Adds a variable in user cache only if variable does not already exist in the cache

wincache_scache_meminfo
wincache_ucache_cas
WinCache Functions
PHP Manual

# wincache_ucache_add

(PECL wincache >= 1.1.0)

wincache_ucache_add — Adds a variable in user cache only if variable does not already exist in the cache

### Description

bool wincache_ucache_add ( string `$key` , mixed `$value` [, int `$ttl` = 0 ] )
bool wincache_ucache_add ( array `$values` [, mixed `$unused` [, int `$ttl` = 0 ]] )

Adds a variable in user cache, only if this variable doesn't already exist in the cache. The added variable remains in the user cache unless its time to live expires or it is deleted by using wincache_ucache_delete() or wincache_ucache_clear() functions.

### Parameters

`key`

  Store the variable using this `key` name. If a variable with same key is already present the function will fail and return `FALSE`. `key` is case sensitive. To override the value even if `key` is present use wincache_ucache_set() function instad. `key` can also take array of name => value pairs where names will be used as keys. This can be used to add multiple values in the cache in one operation, thus avoiding race condition.

`value`

  Value of a variable to store. `Value` supports all data types except resources, such as file handles. This paramter is ignored if first argument is an array. A general guidance is to pass `NULL` as `value` while using array as `key`. If `value` is an object, or an array containing objects, then the objects will be serialized. See __sleep() for details on serializing objects.

`values`

  Associative array of keys and values.

`ttl`

  Time for the variable to live in the cache in seconds. After the value specified in `ttl` has passed the stored variable will be deleted from the cache. This parameter takes a default value of 0 which means the variable will stay in the cache unless explicitly deleted by using wincache_ucache_delete() or wincache_ucache_clear() functions.

### Return Values

If `key` is string, the function returns `TRUE` on success and `FALSE` on failure.

If `key` is an array, the function returns:

- If all the name => value pairs in the array can be set, function returns an empty array;
- If all the name => value pairs in the array cannot be set, function returns `FALSE`;
- If some can be set while others cannot, function returns an array with name=>value pair for which the addition failed in the user cache.

### Examples

Example #1 wincache_ucache_add() with `key` as a string

`<?php
$bar = 'BAR';
var_dump(wincache_ucache_add('foo', $bar));
var_dump(wincache_ucache_add('foo', $bar));
var_dump(wincache_ucache_get('foo'));
?>`

The above example will output:

    bool(true)
    bool(false)
    string(3) "BAR"

Example #2 wincache_ucache_add() with `key` as an array

`<?php
$colors_array = array('green' => '5', 'Blue' => '6', 'yellow' => '7', 'cyan' => '8');
var_dump(wincache_ucache_add($colors_array));
var_dump(wincache_ucache_add($colors_array));
var_dump(wincache_ucache_get('Blue'));
?>`

The above example will output:

    array(0) { }
    array(4) {
      ["green"]=> int(-1)
      ["Blue"]=> int(-1)
      ["yellow"]=> int(-1)
      ["cyan"]=> int(-1)
    }
    string(1) "6"

### See Also

- wincache_ucache_set() - Adds a variable in user cache and overwrites a variable if it already exists in the cache
- wincache_ucache_get() - Gets a variable stored in the user cache
- wincache_ucache_delete() - Deletes variables from the user cache
- wincache_ucache_clear() - Deletes entire content of the user cache
- wincache_ucache_exists() - Checks if a variable exists in the user cache
- wincache_ucache_meminfo() - Retrieves information about user cache memory usage
- wincache_ucache_info() - Retrieves information about data stored in the user cache
- __sleep()

wincache_scache_meminfo
wincache_ucache_cas
WinCache Functions
PHP Manual