rootslab / toni Goto Github PK

Toni, a simple and efficient bitmap implementation for positive integer sets (max 32 bits), with no element repetition, using bitwise operations and a Buffer.

Modifying a single bit instead of an entire byte, to signal item presence in the current set, obviously saves 87.5% of Buffer space.

See BitArray.

$ npm install toni [-g]

require:

var Toni = require( 'toni' );

to run all test files, install devDependencies:

 $ cd toni/
 # install or update devDependencies
 $ npm install 
 # run tests
 $ npm test

run benchmarks for Toni.

$ cd toni/
$ npm run bench

minimun range is 1 item/bit, max is 2^32 (from 1 to 4 bytes).

Toni( Number range )
// or
new Toni( Number range )

 /*
  * the bitmap buffer.
  */
 Toni.bitmap : Buffer

 /*
  * max range for values (from 0 to range - 1).
  */
 Toni.range : Number

 /*
  * current items in the set.
  */
 Toni.items : Number

/*
  * a shortcut for the bitmap buffer length.
  */
 Toni.bmlen : Number

Arguments within [ ] are optional.

/*
 * Clear the bitmap / set (filling with 0's).
 */
Toni#clear : function () : Toni

/*
 * Check for item presence in the set.
 * It returns 1 if item is present, 0 otherwise.
 */
Toni#chk : function ( Number value ) : Number

/*
 * Add an integer value to the set and test item/value presence in the set.
 * When the value is out of range, or if the element is already present, the
 * operation fails and it returns -1.
 *
 */
Toni#add : function ( Number value ) : Number

/*
 * Remove an integer value from the set and test item/value presence in the set.
 * When the value is out of range, or if the element is not in the set,
 * the operation fails and it returns -1.
 */
Toni#del : function ( Number value ) : Number

/*
 * It returns the occurrences of bit 1 until index i, then the total
 * number of 0s = index - rank( index ), if index is into the current
 * range, otherwise it returns -1
 */
Toni#rank : function ( Number index ) : Number

Copyright (c) 2014-present < Guglielmo Ferri : [email protected] >

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.