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

Array with integers 0 through 1024 as strings, 1024 times

Dictionary with 1 million small objects

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