_StringKey are MessagePack for C# options. All MessagePack for C# options achive zero memory allocation on deserialization process. JsonNetString/JilString is deserialized from string. JsonNetStreamReader/JilStreamReader is deserialized from UTF8 byte[] with StreamReader. Deserialization is normally read from Stream. Thus, it will be restored from byte[](or Stream) instead of string.

MessagePack for C# IntKey is fastest. StringKey is slower than IntKey because matching from the character string is required. If IntKey, read array length, for(array length) { binary decode }. If StringKey, read map length, for(map length) { decode key, lookup by key, binary decode } so requires additional two steps(decode key and lookup by key).

String key is often useful, contractless, simple replacement of JSON, interoperability with other languages, and more certain versioning. MessagePack for C# is also optimized for String Key. First of all, it do not decode UTF8 byte[] to String for matching with the member name, it will look up the byte[] as it is(avoid decode cost and extra allocation).

And It will try to match each long type (per 8 character, if it is not enough, pad with 0) using automata and inline it when IL code generating.

This also avoids calculating the hash code of byte[], and the comparison can be made several times on a long unit.

This is the sample decompile of generated deserializer code by ILSpy.

If the number of nodes is large, search with a embedded binary search.

Extra note, this is serialize benchmark result.

Method	Mean	Error	Scaled	Gen 0	Allocated
IntKey	84.11 ns	NA	1.00	0.0094	40 B
StringKey	126.75 ns	NA	1.51	0.0341	144 B
Typeless_IntKey	183.31 ns	NA	2.18	0.0265	112 B
Typeless_StringKey	193.95 ns	NA	2.31	0.0513	216 B
MsgPackCliMap	967.68 ns	NA	11.51	0.1297	552 B
MsgPackCliArray	284.20 ns	NA	3.38	0.1006	424 B
ProtobufNet	176.43 ns	NA	2.10	0.0665	280 B
Hyperion	280.14 ns	NA	3.33	0.1674	704 B
ZeroFormatter	149.95 ns	NA	1.78	0.1009	424 B
JsonNetString	1,432.55 ns	NA	17.03	0.4616	1944 B
JsonNetStreamWriter	1,775.72 ns	NA	21.11	1.5526	6522 B
JilString	547.51 ns	NA	6.51	0.3481	1464 B
JilStreamWriter	778.78 ns	NA	9.26	1.4448	6066 B

Of course, IntKey is fastest but StringKey also good.

LZ4 Compression

MessagePack is a fast and compact format but it is not compression. LZ4 is extremely fast compression algorithm, with MessagePack for C# can achive extremely fast perfrormance and extremely compact binary size!

MessagePack for C# has built-in LZ4 support. You can use LZ4MessagePackSerializer instead of MessagePackSerializer. Builtin support is special, I've created serialize-compression pipeline and special tuned for the pipeline so share the working memory, don't allocate, don't resize until finished.

Serialized binary is not simply compressed lz4 binary. Serialized binary is valid MessagePack binary used ext-format and custom typecode(99).

var array= Enumerable.Range(1, 100).Select(x => new MyClass { Age = 5, FirstName = "foo", LastName = "bar" }).ToArray();

// call LZ4MessagePackSerializer instead of MessagePackSerializer, api is completely same
var lz4Bytes = LZ4MessagePackSerializer.Serialize(array);
var mc2 = LZ4MessagePackSerializer.Deserialize<MyClass[]>(lz4Bytes);

// you can dump lz4 message pack
// [[5,"hoge","huga"],[5,"hoge","huga"],....]
var json = LZ4MessagePackSerializer.ToJson(lz4Bytes);
Console.WriteLine(json);

// lz4Bytes is valid MessagePack, it is using ext-format( [TypeCode:99, SourceLength|CompressedBinary] )
// [99,"0gAAA+vf3ABkkwWjZm9vo2JhcgoA////yVBvo2Jhcg=="]
var rawJson = MessagePackSerializer.ToJson(lz4Bytes);
Console.WriteLine(rawJson);

Built-in LZ4 support uses primitive LZ4 API. The LZ4 API is more efficient if you know the size of original source length. Therefore, size is written as a header to the extension payload as a msgpack Int32 value. To decompress with a different LZ4 implementation you may need to read or manually seek past this length header.

