ocramius/lazy-map

A library that provides lazy instantiation logic for a map of objects

Installs: 351 051

Dependents: 4

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Language: PHP

1.0.0 2013-11-09 22:30 UTC

README

This small library aims at providing a very simple and efficient map of lazy-instantiating objects.

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Installation

The suggested installation method is via composer:

php composer.phar require ocramius/lazy-map:1.0.*

Usage

The current implementation is very simple and allows to define a map of "services" through a LazyMap\CallbackMap:

$map = new \LazyMap\CallbackLazyMap(function ($name) {
    $object = new \stdClass();

    $object->name = $name;

    return $object;
});

var_dump($map->foo);
var_dump($map->bar);
var_dump($map->{'something special'});

Purpose

The idea behind the library is to avoid un-efficient lazy-loading operations like following:

private function getSomething($name)
{
    if (isset($this->initialized[$name]) || array_key_exists($name, $this->initialized)) {
        return $this->initialized[$name];
    }

    return $this->initialized[$name] = new Something($name);
}

This reduces overhead greatly when you'd otherwise call getSomething() thousands of times. That's especially useful when mapping a lot of different services and iterating over them over and over again.

Performance

LazyMap actually performs much better than the "un-efficient" example that I've shown above. You can look directly at the performance test suite for details on the tested implementations, but here are some results for you to have an idea of the boost:

Initialized Map Performance: Method Name Ops/s Relative initializedArrayPerformance 2,277,272.90002 100.00% initializedArrayMapPerformance 1,536,988.76108 148.16% initializedLazyMapPerformance 4,446,227.23514 51.22% Un-Initialized Map Performance: Method Name Ops/s Relative unInitializedArrayPerformance : 1,091,720.80627 100.00% unInitializedArrayMapPerformance 688,132.30083 158.65% unInitializedLazyMapPerformance: 912,191.90744 119.68%