$ npm install node-object-hash
Tiny and fast node.js object hash library with properties/arrays sorting to provide constant hashes. It also provides a method that returns sorted object strings that can be used for object comparison without hashes. One of the fastest among other analogues (see benchmarks).
Hashes are built on top of node's crypto module. If you want to use it in browser it's recommented to use objectSorter
only. It will provide you with unique string representation of your object. Afterwards you may use some hash library to reduce string size. Also you may use something like browserify-crypto or some kind of crypto functions polyfills.
coerce=false
Set
s will no longer generate the same hashes as Array
s. In order to restore previous behavior set coerce.set=true
.coerce=false
Symbol
s will generate hash based on symbol .toString
value. That's useful for Symbol.for('smth')
. If coerce.symbol=true
all Symbols
s will have equal hashes.
TLDR; If you use library with Set
s or Symbol
s with coerce=false
in order to keep hashes the same as in v1.X.X
you should use following constructor:const hasher = require('node-object-hash')({coerce: {set: true, symbol: true}})
dist
directory. If you required it directly via require('node-object-hash/objectSorter')
you should change it to require('node-object-hash/dist/objectSorter').v0
version from code.trim
option. It can be used to remove unncecessary spaces in string
s or function
bodies.npm i node-object-hash -S
This map displays what types will have identical string representation (e.g. new Set([1, 2, 3]) and [1, 2, 3] will have equal string representations and hashes.
Initial type | Mapped type |
---|---|
Array ([]) | array |
ArrayObject (new Array()) | |
Int8Array | |
Uint8Array | |
Uint8ClampedArray | |
Int16Array | |
Uint16Array | |
Int32Array | |
Uint32Array | |
Float32Array | |
Float64Array | |
Buffer | |
Set | |
Map | array[array] |
string ('') | string |
String (new String()) | |
boolean (true) | boolean |
Boolean (new Boolean()) | |
number (true) | number |
Number (new Number()) | |
Date | date |
Symbol | symbol |
undefined | undefined |
null | null |
function | function |
Object ({}) | object |
Object (new Object()) | |
other | unknown |
Initial "type" | Coerced type | Example |
---|---|---|
boolean | string | true -> 1 |
number | string | '1' -> 1 |
string | string | 'a' -> a |
null | string (empty) | null -> |
undefined | string (empty) | undefined -> |
See changelog
Full API docs could be found in docs.
require('node-object-hash')([options])
Returns preconfigured object with API
Parameters:
options
:object
- object with hasher config optionsoptions.coerce
:boolean|object
- if true performs type coercion (default: true
);
e.g. hash(true) == hash('1') == hash(1)
, hash(false) == hash('0') == hash(0)
options.sort
:boolean|object
- if true performs sorting on objects, arrays, etc. (default: true
);options.trim
:boolean|object
- if true performs trim of spaces and replaces space-like characters with single space (default: false
);options.alg
:string
- sets default hash algorithm (default: 'sha256'
); can be overridden in hash
method;options.enc
:string
- sets default hash encoding (default: 'hex'
); can be overridden in hash
method;hash(object[, options])
Returns hash string.
object
:*
object for calculating hash;options
:object
object with options;options.alg
:string
- hash algorithm (default: 'sha256'
);options.enc
:string
- hash encoding (default: 'hex'
);sort(object)
Returns sorted string generated from object (can be used for object comparison)
object
:*
- object for sorting;>=nodejs-0.10.0
>=nodejs-6.0.0
>=nodejs-4.0.0
(requires to run node with --harmony
flag)var hasher = require('node-object-hash');
var hashSortCoerce = hasher({sort:true, coerce:true});
// or
// var hashSortCoerce = hasher();
// or
// var hashSort = hasher({sort:true, coerce:false});
// or
// var hashCoerce = hasher({sort:false, coerce:true});
var objects = {
a: {
a: [{c: 2, a: 1, b: {a: 3, c: 2, b: 0}}],
b: [1, 'a', {}, null],
},
b: {
b: ['a', 1, {}, undefined],
a: [{c: '2', b: {b: false, c: 2, a: '3'}, a: true}]
},
c: ['4', true, 0, 2, 3]
};
hashSortCoerce.hash(objects.a) === hashSortCoerce.hash(objects.b);
// returns true
hashSortCoerce.sort(object.c);
// returns '[0,1,2,3,4]'
For more examples you can see tests or try it out online at runkit
Bench data - array of 100000 complex objects
npm run bench
to run custom benchmarknpm run benchmark
to run benchmark suiteLibrary | Time (ms) | Memory (Mb) |
---|---|---|
node-object-hash-0.2.1 | 5813.575 | 34 |
node-object-hash-1.0.X | 2805.581 | 27 |
node-object-hash-1.1.X (node v7) | 2555.583 | 27 |
node-object-hash-1.2.X (node v7) | 2390.752 | 28 |
node-object-hash-2.X.X (node v12) | 1990.622 | 24 |
object-hash-1.1.5 (node v7) | 28115.553 | 39 |
object-hash-1.1.4 | 534528.254 | 41 |
object-hash-1.1.3 | ERROR | Out of heap memory |
hash-object-0.1.7 | 9219.826 | 42 |
Library (node v12) | Perf (ops/s) |
---|---|
node-object-hash-2.0.0 | 2087 ±0.59% |
object-hash-1.3.1 | 239 ±0.39% |
hash-object-0.1.7 | 711 ±0.18% |
MIT
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