PHP's Memcache class sharing

  This article mainly introduces the use of PHP Memcache class (Memcache queue), the need for friends can refer to the following

memcachequeue.class.php    Code is as follows: <?php/**  * php memcache Queue class  * @author lkk/lianq.net  * @ve Rsion 0.3  * @ modification Note:  * 1. The previous AB rotation was discarded and the class was rewritten using an array-like construct.  * 2. The queue defaults to FIFO, but it adds a reverse read function.  * 3. Thanks to netizens foxhunter for their valuable advice.  * @example:  * $obj = new Memcachequeue (' Duilie ');  * $obj->add (' 1asdf ');  * $obj->getqueuelength ();  * $obj->read (10);  * $obj->get (8);  */class memcachequeue{ public static $client  //memcache Client connection  public   $access;  //queue Whether  private   $expire can be updated;  //Expiration time, seconds, 1~2592000, that is, within 30 days  private   $sleepTime;  /Waiting for unlock time, microsecond  private   $queueName;  //queue name, unique value  private   $retryNum;  //retry times, = 10 * Theoretical concurrency number  public   $currentHead;  //Current team first value  public   $currentTail;  //Current team tail value    const maxnum  = 20000;    //Maximum number of queues, recommended cap 10K  const head_key = ' _lkkqueuehead_ ';  //queuesThe first kye  const tail_key = ' _lkkqueuetail_ ';  //Queue Tail KEY  const valu_key = ' _lkkqueuevalu_ ';  //Queue value KEY  const lock_key = ' _lkkqueuelock_ ';  //Queue lock key      /**      * constructor      * @param string $queueName   queue Name      * @param int $expire expiration      * @param array $config  memcache configuration      *       * @return <type>      */ public function __construct ($queueN Ame = ', $expire =0, $config = ') {  if (empty ($config)) {   self:: $client = Memcache_pconnect (' 127.0.0.1 '), 11211);  }elseif (Is_array ($config)) {//array (' host ' => ' 127.0.0.1 ', ' Port ' => ' 11211 ')    self:: $client = Memcache_pconnect ($config [' Host '], $config [' Port ']);  }elseif (is_string ($config)) {//"127.0.0.1:11211"     $tmp = explode (': ', $config);     $conf [' Host '] = isset ($tmp [0])? $tmp [0]: ' 127.0.0.1 ';     $CONF[' port '] = Isset ($tmp [1])? $tmp [1]: ' 11211 ';    self:: $client = Memcache_pconnect ($conf [' Host '], $conf [' Port ']);  }   if (!self:: $client) return false;     Ignore_user_abort (TRUE)//////////When customer disconnects, allow execution of   set_time_limit (0);//Cancel Script Execution Latency limit     $this-> Access = false;   $this->sleeptime = 1000;   $expire = Empty ($expire)? 3600:intval ($expire) +1;   $this->expire = $expire;   $this->queuename = $queueName;   $this->retrynum = 1000;     $this->head_key = $this->queuename. Self::head_key;   $this->tail_key = $this->queuename. Self::tail_key;   $this->lock_key = $this->queuename. Self::lock_key;     $this->_initsetheadntail (); &NBSP}      /**      * initialization set queue end value      */ private function _initsethe Adntail () { //current queue first value   $this->currenthead = Memcache_get (self:: $client, $this->head_key);   IF ($this->currenthead = false) $this->currenthead = 0;    //Current queue tail value   $this->currenttail = Memcache_get (self:: $client, $this->tail_key);   if ($this->currenttail = false) $this->currenttail = 0; &NBSP}      /**      * When the element is taken out, change the value of the queue first   * @param int $step step value      * / private function _changehead ($step =1) {  $this->currenthead + = $step;   Memcache_set (self:: $client , $this->head_key, $this->currenthead,false, $this->expire); &NBSP}      /**      * When adding elements, change the value of the queue at the end of   * @param int $step step value      * @param bool $reverse reverse      * @return null      */ private function _changetail ($s Tep=1, $reverse =false) {  if (! $reverse) {    $this->currenttail + = $step;  }else{    $th Is->currenttail-= $step;  }     Memcache_set (self:: $client, $this->Tail_key, $this->currenttail,false, $this->expire); &NBSP}      /**      * queue null      * @return bool      */&N bsp;private function _isempty () {  return (bool) ($this->currenthead = = $this->currenttail);  }   & nbsp  /**      * queue is full      * @return bool      */ private Function _ Isfull () {  $len = $this->currenttail-$this->currenthead;   return (bool) ($len = = Self::maxnum);   }      /**      * queue lock      */ private function _getlock () {  if ( $this->access = = False) {   while!memcache_add (self:: $client, $this->lock_key, 1, false, $this-> Expire) {    usleep ($this->sleeptime)     @ $i + +     if ($i > $this->retrynum) {// Try to wait n times      return false;      break;    }  &NBSP}       $this->_initsetheadntail ();    return $this->access = true;       return $this->access; &NBSP}      /**      * queue unlock      */ private function _unlock () {&nbsp ; Memcache_delete (self:: $client, $this->lock_key, 0);   $this->access = false; &NBSP}      /**      * Get the length of the current queue      * The length is theoretical length, some elements are lost due to expiration, the true length <= the length      * @return int      */ public function getqueuelength () {  $this->_initse Theadntail ();   Return intval ($this->currenttail-$this->currenthead); &NBSP}      /**      * add queue data      * @param void $data data to add      * @return bool      */ public function Add ($data) {  if (! $this->_getlock ()) return FAL Se     if ($this->_isfull ()) {    $this; _unlock ();    return false;  }     $value _key = $this->queuename. Self::valu_key. Strval ($this->currenttail + 1);   $result = Memcache_set (self:: $client, $value _key, $data, memcache_compressed, $this->expire);   if ($result) {    $this->_changetail ()  }     $this->_unlock ();   return $result; &NBSP}      /**      * read queue data      * @param int $length The length to read (negative read used) &N Bsp    * @return Array      */ public function read ($length =0) {  if (!is_numeric ($length) ) return false;   $this->_initsetheadntail ();     if ($this->_isempty ()) {   return false;  }     if (empty ($length)) $length = Sel f::maxnum;//default all   $KEYARR = Array ();   if ($length >0) {//forward read (from queue header end)     $tmpMin = $this->currenthead;     $tmpMax = $tmpMin + $ Length    for ($i = $tmpMIn; $i <= $tmpMax; $i + +) {    $KEYARR [] = $this->queuename. Self::valu_key. $i;      }else{//Reverse read (from the end of the queue to the head of the queue) & nbsp   $tmpMax = $this->currenttail;     $tmpMin = $tmpMax + $length;    for ($i = $tmpMax; $i > $tmpMin; $i-) {    $KEYARR [] = $this->queuename. Self::valu_key. $i;   &NBSP}       $result = @memcache_get (self:: $client, $KEYARR);     return $result; &NBSP}      /**      * take out queue data      * @param int $length length to be fetched (negative read use minus) &N Bsp    * @return Array      */ public function get ($length =0) {  if (!is_numeric ($length)) return false;   if (! $this->_getlock ()) return false;     if ($this->_isempty ()) {    $this->_unlock ();    return false;  }   &nbs P if (empty ($length)) $length = self::maxnum;//default all   $length = Intval ($length);   $KEYARR= Array ();   if ($length >0) {//forward read (from queue header end)     $tmpMin = $this->currenthead;     $tmpMax = $tmpMin + $ Length    for ($i = $tmpMin; $i <= $tmpMax; $i + +) {    $KEYARR [] = $this->queuename. Self::valu_key. $i;   &nbsp     $this->_changehead ($length);  }else{//Reverse read (from queue end to queue head)     $tmpMax = $this->currenttail;     $tmpMin = $tmpMax + $length; &nbs P  for ($i = $tmpMax; $i > $tmpMin; $i-) {    $KEYARR [] = $this->queuename. Self::valu_key. $i;   &NBSP}     $this->_changetail (ABS ($length), true);  }   $result = @memcache_get (self:: $client, $KEYARR);     foreach ($keyArr as $v) {//delete after removal     @memcache_delete (self:: $client, $v, 0);  }     $this->_unlock ();     return $result; &NBSP}      /**      * emptying queue      */ public function Clear () {  I F (! $thIs->_getlock ()) return false;     if ($this->_isempty ()) {    $this->_unlock ();    return false;  }   &nbs P $tmpMin = $this->currenthead--;   $tmpMax = $this->currenttail++;     for ($i = $tmpMin $i <= $tmpMax $i + +) {    $tmpKey = $this->queuename. Self::valu_key $i; &n Bsp   @memcache_delete (self:: $client, $tmpKey, 0);  }     $this->currenttail = $this->currenthead = 0;   Memcache_set (self:: $client, $this->head_key, $this->currenthead,false, $this->expire);   Memcache_set (self:: $client, $this->tail_key, $this->currenttail,false, $this->expire);     $this->_unlock (); &NBSP}    /*   * Clear all memcache cache data  / public function Memflush () {  Memcache_flush (self:: $client); &NBSP}  }//end class