本文实例讲述了以文件形式缓存php变量的方法。分享给大家供大家参考。具体实现方法如下：

<?php /* $cache_set = array( //缓存路径 , 最后要加"/" 'cacheRoot'=>'./cache/', //缓存时间 'cacheTime'=>20, //cache type 'cacheType'=>1, //扩展名 'cacheExe'=>'.php' ); $cache = new Cache($cache_set); $a=array('1','2'); $a="aaa"; $b=''; if($cache->cache_is("d")){ $c=$cache->cache_read("d"); echo "c"; print_r($c); }else { $b=$cache->cache_data('d',$a); } print_r($b); //$cache->clear("a"); //echo $cache->cache_read("./cache/d.php"); //echo $d; */ /** * 数据缓存类 v1.0 * @author shooke * 2009-11-13 16:02:26 * 用于缓存数据,如变量,但不能缓存页面 */ class Cache{ //配置 public $config = array( //缓存路径 'cacheRoot'=>'./cache/', //缓存时间 'cacheTime'=>1, //cache 类型 1串化数据 2变量 'cacheType'=>2, //扩展名 'cacheExe'=>'.php' //转换中间变量 ); public $return_name=array(); function __construct($cache_set = array()) { if(!empty($cache_set)) $this->config=array_merge($this->config,$cache_set); $this->config['ClassName'] = __CLASS__; } public function clear($filename=''){ if (file_exists($this->cache_file($filename))) { @unlink($this->cache_file($filename)); }elseif (empty($filename)){ $this->clear_dir($this->config['cacheRoot']); }else{ $this->clear_dir($this->config['cacheRoot'].$filename); echo $this->config['cacheRoot'].$filename; } } //循环删除路径 private function clear_dir($dir,$to = false) { if ($list = glob($dir.'/*')) { foreach ($list as $file) { is_dir($file) ? $this->clear_dir($file) : unlink($file); } } if ($to === false) rmdir($dir); } //写入缓存 private function cache_write($filename, $writetext, $openmod='w'){ if (!file_exists($filename)) { @$this->makeDir( dirname($filename )); } if(@$fp = fopen($filename, $openmod)) { flock($fp, 2); fwrite($fp, $writetext); fclose($fp); return true; } else { echo "File: $filename write error."; return false; } } //缓存有效期 有效返回 true public function cache_is($fileName){ $fileName=$this->cache_file($fileName); if( file_exists( $fileName ) ) { //如果缓存时间为负数则永不过期 if ($this->config['cacheTime'] < 0) { return true; } //如果缓存时间为0则一直过期 if ($this->config['cacheTime'] == 0) { return false; } //获取缓存文件的建立时间 $ctime = intval(filemtime( $fileName )); //比较是否大于缓存时间,是则过期 否则不过期 if (time() - $ctime > $this->config['cacheTime']) { return false; }else { return true; } //文件不存在视为过期失效 }else { return false; } } public function cache_data($name,$data){ $varname=$name; $name = $this->cache_file($name); //config['cacheTime']==0也就是不启用缓存是直接返回数据 if ($this->config['cacheTime'] <> 0) { if($this->config['cacheType']==1){ $write_data = "<?php exit;".serialize($data); //return $data; }else { $write_data = "<?phprn$var= "; $write_data .= var_export($data,true); $write_data .=";rn"; } $this->cache_write($name,$write_data); } return $data; } //缓存文件名 private function cache_file($filename){ return $this->config['cacheRoot'].$filename.$this->config['cacheExe']; } //读取文件 public function cache_read($file){ $file=$this->cache_file($file); if (!file_exists($file)) { return ''; } if($this->config['cacheType']==1){ if (function_exists('file_get_contents')){ $cache_Content= file_get_contents($file); }else{ $fopen = fopen($file,'r'); $cache_Content = ''; do { $data = fread($fopen,filesize($file)); if (strlen($data)===0) break; $cache_Content .= $data; }while(1); fclose($fopen); } $cache_Content = substr($cache_Content,13);/* 去除<?php exit;?> */ $cache_Content = unserialize($cache_Content); return $cache_Content; }else{ include_once($file); return $var; } } //循环创建目录 private function makeDir( $dir, $mode = 0777 ) { if( ! $dir ) return 0; $dir = str_replace( "", "/", $dir ); $mdir = ""; foreach( explode( "/", $dir ) as $val ) { $mdir .= $val."/"; if( $val == ".." || $val == "." || trim( $val ) == "" ) continue; if( ! file_exists( $mdir ) ) { if(!@mkdir( $mdir, $mode )){ return false; } } } return true; } } ?>

希望本文所述对大家的php程序设计有所帮助。