APC replacement functions for code using apc_* user based caching functions for servers running PHP 5.5 (where APC is no longer supported) or where APC is otherwise not installed. Stores data in file based cache files.

apc_overloads.php

<?php
/*

APC replacement functions

Replaces APC user cache functionality with file based caching.

Notes:
- cache files stored in result of sys_get_temp_dir()
- ttl not supported, cache files must be cleaned up manually

*/

if (!function_exists('apc_fetch')) {
function apc_fetch($key, &$success = true) {
	if (!($filename = apc_get_tmpfile($key, $f))) {
		return false;
	}

	$size = filesize($filename);
	if ($size == 0) {
		return false;
	}

	if (!($d = fread($f, $size))) {
		$success = false;
		return false;
	}

	fclose($f);

	if (!($unserialized_d = unserialize($d))) {
		$success = false;
		return false;
	}

	return $unserialized_d;
}
}

if (!function_exists('apc_store')) {
function apc_store($key, $var, $ttl = 0) {
	if (!($filename = apc_get_tmpfile($key, $f))) {
		return false;
	}

	if (!($serialized_d = serialize($var))) {
		return false;
	}

	if (!ftruncate($f, filesize($filename))) {
		return false;
	}

	if (!fwrite($f, $serialized_d)) {
		return false;
	}

	fclose($f);
	clearstatcache($true, $filename);

	return true;
}
}

if (!function_exists('apc_add')) {
function apc_add($key, $var, $ttl = 0) {
	if (!($filename = apc_get_tmpfile($key, $f))) {
		return false;
	}

	$size = filesize($filename);
	if ($size != 0) {
		// cache data already exists, don't overwrite
		return false;
	}
	return apc_store($key, $var, $ttl);
}
}

if (!function_exists('apc_delete')) {
function apc_delete($key) {
	if (!($filename = apc_get_tmpfile($key, $f))) {
		return false;
	}

	$success = unlink($filename);
	clearstatcache($true, $filename);

	return $success;
}
}

function apc_get_tmpfile($name, &$f) {
	$tmpdir = sys_get_temp_dir();

	if (!($f = fopen($tmpdir . '/' . $name, 'c+'))) {
		return false;
	}

	return $tmpdir . '/' . $name;
}

apc_test.php

<pre>
<?php

include 'apc_overloads.php';

function runtest($key, $value, $ttl) {
	$dumpval = (bool)(isset($_GET['dump']) ? $_GET['dump'] : false);

	echo "-- Testing type: " . gettype($value) . " --\n";

	$result = apc_store($key, $value, $ttl);
	echo "apc_store result: " . ($result ? 'pass' : 'fail') . "\n";
	if ($dumpval) var_dump($key, $value);

	$test = apc_fetch($key);
	echo "apc_fetch result: " . ($test == $value ? 'pass' : 'fail') . "\n";
	if ($dumpval) var_dump($key, $value);

	$result = apc_add($key, $value, $ttl);
	echo "apc_add result - data exists: " . ($result ? 'fail' : 'pass') . "\n";
	if ($dumpval) var_dump($key, $value);

	$result = apc_delete($key);
	echo "apc_delete result: " . ($result ? 'pass' : 'fail') . "\n";
	if ($dumpval) var_dump($key);

	$result = apc_add($key, $value);
	echo "apc_add result - data previously deleted: " . ($result ? 'pass' : 'fail') . "\n";
	if ($dumpval) var_dump($key, $value);

	$result = apc_delete($key);
	echo "apc_delete result: " . ($result ? 'pass' : 'fail - cache data not cleaned up') . "\n";
	if ($dumpval) var_dump($key);

	echo "\n";
}

$key = 'test-data';
$value = 123456789;
$ttl = 1234;
runtest($key, $value, $ttl);

$key = 'test-data';
$value = '*** test string ***';
$ttl = 1234;
runtest($key, $value, $ttl);

$key = 'test-data';
$value = array(
	'test-int' => 123456789,
	'test-string' => '*** test data ***',
);
$ttl = 1234;
runtest($key, $value, $ttl);
?>
</pre>