SimdJsonSharp: Parsing gigabytes of JSON per second

C# version of Daniel Lemire's SimdJson fully ported from C to C#, I tried to keep the same format and API). The library accelerates JSON parsing and minification using SIMD instructions including AVX2 (C# version uses System.Runtime.Intrinsics API).

Benchmarks

The following benchmark compares SimdJsonSharp with .NET Core 3.0 Utf8JsonReader, Json.NET and SpanJson libraries. Test json files can be found here.

1. Parse doubles

Open canada.json and parse all coordinates as System.Double:

|          Method |     fileName |    fileSize |      Mean | Ratio |
|---------------- |------------- |-------------|----------:|------:|
|        SimdJson |  canada.json | 2,251.05 Kb |  4,733 ms |  1.00 |
|  Utf8JsonReader |  canada.json | 2,251.05 Kb | 56,692 ms | 11.98 |
|         JsonNet |  canada.json | 2,251.05 Kb | 70,078 ms | 14.81 |
|    SpanJsonUtf8 |  canada.json | 2,251.05 Kb | 54,878 ms | 11.60 |

2. Count all tokens

|            Method |           fileName |    fileSize |         Mean | Ratio |
|------------------ |------------------- |------------ |-------------:|------:|
|          SimdJson | apache_builds.json |   127.28 Kb |     99.28 us |  1.00 |
|    Utf8JsonReader | apache_builds.json |   127.28 Kb |    226.42 us |  2.28 |
|           JsonNet | apache_builds.json |   127.28 Kb |    461.30 us |  4.64 |
|      SpanJsonUtf8 | apache_builds.json |   127.28 Kb |    168.08 us |  1.69 |
|                   |                    |             |              |       |
|          SimdJson |        canada.json | 2,251.05 Kb |  4,494.44 us |  1.00 |
|    Utf8JsonReader |        canada.json | 2,251.05 Kb |  6,308.01 us |  1.40 |
|           JsonNet |        canada.json | 2,251.05 Kb | 67,718.12 us | 15.06 |
|      SpanJsonUtf8 |        canada.json | 2,251.05 Kb |  6,679.82 us |  1.49 |
|                   |                    |             |              |       |
|          SimdJson |  citm_catalog.json | 1,727.20 Kb |  1,572.78 us |  1.00 |
|    Utf8JsonReader |  citm_catalog.json | 1,727.20 Kb |  3,786.10 us |  2.41 |
|           JsonNet |  citm_catalog.json | 1,727.20 Kb |  5,903.38 us |  3.75 |
|      SpanJsonUtf8 |  citm_catalog.json | 1,727.20 Kb |  3,021.13 us |  1.92 |
|                   |                    |             |              |       |
|          SimdJson | github_events.json |    65.13 Kb |     46.01 us |  1.00 |
|    Utf8JsonReader | github_events.json |    65.13 Kb |    113.80 us |  2.47 |
|           JsonNet | github_events.json |    65.13 Kb |    214.01 us |  4.65 |
|      SpanJsonUtf8 | github_events.json |    65.13 Kb |     89.09 us |  1.94 |
|                   |                    |             |              |       |
|          SimdJson |     gsoc-2018.json | 3,327.83 Kb |  2,209.42 us |  1.00 |
|    Utf8JsonReader |     gsoc-2018.json | 3,327.83 Kb |  4,010.10 us |  1.82 |
|           JsonNet |     gsoc-2018.json | 3,327.83 Kb |  6,729.44 us |  3.05 |
|      SpanJsonUtf8 |     gsoc-2018.json | 3,327.83 Kb |  2,759.59 us |  1.25 |
|                   |                    |             |              |       |
|          SimdJson |   instruments.json |   220.35 Kb |    257.78 us |  1.00 |
|    Utf8JsonReader |   instruments.json |   220.35 Kb |    594.22 us |  2.31 |
|           JsonNet |   instruments.json |   220.35 Kb |    980.42 us |  3.80 |
|      SpanJsonUtf8 |   instruments.json |   220.35 Kb |    409.47 us |  1.59 |
|                   |                    |             |              |       |
|          SimdJson |      truenull.json |    12.00 Kb |  16,032.6 ns |  1.00 |
|    Utf8JsonReader |      truenull.json |    12.00 Kb |  58,365.2 ns |  3.64 |
|           JsonNet |      truenull.json |    12.00 Kb |  60,977.3 ns |  3.80 |
|      SpanJsonUtf8 |      truenull.json |    12.00 Kb |  24,069.2 ns |  1.50 |

3.Json minification:

|                Method |           fileName |    fileSize |         Mean | Ratio |
|---------------------- |------------------- |------------ |-------------:|------:|
|  SimdJsonNoValidation | apache_builds.json |   127.28 Kb |     186.8 us |  1.00 |
|              SimdJson | apache_builds.json |   127.28 Kb |     262.5 us |  1.41 |
|               JsonNet | apache_builds.json |   127.28 Kb |   1,802.6 us |  9.65 |
|                       |                    |             |              |       |
|  SimdJsonNoValidation |        canada.json | 2,251.05 Kb |   4,130.7 us |  1.00 |
|              SimdJson |        canada.json | 2,251.05 Kb |   7,940.7 us |  1.92 |
|               JsonNet |        canada.json | 2,251.05 Kb | 181,884.0 us | 44.06 |
|                       |                    |             |              |       |
|  SimdJsonNoValidation |  citm_catalog.json | 1,727.20 Kb |   2,346.9 us |  1.00 |
|              SimdJson |  citm_catalog.json | 1,727.20 Kb |   4,064.0 us |  1.75 |
|               JsonNet |  citm_catalog.json | 1,727.20 Kb |  34,831.0 us | 14.84 |

Usage

The C# API is not stable yet and currently fully copies the original C-style API thus it involves some Unsafe magic including pointers.

Add nuget package SimdJsonSharp e.g. via CLI:

dotnet add package SimdJsonSharp

The following sample parses a file and iterate numeric tokens

byte[] bytes = File.ReadAllBytes(somefile);
fixed (byte* ptr = bytes) // pin bytes while we are working on them
using (ParsedJson doc = SimdJson.ParseJson(ptr, bytes.Length))
using (var iterator = doc.CreateIterator())
{
    while (iterator.MoveForward())
    {
        if (iterator.GetTokenType() == JsonTokenType.Number)
            Console.WriteLine("integer: " + iterator.GetInteger());
    }
}

As you can see the API looks similiar to Utf8JsonReader that was introduced recently in .NET Core 3.0

Also it's possible to just validate JSON or minify it (remove whitespaces, etc):

string someJson = ...;
string minifiedJson = SimdJson.MinifyJson(someJson);

Requirements

• AVX2 enabled CPU
• .NET Core 3.0 (because of System.Runtime.Intrinsics)