# FastJsonparser

## Fastest Json parser for Ruby

Ruby wrapper for [simdjson](https://simdjson.org) (Parsing gigabytes of JSON per second)

The simdjson library uses commonly available SIMD instructions and microparallel algorithms to parse JSON 2.5 times faster than anything else out there.

Initial code imported from [simdjson_ruby](https://github.com/saka1/simdjson_ruby)

Comparison with [Oj](https://github.com/ohler55/oj) gem & JSON.parse

1. Parsing JSON from file
```
FastJsonparser.load(src) is 40% faster than Oj.load_file(src)
FastJsonparser.load(src) is 155% faster than JSON.parse(File.read(src))
```
[Benchmark result](https://github.com/anilmaurya/fast_jsonparser/blob/master/benchmark/file_benchmark.rb)

```
# virus-info.json 1.2M
#                 user     system      total        real
# FastJsonparser  4.772700   0.321748   5.094448 (  5.100354)
# OJ              6.944966   0.267082   7.212048 (  7.253477) ~ 42% more
# standard JSON   13.311654   0.167076  13.478730 ( 13.504489) ~  164% more
```

2. Parsing local JSON
```
FastJsonparser.parse(json) is 19% faster than Oj.load(json)
FastJsonparser.parse(json) is 96% faster than JSON.parse(json)
```
[Benchmark result](https://github.com/anilmaurya/fast_jsonparser/blob/master/benchmark/json_benchmark.rb)
```
#                 user     system      total        real
# FastJsonparser  6.732325   0.005716   6.738041 (  6.750285)
# OJ              8.029406   0.006582   8.035988 (  8.055000) ~ 19% more
# standard JSON   13.025884   0.031287  13.057171 ( 13.264931) ~ 96% more
```

3. Streaming json from file
```
FastJsonparser.load_many(src) is 153% faster than Yajl::Parser.new.parse(File.new(src, 'r'))
```
[Benchmark result](https://github.com/anilmaurya/fast_jsonparser/blob/master/benchmark/stream_benchmark.rb)
```
#                   user     system      total        real
# FastJsonparser  3.844446   0.141822   3.986268 (  3.884655)
# YAJL            9.699621   0.110060   9.809681 (  9.826104) ~ 150% more
```

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'fast_jsonparser'
```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install fast_jsonparser

## Usage

1. Parsing JSON from file

```
FastJsonparser.load(src) # src is source path for json file

Example:

FastJsonparser.load("./benchmark/graduation.json")

```

2. Parsing local JSON

```
FastJsonparser.parse(json)

Example:

FastJsonparser.parse('{"one": 1, "two": 2}')

```

3. Streaming JSON from file

File with multiple json can be stream with `load_many` method

Example: logs.json with following content
```
{"time": "17/May/2015:08:05:32 +0000", "remote_ip": "93.180.71.3", "remote_user": "-"}
{"time": "17/May/2015:08:05:23 +0000", "remote_ip": "93.180.71.3", "remote_user": "-"}
{"time": "17/May/2015:08:05:24 +0000", "remote_ip": "80.91.33.133", "remote_user": "-"}
```

`load_many` accepts file_path & block as arguments
```
> FastJsonparser.load_many(file_path) { |obj| p obj[:time]}
"17/May/2015:08:05:32 +0000"
"17/May/2015:08:05:23 +0000"
"17/May/2015:08:05:24 +0000"
```


4. Raise FastJsonparser::ParseError when invalid JSON provided for parsing

```
FastJsonparser.parse("123: 1") # FastJsonparser::ParseError (parse error)
```

### Example

```
> sample_json = '{"a":"Alpha","b":true,"c":12345,"d":[true,[false,[-123456789,null],3.9676,["Something else.",false],null]],"e":{"zero":null,"one":1,"two":2,"three":[3],"four":[0,1,2,3,4]},"f":null,"h":{"a":{"b":{"c":{"d":{"e":{"f":{"g":null}}}}}}},"i":[[[[[[[null]]]]]]]}'
> FastJsonparser.parse(sample_json)
=> {:a=>"Alpha", :b=>true, :c=>12345, :d=>[true, [false, [-123456789, nil], 3.9676, ["Something else.", false], nil]], :e=>{:zero=>nil, :one=>1, :two=>2, :three=>[3], :four=>[0, 1, 2, 3, 4]}, :f=>nil, :h=>{:a=>{:b=>{:c=>{:d=>{:e=>{:f=>{:g=>nil}}}}}}}, :i=>[[[[[[[nil]]]]]]]} 
```
## Development

After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).

## Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/anilmaurya/fast_jsonparser. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.

## License

The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).

## Code of Conduct

Everyone interacting in the FastJsonparser project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/anilmaurya/fast_jsonparser/blob/master/CODE_OF_CONDUCT.md).