Package weight computing for Composer

compute.php

<?php

$stable_sort = function(&$array, $picker=null)
{
	static $transform, $restore;

	$i = 0;

	if (!$transform)
	{
		$transform = function(&$v, $k) use (&$i)
		{
			$v = array($v, ++$i, $k, $v);
		};

		$restore = function(&$v, $k)
		{
			$v = $v[3];
		};
	}

	if ($picker)
	{
		array_walk
		(
			$array, function(&$v, $k) use (&$i, $picker)
			{
				$v = array($picker($v), ++$i, $k, $v);
			}
		);
	}
	else
	{
		array_walk($array, $transform);
	}

	asort($array);

	array_walk($array, $restore);
};

/*
 *
 */

$lock = json_decode(file_get_contents('composer.lock'), true);

$packages = array();

foreach ($lock['packages'] as $package)
{
	if (empty($package['require']))
	{
		continue;
	}

	$keys = array_keys($package['require']);
	$packages[$package['name']] = array_combine($keys, $keys);
}

$usage = array_combine(array_keys($packages), array_fill(0, count($packages), 0));

$count_required = function($package_id) use (&$packages, &$count_required)
{
	$i = 0;

	foreach ($packages as $require_id => $require)
	{
		if (empty($require[$package_id]))
		{
			continue;
		}

		$i += 1 + $count_required($require_id);
	}

	return $i;
};

foreach ($usage as $package_id => &$count)
{
	$count = $count_required($package_id);
}

$sorted = $usage;
$stable_sort($sorted);
$sorted = array_reverse($sorted, true);

var_dump($sorted);