PHP+memcache implements message queue case sharing

The principle of memche message queue is to make a fuss about the key, which is used to make a continuous number plus a prefix to record the message or log after serialization. Then the content is dropped to the file or database through a scheduled program.

The use of PHP to implement message queues, such as when sending a large number of emails is time-consuming, you can use queues.
The lightweight queue server that facilitates queue implementation is:
starling is a lightweight persistence server that supports the memcache protocol
https://github.com/starling/starling
Beanstalkd is lightweight and efficient , supports persistence and can handle about 3,000 queues per second
http://kr.github.com/beanstalkd/
Memcache/memcached can also be used in php to implement message queues.

Copy code The code is as follows:

        /**
* Memcache message queue class
*/
    class QMC {
    const PREFIX = 'ASDFASDFFWQKE';
    /**
* Initialize mc
* @staticvar string $mc
* @return Memcache
*/
    static private function mc_init() {
    static $mc = null;
    if (is_null($mc)) {
    $mc = new Memcache;
    $mc->connect('127.0.0.1', 11211);
    }
    return $mc;
    }
    /**
* mc counter, increment the count and return the new count
* @param string $key Counter
* @param int $offset Count increment, can be a negative number. 0 means no change in the count
* @param int $time Time
* @return int/false Returns false on failure, returns the count after updating the counter on success
*/
    static public function set_counter( $key, $offset, $time=0 ){
    $mc = self::mc_init();
    $val = $mc->get($key);
    if( !is_numeric($val) || $val < 0 ){
    $ret = $mc->set( $key, 0, $time );
    if( !$ret ) return false;
    $val = 0;
    }
    $offset = intval( $offset );
    if( $offset > 0 ){
    return $mc->increment( $key, $offset );
    }elseif( $offset < 0 ){
    return $mc->decrement( $key, -$offset );
    }
    return $val;
    }
    /**
* Write to queue
* @param string $key
* @param mixed $value
* @return bool
*/
    static public function input( $key, $value ){
    $mc = self::mc_init();
    $w_key = self::PREFIX.$key.'W';
    $v_key = self::PREFIX.$key.self::set_counter($w_key, 1);
    return $mc->set( $v_key, $value );
    }
    /**
* Read the data in the queue
* @param string $key
* @param int $max The maximum number of items to read
* @return array
*/
    static public function output( $key, $max=100 ){
    $out = array();
    $mc = self::mc_init();
    $r_key = self::PREFIX.$key.'R';
    $w_key = self::PREFIX.$key.'W';
    $r_p   = self::set_counter( $r_key, 0 );//读指针
    $w_p   = self::set_counter( $w_key, 0 );//写指针
    if( $r_p == 0 ) $r_p = 1;
    while( $w_p >= $r_p ){
    if( --$max < 0 ) break;
    $v_key = self::PREFIX.$key.$r_p;
    $r_p = self::set_counter( $r_key, 1 );
    $out[] = $mc->get( $v_key );
    $mc->delete($v_key);
    }
    return $out;
    }
    }
    /**
Usage:
QMC::input($key, $value);//Write queue
$list = QMC::output($key);//Read queue
*/
    ?>

基于PHP共享内存实现的消息队列:

复制代码代码如下:

/**
* Implementation of PHP circular memory queue using shared memory
* Supports multiple processes and supports storage of various data types
* Note: After completing the enqueue or dequeue operation, use unset() as soon as possible to release Critical section
*
* @author wangbinandi@gmail.com
* @created 2009-12-23
*/
class ShmQueue
{
private $maxQSize = 0; // Maximum queue length
private $front = 0; // Queue head pointer
private $rear = 0; // Queue tail pointer
private $blockSize = 256; // Block size (byte)
private $memSize = 25600; // Maximum shared memory (byte)
private $shmId = 0;
private $filePtr = './shmq.ptr';
private $semId = 0;
public function __construct()
{
$shmkey = ftok(__FILE__, 't');
$this->shmId = shmop_open($shmkey, "c", 0644, $this->memSize );
$this ->maxQSize = $this->memSize / $this->blockSize;
// Apply for a semaphore
$this->semId = sem_get($shmkey, 1);
sem_acquire($this->semId); // Apply to enter the critical section
$this->init();
}
private function init()
{
if ( file_exists ($this->filePtr) ){
$contents = file_get_contents($this->filePtr);
$data = explode( '|', $contents );
if ( isset($ data[0]) && isset($data[1])){
$this->front = (int)$data[0];
$this->rear = (int)$data [1];
}
}
}
public function getLength()
{
return (($this->rear - $this->front + $this ->memSize) % ($this->memSize) )/$this->blockSize;
}
public function enQueue( $value )
{
if ( $this-> ;ptrInc($this->rear) == $this->front ){ // The queue is full
return false;
}
$data = $this->encode($value) ;
shmop_write($this->shmId, $data, $this->rear );
$this->rear = $this->ptrInc($this->rear);
return true;
}
public function deQueue()
{
if ( $this->front == $this->rear ){ // Queue empty
return false;
}
$value = shmop_read($this->shmId, $this->front, $this->blockSize-1);
$this->front = $this ->ptrInc($this->front);
return $this->decode($value);
}
private function ptrInc( $ptr )
{
return ($ptr + $this->blockSize) % ($this->memSize);
}
private function encode( $value )
{
$data = serialize($value) . "__eof";
echo '';
echo strlen($data);
echo '';
echo $this->blockSize -1;
echo '';
if ( strlen($data) > $this->blockSize -1 ){
throw new Exception(strlen($data)." is overload block size!");
}
return $data;
}
private function decode( $value )
{
$data = explode("__eof", $value);
return unserialize($data[0]) ;
}
public function __destruct()
{
$data = $this->front . '|' . $this->rear;
file_put_contents($this-> ;filePtr, $data);
sem_release($this->semId); // Exit the critical section and release the semaphore
}
}
/*
// Enter the queue operation
$shmq = new ShmQueue();
$data = 'test data';
$shmq->enQueue($data);
unset($shmq);
// Dequeue operation
$shmq = new ShmQueue();
$data = $shmq->deQueue();
unset($shmq);
*/
?>

