キャッシュファイルのディレクトリ分割

<?php
function make_directory_256_level3 ($basedir) {
	for ($i = 0; $i < 256; $i++) {
		$x = sprintf ("%02x", $i);
		for ($j = 0; $j < 256; $j++) {
			$y = sprintf ("%02x", $j);
			for ($k = 0; $k < 256; $k++) {
				$z = sprintf ("%02x", $k);
				$d = "$x/$y/$z";
				$mode = 0777;
				$recursive = true;
				mkdir ($basedir .'/'.$d,
						$mode, $recursive);
			}
		}
	}
}
make_directory_256_level3 ('.');
?>

<?php

$hash = md5 ($url);
$hash_dir = '';
if (preg_match ('/^(..)(..)(..)/', $hash, $match) ) {
	$hash_dir = $match[1] . '/' . $match[2] . '/' . $match[3] . '/';
	$filepath = $api_cache_dir . '/' . $hash_dir . $hash;
}

?>

<?php
function make_directory_256_level2 ($basedir) {
	for ($i = 0; $i < 256; $i++) {
		$x = sprintf ("%02x", $i);
		for ($j = 0; $j < 256; $j++) {
			$y = sprintf ("%02x", $j);
			$d = "$x/$y";
			$mode = 0777;
			$recursive = true;
			mkdir ($basedir .'/'.$d, $mode, $recursive);
			}
		}
	}
}
make_directory_256_level2 ('.');
?>

<?php
$hash = md5 ($url);
$hash_dir = '';
if (preg_match ('/^(..)(..)/', $hash, $match) ) {
	$hash_dir = $match[1] . '/' . $match[2] . '/';
	$filepath = $api_cache_dir . '/' . $hash_dir . $hash;
}
?>