Home Backend Development PHP Tutorial PHP实现的memcache环形队列类实例

PHP实现的memcache环形队列类实例

Jun 20, 2016 pm 12:37 PM

本文实例讲述了PHP实现的memcache环形队列类。分享给大家供大家参考。具体如下:

这里介绍了PHP实现的memcache环形队列类。没咋学过数据结构,因为业务需要,所以只是硬着头皮模拟的! 参考PHP memcache 队列代码。为使队列随时可入可出,且不受int长度越界危险(单链采取Head自增的话不作处理有越界可能),所以索性改写成环形队列。可能还有BUG,忘见谅!

<?php/** * PHP memcache 环形队列类 * 原作者 LKK/lianq.net * 修改 FoxHunter * 因业务需要只保留的队列中的Pop和Push,修改过期时间为0即永久 */class MQueue{ public static $client; private $expire; //过期时间,秒,1~2592000,即30天内 private $sleepTime; //等待解锁时间,微秒 private $queueName; //队列名称,唯一值 private $retryNum; //尝试次数 private $MAXNUM; //最大队列容量 private $canRewrite; //是否可以覆写开关,满出来的内容从头部开始覆盖重写原来的数据 private $HEAD; //下一步要进入的指针位置 private $TAIL; //下一步要进入的指针位置 private $LEN; //队列现有长度 const LOCK_KEY = '_Fox_MQ_LOCK_'; //锁存储标示 const LENGTH_KEY = '_Fox_MQ_LENGTH_'; //队列现长度存储标示 const VALU_KEY = '_Fox_MQ_VAL_'; //队列键值存储标示 const HEAD_KEY = '_Fox_MQ_HEAD_'; //队列HEAD指针位置标示 const TAIL_KEY = '_Fox_MQ_TAIL_'; //队列TAIL指针位置标示 /*  * 构造函数  * 对于同一个$queueName,实例化时必须保障构造函数的参数值一致,否则pop和push会导队列顺序混乱  */ public function __construct($queueName = '', $maxqueue = 1, $canRewrite = false, $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); //当客户断开连接,允许继续执行  set_time_limit(0); //取消脚本执行延时上限  $this->access  = false;  $this->sleepTime = 1000;  $expire   = (empty($expire)) ? 0 : (int) $expire + 1;  $this->expire  = $expire;  $this->queueName = $queueName;  $this->retryNum = 20000;  $this->MAXNUM  = $maxqueue != null ? $maxqueue : 1;  $this->canRewrite = $canRewrite;  $this->getHeadAndTail();  if (!isset($this->HEAD) || empty($this->HEAD))   $this->HEAD = 0;  if (!isset($this->TAIL) || empty($this->TAIL))   $this->TAIL = 0;  if (!isset($this->LEN) || empty($this->LEN))   $this->LEN = 0; } //获取队列首尾指针信息和长度 private function getHeadAndTail() {  $this->HEAD = (int) memcache_get(self::$client, $this->queueName . self::HEAD_KEY);  $this->TAIL = (int) memcache_get(self::$client, $this->queueName . self::TAIL_KEY);  $this->LEN = (int) memcache_get(self::$client, $this->queueName . self::LENGTH_KEY); } // 利用memcache_add原子性加锁 private function lock() {  if ($this->access === false) {   $i = 0;   while (!memcache_add(self::$client, $this->queueName . self::LOCK_KEY, 1, false, $this->expire)) {    usleep($this->sleepTime);    @$i++;    if ($i > $this->retryNum) { //尝试等待N次     return false;     break;    }   }   return $this->access = true;  }  return false; } //更新头部指针指向,指向下一个位置 private function incrHead() {  //$this->getHeadAndTail(); //获取最新指针信息 ,由于本方法体均在锁内调用,其锁内已调用了此方法,本行注释  $this->HEAD++; //头部指针下移  if ($this->HEAD >= $this->MAXNUM) {   $this->HEAD = 0; //边界值修正  }  ;  $this->LEN--; //Head的移动由Pop触发,所以相当于数量减少  if ($this->LEN < 0) {   $this->LEN = 0; //边界值修正  }  ;  memcache_set(self::$client, $this->queueName . self::HEAD_KEY, $this->HEAD, false, $this->expire); //更新  memcache_set(self::$client, $this->queueName . self::LENGTH_KEY, $this->LEN, false, $this->expire); //更新 } //更新尾部指针指向,指向下一个位置 private function incrTail() {  //$this->getHeadAndTail(); //获取最新指针信息,由于本方法体均在锁内调用,其锁内已调用了此方法,本行注释  $this->TAIL++; //尾部指针下移  if ($this->TAIL >= $this->MAXNUM) {   $this->TAIL = 0; //边界值修正  }  ;  $this->LEN++; //Head的移动由Push触发,所以相当于数量增加  if ($this->LEN >= $this->MAXNUM) {   $this->LEN = $this->MAXNUM; //边界值长度修正  }  ;  memcache_set(self::$client, $this->queueName . self::TAIL_KEY, $this->TAIL, false, $this->expire); //更新  memcache_set(self::$client, $this->queueName . self::LENGTH_KEY, $this->LEN, false, $this->expire); //更新 } // 解锁 private function unLock() {  memcache_delete(self::$client, $this->queueName . self::LOCK_KEY);  $this->access = false; } //判断是否满队列 public function isFull() {  //外部直接调用的时候由于没有锁所以此处的值是个大概值,并不很准确,但是内部调用由于在前面有lock,所以可信  if ($this->canRewrite)   return false;  return $this->LEN == $this->MAXNUM ? true : false; } //判断是否为空 public function isEmpty() {  //外部直接调用的时候由于没有锁所以此处的值是个大概值,并不很准确,但是内部调用由于在前面有lock,所以可信  return $this->LEN == 0 ? true : false; } public function getLen() {  //外部直接调用的时候由于没有锁所以此处的值是个大概值,并不很准确,但是内部调用由于在前面有lock,所以可信  return $this->LEN; } /*  * push值  * @param mixed 值  * @return bool  */ public function push($data = '') {  $result = false;  if (empty($data))   return $result;  if (!