Object-Hash

Generate hashes from objects and values in node and the browser. Uses node.js crypo module for hashing. Supports sha1, md5 and many others (depending on the platform).

Hash values of any type.
Provides a hash table implementation.
Supports a keys only option for grouping like objects with different values.

var hash = require('object-hash');

hash(value, options);

Generate a hash from any object or type. Defaults to sha1 with hex encoding.

algorithm hash algo to be used: 'sha1', 'md5'. default: sha1
excludeValues {true|false} hash object keys, values ignored. default: false
encoding hash encoding, supports 'buffer', 'hex', 'binary', 'base64'. default: hex

hash.sha1(value);

Hash using the sha1 algorithm.

Sugar method, equivalent to hash(value, {algorithm: 'sha1'})

hash.keys(value);

Hash object keys using the sha1 algorithm, values ignored.

Sugar method, equivalent to hash(value, {excludeValues: true})

hash.MD5(value);

Hash using the md5 algorithm.

Sugar method, equivalent to hash(value, {algorithm: 'md5'})

hash.keysMD5(value);

Hash object keys using the md5 algorithm, values ignored.

Sugar method, equivalent to hash(value, {algorithm: 'md5', excludeValues: true})

var hashTable = new hash.HashTable(options);

Create a new HashTable instance. Hashing options are supported and applied to all values added to the table.

hashTable.add(value1, value2, ...);

Add an object to the hash table. Supports n parameters or an array of values to be added to the table.

Note: if you wish to evaluate an array as a single table entry you must wrap it first {[1,2,3,4]} otherwise each element will be added to the table separately.

hashTable.getValue(hashKey);

Retrive the objects value from the table by hash key. If there is no matching entry returns undefined.

hashTable.getCount(hashKey);

Retrieve a counter representing the number of times an object was added to the table. Returns 0 if a matching key is not found.

hashTable.hasKey(hashKey);

Returns true if the specified hash is in the hash table otherwise false.

hashTable.toArray();

Returns an array of the hash table contents in the following format:

[ {hash:'14fa461bf4b98155e82adc86532938553b4d33a9',
    count: 2, value: {foo: 'bar', baz: true }},
  {hash:'14fa461bf4b98155e82adc86532938553b4d33a9',
    count: 1, value: {foo: 'bar', baz: true }} ]

Note: when the excludeValues option is set, the value of the hash table is an array of objects with matching keys.

hashTable.reset();

Clears the contents of the hash table.

Installation

node:

npm install object-hash

browser: /dist/object_hash.js

<script src="object_hash.js" type="text/javascript"></script>

Example usage

var hash = require('object-hash');

var peter = {name: 'Peter', stapler: false, friends: ['Joanna', 'Michael', 'Samir'] };
var michael = {name: 'Michael', stapler: false, friends: ['Peter', 'Samir'] };
var bob = {name: 'Bob', stapler: true, friends: [] };

/***
 * sha1 hex encoding (default)
 */
hash(peter);
// 14fa461bf4b98155e82adc86532938553b4d33a9
hash(michael);
// 4b2b30e27699979ce46714253bc2213010db039c
hash(bob);
// 38d96106bc8ef3d8bd369b99bb6972702c9826d5

/***
 * hash object keys, values ignored
 */
hash(peter, { excludeValues: true });
// 48f370a772c7496f6c9d2e6d92e920c87dd00a5c
hash(michael, { excludeValues: true });
// 48f370a772c7496f6c9d2e6d92e920c87dd00a5c
hash.keys(bob);
// 48f370a772c7496f6c9d2e6d92e920c87dd00a5c

/***
 * md5 base64 encoding
 */
hash(peter, { algorithm: 'md5', encoding: 'base64' });
// 6rkWaaDiG3NynWw4svGH7g==
hash(michael, { algorithm: 'md5', encoding: 'base64' });
// djXaWpuWVJeOF8Sb6SFFNg==
hash(bob, { algorithm: 'md5', encoding: 'base64' });
// lFzkw/IJ8/12jZI0rQeS3w==

/***
 * HashTable example
 */
var hashTable = new hash.HashTable();
var peterHash = hash(peter);

hashTable.add(peter, michael, bob);
hashTable.getValue(peterHash);
// {name: 'Peter', stapler: false, friends: ['Joanna', 'Michael', 'Samir'] };
hashTable.getCount(peterHash);
// 1
hashTable.add({name: 'Peter', stapler: false, friends: ['Joanna', 'Michael', 'Samir'] });
hashTable.getCount(peterHash);
// 2
hashTable.hasKey(peterHash);
// true
hashTable.toArray();
// [ {hash:'14fa461bf4b98155e82adc86532938553b4d33a9',
//    count: 2, value: {name: 'Peter', stapler: false, friends: ['Joanna', 'Michael', 'Samir'] }},
//  {hash:'4b2b30e27699979ce46714253bc2213010db039c',
//    count: 1, value: {name: 'Michael', stapler: false, friends: ['Peter', 'Samir'] }},
//  {hash:'38d96106bc8ef3d8bd369b99bb6972702c9826d5',
//    count: 1, value: {name: 'Bob', stapler: true, friends: [] }} ]

Legacy Browser Support

IE <= 8 and Opera <= 11 support dropped in version 0.3.0. If you require legacy browser support you must either use an ES5 shim or use version 0.2.5 of this module.

Development

git clone https://github.com/puleos/object-hash

gulp tasks

gulp watch (default) watch files, test and lint on change/add
gulp test unit tests
gulp lint jshint
gulp dist create browser version in /dist

License

MIT

gaarf/object-hash