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());
?>
apc_store
(PECL apc >= 3.0.0)
apc_store — 変数をデータ領域にキャッシュする
説明
変数をデータ領域にキャッシュします。
注意: PHP の他の多くの仕組みと異なり、apc_store() を用いて格納された変数はリクエストを超えて （その値がキャッシュから取り除かれるまで）持続します。
パラメータ
-
key -
この名前を用いて変数を格納します。
keyは キャッシュ内で一意です。そのため、同一のkeyで新しい値を格納すると、元の値は上書きされます。 -
var -
格納する変数。
-
ttl -
有効期間。
varは、キャッシュにttl秒間だけ格納されます。ttlが経過すると、格納されている変数は （次のリクエスト時に）キャッシュから削除されます。ttlが指定されていない（あるいはttlが0の場合）は、 キャッシュから手動で削除される・あるいはキャッシュに存在できなくなる （clear, restart など）まで値が持続します。 -
values -
名前をキー、変数を値に指定します。
返り値
成功した場合に TRUE を、失敗した場合に FALSE を返します。
二番目の構文は、エラーになったキーを含む配列を返します。
例
例1 A apc_store() の例
<?php
$bar = 'BAR';
apc_store('foo', $bar);
var_dump(apc_fetch('foo'));
?>
上の例の出力は以下となります。
string(3) "BAR"
参考
- apc_add() - 新規の変数をデータ領域にキャッシュする
- apc_fetch() - 格納されている変数をキャッシュから取得する
- apc_delete() - 格納されている変数をキャッシュから取り除く
add a note
User Contributed Notes 15 notes
JaskaS ¶
17 years ago
sebastian at 7val dot com ¶
16 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).
MaxTheDragon at home dot nl ¶
12 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'); // $test equals false.
// at this point, the key no longer exists physically.
?>
Although you could mimic apc_delete with a negative TTL (like when dealing with cookies), note that the difference is that apc_delete actually physically removes the entry.
This example comes in handy when you want to unit-test a class that uses APC. It's faster to use a negative TTL than a positive in combination with a sleep call to test whether the cache entry has actually been deleted. Other than that I can't think of any situations in which you could use this example, but I'm simply pointing out that doing this will not generate Exceptions or errors.
alexey dot maksutov at gmail dot com ¶
11 years ago
APC does serialization/deserialization during store/fetch operations as well as it calls __sleep()/__wakeup(), or Serializable::serialize()/Serializable::unserialize(). Tested on PHP 5.4.1.0.
cycne001 at hotmail dot com ¶
4 years ago
simple implementation with persistence using tmpfs on Linux system
<?php
// Escrito por Renato Martins
define('MYSHM_PATH', "/dev/shm/.php_myshm");
@mkdir(MYSHM_PATH);
function shm_set($key, $val, $ttl = 0) {
$key = md5($key);
if ( $ttl > 0 ) $ttl = time() + $ttl;
return file_put_contents(MYSHM_PATH . "/$key" , serialize([$ttl, $val]) , LOCK_EX);
}
function shm_get($key) {
$key = md5($key);
$f = MYSHM_PATH . "/$key";
$v = unserialize(@file_get_contents($f));
if ( ! $v || ($v[0] > 0 && time() > $v[0]) ) {
@unlink($f);
return null;
}
return $v[1];
}
shm_set('teste', ['a', 222 ,453] , 60);
print_r( shm_get('teste') );
?>
mys5droid at gmail dot com ¶
8 years ago
"Note APC version 3.1.3 there is a bug (http://pecl.php.net/bugs/bug.php?id=16814) that will display a cache slam averted warning for all writes to a cache var that exists. Slam checking can be disabled by setting apc.slam_defense = 0."
This is not a bug. Surprisingly, it has been assigned a bug id.It is obviously not a bug, because there is a man-made error message, as well as a switch to turn off slam checking.
Think about it, would you release code which modifies core system files without warning? No, you would make a warning for the user. Same is true with shared memory.
I happen to think it is a good feature, it tells you are overwriting something... And if you dislike it, turn it off using that setting, or use an @ in front of the function calls...
brunohass2303 at gmail dot com ¶
11 years ago
Functions to update arrays and get the values from an unique key.
<?php
function apc_array_store($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;
}
?>
danil dot gazizov at gmail dot com ¶
12 years ago
Don't save empty arrays and empty values. Sometimes, you can get wrong apc_exists($someKey) result, that this key doesn't exists.
eda-qa at disemia dot com ¶
14 years ago
Note that the TTL only takes effect when you attempt to access the variable again (at least in my version). That is, just issuing a new request to a page won't clear outdated items -- you have to call apc_fetch on that specific item.
If you call apc_info after the TTL of an item it will still be listed.
This is important if you are expecting items to be cleared to conserve memory.
Roberto Spadim ¶
17 years ago
be sure that setting FALSE values can be wrong returned from fetch since fetch return FALSE on errors
php at tequilasolutions dot com ¶
18 years ago
Seems to be no (easy) way at the to know how old a value fetched is and to check whether it is out of date.
I've made these wrappers so that you can fetch and store values based on a udt returned from get_last_modified_date() which should return a udt of when your data was last changed, and hence needs junking out of the cache.
<?php
function apc_fetch_udt($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);
}
?>
Anonymous ¶
11 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
pere dot cil dot remove dot this at wanadoo dot fr ¶
13 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.
Dominik Deobald / Interdose ¶
14 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.
TaRaKa ¶
14 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.
