apc_store
(PECL apc >= 3.0.0)
apc_store — Cache a variable in the data store
说明
apc_store ( string$key
, mixed $var
[, int $ttl = 0
] ) : bool
apc_store
( array $values
[, mixed $unused = NULL
[, int $ttl = 0
]] ) : array
缓å˜ä¸€ä¸ªå˜é‡åˆ°APCä¸
Note: 与PHPä¸å…¶ä»–的机制ä¸åŒï¼Œä½¿ç”¨apc_store() å˜å‚¨çš„å˜é‡ 在ä¸åŒçš„请求之间一直æŒä¹…å˜åœ¨ï¼ˆç›´åˆ°ä»Žç¼“å˜ç³»ç»Ÿä¸ç§»é™¤ï¼‰ã€‚
å‚æ•°
key
å˜å‚¨ç¼“å˜å˜é‡ä½¿ç”¨çš„å称.key是唯一的，所以
两个值使用åŒä¸€ä¸ª key，原æ¥çš„将被新的值覆盖。
var
The variable to store
ttl
生å˜æ—¶é—´;在缓å˜ä¸å˜å‚¨varå…±ttl秒,
在ttl秒过去åŽ,å˜å‚¨çš„å˜é‡å°†ä¼šä»Žç¼“å˜ä¸æ“¦é™¤(在下一次请求时),
如果没有设置ttl(或者ttl是0),
å˜é‡å°†ä¸€ç›´å˜æ´»åˆ°è¢«æ‰‹åŠ¨ç§»é™¤ä¸ºæ¢,除æ¤ä¹‹å¤–ä¸åœ¨ç¼“å˜ä¸çš„å¯èƒ½åŽŸå› 是，
缓å˜ç³»ç»Ÿä½¿ç”¨clear，或者restartç‰ã€‚
values
Names in key, variables in value.
返回值
æˆåŠŸæ—¶è¿”回 TRUE， 或者在失败时返回 FALSE。
Second syntax returns array with error keys.
范例
Example #1 apc_store() 例å
<?php
$bar = 'BAR';
apc_store('foo', $bar);
var_dump(apc_fetch('foo'));
?>
以上例程会输出：
string(3) "BAR"
å‚è§
apc_add() - 缓å˜ä¸€ä¸ªå˜é‡åˆ°æ•°æ®å˜å‚¨ apc_fetch() - 从缓å˜ä¸å–出å˜å‚¨çš„å˜é‡ apc_delete() - 从用户缓å˜ä¸åˆ 除æŸä¸ªå˜é‡
User Contributed Notes 14 notes
up down 18 JaskaS ¶12 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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5
alexey dot maksutov at gmail dot com ¶6 years 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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MaxTheDragon at home dot nl ¶6 years 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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sebastian at 7val dot com ¶11 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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mys5droid at gmail dot com ¶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."
This is not a bug. Surprisingly, it has been assigned a bug id.It is obviously not a bug, because there is a man-made error message, as well as a switch to turn off slam checking.
Think about it, would you release code which modifies core system files without warning? No, you would make a warning for the user. Same is true with shared memory.
I happen to think it is a good feature, it tells you are overwriting something... And if you dislike it, turn it off using that setting, or use an @ in front of the function calls...
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Anonymous ¶6 years ago
Interesting info to read before apc_store() implementation:
http://stackoverflow.com/questions/10494744/deadlock-with-apc-exists-apc-add-apc-php
http://stackoverflow.com/questions/4468805/apc-values-randomly-disappear/4532905#4532905
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danil dot gazizov at gmail dot com ¶7 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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eda-qa at disemia dot com ¶9 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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-1
brunohass2303 at gmail dot com ¶6 years 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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Roberto Spadim ¶12 years ago
be sure that setting FALSE values can be wrong returned from fetch since fetch return FALSE on errors
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php at tequilasolutions dot com ¶12 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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pere dot cil dot remove dot this at wanadoo dot fr ¶7 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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Dominik Deobald / Interdose ¶8 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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TaRaKa ¶8 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.
add a note
官方地址：https://www.php.net/manual/en/function.apc-store.php