<?php

class MemoryManager
{
    public function __construct($maxSize, $maxClients)
    {

        // Validation
        $shm_key = ftok(__FILE__, 't');
        $this->_memoryPointer = shmop_open($shm_key, "c", 0644, $maxSize * $maxClients);
        $this->_maxSize = $maxSize;
        $this->_maxClient = $maxSize;
    }

    public function writeClientData($clientId, $data)
    {
        $paddedData = str_pad($data, $this->_maxSize, $this->_padSymbol);
        shmop_write(
            $this->_memoryPointer,
            $paddedData,
            ($clientId - 1) * $this->_maxSize
        );
    }

    public function readClientData($clientId)
    {
        $data = shmop_read(
            $this->_memoryPointer,
            ($clientId - 1) * $this->_maxSize,
            $this->_maxSize
        );

        return trim($data, $this->_padSymbol);
    }

    public function close()
    {
        shmop_delete($this->_memoryPointer);
        shmop_close($this->_memoryPointer);
    }


    private $_padSymbol = "|";
}


$mem = new MemoryManager(100, 100);

$mem->writeClientData(1, 'aaaaa');
$mem->writeClientData(2, 'bbbbbbbb');
var_dump($mem->readClientData(1));
var_dump($mem->readClientData(2));


$mem->writeClientData(2, 'cc');
var_dump($mem->readClientData(2));


$mem->close();