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apc_add(3) [php man page]

APC_ADD(3)								 1								APC_ADD(3)

apc_add - Cache a new variable in the data store

SYNOPSIS
bool apc_add (string $key, mixed $var, [int $ttl]) DESCRIPTION
array apc_add (array $values, [mixed $unused = NULL], [int $ttl]) Caches a variable in the data store, only if it's not already stored. Note Unlike many other mechanisms in PHP, variables stored using apc_add(3) will persist between requests (until the value is removed from the cache). PARAMETERS
o $key - Store the variable using this name. $keys are cache-unique, so attempting to use apc_add(3) 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(3) and apc_store(3).) o $var - The variable to store o $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.). o $values - Names in key, variables in value. RETURN VALUES
Returns TRUE if something has effectively been added into the cache, FALSE otherwise. Second syntax returns array with error keys. EXAMPLES
Example #1 A apc_add(3) example <?php $bar = 'BAR'; apc_add('foo', $bar); var_dump(apc_fetch('foo')); echo " "; $bar = 'NEVER GETS SET'; apc_add('foo', $bar); var_dump(apc_fetch('foo')); echo " "; ?> The above example will output: string(3) "BAR" string(3) "BAR" SEE ALSO
apc_store(3), apc_fetch(3), apc_delete(3). PHP Documentation Group APC_ADD(3)

Check Out this Related Man Page

MYSQLND_QC_SET_IS_SELECT(3)						 1					       MYSQLND_QC_SET_IS_SELECT(3)

mysqlnd_qc_set_is_select - Installs a callback which decides whether a statement is cached

SYNOPSIS
mixed mysqlnd_qc_set_is_select (string $callback) DESCRIPTION
Installs a callback which decides whether a statement is cached. There are several ways of hinting PELC/mysqlnd_qc to cache a query. By default, PECL/mysqlnd_qc attempts to cache a if caching of all statements is enabled or the query string begins with a certain SQL hint. The plugin internally calls a function named is_select() to find out. This internal function can be replaced with a user-defined callback. Then, the user-defined callback is responsible to decide whether the plugin attempts to cache a statement. Because the internal function is replaced with the callback, the callback gains full control. The callback is free to ignore the configuration setting mysqlnd_qc.cache_by_default and SQL hints. The callback is invoked for every statement inspected by the plugin. It is given the statements string as a parameter. The callback returns FALSE if the statement shall not be cached. It returns TRUE to make the plugin attempt to cache the statements result set, if any. A so-created cache entry is given the default TTL set with the PHP configuration directive mysqlnd_qc.ttl. If a different TTL shall be used, the callback returns a numeric value to be used as the TTL. The internal is_select function is part of the internal cache storage handler interface. Thus, a user-defined storage handler offers the same capabilities. PARAMETERS
This function has no parameters. RETURN VALUES
Returns TRUE on success or FALSE on failure. EXAMPLES
Example #1 mysqlnd_qc_set_is_select(3) example <?php /* callback which decides if query is cached */ function is_select($query) { static $patterns = array( /* true - use default from mysqlnd_qc.ttl */ "@SELECTs+.*s+FROMs+test@ismU" => true, /* 3 - use TTL = 3 seconds */ "@SELECTs+.*s+FROMs+news@ismU" => 3 ); /* check if query does match pattern */ foreach ($patterns as $pattern => $ttl) { if (preg_match($pattern, $query)) { printf("is_select(%45s): cache ", $query); return $ttl; } } printf("is_select(%45s): do not cache ", $query); return false; } mysqlnd_qc_set_is_select("is_select"); /* Connect, create and populate test table */ $mysqli = new mysqli("host", "user", "password", "schema"); $mysqli->query("DROP TABLE IF EXISTS test"); $mysqli->query("CREATE TABLE test(id INT)"); $mysqli->query("INSERT INTO test(id) VALUES (1), (2), (3)"); /* cache put */ $mysqli->query("SELECT id FROM test WHERE id = 1"); /* cache hit */ $mysqli->query("SELECT id FROM test WHERE id = 1"); /* cache put */ $mysqli->query("SELECT * FROM test"); ?> The above examples will output: is_select( DROP TABLE IF EXISTS test): do not cache is_select( CREATE TABLE test(id INT)): do not cache is_select( INSERT INTO test(id) VALUES (1), (2), (3)): do not cache is_select( SELECT id FROM test WHERE id = 1): cache is_select( SELECT id FROM test WHERE id = 1): cache is_select( SELECT * FROM test): cache SEE ALSO
Runtime configuration, mysqlnd_qc.ttl, mysqlnd_qc.cache_by_default, mysqlnd_qc_set_user_handlers(3). PHP Documentation Group MYSQLND_QC_SET_IS_SELECT(3)
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