PHP 5.4.31 Released

apc_store

(PECL apc >= 3.0.0)

apc_store Cache a variable in the data store

Descrizione

bool apc_store ( string $key , mixed $var [, int $ttl = 0 ] )
array apc_store ( array $values [, mixed $unused = NULL [, int $ttl = 0 ]] )

Cache a variable in the data store.

Nota: Unlike many other mechanisms in PHP, variables stored using apc_store() will persist between requests (until the value is removed from the cache).

Elenco dei parametri

key

Store the variable using this name. keys are cache-unique, so storing a second value with the same key will overwrite the original value.

var

The variable to store

ttl

Time To Live; store var in the cache for ttl seconds. After the ttl has passed, the stored variable will be expunged from the cache (on the next request). If no ttl is supplied (or if the ttl is 0), the value will persist until it is removed from the cache manually, or otherwise fails to exist in the cache (clear, restart, etc.).

values

Names in key, variables in value.

Valori restituiti

Restituisce TRUE in caso di successo, FALSE in caso di fallimento. Second syntax returns array with error keys.

Esempi

Example #1 A apc_store() example

<?php
$bar 
'BAR';
apc_store('foo'$bar);
var_dump(apc_fetch('foo'));
?>

Il precedente esempio visualizzerà:

string(3) "BAR"

Vedere anche:

  • apc_add() - Cache a new variable in the data store
  • apc_fetch() - Fetch a stored variable from the cache
  • apc_delete() - Removes a stored variable from the cache

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User Contributed Notes 13 notes

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6
JaskaS
7 years ago
if you want to store array of objects in apc use ArrayObject wrapper (PHP5).

<?php
$objs
= array();
$objs[] = new TestClass();
$objs[] = new TestClass();
$objs[] = new TestClass();

//Doesn't work
apc_store('objs',$objs,60);
$tmp = apc_fetch('objs');
print_r($tmp);

//Works
apc_store('objs',new ArrayObject($objs),60);
$tmp = apc_fetch('objs');
print_r($tmp->getArrayCopy());

?>
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3
php at tequilasolutions dot com
7 years ago
Seems to be no (easy) way at the to know how old a value fetched is and to check whether it is out of date.

I've made these wrappers so that you can fetch and store values based on a udt returned from get_last_modified_date() which should return a udt of when your data was last changed, and hence needs junking out of the cache.

<?php
function apc_fetch_udt($key){
   
$g = apc_fetch($key);
    if (
$g){
        list(
$udt,$val) = $g;
        if (
get_last_modified_date()<$udt) {
           
$val = unserialize($val);
            return
$val;
        } else {
           
apc_delete($key);
        }
    }
}
function
apc_store_udt($key,$g){
   
$udt = time();
   
$g   = serialize($g);
   
$apc = array($udt,$g);
   
apc_store($key, $apc);
}
?>
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2
TaRaKa
3 years ago
Note APC version 3.1.3 there is a bug (http://pecl.php.net/bugs/bug.php?id=16814) that will display a cache slam averted warning for all writes to a cache var that exists. Slam checking can be disabled by setting apc.slam_defense = 0.
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1
pere dot cil dot remove dot this at wanadoo dot fr
2 years ago
Note that caching resources is not possible; even if the apc cache doesn't seems to call the serialize / unserialize functions, that doesn't means that resources can be cached!

Small non-working example:

<?php
// Setter code
$r = fopen( '/tmp/test.txt', 'r' );
var_dump( $r );
apc_store( 'test', $r );
?>

<?php
// Getter code
$d = apc_fetch( 'test' );
var_dump( $d );
echo
fread( $d, 1024 );
?>

var_dump( $d ) returns Resource #n of type (Unknown). The resource is still here, but unavailable.
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0
brunohass2303 at gmail dot com
1 year ago
Functions to update arrays and get the values from an unique key.

