apcu_entry
Atomically fetch or generate a cache entry
Description
mixed apcu_entry(string $key, callable $generator, int $ttl = 0)
Note:
When control enters apcu_entry the lock for the cache is acquired exclusively, it is released when control leaves apcu_entry:
In effect, this turns the body of generator into a critical section, disallowing two processes from executing the same code paths concurrently.
In addition, it prohibits the concurrent execution of any other APCu functions, since they will acquire the same lock.
Warning
The only APCu function that can be called safely by generator is apcu_entry.
Parameters
-
key
-
Identity of cache entry
-
generator
-
A callable that accepts key as the only argument and returns the value to cache.
-
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.).
Return Values
Returns the cached value
Examples
Example #1 An apcu_entry example
<?php
$config = apcu_entry("config", function($key) {
return [
"fruit" => apcu_entry("config.fruit", function($key){
return [
"apples",
"pears"
];
}),
"people" => apcu_entry("config.people", function($key){
return [
"bob",
"joe",
"niki"
];
})
];
});
var_dump($config);
?>
The above example will output:
array(2) {
["fruit"]=>
array(2) {
[0]=>
string(6) "apples"
[1]=>
string(5) "pears"
}
["people"]=>
array(3) {
[0]=>
string(3) "bob"
[1]=>
string(3) "joe"
[2]=>
string(4) "niki"
}
}
See Also
- apcu_store
- apcu_fetch
- apcu_delete