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
(so for using in browser use something like browserify-crypto or some kind of crypto functions polyfills). Or you can use only objectSorter
(source) for getting your objects' string representation and compare or pass them to your own hash function.
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
require('node-object-hash')([options])
Returns preconfigured object with API
Parameters:
options
:object
- object with hasher config optionsoptions.coerce
:boolean
- if true performs type coercion (default: true
);
e.g. hash(true) == hash('1') == hash(1)
, hash(false) == hash('0') == hash(0)
options.sort
:boolean
- if true performs sorting on objects, arrays, etc. (default: true
);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;objectToString
Object sorter module. It provides object sorter function constructor.
apiConstructor
Node object hash module. It provides a methods that return object hash or sorted object string.
objectToString
Object sorter module. It provides object sorter function constructor.
objectToString
string
℗string
℗objectToString
℗
string
℗string
℗Guesses object's type
Kind: inner method of node-object-hash/objectSorter
Returns: string
- Object type
Access: private
Param | Type | Description |
---|---|---|
obj | Object |
Object to guess type |
Example
var a = [];
_guessObjectType(a) === 'array'; // true
string
℗Guesses variable type
Kind: inner method of node-object-hash/objectSorter
Returns: string
- Variable type
Access: private
Param | Type | Description |
---|---|---|
obj | * |
Variable to guess type |
Example
var a = '';
_guessType(a) === 'string'; // true
objectToString
℗Creates object sorter function
Kind: inner method of node-object-hash/objectSorter
Returns: objectToString
- Object sorting function
Access: private
Param | Type | Default | Description |
---|---|---|---|
[options] | Object |
Sorter options | |
[options.coerce] | boolean |
true |
Performs type coercion |
[options.sort] | boolean |
true |
Performs array, object, etc. sorting |
Example
// with coercion
var sorter = makeObjectSorter({coerce: true, sort: false});
sorter(1) === "1"; // true
// with sort
var sorter = makeObjectSorter({coerce: false, sort: true});
sorter([2, 3, 1]) === [1, 2, 3]; // true
string
℗Object sorting function
Kind: inner method of makeObjectSorter
Returns: string
- Sorted string
Access: private
Param | Type | Description |
---|---|---|
obj | Object |
Object to sort |
apiConstructor
Node object hash module. It provides a methods that return object hash or sorted object string.
apiConstructor
string
string
API
Object
string
Creates sorted string from given object
Kind: instance method of node-object-hash
Returns: string
- Sorted object string
Access: public
See: objectToString
Param | Type | Description |
---|---|---|
obj | * |
JS object to be sorted |
Example
var apiConstructor = require('node-object-hash');
var sorter = apiConstructor({sort:true, coerce:true}).sort;
sort({b: {b: 1, d: 'x'}, c: 2, a: [3, 5, 1]});
// "{a:[1,3,5],b:{b:1,d:x},c:2}"
string
Creates hash from given object
Kind: instance method of node-object-hash
Returns: string
- Object hash value
Access: public
Param | Type | Default | Description |
---|---|---|---|
obj | * |
JS object to hash | |
[opts] | Object |
Options | |
[opts.alg] | string |
"sha256" |
Crypto algorithm to use |
[opts.enc] | string |
"hex" |
Hash string encoding |
Example
var apiConstructor = require('node-object-hash');
var hasher = apiConstructor({sort:true, coerce:true}).hash;
hash({b: {b: 1, d: 'x'}, c: 2, a: [3, 5, 1]});
// "4c18ce0dcb1696b329c8568d94a9830da810437d8c9e6cecf5d969780335a26b"
API
Generates node-object-hash API object
Kind: inner method of node-object-hash
Returns: API
- Node object hash API instance
Param | Type | Default | Description |
---|---|---|---|
[options] | Object |
Library options | |
[options.coerce] | boolean |
true |
Performs type coercion |
[options.sort] | boolean |
true |
Performs array, object, etc. sorting |
[options.alg] | string |
"sha256" |
Default crypto algorithm to use (can be overridden) |
[options.enc] | string |
"hex" |
Hash string encoding (can be overridden) |
Example
var apiConstructor = require('node-object-hash');
var hashSortCoerce = apiConstructor({sort:true, coerce:true});
// or
var hashSort = apiConstructor({sort:true, coerce:false});
// or
var hashCoerce = apiConstructor({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]'
Object
Node object hash API object
Kind: inner typedef of node-object-hash
Properties
Name | Type | Description |
---|---|---|
hash | function |
Returns object hash string (see hash) |
sort | function |
Returns sorted object string (see sort) |
>=nodejs-0.10.0
>=nodejs-6.0.0
>=nodejs-4.0.0
(requires to run node with --harmony
flag)crypto
module for browsers (e.g. browserify-crypto).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 file or try it out online at runkit
Bench data - array of 100000 complex objects
npm run bench
to run custom benchmarknpm run bench2
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 |
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 v7) | Perf (ops/s) |
---|---|
node-object-hash-0.2.1 | 540 ±1.34% |
node-object-hash-1.1.X | 844 ±2.51% |
node-object-hash-1.2.X | 1021 ±1.81% |
object-hash-1.1.5 | 106 ±0.88% |
hash-object-0.1.7 | 305 ±1.66% |
Library (node v10) | Perf (ops/s) |
---|---|
node-object-hash-0.X.X | 758 ±1.40% |
node-object-hash-1.4.X | 1266 ±1.44% |
object-hash-1.3.0 | 132 ±4.08% |
hash-object-0.1.7 | 378 ±1.36% |
ISC