apc_compile_file

highcode at yahoo dot com (2009-08-06 04:09:38)

if your goal is to pre-compile PHP script into bytecode and then transparently loaded the script, better use monas, its a free php extension to encode/decode PHP 4 and PHP 5. check it at http://ombudi.com, i've try using it to encode phpmyadmin and works nicely

Glen (2009-03-31 14:44:05)

There are reasons to use this routine. I can think of two:
- a busy website will have multiple web servers, and before one is brought online (via load balancer), the cache is built. This prevents problems of having too many cache misses in a short period on your entire code base, which could be massive, and cause problems.
- a website where the apc.stat flag is set to zero. That setting provides significant performance savings because no 'stat' needs to be performed on PHP code files. But they are not automatically rebuilt when changed. So what do you do when your code changes? Restart Apache, or manually clearing the APC cache with apc_clear_cache() - but both will clear the entire cache. There may be cases where it is much better to recompile select files instead. Some sites store data (that rarely changes) in PHP code to make good use of the opcode cache, updating that file and selectively compiling it would make writes efficient too.

A.R. (2009-03-22 07:15:31)

It should be noted, that the above suggestion to "compile your entire project", or for any web developer to ever call this apc_compile_file function at all, is superfluous, because APC will automatically compile pages for you on demand. This function does not do anything useful.

I had actually avoided installing APC for a long time because I thought it would be very complex, partly because of this manual page which tells you how to compile but doesn't tell you how to execute a compiled page.

After installing APC, you can tell if it's working, by adding this to one of your webpages:

<?php
    echo("<pre>");
    print_r(apc_cache_info());
    echo("</pre>");
?>

Run this before and after hitting a few pages on the site, to see the compiled files automatically show up in the list.

Again, there is no need to ever call apc_compile_file explicitly. This function is probably available for some sort of very advanced use.

Andrea Giammarchi (2008-02-15 07:40:13)

This is a simple way to cache a project entirely.

<?php // apc_compile_dir.php
function apc_compile_dir($root, $recursively = true){
    $compiled   = true;
    switch($recursively){
        case    true:
            foreach(glob($root.DIRECTORY_SEPARATOR.'*', GLOB_ONLYDIR) as $dir)
                $compiled   = $compiled && apc_compile_dir($dir, $recursively);
        case    false:
            foreach(glob($root.DIRECTORY_SEPARATOR.'*.php') as $file)
                $compiled   = $compiled && apc_compile_file($file);
            break;
    }
    return  $compiled;
}
?>

This is an example on how to use the function to compile your project.
<?php
echo    '<pre>'.PHP_EOL;
if(function_exists('apc_compile_file')){
    define('APC_CLEAR_CACHE',           true);
    define('APC_COMPILE_RECURSIVELY',   true);
    define('APC_COMPILE_DIR',           '.');
    require 'apc_compile_dir.php';
    echo    'APC Directory Compiler '.gmdate('Y-m-d H:i:s').PHP_EOL;
    echo    PHP_EOL.'-------------------------'.PHP_EOL;
    if(APC_CLEAR_CACHE){
        echo    (apc_clear_cache() ? 'Cache Cleaned' : 'Cache Not Cleaned').PHP_EOL;
        var_dump(apc_cache_info());
        echo    PHP_EOL.'-------------------------'.PHP_EOL;
    }
    echo    'Runtime Errors'.PHP_EOL;
    echo    (apc_compile_dir(APC_COMPILE_DIR, APC_COMPILE_RECURSIVELY) ? 'Cache Created' : 'Cache Not Created').PHP_EOL;
    echo    PHP_EOL.'-------------------------'.PHP_EOL;
    var_dump(apc_cache_info());
}
else
    echo    'APC is not present, nothing to do.'.PHP_EOL;
echo    '</pre>';
?>