以文件形式缓存php变量的方法

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 {    $write_data = "<?php//r//n//$var= ";    $write_data .= var_export($data,true);    $write_data .=";//r//n?>";   }   $this->cache_write($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; }}?>