120 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			120 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|  | # fast-json-stable-stringify
 | ||
|  | 
 | ||
|  | Deterministic `JSON.stringify()` - a faster version of [@substack](https://github.com/substack)'s json-stable-strigify without [jsonify](https://github.com/substack/jsonify). | ||
|  | 
 | ||
|  | You can also pass in a custom comparison function. | ||
|  | 
 | ||
|  | [](https://travis-ci.org/epoberezkin/fast-json-stable-stringify) | ||
|  | [](https://coveralls.io/github/epoberezkin/fast-json-stable-stringify?branch=master) | ||
|  | 
 | ||
|  | # example
 | ||
|  | 
 | ||
|  | ``` js | ||
|  | var stringify = require('fast-json-stable-stringify'); | ||
|  | var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 }; | ||
|  | console.log(stringify(obj)); | ||
|  | ``` | ||
|  | 
 | ||
|  | output: | ||
|  | 
 | ||
|  | ``` | ||
|  | {"a":3,"b":[{"x":4,"y":5,"z":6},7],"c":8} | ||
|  | ``` | ||
|  | 
 | ||
|  | 
 | ||
|  | # methods
 | ||
|  | 
 | ||
|  | ``` js | ||
|  | var stringify = require('fast-json-stable-stringify') | ||
|  | ``` | ||
|  | 
 | ||
|  | ## var str = stringify(obj, opts)
 | ||
|  | 
 | ||
|  | Return a deterministic stringified string `str` from the object `obj`. | ||
|  | 
 | ||
|  | 
 | ||
|  | ## options
 | ||
|  | 
 | ||
|  | ### cmp
 | ||
|  | 
 | ||
|  | If `opts` is given, you can supply an `opts.cmp` to have a custom comparison | ||
|  | function for object keys. Your function `opts.cmp` is called with these | ||
|  | parameters: | ||
|  | 
 | ||
|  | ``` js | ||
|  | opts.cmp({ key: akey, value: avalue }, { key: bkey, value: bvalue }) | ||
|  | ``` | ||
|  | 
 | ||
|  | For example, to sort on the object key names in reverse order you could write: | ||
|  | 
 | ||
|  | ``` js | ||
|  | var stringify = require('fast-json-stable-stringify'); | ||
|  | 
 | ||
|  | var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 }; | ||
|  | var s = stringify(obj, function (a, b) { | ||
|  |     return a.key < b.key ? 1 : -1; | ||
|  | }); | ||
|  | console.log(s); | ||
|  | ``` | ||
|  | 
 | ||
|  | which results in the output string: | ||
|  | 
 | ||
|  | ``` | ||
|  | {"c":8,"b":[{"z":6,"y":5,"x":4},7],"a":3} | ||
|  | ``` | ||
|  | 
 | ||
|  | Or if you wanted to sort on the object values in reverse order, you could write: | ||
|  | 
 | ||
|  | ``` | ||
|  | var stringify = require('fast-json-stable-stringify'); | ||
|  | 
 | ||
|  | var obj = { d: 6, c: 5, b: [{z:3,y:2,x:1},9], a: 10 }; | ||
|  | var s = stringify(obj, function (a, b) { | ||
|  |     return a.value < b.value ? 1 : -1; | ||
|  | }); | ||
|  | console.log(s); | ||
|  | ``` | ||
|  | 
 | ||
|  | which outputs: | ||
|  | 
 | ||
|  | ``` | ||
|  | {"d":6,"c":5,"b":[{"z":3,"y":2,"x":1},9],"a":10} | ||
|  | ``` | ||
|  | 
 | ||
|  | ### cycles
 | ||
|  | 
 | ||
|  | Pass `true` in `opts.cycles` to stringify circular property as `__cycle__` - the result will not be a valid JSON string in this case. | ||
|  | 
 | ||
|  | TypeError will be thrown in case of circular object without this option. | ||
|  | 
 | ||
|  | 
 | ||
|  | # install
 | ||
|  | 
 | ||
|  | With [npm](https://npmjs.org) do: | ||
|  | 
 | ||
|  | ``` | ||
|  | npm install fast-json-stable-stringify | ||
|  | ``` | ||
|  | 
 | ||
|  | 
 | ||
|  | # benchmark
 | ||
|  | 
 | ||
|  | To run benchmark (requires Node.js 6+): | ||
|  | ``` | ||
|  | node benchmark | ||
|  | ``` | ||
|  | 
 | ||
|  | Results: | ||
|  | ``` | ||
|  | fast-json-stable-stringify x 17,189 ops/sec ±1.43% (83 runs sampled) | ||
|  | json-stable-stringify x 13,634 ops/sec ±1.39% (85 runs sampled) | ||
|  | fast-stable-stringify x 20,212 ops/sec ±1.20% (84 runs sampled) | ||
|  | faster-stable-stringify x 15,549 ops/sec ±1.12% (84 runs sampled) | ||
|  | The fastest is fast-stable-stringify | ||
|  | ``` | ||
|  | 
 | ||
|  | 
 | ||
|  | # license
 | ||
|  | 
 | ||
|  | [MIT](https://github.com/epoberezkin/fast-json-stable-stringify/blob/master/LICENSE) |