apc_add

(PECL apc >= 3.0.13)

apc_add — Cache a new variable in the data store

Opis

apc_add ( string $key , mixed $var [, int $ttl = 0 ] ) : bool

apc_add ( array $values [, mixed $unused = NULL [, int $ttl = 0 ]] ) : array

Caches a variable in the data store, only if it's not already stored.

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

Parametry

key: Store the variable using this name. keys are cache-unique, so attempting to use apc_add() to store data with a key that already exists will not overwrite the existing data, and will instead return FALSE. (This is the only difference between apc_add() and apc_store().)
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.

Zwracane wartości

Returns TRUE if something has effectively been added into the cache, FALSE otherwise. Second syntax returns array with error keys.

Przykłady

Przykład #1 A apc_add() example


<?php
$bar = 'BAR';
apc_add('foo', $bar);
var_dump(apc_fetch('foo'));
echo "\n";
$bar = 'NEVER GETS SET';
apc_add('foo', $bar);
var_dump(apc_fetch('foo'));
echo "\n";
?>

Powyższy przykład wyświetli:

string(3) "BAR"
string(3) "BAR"

Zobacz też:

apc_store() - Cache a 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 1 note

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liv_romania at yahoo dot com ¶

8 years ago


In order to understand better how APC caching works you can do the following:

1. Restart web server (Apache or Nginx)

2. Create file "apc_fetch.php":
<?php
var_dump(apc_fetch(array(
    'CUR_DATE_5s_1',
    'CUR_DATE_5s_2',
    'CUR_DATE_5s_3',
    'CUR_DATE_0s_1',
    'CUR_DATE_0s_2',
    'CUR_DATE_0s_3',
)));
?>

3. Create file "apc_add.php":
<?php
$ttl = 5;

$key = 'CUR_DATE_5s_1';
$var = date('c');
$result = apc_add($key, $var, $ttl);
var_dump($result);
echo "\n";

$var = date('c');
$result = apc_add($key, $var, $ttl);
var_dump($result);
echo "\n";

$key = 'CUR_DATE_0s_1';
$var = date('c');
$result = apc_add($key, $var);
var_dump($result);
echo "\n";

$values = array(
    'CUR_DATE_5s_2' => date('c'),
    'CUR_DATE_5s_3' => rand(),
);
$result = apc_add($values, null, $ttl);
var_dump($result);
echo "\n";

$values = array(
    'CUR_DATE_0s_2' => date('c'),
    'CUR_DATE_0s_3' => rand(),
);
$result = apc_add($values, null);
var_dump($result);
?>

4. Run "apc_fetch.php" and "apc_add.php" several times in order to see the persistent result and how values change from one request to another.

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