You can directly use the LZ4 support on binary for compression.

//sufficiently large enough byte array
byte[] myByteArray = Encoding.Default.GetBytes(new string('a', 128));
byte[] compressed = LZ4MessagePackSerializer.Serialize(myByteArray);
byte[] clonedOriginal = LZ4MessagePackSerializer.Deserialize<byte[]>(compressed);

Note the deserialization type provided of byte[].

Compression speed is not always fast. Depending on the target binary, it may be short or longer. However, even at worst, it is about twice, but it is still often faster than other uncompressed serializers.

If target binary size under 64 bytes, LZ4MessagePackSerializer does not compress to optimize small size serialization.

Attributions

lz4 compression support is using Milosz Krajewski's lz4net code with some modified.

Compare with protobuf, JSON, ZeroFormatter

protbuf-net is major, most used binary-format library on .NET. I love protobuf-net and respect that great work. But if uses protobuf-net for general-purpose serialization format, you may encounts annoying issue.

[ProtoContract]
public class Parent
{
    [ProtoMember(1)]
    public int Primitive { get; set; }
    [ProtoMember(2)]
    public Child Prop { get; set; }
    [ProtoMember(3)]
    public int[] Array { get; set; }
}

[ProtoContract]
public class Child
{
    [ProtoMember(1)]
    public int Number { get; set; }
}

using (var ms = new MemoryStream())
{
    // serialize null.
    ProtoBuf.Serializer.Serialize<Parent>(ms, null);

    ms.Position = 0;
    var result = ProtoBuf.Serializer.Deserialize<Parent>(ms);

    Console.WriteLine(result != null); // True, not null. but all property are zero formatted.
    Console.WriteLine(result.Primitive); // 0
    Console.WriteLine(result.Prop); // null
    Console.WriteLine(result.Array); // null
}

using (var ms = new MemoryStream())
{
    // serialize empty array.
    ProtoBuf.Serializer.Serialize<Parent>(ms, new Parent { Array = new int[0] });

    ms.Position = 0;
    var result = ProtoBuf.Serializer.Deserialize<Parent>(ms);

    Console.WriteLine(result.Array == null); // True, null!
}

protobuf(-net) can not handle null and empty collection correctly. Because protobuf has no null representation( this is the protobuf-net authors answer).

MessagePack specification can completely serialize C# type system. This is the reason to recommend MessagePack over protobuf.

Protocol Buffers has good IDL and gRPC, that is a much good point than MessagePack. If you want to use IDL, I recommend Google.Protobuf than MessagePack.

JSON is good general-purpose format. It is perfect, simple and enough spec. Utf8Json which created me that adopts same architecture as MessagePack for C# and avoid encoding/decoing cost so work like binary. If you want to know about binary vs text, see Utf8Json/which serializer should be used section.

ZeroFormatter is similar as FlatBuffers but specialized to C#. It is special. Deserialization is infinitely fast but instead the binary size is large. And ZeroFormatter's caching algorithm requires additional memory.

Again, ZeroFormatter is special. When situation matches with ZeroFormatter, it demonstrates power of format. But for many common uses, MessagePack for C# would be better.

Extensions

MessagePack for C# has extension point and you can add external type's serialization support. There are official extension support.

Install-Package MessagePack.ImmutableCollection
Install-Package MessagePack.ReactiveProperty
Install-Package MessagePack.UnityShims
Install-Package MessagePack.AspNetCoreMvcFormatter

MessagePack.ImmutableCollection package add support for System.Collections.Immutable library. It adds ImmutableArray<>, ImmutableList<>, ImmutableDictionary<,>, ImmutableHashSet<>, ImmutableSortedDictionary<,>, ImmutableSortedSet<>, ImmutableQueue<>, ImmutableStack<>, IImmutableList<>, IImmutableDictionary<,>, IImmutableQueue<>, IImmutableSet<>, IImmutableStack<> serialization support.

MessagePack.ReactiveProperty package add support for ReactiveProperty library. It adds ReactiveProperty<>, IReactiveProperty<>, IReadOnlyReactiveProperty<>, ReactiveCollection<>, Unit serialization support. It is useful for save viewmodel state.

