PHP 5.4.31 Released

apc_define_constants

(PECL apc >= 3.0.0)

apc_define_constants Defines a set of constants for retrieval and mass-definition

Beschreibung

bool apc_define_constants ( string $key , array $constants [, bool $case_sensitive = true ] )

define() is notoriously slow. Since the main benefit of APC is to increase the performance of scripts/applications, this mechanism is provided to streamline the process of mass constant definition. However, this function does not perform as well as anticipated.

For a better-performing solution, try the » hidef extension from PECL.

Hinweis: To remove a set of stored constants (without clearing the entire cache), an empty array may be passed as the constants parameter, effectively clearing the stored value(s).

Parameter-Liste

key

The key serves as the name of the constant set being stored. This key is used to retrieve the stored constants in apc_load_constants().

constants

An associative array of constant_name => value pairs. The constant_name must follow the normal constant naming rules. value must evaluate to a scalar value.

case_sensitive

The default behaviour for constants is to be declared case-sensitive; i.e. CONSTANT and Constant represent different values. If this parameter evaluates to FALSE the constants will be declared as case-insensitive symbols.

Rückgabewerte

Gibt bei Erfolg TRUE zurück. Im Fehlerfall wird FALSE zurückgegeben.

Beispiele

Beispiel #1 apc_define_constants() example

<?php
$constants 
= array(
    
'ONE'   => 1,
    
'TWO'   => 2,
    
'THREE' => 3,
);
apc_define_constants('numbers'$constants);
echo 
ONETWOTHREE;
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

123

Siehe auch

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User Contributed Notes 2 notes

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0
jmucchiello AT yahoooooooo DOT com
4 years ago
It doesn't introduce much overhead if you make use of conditional function definitions:

<?php
if (function_exists('apc_load_constants')) {
    function
define_array($key, $arr, $case_sensitive = true)
    {
        if (!
apc_load_constants($key, $case_sensitive)) {
           
apc_define_constants($key, $arr, $case_sensitive);
        }
    }
} else {
    function
define_array($key, $arr, $case_sensitive = true)
    {
        foreach (
$arr as $name => $value)
           
define($name, $value, $case_sensitive);
    }
}

//in your code you just write something like this:

define_array('NUMBERS', Array('ONE' => 1, 'TWO' => 2, 'THREE' => 3));
?>
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0
webmaster at thedigitalorchard dot ca
4 years ago
An observation that I've made is that the nature of apc_define_constants() binding the list of constants to a key and then requiring that key to load the constants is limiting. Furthermore, there's no way to append additional constants to a given key.

A solution that I've been adopting is to build a list of constants to be defined, and then do one of two things:

1) if APC is enabled, then use apc_define_constants();
2) ...else loop through the list and define each constant normally.

The problem I've run into is when this process happens at different places in a large application, it can introduce overhead that otherwise wouldn't be there if it was possible to append to an existing list of defined constants in APC.
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