cvs: php4 /pear Makefile.in /pear/Cache Function_Cache.php

sbergmann Sun Dec 10 10:40:23 2000 EDT Added files: /php4/pear/Cache Function_Cache.php Modified files: /php4/pear Makefile.in Log: Initial commit of Function_Cache. Index: php4/pear/Makefile.in diff -u php4/pear/Makefile.in:1.52 php4/pear/Makefile.in:1.53 --- php4/pear/Makefile.in:1.52 Thu Dec 7 03:27:35 2000 +++ php4/pear/Makefile.in Sun Dec 10 10:40:23 2000 @@ -11,6 +11,7 @@ PEAR_SUBDIRS = \ Benchmark \ + Cache \ Crypt \ Date \ DB \ @@ -26,6 +27,7 @@ PEAR_FILES = \ Benchmark/Iterate.php \ Benchmark/Timer.php \ + Cache/Function_Cache.php \ Crypt/HCEMD5.php \ Date/Calc.php \ DB.php \ Index: php4/pear/Cache/Function_Cache.php +++ php4/pear/Cache/Function_Cache.php <?php // // +----------------------------------------------------------------------+ // | PHP version 4.0 | // +----------------------------------------------------------------------+ // | Copyright (c) 1997, 1998, 1999, 2000 The PHP Group | // +----------------------------------------------------------------------+ // | This source file is subject to version 2.02 of the PHP license, | // | that is bundled with this package in the file LICENSE, and is | // | available at through the world-wide-web at | // | http://www.php.net/license/2_02.txt. | // | If you did not receive a copy of the PHP license and are unable to | // | obtain it through the world-wide-web, please send a note to | // | license@php.net so we can mail you a copy immediately. | // +----------------------------------------------------------------------+ // | Authors: Sebastian Bergmann <sb@sebastian-bergmann.de> | // +----------------------------------------------------------------------+ // // $Id: Function_Cache.php,v 1.1 2000/12/10 18:40:23 sbergmann Exp $ // /** * Function_Cache * * Purpose: * * Caching the result and output of functions. * * Example: * * require_once "Cache/Function_Cache.php"; * * function foo( $string ) * { * print $string . "<br>"; * return strrev( $string ); * } * * print cache_call( "foo", "test" ) . "<br><br>"; * print cache_call( "foo", "test" ) . "<br><br>"; * * The function foo() will be executed only once, since the * arguments of the second call are the same as before. But of * course you will get the following output: * * test * tset * * test * tset * * Note: * * You cannot cache every function. You should only cache * functions that only depend on their arguments and don't use * global or static variables, don't rely on database queries or * files, and so on. * * @author Sebastian Bergmann <sb@sebastian-bergmann.de> * @module Function_Cache * @version $Revision: 1.1 $ * @access public */ /** * @const CACHE_SHM_KEY */ define( "CACHE_SHM_KEY", 22478 ); /** * @const CACHE_SHM_VAR */ define( "CACHE_SHM_VAR", 224 ); /** * @const CACHE_SHM_SIZE */ define( "CACHE_SHM_SIZE", 524288 ); // check, if Shared Memory support is available if( function_exists( "sem_get" ) && function_exists( "shm_attach" ) ) { // use Shared Memory to store cache $GLOBALS[ "_cache" ][ "mode" ] = "shared_memory"; } else { // use global variable to store cache $GLOBALS[ "_cache" ][ "mode" ] = "global"; } // {{{ cache_call() /** * Calls a cacheable function or method. * * @return mixed $result * @access public */ function cache_call() { // get arguments $arguments = func_get_args(); // init cache _cache_init(); // reference $GLOBALS[ "_cache" ][ "cache" ] as $cache $cache =& $GLOBALS[ "_cache" ][ "cache" ]; // calculate hash for function call $hash = md5( serialize( $arguments ) ); // get function name $func_name = array_shift( $arguments ); // check, if function call is cached if( !isset( $cache[ $hash ] ) || ( isset( $GLOBALS[ "_cache" ][ "lifetime" ][ $func_name ] ) && ( time() - $cache[ $hash ][ "last_executed" ] ) > $GLOBALS[ "_cache" ][ "lifetime" ][ $func_name ] ) ) { // start output buffering ob_start(); // call function, store result in cache $cache[ $hash ][ "return" ] = call_user_func_array( $func_name, $arguments ); // store function's output in cache $cache[ $hash ][ "output" ] = ob_get_contents(); // store timestamp $cache[ $hash ][ "last_executed" ] = time(); // end output buffering ob_end_clean(); // if cache is stored in shared memory update // the shared memory segment if( $GLOBALS[ "_cache" ][ "mode" ] == "shared_memory" ) { _cache_shm_write( $hash ); } } // output cached output print $cache[ $hash ][ "output" ]; // return cached result return $cache[ $hash ][ "return" ]; } // }}} // {{{ cache_flush() /** * Flushes the Function Cache. * * @access public */ function cache_flush() { // reset global cache array $GLOBALS[ "_cache" ][ "cache" ] = array(); // update shared memory segment, if needed if( $GLOBALS[ "_cache" ][ "mode" ] == "shared_memory" ) { _cache_shm_write( "flush" ); } } // }}} // {{{ cache_set_lifetime() /** * Sets the lifetime for a cacheable function or method. * * @param mixed $func_name * @param integer $lifetime * @access public */ function cache_set_lifetime( $func_name, $lifetime ) { // check $lifetime argument if( is_number( $lifetime ) ) { // store $lifetime $GLOBALS[ "_cache" ][ "lifetime" ][ $func_name ] = $lifetime; } // I'm currently unsure on whether we need to store the // new lifetime to Shared Memory if it's used } // }}} // {{{ cache_set_mode() /** * Sets the mode of storage for the Function Cache. * * @param string $mode * @access public */ function cache_set_mode( $mode ) { // check $mode argument if( $mode == "global" || $mode == "shared_memory" ) { // store $mode $GLOBALS[ "_cache" ][ "mode" ] = $mode; } } // }}} // {{{ _cache_init() /** * Initializes the cache. * * @access private */ function _cache_init() { // check, if we're using Shared Memory if( $GLOBALS[ "_cache" ][ "mode" ] == "shared_memory" ) { // read cache from Shared Memory $GLOBALS[ "_cache" ][ "cache" ] = _cache_shm_read(); } } // }}} // {{{ _cache_shm_read() /** * Reads the cache from a Shared Memory segement. * * @return array $cache * @access private */ function _cache_shm_read() { $sem = sem_get( CACHE_SHM_KEY ); // lock shared memory sem_acquire( $sem ); // get shared memory segment $shm = shm_attach( CACHE_SHM_KEY, CACHE_SHM_SIZE ); // read cache contents $cache = shm_get_var( $shm, CACHE_SHM_VAR ); // release shared memory sem_release( $sem ); // disconnect from shared memory shm_detach( $shm ); // return cache contents return $cache; } // }}} // {{{ _cache_shm_write() /** * Writes the cache to a Shared Memory segement. * * @access private */ function _cache_shm_write( $hash ) { if( $hash != "flush" ) { // get current cache $cache = _cache_shm_read(); // update cache segment for current function call $cache[ "_cache" ][ $hash ][ "last_executed" ] = $GLOBALS[ "_cache" ][ "cache" ][ $hash ][ "last_executed" ]; $cache[ "_cache" ][ $hash ][ "output" ] = $GLOBALS[ "_cache" ][ "cache" ][ $hash ][ "output" ]; $cache[ "_cache" ][ $hash ][ "return" ] = $GLOBALS[ "_cache" ][ "cache" ][ $hash ][ "return" ]; } else { // flush cache $cache = array(); } $sem = sem_get( CACHE_SHM_KEY ); // lock shared memory sem_acquire( $sem ); // get shared memory segment $shm = shm_attach( CACHE_SHM_KEY ); // update shared memory segment shm_put_var( $shm, CACHE_SHM_VAR, $cache ); // release shared memory sem_release( $sem ); // disconnect from shared memory shm_detach( $shm ); } // }}} ?>