A Simple and Practical Complete Example of PHP Cache Class

This paper describes a simple and practical PHP cache class, which can be used to check whether the cache file is within the set update time, clear the cache file, generate the cache file name according to the current dynamic file, create the directory continuously, and output the cache file statically. To use PHP to develop CMS system, it is necessary to deal with cache. Reasonable use of cache can effectively improve the efficiency of program execution.

The complete code for the php cache class file is as follows:

<?php
/*
*  Cache class  cache
*/
class cache {
// Cache directory 
var $cacheRoot = "./cache/";
// Cache update time seconds, 0 Is not cached 
var $cacheLimitTime = 0;
// Cache file name 
var $cacheFileName = "";
// Cache extension 
var $cacheFileExt = "php";
/*
  *  Constructor 
  * int $cacheLimitTime  Cache update time 
  */
function cache( $cacheLimitTime ) {
  if( intval( $cacheLimitTime ) )
  $this->cacheLimitTime = $cacheLimitTime;
  $this->cacheFileName = $this->getCacheFileName();
  ob_start();
} 
/*
  *  Check whether the cache file is within the set update time 
  *  Return: If it is within the update time, the file contents will be returned, otherwise, it will fail 
  */
function cacheCheck(){
  if( file_exists( $this->cacheFileName ) ) {
  $cTime = $this->getFileCreateTime( $this->cacheFileName );
  if( $cTime + $this->cacheLimitTime > time() ) {
  echo file_get_contents( $this->cacheFileName );
  ob_end_flush();
  exit;
  }
  }
  return false;
}
/*
  *  Cache files or output static 
  * string $staticFileName  Static file name (including relative path) 
  */
function caching( $staticFileName = "" ){
  if( $this->cacheFileName ) {
  $cacheContent = ob_get_contents();
  ob_end_flush();
  if( $staticFileName ) {
  $this->saveFile( $staticFileName, $cacheContent );
  }
  if( $this->cacheLimitTime )
  $this->saveFile( $this->cacheFileName, $cacheContent );
  }
} 
/*
  *  Clear the cache file 
  * string $fileName  Specify a file name ( Containing function ) Or all (All) 
  *  Return: Clear successfully returns true Otherwise, return false
  */
function clearCache( $fileName = "all" ) {
  if( $fileName != "all" ) {
  $fileName = $this->cacheRoot . strtoupper(md5($fileName)).".".$this->cacheFileExt;
  if( file_exists( $fileName ) ) {
  return @unlink( $fileName );
  }else return false;
  }
  if ( is_dir( $this->cacheRoot ) ) {
  if ( $dir = @opendir( $this->cacheRoot ) ) {
  while ( $file = @readdir( $dir ) ) {
  $check = is_dir( $file );
  if ( !$check )
  @unlink( $this->cacheRoot . $file );
  }
  @closedir( $dir );
  return true;
  }else{
  return false;
  }
  }else{
  return false;
  }
}
/* Generate the cache file name from the current dynamic file */
function getCacheFileName() {
  return $this->cacheRoot . strtoupper(md5($_SERVER["REQUEST_URI"])).".".$this->cacheFileExt;
}
/*
  *  Cache file establishment time 
  * string $fileName  Cache file name (including relative path) 
  *  Return: The number of seconds when the file was generated, and the file did not exist. Return 0
  */
function getFileCreateTime( $fileName ) {
  if( ! trim($fileName) ) return 0;
  if( file_exists( $fileName ) ) {
  return intval(filemtime( $fileName ));
  }else return 0;
} 
/*
  *  Save a file 
  * string $fileName  File name (including relative path) 
  * string $text  File content 
  *  Return: Successful return ture Failure returns false
  */
function saveFile($fileName, $text) {
  if( ! $fileName || ! $text ) return false;
  if( $this->makeDir( dirname( $fileName ) ) ) {
  if( $fp = fopen( $fileName, "w" ) ) {
  if( @fwrite( $fp, $text ) ) {
  fclose($fp);
  return true;
  }else {
  fclose($fp);
  return false;
  }
  }
  }
  return false;
}
/*
  *  Continuous catalogue building 
  * string $dir  Directory string 
  * int $mode  Authority number 
  *  Return: Successfully created or all built returns true Return in other ways false
  */
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;
}
}
?>

When using this cache class, you can save the above code as cache. php as follows:

include( "cache.php" );
$cache = new cache(30);
$cache->cacheCheck();
echo date("Y-m-d H:i:s");
$cache->caching();