$this->lock()) {   return $result;  }  $this->getHeadAndTail(); //获取最新指针信息  if ($this->isFull()) { //只有在非覆写下才有Full概念   $this->unLock();   return false;  }  if (memcache_set(self::$client, $this->queueName . self::VALU_KEY . $this->TAIL, $data, MEMCACHE_COMPRESSED, $this->expire)) {   //当推送后,发现尾部和头部重合(此时指针还未移动),且右边仍有未由Head读取的数据,那么移动Head指针,避免尾部指针跨越Head   if ($this->TAIL == $this->HEAD && $this->LEN >= 1) {    $this->incrHead();   }   $this->incrTail(); //移动尾部指针   $result = true;  }  $this->unLock();  return $result; } /*  * Pop一个值  * @param [length] int 队列长度  * @return array  */ public function pop($length = 0) {  if (!is_numeric($length))   return false;  if (!$this->lock())   return false;  $this->getHeadAndTail();  if (empty($length))   $length = $this->LEN; //默认读取所有  if ($this->isEmpty()) {   $this->unLock();   return false;  }  //获取长度超出队列长度后进行修正  if ($length > $this->LEN)   $length = $this->LEN;  $data = $this->popKeyArray($length);  $this->unLock();  return $data; } /*  * pop某段长度的值  * @param [length] int 队列长度  * @return array  */ private function popKeyArray($length) {  $result = array();  if (empty($length))   return $result;  for ($k = 0; $k < $length; $k++) {   $result[] = @memcache_get(self::$client, $this->queueName . self::VALU_KEY . $this->HEAD);   @memcache_delete(self::$client, $this->queueName . self::VALU_KEY . $this->HEAD, 0);   //当提取值后,发现头部和尾部重合(此时指针还未移动),且右边没有数据,即队列中最后一个数据被完全掏空,此时指针停留在本地不移动,队列长度变为0   if ($this->TAIL == $this->HEAD && $this->LEN <= 1) {    $this->LEN = 0;    memcache_set(self::$client, $this->queueName . self::LENGTH_KEY, $this->LEN, false, $this->expire); //更新    break;   } else {    $this->incrHead(); //首尾未重合,或者重合但是仍有未读取出的数据,均移动HEAD指针到下一处待读取位置   }  }  return $result; } /*  * 重置队列  * * @return NULL  */ private function reset($all = false) {  if ($all) {   memcache_delete(self::$client, $this->queueName . self::HEAD_KEY, 0);   memcache_delete(self::$client, $this->queueName . self::TAIL_KEY, 0);   memcache_delete(self::$client, $this->queueName . self::LENGTH_KEY, 0);  } else {   $this->HEAD = $this->TAIL = $this->LEN = 0;   memcache_set(self::$client, $this->queueName . self::HEAD_KEY, 0, false, $this->expire);   memcache_set(self::$client, $this->queueName . self::TAIL_KEY, 0, false, $this->expire);   memcache_set(self::$client, $this->queueName . self::LENGTH_KEY, 0, false, $this->expire);  } } /*  * 清除所有memcache缓存数据  * @return NULL  */ public function memFlush() {  memcache_flush(self::$client); } public function clear($all = false) {  if (!$this->lock())   return false;  $this->getHeadAndTail();  $Head = $this->HEAD;  $Length = $this->LEN;  $curr = 0;  for ($i = 0; $i < $Length; $i++) {   $curr = $this->$Head + $i;   if ($curr >= $this->MAXNUM) {    $this->HEAD = $curr = 0;   }   @memcache_delete(self::$client, $this->queueName . self::VALU_KEY . $curr, 0);  }  $this->unLock();  $this->reset($all);  return true; }}
Copy after login

希望本文所述对大家的php程序设计有所帮助。

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

Describe the SOLID principles and how they apply to PHP development. Describe the SOLID principles and how they apply to PHP development. Apr 03, 2025 am 12:04 AM

The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.

How to automatically set permissions of unixsocket after system restart? How to automatically set permissions of unixsocket after system restart? Mar 31, 2025 pm 11:54 PM

How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...

How to debug CLI mode in PHPStorm? How to debug CLI mode in PHPStorm? Apr 01, 2025 pm 02:57 PM

How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...

Explain the concept of late static binding in PHP. Explain the concept of late static binding in PHP. Mar 21, 2025 pm 01:33 PM

Article discusses late static binding (LSB) in PHP, introduced in PHP 5.3, allowing runtime resolution of static method calls for more flexible inheritance.Main issue: LSB vs. traditional polymorphism; LSB's practical applications and potential perfo

How to send a POST request containing JSON data using PHP's cURL library? How to send a POST request containing JSON data using PHP's cURL library? Apr 01, 2025 pm 03:12 PM

Sending JSON data using PHP's cURL library In PHP development, it is often necessary to interact with external APIs. One of the common ways is to use cURL library to send POST�...

Explain late static binding in PHP (static::). Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

See all articles