[英]Caching function results in PHP
I'm making a simple tool to cache function results 我正在制作一个缓存功能结果的简单工具
It look like: 它看起来像:
global $function_results;
$function_results = array();
function getMembers($conditions, $default = array('order' => 'name', array('abc', 'def'))){
//****Help need from here******
//make unique id from parameters value and function name
//ex: $uid;
//****to here******
global $function_results;
if(isset($function_results[$uid])) return $function_results[$uid];
else{
//do function logic...
}
}
(the function and its parameters are just an example) (函数及其参数只是一个例子)
Any suggestions? 有什么建议么?
Here is your missing code: 这是你遗漏的代码:
$numargs = func_num_args();
$arg_list = func_get_args();
$md5this = '';
for ($i = 0; $i < $numargs; $i++) {
$md5this .= $i.':'.serialize($arg_list[$i]).';';
}
$uid = md5($md5this);
For your reference: http://php.net/manual/en/function.func-get-args.php 供您参考: http : //php.net/manual/en/function.func-get-args.php
Here is a generic memoization solution that is compatible with PHP 5.2.x. 这是一个与PHP 5.2.x兼容的通用memoization解决方案。
The call_memoized function: call_memoized函数:
Instead of using call_memoized directly, use the provided memoize function, which returns a new version of the given function that will automatically cache results from the same combination of parameters. 而不是直接使用call_memoized,使用提供的memoize函数,该函数返回给定函数的新版本,该函数将自动缓存来自相同参数组合的结果。
See example below. 见下面的例子。
Enjoy! 请享用!
global $MEMO_CACHE;
$MEMO_CACHE = array();
/** Returns the result of the function with the given arguments.
* Invokes the function only once, thereafter returns the result
* cached by a key based on the function name and arguments. */
function call_memoized($fun, $args=array()) {
global $MEMO_CACHE;
// generate a cache key based on the function name and arguments
$uid = md5(
implode("|", array_merge((array)$fun, array_map(
"serialize",
$args)
))
);
// if there result hasn't been cached, call the function
// and update the cache with the result.
if(!array_key_exists($uid, $MEMO_CACHE)) {
$MEMO_CACHE[$uid] = call_user_func_array($fun, $args);
}
return $MEMO_CACHE[$uid];
}
/** Returns a memoized version of the given function that will cache
* its results for each unique set of inputs. */
function memoize($fun) {
return create_function(
'',
"\$args = func_get_args(); return call_memoized('$fun', \$args);"
);
}
Example: 例:
/** Returns a random number with the given greeting. */
function random($greeting) {
return "$greeting! " . rand();
};
print("Five random numbers:</br />");
for($i=0; $i<5; $i++) {
print(random("Spin the wheel") . "<br />");
}
print "<br />";
print("After memoizing the random function, it's not so random:<br />");
$not_so_random = memoize("random");
for($i=0; $i<5; $i++) {
print($not_so_random("Spin the wheel") . "<br />");
}
print "<br />";
print("The same memoized function is invoked with a different argument, and
thus creates a different cache key:<br />");
for($i=0; $i<5; $i++) {
print($not_so_random("Twirl the tire") . "<br />");
}
/* OUTPUT
Five random numbers:
Spin the wheel! 26488
Spin the wheel! 20049
Spin the wheel! 14006
Spin the wheel! 28599
Spin the wheel! 804
After memoizing the random function, it's not so random:
Spin the wheel! 32397
Spin the wheel! 32397
Spin the wheel! 32397
Spin the wheel! 32397
Spin the wheel! 32397
The same memoized function is invoked with a different argument, and
thus creates a different cache key:
Twirl the tire! 2114
Twirl the tire! 2114
Twirl the tire! 2114
Twirl the tire! 2114
Twirl the tire! 2114
*/
Have a look at memoized function implementation from Nspl : 看看memoized从功能实现NSPL :
function memoized(callable $function)
{
return function() use ($function) {
static $memory = array();
$args = func_get_args();
$key = serialize($args);
if (!isset($memory[$key]) && !array_key_exists($key, $memory)) {
$memory[$key] = call_user_func_array($function, $args);
}
return $memory[$key];
};
}
Or if you looking for caching function results between server requests you can use Cachalot : 或者,如果您在服务器请求之间查找缓存函数结果,则可以使用Cachalot :
$cache = new \Cachalot\ApcCache();
$result = $cache->getCached($function, $args);
Different back-ends are supported: Apc, Xcache, Memcached, Redis, Couchbase. 支持不同的后端:Apc,Xcache,Memcached,Redis,Couchbase。
I suppose $conditions
is an array of some values and you want to create a unique identifier for each variant of that array? 我想$conditions
是一些值的数组,你想为该数组的每个变体创建一个唯一的标识符? There is several ways to do that, eg.: 有几种方法可以做到这一点,例如:
$uid = md5(serialize($conditions));
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