aaac7fed
 liuqimichale
add
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
# Javascript implementation of xxHash
## Synopsis
xxHash is a very fast hashing algorithm (see the details [here](https://code.google.com/p/xxhash/)). 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_:
```javascript
<script src="/your/path/to/xxhash.js"></script>
```
## Examples
* In one step:
```javascript
var h = XXH.h32( 'abcd', 0xABCD ).toString(16) // seed = 0xABCD
```
> 0xCDA8FAE4
* In several steps (useful in conjunction of NodeJS streams):
```javascript
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(<radix>).
* `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(<radix>).
## License
MIT
|