For a large message queue, frequent serialization and deserialization of a large database is too time-consuming. Below is a message queue I implemented using PHP. I only need to insert a piece of data at the tail and operate the tail. There is no need to operate the entire message queue to read and operate. However, this message queue is not thread-safe, I just try to avoid the possibility of conflicts. If the messages are not very dense, for example, only one message every few seconds, you can still consider using it this way.
If you want to achieve thread safety, one suggestion is to lock through the file and then operate. The code is as follows:
The code is as follows:

Copy code The code is as follows:

    class Memcache_Queue
    {
    private $memcache;
    private $name;
    private $prefix;
    function __construct($maxSize, $name, $memcache, $prefix = "__memcache_queue__")
    {
    if ($memcache == null) {
    throw new Exception("memcache object is null, new the object first.");
    }
    $this->memcache = $memcache;
    $this->name = $name;
    $this->prefix = $prefix;
    $this->maxSize = $maxSize;
    $this->front = 0;
    $this->real = 0;
    $this->size = 0;
    }
    function __get($name)
    {
    return $this->get($name);
    }
    function __set($name, $value)
    {
    $this->add($name, $value);
    return $this;
    }
    function isEmpty()
    {
    return $this->size == 0;
    }
    function isFull()
    {
    return $this->size == $this->maxSize;
    }
    function enQueue($data)
    {
    if ($this->isFull()) {
    throw new Exception("Queue is Full");
    }
    $this->increment("size");
    $this->set($this->real, $data);
    $this->set("real", ($this->real + 1) % $this->maxSize);
    return $this;
    }
    function deQueue()
    {
    if ($this->isEmpty()) {
    throw new Exception("Queue is Empty");
    }
    $this->decrement("size");
    $this->delete($this->front);
    $this->set("front", ($this->front + 1) % $this->maxSize);
    return $this;
    }
    function getTop()
    {
    return $this->get($this->front);
    }
    function getAll()
    {
    return $this->getPage();
    }
    function getPage($offset = 0, $limit = 0)
    {
    if ($this->isEmpty() || $this->size < $offset) {
    return null;
    }
    $keys[] = $this->getKeyByPos(($this->front + $offset) % $this->maxSize);
    $num = 1;
    for ($pos = ($this->front + $offset + 1) % $this->maxSize; $pos != $this->real; $pos = ($pos + 1) % $this->maxSize)
    {
    $keys[] = $this->getKeyByPos($pos);
    $num++;
    if ($limit > 0 && $limit == $num) {
    break;
    }
    }
    return array_values($this->memcache->get($keys));
    }
    function makeEmpty()
    {
    $keys = $this->getAllKeys();
    foreach ($keys as $value) {
    $this->delete($value);
    }
    $this->delete("real");
    $this->delete("front");
    $this->delete("size");
    $this->delete("maxSize");
    }
    private function getAllKeys()
    {
    if ($this->isEmpty())
    {
    return array();
    }
    $keys[] = $this->getKeyByPos($this->front);
    for ($pos = ($this->front + 1) % $this->maxSize; $pos != $this->real; $pos = ($pos + 1) % $this->maxSize)
    {
    $keys[] = $this->getKeyByPos($pos);
    }
    return $keys;
    }
    private function add($pos, $data)
    {
    $this->memcache->add($this->getKeyByPos($pos), $data);
    return $this;
    }
    private function increment($pos)
    {
    return $this->memcache->increment($this->getKeyByPos($pos));
    }
    private function decrement($pos)
    {
    $this->memcache->decrement($this->getKeyByPos($pos));
    }
    private function set($pos, $data)
    {
    $this->memcache->set($this->getKeyByPos($pos), $data);
    return $this;
    }
    private function get($pos)
    {
    return $this->memcache->get($this->getKeyByPos($pos));
    }
    private function delete($pos)
    {
    return $this->memcache->delete($this->getKeyByPos($pos));
    }
    private function getKeyByPos($pos)
    {
    return $this->prefix . $this->name . $pos;
    }
    }

PHP+memcache implements message queue case sharing_PHP tutorial