MessagePack.UnityShims package provides shim of Unity's standard struct(Vector2, Vector3, Vector4, Quaternion, Color, Bounds, Rect, AnimationCurve, Keyframe, Matrix4x4, Gradient, Color32, RectOffset, LayerMask, Vector2Int, Vector3Int, RangeInt, RectInt, BoundsInt) and their formatters. It can enable to communicate between server and Unity client.

After install, extension package must enable by configuration. Here is sample of enable all extension.

// set extensions to default resolver.
MessagePack.Resolvers.CompositeResolver.RegisterAndSetAsDefault(
    // enable extension packages first
    ImmutableCollectionResolver.Instance,
    ReactivePropertyResolver.Instance,
    MessagePack.Unity.Extension.UnityBlitResolver.Instance,
    MessagePack.Unity.UnityResolver.Instance,

    // finaly use standard(default) resolver
    StandardResolver.Instance
);

Configuration details, see:Extension Point section.

MessagePack.AspNetCoreMvcFormatter is add-on of ASP.NET Core MVC's serialization to boostup performance. This is configuration sample.

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc().AddMvcOptions(option =>
    {
        option.OutputFormatters.Clear();
        option.OutputFormatters.Add(new MessagePackOutputFormatter(ContractlessStandardResolver.Instance));
        option.InputFormatters.Clear();
        option.InputFormatters.Add(new MessagePackInputFormatter(ContractlessStandardResolver.Instance));
    });
}

Author is creating other extension packages, too.

• MasterMemory - Embedded Readonly In-Memory Document Database
• MagicOnion - gRPC based HTTP/2 RPC Streaming Framework
• DatadogSharp - C# Datadog client

You can make your own extension serializers or integrate with framework, let's create them and share it!

• MessagePack.FSharpExtensions - supports F# list,set,map,unit,option,discriminated union
• MessagePack.NodaTime - Support for NodaTime types to MessagePack C#
• WebApiContrib.Core.Formatter.MessagePack - supports ASP.NET Core MVC(details in blog post)
• MessagePack.MediaTypeFormatter - MessagePack MediaTypeFormatter

API

High-Level API (MessagePackSerializer)

The MessagePackSerializer class is the entry point of MessagePack for C#. Its static methods make up the main API of MessagePack for C#.

API	Description
Serialize<T>	Serializes an object graph to msgpack binary. Async variety for Stream available. Non-generic overloads available.
Deserialize<T>	Deserializes msgpack binary to an object graph. Async variety for Stream available. Non-generic overloads available.
SerializeToJson	Serialize a MessagePack-compatible object graph to JSON instead of msgpack. Useful for debugging.
ConvertToJson	Convert msgpack binary to JSON. Useful for debugging.
ConvertFromJson	Convert JSON to msgpack binary.

A MessagePackSerializer.Typeless class offers most of the same APIs as above, but removes all type arguments, forcing serialization to include the full type name of the root object. It uses the TypelessContractlessStandardResolver. Consider the result to be a .NET-specific msgpack binary.

MessagePack for C# fundamentally serializes with IBufferWriter<byte> level and deserializes with ReadOnlySequence<byte> or Memory<byte>. Method overloads are provided for conveniently working with common buffer types and the .NET Stream class, but some of these convenience overloads require copying a buffer once.

High-Level API uses memory pool internally to avoid unnecessary memory allocation. If result size is under 64K, allocates GC memory only for the return bytes.

Each serialize/deserialize method takes an optional MessagePackSerializerOptions parameter which can be used to specify a custom IFormatterResolver to use or to activate LZ4 compression support.

Low-Level API (IMessagePackFormatter<T>)

The IMessagePackFormatter<T> interface is responsible for serializing a unique type. For example Int32Formatter : IMessagePackFormatter<Int32> represents Int32 MessagePack serializer.

public interface IMessagePackFormatter<T>
{
    void Serialize(ref MessagePackWriter writer, T value, MessagePackSerializerOptions options);
    T Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions options);
}

Many built-in formatters exists under MessagePack.Formatters. Your custom types are usually automatically supported with the built-in type resolvers that generate new IMessagePackFormatter<T> types on-the-fly using dynamic code generation. See our AOT code generation support for platforms that do not support this.

To take more control over the serialization of your custom types, write your own IMessagePackFormatter<T> implementation. Here is sample of write own formatter. Note its use of the primitive API that is described in the next section.

