Hazz, a pseudo-random-data-filled-table to generate k indipendent and uniform, very fast (non-cryptographic) hash functions.
npm install hazz
!NODE VERSION
!NPM YEARLY
> __Hazz__, a __pseudo-random-data-filled-table__ to generate __k indipendent__ and __uniform__, __very fast__ (non-cryptographic) hash functions.
> If you need to hash __arbitrary long length__ inputs, without using a fixed (big) size pseudo-random table, a fast way is to __simulate__ a set of indipendent hash functions using a single crpyto-digest (with a sha-512 digest we can simulate up to 16 functions). Take a look to __Mazz__ (the fast way of the __tonto__).
``bash`
$ npm install hazz [-g]
> __require__:
`javascript`
var Hazz = require( 'hazz' );$3
> __to run all test files, install devDependencies:__
`bash`
$ cd hazz/
# install or update devDependencies
$ npm install
# run tests
$ npm test
> __to execute a single test file simply do__:
`bash`
$ node test/file-name.js
> Specify how many bytes to parse (at max), from every
> input key to hash, then the number of functions to use.
> NOTE:
> - default value for input length is 16 byte.
> - default and minimum value for hfn is 2
> Arguments between [] are optional.
`javascript`
Hazz( [ Number max_input_length [, Number hfn ] ] )
// or
new Hazz( [ Number max_input_length [, Number hfn ] ] )
`javascript
/*
* the table containing pseudo-random data for generating hash numbers.
NOTE: the size of the table is: (max_input_length hfn) kilobytes,
* it doesn't depends on the expected population.
*/
Hazz.table
/*
* max input key length
*/
Hazz.ilength
/*
* total number of hash functions
*/
Hazz.hfn
`
> Arguments between [] are optional.
`javascript
/*
* re-fill table with fresh pseudo-random numbers
*/
Hazz#refill() : Hazz
/*
* Specify a positive integer (from 0 to k-1) to use the k-th
* hash function. If specified it returns a number within a
* range.
*
* NOTE:
* - the input should be a Buffer (no Strings or Arrays).
* - the minimum range is obviously 2 (0, 1).
* - the integers produced are at min 4 byte long (>= 2^24),
* longer the input parsed, bigger the numbers produced.
*/
Hazz#do( Number hfn, Buffer data [, Number range ] ) : Number
/*
* hash with all functions in parallel,
* it returns an array of results
*/
Hazz#all( Buffer data [, Number range ] ) : Array
``
> See examples.
> Copyright (c) 2017-present < Guglielmo Ferri : 44gatti@gmail.com >
> Permission is hereby granted, free of charge, to any person obtaining
> a copy of this software and associated documentation files (the
> 'Software'), to deal in the Software without restriction, including
> without limitation the rights to use, copy, modify, merge, publish,
> distribute, sublicense, and/or sell copies of the Software, and to
> permit persons to whom the Software is furnished to do so, subject to
> the following conditions:
> __The above copyright notice and this permission notice shall be
> included in all copies or substantial portions of the Software.__
> THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
> EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
> IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
> CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
> TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
> SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
