Forgetting map

A fixed size prioritised hash table, optimised for lookup.

Implemented in Python 3 and Javascript

Python

Install

$ git clone https://github.com/cob16/forgetting_hash_map
$ cd forgetting_hash_map
$ pip install .

Test

$ git clone https://github.com/cob16/forgetting_hash_map
$ cd forgetting_hash_map
$ pip install -e .[test]
$ nosetests

Usage

from forgetting_hash_map import ForgettingHash

# 2 is number is the max size the hash should be
fh = ForgettingHash(2)
# or add exsting elements
fh = ForgettingHash(2, {'one': 'foo', 'two': 'bar'})

# Returns the 'one' key
fh.find('one')

# This will add the one key and remove the two key as it was the least used
fh.add('three')

Javascript

Written in Babel for ES6 support. To change transpilation settings, see .babelrc.

Install

$ git clone https://github.com/cob16/forgetting_hash_map
$ cd forgetting_hash_map
$ npm install

Test

$ git clone https://github.com/cob16/forgetting_hash_map
$ cd forgetting_hash_map
$ npm install
$ npm run test

Altrenatively, use npm run ci in your CI builds to produce code coverage and test result reports

Usage

import ForgettinghMap from 'src/forgettingMap.js';

const mapSize = 2;
let map = new ForgettingMap(mapSize);

map.addItem('key', 'value');

let item = map.findItem('key');
/**
 * item = {
 *   key: 'key',
 *   value: 'value,
 *   findCount: 1'
 * }
 */

map.addItem('lessUsedKey', 'lessUsedValue');
let evicted = map.addItem('newerKey', 'newerValue');
/**
 * evicted = {
 *   key: 'lessUsedKey',
 *   value: 'lessUsedValue',
 *   findCount: 0
 * }
 */