Cameronism.Json

Very fast JSON serializer for .NET

Writing directly to byte sequences (byte* or Stream) rather than TextWriter allows this JSON serializer to achieve the speed of binary serializers.

// Easiest serialization method
void Serializer.Serialize<T>(T item, Stream destination, byte[] buffer)

// Fastest serialization method
int Serializer.Serialize<T>(T item, byte* destination, int available)

Deserialization is not currently supported, I recommend Jil for your deserialization needs.

Benchmarks

Array with integers 0 through 1024, 1024 times

Serializer	Average Milliseconds
Cameronism.Json	9
Jil	41
ProtoBuf	170
Newtonsoft	179

Array with integers 0 through 1024 as strings, 1024 times

Serializer	Average Milliseconds
Cameronism.Json	24
Jil	85
ProtoBuf	107
Newtonsoft	134

Dictionary with 1 million small objects

Serializer	Average Milliseconds
Cameronism.Json	415
ProtoBuf	889
Jil	1230
Newtonsoft	3195

Small object:

new
{
	SessionId = Guid.NewGuid(),
	Timestamp = DateTime.UtcNow,
	UserAgent = i + "/" + i,
	PageId = (uint)i,
	Options = new Dictionary<string,string>(),
	Groups = new List<GroupInfo>(),
}

Usage

Stream Usage:

var stuffToSerialize = GetSomeStuff();
Stream destination = GetDestinationStream();
byte[] buffer = GetReusedBuffer();
Serializer.Serialize(stuffToSerialize, destination, buffer);

// destination now has the JSON

Pointer Usage:

var stuffToSerialize = GetSomeStuff();
byte[] buffer = GetReusedBuffer();
int position;
unsafe
{
	fixed (byte* ptr = buffer)
	{
		position = Serializer.Serialize(stuffToSerialize, ptr, buffer.Length);
	}
}

if (position < 0) return; // buffer was too small

/* buffer now has the JSON */

// copy it elsewhere
otherStream.Write(buffer, 0, position);

// or create a stream of your own
var myStream = new MemoryStream(buffer, 0, position);

// or get the string version of the JSON 
string debug = Encoding.UTF8.GetString(buffer, 0, position);
// if you need a string for more than debugging, use a TextWriter based serializer like Jil

BufferManager is an option for reusing buffers.

Serialize may be also be called with an UnmanagedMemoryStream. MemoryMappedFile can be used to get an unmanaged stream for a file on disk (or not on disk at all).

Install Cameronism.Json

PM> Install-Package Cameronism.Json

Logger

TODO Show the logger

TODO Show logger benchmarks

JSON types from .NET types

No deserialization (use Jil or Newtonsoft)

string
- from System.String
  writer done
- from System.Char
  writer done
- from System.Guid
  writer done, only the "D" format
- from System.DateTime
  writer done, only ISO8601
- from System.DateTimeOffset
  TODO
- from System.Net.IPAddress
  handled by delegate generator, very Windows specific
- from byte[] done, base64
- from enum
  - FlagAttribute
    TODO
  - non flag
    TODO
number
- from System.Int32
  writer done
- from System.UInt32
  writer done
- from System.Int16
  cast to Int32, probably not worth special case
- from System.UInt16
  cast to UInt32, probably not worth special case
- from System.Byte
  cast to UInt32, probably not worth special case
- from System.SByte
  cast to Int32, probably not worth special case
- from System.Int64
  writer done
- from System.UInt64
  writer done
- from System.Double
  writer done, wastefully uses ToString
- from System.Single
  writer done, wastefully uses ToString
- from System.Decimal
  writer done, wastefully uses ToString
- from System.DateTime
  TODO
- from enum
  handled by delegate generator
object
- from type composed of other supported types
  handled by delegate generator
- from IDictionary<TKey, TValue>
  - string TKey
    handled by delegate generator
  - enum TKey
    TODO
array
- from array
  handled by delegate generator
- from IEnumerable<>
  handled by delegate generator
true
- from System.Boolean
  writer done
false
- from System.Boolean
  writer done
null
- from System.String
  writer done
- from System.Nullable<>
  handled by delegate generator for primitives and non-dictionary objects

Optimizations

Not TextWriter based, byte* based
Member order
TODO
Whitespace for 8 byte alignment
TODO
Inline constant properties Properties that return a constant will not be called, the serialized value will be calculated when generating serialization method

TODO

Test for inlined constant properties around stream boundaries
Better return value when insufficient space
- object serializer
  - currently just doubles original avail param
  - member result - minLength might be sufficient
  - should decrease available before serializing member, save some room for following members
Minimum length (and maybe reserved length) per schema
DateTime and Guid are JSON type string but we know a lot more about their length than the general string case
Call Dispose on enumerators
Performance test array with unrolled first iteration

cameronism/Cameronism.Json