/// <summary>Serializes a <see cref="FileInfo" /> by its full path as a string.</summary>
public class FileInfoFormatter<T> : IMessagePackFormatter<FileInfo>
{
    public void Serialize(ref MessagePackWriter writer, FileInfo value, MessagePackSerializerOptions optionsr)
    {
        if (value == null)
        {
            writer.WriteNil();
            return;
        }

        writer.WriteString(value.FullName);
    }

    public FileInfo Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions options)
    {
        if (reader.TryReadNil())
        {
            return null;
        }

        var path = reader.ReadString();
        return new FileInfo(path);
    }
}

Your custom formatters must be discoverable via some IFormatterResolver. Learn more in our resolvers.

You can see many other samples from builtin formatters.

Primitive API (MessagePackWriter, MessagePackReader)

The MessagePackWriter and MessagePackReader structs make up the lowest-level API. They read and write the primitives types defined in the msgpack specification.

MessagePackReader

A MessagePackReader can efficiently read from ReadOnlyMemory<byte> or ReadOnlySequence<byte> without any allocating except to allocate a new string as required by the ReadString() method. All other methods return either value structs or ReadOnlySequence<byte> slices for extensions/arrays. Reading directly from ReadOnlySequence<byte> means the reader can directly consume some modern high perforamnce APIs such as PipeReader.

Method	Description
Skip	Advances the reader's position past the current value. If the value is complex (e.g. map, array) the entire structure is skipped.
Read*	Read and return a value whose type is named by the method name from the current reader position. Throws if the expected type does not match the actual type. When reading numbers, the type need not match the binary-specified type exactly. The numeric value will be coerced into the desired type or throw if the integer type is too small for a large value.
TryReadNil	Advances beyond the current value if the current value is nil and returns true; otherwise leaves the reader's position unchanged and returns false.
ReadBytes	Returns a slice of the input sequence representing the contents of a byte[], and advances the reader.
ReadStringSequence	Returns a slice of the input sequence representing the contents of a string without decoding it, and advances the reader.
Clone	Creates a new MessagePackReader with the specified input sequence and the same settings as the original reader.
CreatePeekReader	Creates a new reader with the same position as this one, allowing the caller to "read ahead" without impacting the original reader's position.
NextCode	Reads the low-level msgpack byte that describes the type of the next value. Does not advance the reader. See msgpack format of first byte. Its static class has ToMessagePackType and ToFormatName utility methods. MessagePackRange means Min-Max fix range of msgpack format.
NextMessagePackType	Describes the NextCode value as a higher level category. Does not advance the reader. See msgpack spec of source types.
(others)	Other methods and properties as described by the .xml doc comment file and Intellisense.

The MessagePackReader is capable of automatically interpreting both the old and new msgpack spec.

MessagePackWriter

A MessagePackWriter writes to a given instance of IBufferWriter<byte>. Several common implementations of this exist, allowing zero allocations and minimal buffer copies while writing directly to several I/O APIs including PipeWriter.

The MessagePackWriter writes the new msgpack spec by default, but can write msgpack compatible with the old spec by setting the OldSpec property to true.

Method	Description
Clone	Creates a new MessagePackWriter with the specified underlying IBufferWriter<byte> and the same settings as the original writer.
Flush	Writes any buffered bytes to the underlying IBufferWriter<byte>.
WriteNil	Writes the msgpack equivalent of .NET's null value.
Write	Writes any msgpack primitive value in the most compact form possible. Has overloads for every primitive type defined by the msgpack spec.
Write*IntType*	Writes an integer value in exactly the msgpack type specified, even if a more compact format exists.
WriteMapHeader	Introduces a map by specifying the number of key=value pairs it contains.
WriteArrayHeader	Introduces an array by specifying the number of elements it contains.
WriteExtensionFormat	Writes the full content of an extension value including length, type code and content.
WriteExtensionFormatHeader	Writes just the header (length and type code) of an extension value.
WriteRaw	Copies the specified bytes directly to the underlying IBufferWriter<byte> without any validation.
(others)	Other methods and properties as described by the .xml doc comment file and Intellisense.

DateTime is serialized to MessagePack Timestamp format, it serialize/deserialize UTC and loses Kind info and requires that MessagePackWriter.OldSpec == false. If you use the NativeDateTimeResolver, DateTime values will be serialized using .NET's native Int64 represnetation, which preserves Kind info but may not be interoperable with non-.NET platforms.

