fnv1a
FNV-1a non-cryptographic hash function
FNV-1a has outstanding distribution and collisions are rare.
FNV hashes are designed to be fast while maintaining a low collision rate. The FNV speed allows one to quickly hash lots of data while maintaining a reasonable collision rate. The high dispersion of the FNV hashes makes them well suited for hashing nearly identical strings such as URLs, hostnames, filenames, text, IP addresses, etc.
Install
npm install @sindresorhus/fnv1aUsage
import fnv1a from '@sindresorhus/fnv1a';
fnv1a('🦄🌈', {size: 32});
//=> 2868248295n
fnv1a('🦄🌈', {size: 128});
//=> 13487074350300261116944693128525960095n
Number(fnv1a('🦄🌈', {size: 32}));
//=> 2868248295
const bytes = new Uint8Array([240, 159, 166, 132, 240, 159, 140, 136]);
fnv1a(bytes, {size: 32});
//=> 2868248295nAPI
fnv1a(value, options?)
Returns the hash as a positive BigInt.
If you need it as a number, use 32 as size and wrap the return value in Number(…).
value
Type: string | Uint8Array
A string or UTF-8 bytes.
options
Type: object
size
Type: number
Values: 32 | 64 | 128 | 256 | 512 | 1024
Default: 32
The bit size of the hash.
utf8Buffer
Type: Uint8Array
A Uint8Array used to encode the string into UTF-8 bytes.
This array can be reused across calls to fnv1a. Doing so will improve performance because it avoids allocating a new Uint8Array when encoding the string.
The size of the array does not have to be large enugh to hold the entire string, but performance will be improved if it is.
This option is only used when value is a string.
import fnv1a from '@sindresorhus/fnv1a';
const utf8Buffer = new Uint8Array(100);
fnv1a('🦄🌈', {size: 32, utf8Buffer});
//=> 2868248295n