<?php

function apc_array_store($apc_var, $key, $valor)
{
   
$apcTemp = array();
   
    if (
$valor == NULL ) return FALSE;
   
    if (
$apcTemp = apc_fetch($apc_var) ) // Verifica se a variavel $apc_var existe no cache APC
   
{ // Se existir
       
if ( !array_key_exists($apcTemp, $key) ) // Verifica se a chave $key existe no array
           
$apcTemp[$key] = $valor; // Se $valor não for NULL, adiciona no array
       
       
if ( apc_store("$apc_var", $apcTemp) ) // Tenta atualizar o array no cache
            
return TRUE;
        else return
FALSE;
    }
    else
    {
// Se a variavel $apc_var nao existir no cache adiciona
       
if ( $valor == NULL ) // Se $valor for NULL retorna FALSE
           
return FALSE;
        else
        {   
// Se $valor não for NULL, cria o array
           
$apcTemp[$key] = $valor;
           
            if (
apc_add("$apc_var", $apcTemp) ) // Tenta adicionar o array no cache
                
return TRUE;
            else return
FALSE;
        }
    }
   
}

function
apc_array_fetch($apc_var, $key)
{

    if (
$apcTemp = apc_fetch($apc_var) ) // Verifica se a variavel $apc_var existe no cache APC
   
{ // Se existir
       
if ( !array_key_exists($apcTemp, $key) ) // Verifica se a chave $key existe no array
               
return FALSE; // Se não existir retorna FALSE
           
else
                return
$apcTemp[$key]; // Se existir retorna o valor
   
}
    else
// Se não existir
       
return FALSE;
   
}

?>
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0
alexey dot maksutov at gmail dot com
1 year ago
APC does serialization/deserialization during store/fetch operations as well as it calls __sleep()/__wakeup(), or Serializable::serialize()/Serializable::unserialize(). Tested on PHP 5.4.1.0.
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0
MaxTheDragon at home dot nl
1 year ago
When specifying a ttl (Time-To-Live), you are allowed to use negative values. This causes a stored entry to be invalidated immediately, but note that it will not physically be removed until you read (eg. apc_fetch or apc_exists) it:

<?php
apc_store
('testKey', 'testValue', -1); // ... or any negative integer.

// at this point, the key exists physically but is already technically invalidated by the ttl.

$test = apc_fetch('testKey'); // $test equals false.

// at this point, the key no longer exists physically.
?>

Although you could mimic apc_delete with a negative TTL (like when dealing with cookies), note that the difference is that apc_delete actually physically removes the entry.

This example comes in handy when you want to unit-test a class that uses APC. It's faster to use a negative TTL than a positive in combination with a sleep call to test whether the cache entry has actually been deleted. Other than that I can't think of any situations in which you could use this example, but I'm simply pointing out that doing this will not generate Exceptions or errors.
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0
danil dot gazizov at gmail dot com
2 years ago
Don't save empty arrays and empty values. Sometimes, you can get wrong apc_exists($someKey) result, that this key doesn't exists.
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0
Dominik Deobald / Interdose
3 years ago
It might be interesting to note that storing an object in the cache does not serialize the object, i.e. does not call the __sleep()/__wakeup() or serialize()/unserialize() methods.
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0
eda-qa at disemia dot com
4 years ago
Note that the TTL only takes effect when you attempt to access the variable again (at least in my version).  That is, just issuing a new request to a page won't clear outdated items -- you have to call apc_fetch on that specific item.

If you call apc_info after the TTL of an item it will still be listed.

This is important if you are expecting items to be cleared to conserve memory.
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0
sebastian at 7val dot com
6 years ago
Note that since APC 3.0.15 or 3.0.16, the time-to-live-feature does not work within the same request (see http://pecl.php.net/bugs/bug.php?id=13331).
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0
Roberto Spadim
7 years ago
be sure that setting FALSE values can be wrong returned from fetch since fetch return FALSE on errors
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