(PECL apc >= 3.0.0)
apc_fetch — Fetch a stored variable from the cache
Fetchs a stored variable from the cache.
The key used to store the value (with apc_store()). If an array is passed then each element is fetched and returned.
Set to TRUE in success and FALSE in failure.
The stored variable or array of variables on success; FALSE on failure
Beispiel #1 A apc_fetch() example
$bar = 'BAR';
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
|3.0.17||The success parameter was added.|
Another reason you might be getting null back from apc_fetch when using apc.rfc1867 is if you have only turned this option on using php_admin_value for a virtual host. It needs to be turned on globally in php.ini to work.
Anyone who has enabled apc.rfc1867 for a file upload progress bar. Please note that if you are not getting any results back or a Null() data set. Then set apc.rfc1867_freq to 10k or 100k or whatever you see fit like this.
apc.rfc1867_freq = 10k
In your php.ini.
Hope this helps some of you who were getting blank data results. It seems the 0 default setting will not work on some machines. Hope this helps!
Just to clarify the multi-get capability, the result is returned as an array with cache keys as the array keys. Any missing values re not returned, for example:
$cached = apc_fetch(array('test1', 'test2'));
If no keys are found, you get an empty array.
This function is often cited related to file upload tracking with PHP 5.2. So I thought this is a good place to put a warning.
If you setup PHP with FastCGI, you'll probably run into trouble using this function to get any information about a running upload. At least in my case, every HTTP request is handled by a different PHP process. I could track it with the getmypid() function, which returned a different value upon every request, but only from a limited set. Also, apc_cache_info() gave me all upload_* entries that were created in that process. So when the upload was initially catched by one PHP process, all progress updates must be fetched from the same process, too, because APC cache information does not seem to be shared across multiple processes handling that domain/virtual host. But that's impossible to tell because PHP has its own load management and serves every request by an arbitrary process.
So in short: When using FastCGI and multiple PHP processes (recommended for performance reasons), you cannot use APC upload tracking. You'll only get a status update every few requests.
As of version 3.0.13 APC (released 2007-02-24) you can perform multiple key fetches with apc_fetch. Very useful to further optimize your application!
$keys = array('key1','key2');
$result = apc_fetch($keys); //fetch multiple keys at once!