Xxhashjs NPM | npm.io

Javascript implementation of xxHash

Synopsis

xxHash is a very fast hashing algorithm (see the details here). xxhashjs is a Javascript implementation of it, written in 100% Javascript. Although not as fast as the C version, it does perform pretty well given the current Javascript limitations in handling unsigned 32 bits integers.

Installation

In nodejs:

npm install xxhashjs

In the browser, include the following, and access the constructor with XXH:

<script src="/your/path/to/xxhash.js"></script>

Examples

In one step:

var h = XXH.h32( 'abcd', 0xABCD ).toString(16)	// seed = 0xABCD

0xCDA8FAE4

In several steps (useful in conjunction of NodeJS streams):

var H = XXH.h32( 0xABCD )	// seed = 0xABCD
var h = H.update( 'abcd' ).digest().toString(16)

0xCDA8FAE4

More examples in the examples directory: Compute xxHash from a file data Use xxHashjs in the browser

Usage

XXH makes 2 functions available for 32 bits XXH and 64 bits XXH respectively, with the same signature:
```
	* XXH.h32
	* XXH.h64
```
In one step: XXH.h32(<data>, <seed>) The data can either be a string, an ArrayBuffer or a NodeJS Buffer object. The seed can either be a number or a UINT32 object.
In several steps: * instantiate a new XXH object H: XXH.h32(<seed>) or XXH.h32() The seed can be set later on with the init method
```
* add data to the hash calculation:
```
H.update(<data>)
```
* finish the calculations:
```
H.digest()

The object returned can be converted to a string with toString(<radix>) or a number toNumber(). Once digest() has been called, the object can be reused. The same seed will be used or it can be changed with init(<seed>).

Methods

XXH.h32() .init(<seed>) Initialize the XXH object with the given seed. The seed can either be a number or a UINT32 object. .update(<data>) Add data for hashing. The data can either be a string, an ArrayBuffer or a NodeJS Buffer object.
digest() (UINT32) Finalize the hash calculations and returns an UINT32 object. The hash value can be retrieved with toString().
XXH.h64() .init(<seed>) Initialize the XXH object with the given seed. The seed can either be a number or a UINT64 object. .update(<data>) Add data for hashing. The data can either be a string, an ArrayBuffer or a NodeJS Buffer object. * .digest() (UINT64) Finalize the hash calculations and returns an UINT64 object. The hash value can be retrieved with toString().