shared memory array

shmop-array.php

<?php

/*

$port = 9050;

$proxy_score = new shmop_arr('x', 4*1024);

$proxy_score[$port] = isset($proxy_score[$port]) ? $proxy_score[$port]+1 : 1;

print_r($proxy_score->__toArray());

*/

class shmop_arr
implements ArrayAccess
{
	
	private $shmop_key;
	private $shmop_id;
	private $shmop_block_size = 2048;
	
	private $_data = array();
	
	private function _open(){
		if(!$this->shmop_id)
			$this->shmop_id = shmop_open($this->shmop_key, 'c', 0755, $this->shmop_block_size);
		return $this->shmop_id;
	}
	
	private function _close(){
		if($this->shmop_id) shmop_close($this->shmop_id);
		$this->shmop_id = null;
	}
	
	private function _read(){
		$this->_open();
		
		$this->_data = array();
		
		$size = shmop_size($this->shmop_id);
		$d = $size ? shmop_read($this->shmop_id, 0, $size) : '';
		
		$this->_close();
		
		if(!strlen($d)){
			return;
		}
		
		$d = substr($d, 0, strpos($d, "\0"));
		if(strlen($d)){
			$this->_data = unserialize($d);
		}
		
	}
	
	private function _write(){
		$this->_open();
		shmop_write($this->shmop_id, serialize($this->_data)."\0", 0);
		$this->_close();
	}
	
	public function __construct($project = "\0", $shmop_block_size = null){
		$this->shmop_key = ftok(__FILE__, $project);
		if(isset($shmop_block_size)) $this->shmop_block_size = $shmop_block_size;
	}
	
	public function __get($key){
		$this->_read();
		return isset($this->_data[$key]) ? $this->_data[$key] : null;
	}
	
	public function __set($key, $value){
		$this->_read();
		$this->_data[$key] = $value;
		$this->_write();
	}
	
	public function __isset($key){
		$this->_read();
		return isset($this->_data[$key]);
	}
	
	public function __unset($key){
		$this->_read();
		unset($this->_data[$key]);
		$this->_write();
	}
	
	public function __toArray(){
		$this->_read();
		return $this->_data;
	}
	
	public function __toString(){
		return serialize($this->__toArray());
	}
	
	public function offsetExists($offset){
		return $this->__isset($offset);
	}
	
	public function offsetGet($offset){
		return $this->__get($offset);
	}
	
	public function offsetSet($offset, $value){
		return $this->__set($offset, $value);
	}
	
	public function offsetUnset($offset){
		return $this->__unset($offset, $value);
	}
	
}