Extension Point (IFormatterResolver)

An IFormatterResolver is storage of typed serializers. The MessagePackSerializer API accepts a MessagePackSerializerOptions object which specifies the IFormatterResolver to use, allowing customization of the serialization of complex types.

Resolver Name	Description
BuiltinResolver	Builtin primitive and standard classes resolver. It includes primitive(int, bool, string...) and there nullable, array and list. and some extra builtin types(Guid, Uri, BigInteger, etc...).
StandardResolver	Composited resolver. It resolves in the following order builtin -> attribute -> dynamic enum -> dynamic generic -> dynamic union -> dynamic object -> dynamic object fallback. This is the default of MessagePackSerializer.
ContractlessStandardResolver	Composited StandardResolver(except dynamic object fallback) -> DynamicContractlessObjectResolver -> DynamicObjectTypeFallbackResolver. It enables contractless serialization.
StandardResolverAllowPrivate	Same as StandardResolver but allow serialize/deserialize private members.
ContractlessStandardResolverAllowPrivate	Same as ContractlessStandardResolver but allow serialize/deserialize private members.
PrimitiveObjectResolver	MessagePack primitive object resolver. It is used fallback in object type and supports bool, char, sbyte, byte, short, int, long, ushort, uint, ulong, float, double, DateTime, string, byte[], ICollection, IDictionary.
DynamicObjectTypeFallbackResolver	Serialize is used type in from object type, deserialize is used PrimitiveObjectResolver.
AttributeFormatterResolver	Get formatter from [MessagePackFormatter] attribute.
CompositeResolver	Composes several resolvers and/or formatters together in an ordered list, allowing reuse and overriding of behaviors of existing resolvers and formatters.
NativeDateTimeResolver	Serialize by .NET native DateTime binary format.
UnsafeBinaryResolver	Guid and Decimal serialize by binary representation. It is faster than standard(string) representation.
DynamicEnumResolver	Resolver of enum and there nullable, serialize there underlying type. It uses dynamic code generation to avoid boxing and boostup performance serialize there name.
DynamicEnumAsStringResolver	Resolver of enum and there nullable. It uses reflection call for resolve nullable at first time.
DynamicGenericResolver	Resolver of generic type(Tuple<>, List<>, Dictionary<,>, Array, etc). It uses reflection call for resolve generic argument at first time.
DynamicUnionResolver	Resolver of interface marked by UnionAttribute. It uses dynamic code generation to create dynamic formatter.
DynamicObjectResolver	Resolver of class and struct maked by MessagePackObjectAttribute. It uses dynamic code generation to create dynamic formatter.
DynamicContractlessObjectResolver	Resolver of all classes and structs. It does not needs MessagePackObjectAttribute and serialized key as string(same as marked [MessagePackObject(true)]).
DynamicObjectResolverAllowPrivate	Same as DynamicObjectResolver but allow serialize/deserialize private members.
DynamicContractlessObjectResolverAllowPrivate	Same as DynamicContractlessObjectResolver but allow serialize/deserialize private members.
TypelessObjectResolver	Used for object, embed .NET type in binary by ext(100) format so no need to pass type in deserilization.
TypelessContractlessStandardResolver	Composited resolver. It resolves in the following order nativedatetime -> builtin -> attribute -> dynamic enum -> dynamic generic -> dynamic union -> dynamic object -> dynamiccontractless -> typeless. This is the default of MessagePackSerializer.Typeless

Each invocation of MessagePackSerializer accepts only a single resolver. Most object graphs will need more than one for serialization, so composing a single resolver made up of several is often required, and can be done with the CompositeResolver as shown below:

// Do this once and store it for reuse.
var resolver = new MessagePack.Resolvers.CompositeResolver();
resolver.RegisterResolver(
    // resolver custom types first
    ImmutableCollectionResolver.Instance,
    ReactivePropertyResolver.Instance,
    MessagePack.Unity.Extension.UnityBlitResolver.Instance,
    MessagePack.Unity.UnityResolver.Instance,

    // finally use standard resolver
    StandardResolver.Instance);
var options = MessagePackSerializerOptions.Standard.WithResolver(resolver);

// Each time you serialize/deserialize, specify the options:
byte[] msgpackBytes = MessagePackSerializer.Serialize(myObject, options);
T myObject2 = MessagePackSerializer.Deserialize<MyObject>(msgpackBytes, options);

Here is sample of use DynamicEnumAsStringResolver with DynamicContractlessObjectResolver (It is JSON.NET-like lightweight setting.)

