PHP Conference China 2020


(PECL apc >= 3.0.0)

apc_fetch Выбрать сохраненную переменную из кеша


apc_fetch ( mixed $key [, bool &$success ] ) : mixed

Выбирает сохраненную переменную из кеша.

Список параметров


key используемый для хранения значения (apc_store()). Если передан массив, то каждый элемент будет извлечён и возвращён.


Устанавливается в TRUE, в случае успеха, или FALSE, в случае неудачи.

Возвращаемые значения

Сохраненная переменная или массив переменных. В случае неудачи FALSE


Пример #1 Пример использования apc_fetch()


Результат выполнения данного примера:

string(3) "BAR"

Список изменений

Версия Описание
3.0.17 Был добавлен параметр success.

Смотрите также

  • apc_store() - Кешировать переменную в хранилище данных
  • apc_delete() - Удалить сохраненную переменную из кеша
  • APCIterator

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User Contributed Notes 10 notes

8 years ago
Note that the APC cache accessible from PHP running through Apache is not accessible from CLI-PHP (the commandline PHP version). They are 2 different APC caches.

If you are trying for example to run a script from cron that needs to access the same APC cache as your scripts (executed through Apache) with PHP CLI, use file_get_contents to execute the real script or to send over the data.
Doing so executes the script on Apache.
You can also specify a return value in order to move data around.

marcus at synchromedia dot co dot uk
12 years ago
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:

apc_add('test1', 'test1');
$cached = apc_fetch(array('test1', 'test2'));


array(1) {
  string(5) "test1"

If no keys are found, you get an empty array.
7 years ago
Make sure to check the return value using a strict comparison if you want to know whether apc_fetch failed unless you want anything stored that can be evaluated to false to report an error aswell.

E.g. the following is bad:


= apc_fetch("key");

$result) {
//handle error


If key is an empty array or the value 0, it will naturally evaluate to false and trigger the error. To avoid this, do instead:


= apc_fetch("key");

$result === false) {
//handle error


Side note: avoid storing booleans in APC :)
5 years ago
hint for your fail over:

"return FALSE on failure" means NOT, it returns FALSE on APC-error.
it return FALSE if
- key doesnt exists
- value === FALSE
- APC error

even with $success you cant determine if its a APC-error. this is only for key exists / key doesnt exists things.
nospam dot list at unclassified dot de
12 years ago
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.
aktharmiah at gmail dot com
6 years ago
Note apc_fetch() will return a copy of whatever is stored in the memory and not a reference to it.

For example:

class foo{

apc_add("foo",  new foo());
$fooGot    =    apc_fetch("foo");
$fooGot->bar = 1234;   

will print

foo Object ( [bar] => )
10 years ago
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.
chris at active9 dot com
11 years ago
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!
thijsterlouw at gmail dot com_remove_this
13 years ago
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!
APC changelog:


('key1', 'value1');
apc_store('key2', 'value2');

$keys = array('key1','key2');
$result = apc_fetch($keys);  //fetch multiple keys at once!

zim32 at ukr dot net
8 years ago
I dont know is it a bug or feature but...
After apc_fetch and/or apc_store arrays loose their cursor

= array('foo',2,3,4,5);
var_dump(current($array)); //foo
$array2 = apc_fetch('foo');
var_dump(current($array2)); //false
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