apcu_sma_info - PHP code example

What is a Function in PHP?

A function is a block of code that can be used repeatedly in a program. It takes input in the form of a parameter list and returns a value. PHP has over 1000 built-in functions that can be called from within a script to perform a specific task.

Functions are a powerful programming tool that can help you create your own programs quickly and easily. Whether you need to create a simple math function or a complex array manipulation function, there is probably a built-in function that can do the job for you.

In addition, PHP supports a number of other functions that can be used to perform different tasks. For example, there are array functions that can sort, find, or return the elements of an array; and recursive functions that can be used to iterate over a set of items. There are also functions to help with internationalization and other miscellaneous tasks.

Depending on the data type of a variable, PHP either passes it by value or by reference. Passing a variable by reference causes a new entry to be added to the PHP symbol table which references an internal data structure that contains the variable's value. This means that the same variable can be accessed inside and outside of a function, just like a global variable.

Prior to PHP 8.0, there were two restrictions on private methods in extending classes: they could not be declared final and they could not be made static. These restrictions have been removed in PHP 8.0.

apcu_sma_info example

    public function getConfigCacheInfo()
    {
        $backendCache = $this->cache->getBackend();

        if ($backendCache instanceof Zend_Cache_Backend_Apcu) {
            $info = [];
            $apcInfo = apcu_cache_info('user');
            $info['files'] = $apcInfo['num_entries'];
            $info['size'] = $this->encodeSize($apcInfo['mem_size']);
            $apcInfo = apcu_sma_info();
            $info['freeSpace'] = $this->encodeSize($apcInfo['avail_mem']);
        } elseif ($backendCache instanceof Zend_Cache_Backend_Redis) {
            $info = [];

            /** @var Redis $redis */
            $redis = $backendCache->getRedis();
            $info['files'] = $redis->dbSize();
            $info['size'] = $this->encodeSize($redis->info()['used_memory']);
        } else {
            $dir = null;

return false;
    }

    /** * Return the filling percentage of the backend storage * * @throws Zend_Cache_Exception * @return int integer between 0 and 100 */
    public function getFillingPercentage()
    {
        $mem = apcu_sma_info(true);
        $memSize    = $mem['num_seg'] * $mem['seg_size'];
        $memAvailable= $mem['avail_mem'];
        $memUsed = $memSize - $memAvailable;
        if ($memSize == 0) {
            Zend_Cache::throwException('can\'t get apcu memory size');
        }
        if ($memUsed > $memSize) {
            return 100;
        }
        return ((int) (100. * ($memUsed / $memSize)));
    }