// composite same as StandardResolver
var resolver = new MessagePack.Resolvers.CompositeResolver();
resolver.RegisterResolver(
    MessagePack.Resolvers.BuiltinResolver.Instance,
    MessagePack.Resolvers.AttributeFormatterResolver.Instance,

    // replace enum resolver
    MessagePack.Resolvers.DynamicEnumAsStringResolver.Instance,

    MessagePack.Resolvers.DynamicGenericResolver.Instance,
    MessagePack.Resolvers.DynamicUnionResolver.Instance,
    MessagePack.Resolvers.DynamicObjectResolver.Instance,

    MessagePack.Resolvers.PrimitiveObjectResolver.Instance,

    // final fallback(last priority)
    MessagePack.Resolvers.DynamicContractlessObjectResolver.Instance);

If you want to make your extension package, you should write both the formatter and resolver for easier consumption. Here is sample of a resolver:

public class SampleCustomResolver : IFormatterResolver
{
    // Resolver should be singleton.
    public static readonly IFormatterResolver Instance = new SampleCustomResolver();

    private SampleCustomResolver()
    {
    }

    // GetFormatter<T>'s get cost should be minimized so use type cache.
    public IMessagePackFormatter<T> GetFormatter<T>()
    {
        return FormatterCache<T>.Formatter;
    }

    private static class FormatterCache<T>
    {
        public static readonly IMessagePackFormatter<T> Formatter;

        // generic's static constructor should be minimized for reduce type generation size!
        // use outer helper method.
        static FormatterCache()
        {
            Formatter = (IMessagePackFormatter<T>)SampleCustomResolverGetFormatterHelper.GetFormatter(typeof(T));
        }
    }
}

internal static class SampleCustomResolverGetFormatterHelper
{
    // If type is concrete type, use type-formatter map
    static readonly Dictionary<Type, object> formatterMap = new Dictionary<Type, object>()
    {
        {typeof(FileInfo), new FileInfoFormatter()}
        // add more your own custom serializers.
    };

    internal static object GetFormatter(Type t)
    {
        object formatter;
        if (formatterMap.TryGetValue(t, out formatter))
        {
            return formatter;
        }

        // If target type is generics, use MakeGenericType.
        if (t.IsGenericParameter && t.GetGenericTypeDefinition() == typeof(ValueTuple<,>))
        {
            return Activator.CreateInstance(typeof(ValueTupleFormatter<,>).MakeGenericType(t.GenericTypeArguments));
        }

        // If type can not get, must return null for fallback mecanism.
        return null;
    }
}

MessagePackFormatterAttribute

MessagePackFormatterAttribute is lightweight extension point of class, struct, interface, enum and property/field. This is like JSON.NET's JsonConverterAttribute. For example, serialize private field, serialize x10 formatter.

[MessagePackFormatter(typeof(CustomObjectFormatter))]
public class CustomObject
{
    string internalId;

    public CustomObject()
    {
        this.internalId = Guid.NewGuid().ToString();
    }

    // serialize/deserialize internal field.
    class CustomObjectFormatter : IMessagePackFormatter<CustomObject>
    {
        public void Serialize(ref MessagePackWriter writer, CustomObject value, MessagePackSerializerOptions options)
        {
            options.Resolver.GetFormatterWithVerify<string>().Serialize(ref writer, value.internalId, options);
        }

        public CustomObject Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions options)
        {
            var id = options.Resolver.GetFormatterWithVerify<string>().Deserialize(ref reader, options);
            return new CustomObject { internalId = id };
        }
    }
}

// per field, member

public class Int_x10Formatter : IMessagePackFormatter<int>
{
    public int Deserialize(ref MessagePackReader reader, MessagePackSerializerOptions options)
    {
        return reader.ReadInt32() * 10;
    }

    public void Serialize(ref MessagePackWriter writer, int value, MessagePackSerializerOptions options)
    {
        writer.WriteInt32(value * 10);
    }
}

[MessagePackObject]
public class MyClass
{
    // You can attach custom formatter per member.
    [Key(0)]
    [MessagePackFormatter(typeof(Int_x10Formatter))]
    public int MyProperty1 { get; set; }
}

Formatter is retrieved by AttributeFormatterResolver, it is included in StandardResolver.

