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;
}
}
?>
希望本文所述对大家的php程序设计有所帮助。