How to communicate between php and boost library IPC? - php

Question

I have client and server in php communicating over shared memory, Now I would like to access this shred memory object using Boost.Interprocess how can I access it?
server.php:
function create_image($str){
// Create a blank image and add some text
$im = imagecreatetruecolor(300, 20);
$text_color = imagecolorallocate($im, 233, 14, 91);
$stringBanner=exec("date").$str;
imagestring($im, 1, 5, 5, $stringBanner , $text_color);
ob_start();
imagejpeg($im);
$i = ob_get_contents();
ob_get_clean();
imagedestroy($im);
return $i;
}
echo "\n".__FILE__."\n";
$shm_key = ftok(__FILE__, 't');
echo $shm_key."\n";
$shm_id = shmop_open($shm_key, "a", 0, 0);
if ($shm_id) {
//it is already created
shmop_delete($shm_id);
shmop_close($shm_id);
}
//you need to create it with shmop_open using "c" only
echo "try to create\n";
if(!$shm_id = shmop_open($shm_key, "c", 0777, 1024*4))exit(-1);
echo "ID ".$shm_id."\n";
$i=0;
for(;;){
sleep(1);
$s="i=".$i++;
$str=$i;
$im=serialize(create_image($str));
$data=serialize(strlen($im));
$shm_bytes_written = shmop_write($shm_id, $data, 0);
$shm_bytes_written = shmop_write($shm_id, $im, 32);
echo $shm_bytes_written." bytes is written: ".$s." ID = $shm_id\n";
}
client.php
<?php
$shm_key =1946222626;// ftok(__FILE__, 't');
$shm_id = shmop_open(
$shm_key, "a",
0644,1024*4
);
$s=shmop_size($shm_id);
$data = unserialize(
shmop_read( $shm_id, 0,
31)
);
$im = unserialize(
shmop_read( $shm_id, 32,
$data)
);
// Set the content type header - in this case image/jpeg
header('Content-Type: image/jpeg');
// Output the image
echo $im;
What kind of key I should provide to Boost to get this memory region?
boost_client.cpp
#include <boost/interprocess/shared_memory_object.hpp>
#include <iostream>
#include "sys/msg.h"
int main()
{
int msqid;
key_t key;
char f[]="??????";
int mid;
//key = ftok(, 't');
//msqid = msgget(key, 0666 | IPC_CREAT);
std::cout<<msqid<<std::endl;
boost::interprocess::shared_memory_object
shdmem(boost::interprocess::open_or_create,
f,//"shmem_server",
boost::interprocess::read_write);
shdmem.truncate(1024);
std::cout << shdmem.get_name() << std::endl;
boost::interprocess::offset_t size;
if (shdmem.get_size(size))
std::cout << size << std::endl;
}
EDIT:
Well I found the solution in Boost IPC library Docs:
XSI_KEY based example from boost Docs

Answer 1

I'm not an expert in what you're doing, but from what I read in your question and my knowledge, I would drop that pure IPC thing and wrap it into ZMQ (you'll find wrapper in every language you need). It's meant to solve those kind of problems and provide a single API that could run over IPC or more common TCP socket.