IgnoreFormatter

IgnoreFormatter<T> is lightweight extension point of class and struct, if exists can't serializable type in external type, you can register IgnoreFormatter<T> that serialize to nil.

// CompositeResolver can set custom formatter.
MessagePack.Resolvers.CompositeResolver.RegisterAndSetAsDefault(
    new IMessagePackFormatter[]
    {
        // for example, register reflection infos(can not serialize in default)
        new IgnoreFormatter<MethodBase>(),
        new IgnoreFormatter<MethodInfo>(),
        new IgnoreFormatter<PropertyInfo>(),
        new IgnoreFormatter<FieldInfo>()
    },
    new IFormatterResolver[]
    {
        ContractlessStandardResolver.Instance
    });

Reserved Extension Types

MessagePack for C# already used some messagepack ext type codes, be careful to use same ext code.

Code	Type	Use by
-1	DateTime	msgpack-spec reserved for timestamp
30	Vector2[]	for Unity, UnsafeBlitFormatter
31	Vector3[]	for Unity, UnsafeBlitFormatter
32	Vector4[]	for Unity, UnsafeBlitFormatter
33	Quaternion[]	for Unity, UnsafeBlitFormatter
34	Color[]	for Unity, UnsafeBlitFormatter
35	Bounds[]	for Unity, UnsafeBlitFormatter
36	Rect[]	for Unity, UnsafeBlitFormatter
37	Int[]	for Unity, UnsafeBlitFormatter
38	Float[]	for Unity, UnsafeBlitFormatter
39	Double[]	for Unity, UnsafeBlitFormatter
99	All	LZ4MessagePackSerializer
100	object	TypelessFormatter

Unity support

You can install by package and includes source code. If build target as PC, you can use as is but if build target uses IL2CPP, you can not use Dynamic***Resolver so use pre-code generation. Please see pre-code generation section.

In Unity, MessagePackSerializer can serialize Vector2, Vector3, Vector4, Quaternion, Color, Bounds, Rect, AnimationCurve, Keyframe, Matrix4x4, Gradient, Color32, RectOffset, LayerMask, Vector2Int, Vector3Int, RangeInt, RectInt, BoundsInt and there nullable, there array, there list by built-in extension UnityResolver. It is included StandardResolver by default.

MessagePack for C# has additional unsafe extension. UnsafeBlitResolver is special resolver for extremely fast unsafe serialization/deserialization for struct array.

x20 faster Vector3[] serialization than native JsonUtility. If use UnsafeBlitResolver, serialize special format(ext:typecode 30~39) Vector2[], Vector3[], Quaternion[], Color[], Bounds[], Rect[]. If use UnityBlitWithPrimitiveArrayResolver, supports int[], float[], double[] too. This special feature is useful for serialize Mesh(many Vector3[]) or many transform position.

If you want to use unsafe resolver, you must enables unsafe option and define additional symbols. At first, write -unsafe on smcs.rsp, gmcs.rsp etc. And define ENABLE_UNSAFE_MSGPACK symbol.

Here is sample of configuration.

Resolvers.CompositeResolver.RegisterAndSetAsDefault(
    MessagePack.Unity.UnityResolver.Instance,
    MessagePack.Unity.Extension.UnityBlitWithPrimitiveArrayResolver.Instance,

    // If PC, use StandardResolver
    // MessagePack.Resolvers.StandardResolver.Instance,

    // If IL2CPP, Builtin + GeneratedResolver.
    // MessagePack.Resolvers.BuiltinResolver.Instance,
);

MessagePack.UnityShims NuGet package is for .NET ServerSide serialization support to communicate with Unity. It includes shim of Vector3 etc and Safe/Unsafe serialization extension.

If you want to share class between Unity and Server, you can use SharedProject or Reference as Link or new MSBuild(VS2017)'s wildcard reference etc. Anyway you need to source-code level share. This is sample project structure of use SharedProject.

• SharedProject(source code sharing)
  • Source codes of server-client shared
• ServerProject(.NET 4.6/.NET Core/.NET Standard)
  • [SharedProject]
  • [MessagePack]
  • [MessagePack.UnityShims]
• ClientDllProject(.NET 3.5)
  • [SharedProject]
  • [MessagePack](not dll, use MessagePack.unitypackage's sourcecodes)
• Unity
  • [Builded ClientDll]

Other ways, use plain POCO by DataContract/DataMember can use.

AOT Code Generation (to support Unity/Xamarin)

By default, MessagePack for C# serializes custom objects by using generating IL at runtime for custom, highly tuned formatters for each type. This code generation has a minor upfront perf cost. Because strict-AOT environments such as Xamarin and Unity IL2CPP forbid runtime code generation, MessagePack provides a way for you to run a code generator ahead of time as well.

Note: When Unity targets the PC it allows dynamic code generation, so AOT is not required.

If you want to avoid the upfront dynamic generation cost or you need to run on Xamarin or Unity, you need AOT code generation. mpc.exe(MessagePackCompiler) is the code generator of MessagePack for C#. You can download mpc from the releases page, mpc.zip. mpc uses Roslyn to analyze source code.

mpc arguments help:
-i, --input              [required]Input path of analyze csproj
-o, --output             [required]Output file path
-c, --conditionalsymbol  [optional, default=empty]conditional compiler symbol
-r, --resolvername       [optional, default=GeneratedResolver]Set resolver name
-n, --namespace          [optional, default=MessagePack]Set namespace root name
-m, --usemapmode         [optional, default=false]Force use map mode serialization

// Simple Sample:
mpc.exe -i "..\src\Sandbox.Shared.csproj" -o "MessagePackGenerated.cs"

// Use force map simulate DynamicContractlessObjectResolver
mpc.exe -i "..\src\Sandbox.Shared.csproj" -o "MessagePackGenerated.cs" -m

If you create DLL by msbuild project, you can use Pre/Post build event.

<PropertyGroup>
    <PreBuildEvent>
        mpc.exe, here is useful for analyze/generate target is self project.
    </PreBuildEvent>
    <PostBuildEvent>
        mpc.exe, here is useful for analyze target is another project.
    </PostBuildEvent>
</PropertyGroup>

By default, mpc.exe generates resolver to MessagePack.Resolvers.GeneratedResolver and formatters generates to MessagePack.Formatters.***. You must specify this resolver each time you invoke the MessagePackSerializer.

// Do this once and store it for reuse.
var resolver = MessagePack.Resolvers.CompositeResolver.Create(
    Array.Empty<IMessagePackFormatter>(),
    new IFormatterResolver[]
    {
        MessagePack.Resolvers.GeneratedResolver.Instance,
        MessagePack.Resolvers.StandardResolver.Instance,
    });
var options = MessagePackSerializerOptions.Standard.WithResolver(resolver);

// Each time you serialize/deserialize, specify the options:
byte[] msgpackBytes = MessagePackSerializer.Serialize(myObject, options);
T myObject2 = MessagePackSerializer.Deserialize<MyObject>(msgpackBytes, options);

Note: mpc.exe currently only supports running on Windows. You can run on Mono, that supports Mac and Linux.

RPC

MessagePack advocated MessagePack RPC, but formulation is stopped and it is not widely used.

MagicOnion

I've created gRPC based MessagePack HTTP/2 RPC streaming framework called MagicOnion. gRPC usually communicates with Protocol Buffers using IDL. But MagicOnion uses MessagePack for C# and does not needs IDL. If communicates C# to C#, schemaless(C# classes as schema) is better than IDL.

StreamJsonRpc

The StreamJsonRpc library is based on JSON-RPC and includes a pluggable formatter architecture and includes a sample MessagePack plugin.

How to build

See our contributor's guide.

Author Info

Yoshifumi Kawai(a.k.a. neuecc) is a software developer in Japan. He is the Director/CTO at Grani, Inc. Grani is a mobile game developer company in Japan and well known for using C#. He is awarding Microsoft MVP for Visual C# since 2011. He is known as the creator of UniRx (Reactive Extensions for Unity)

• Blog: https://medium.com/@neuecc (English)
• Blog: http://neue.cc/ (Japanese)
• Twitter: https://twitter.com/neuecc (Japanese)