VilniusPHP 0x4F: Coroutines in PHP: HTTP example

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README.md

Code examples: Coroutines in PHP

HTTP (cURL) example

Usage

docker-compose up

Open 127.0.0.1:8000

Where:

• sse.php – simulating dependent microservice
• client-simple.php – sumulating complex logic after full response
• client-reactive.php – simulating complex logic for each chunk

Reference

• Server Sent Events

Output

sse.php

data: 0

data: 1

data: 2

data: 3

data: 4

client-simple.php

2019-06-05 17:35:57.484100 Receiving...
2019-06-05 17:36:02.490600 Received
2019-06-05 17:36:02.491000 Closed
2019-06-05 17:36:02.491200  Transformation started
2019-06-05 17:36:02.491300    Result: data: 0
2019-06-05 17:36:02.991700  Transformation finished
2019-06-05 17:36:02.991900  Transformation started
2019-06-05 17:36:02.992200    Result: data: 1
2019-06-05 17:36:03.492400  Transformation finished
2019-06-05 17:36:03.492600  Transformation started
2019-06-05 17:36:03.492700    Result: data: 2
2019-06-05 17:36:03.992900  Transformation finished
2019-06-05 17:36:03.993200  Transformation started
2019-06-05 17:36:03.993300    Result: data: 3
2019-06-05 17:36:04.493500  Transformation finished
2019-06-05 17:36:04.493800  Transformation started
2019-06-05 17:36:04.493900    Result: data: 4
2019-06-05 17:36:04.994200  Transformation finished
2019-06-05 17:36:04.994400  Transformation started
2019-06-05 17:36:04.994500    Result: 
2019-06-05 17:36:05.494800  Transformation finished
2019-06-05 17:36:05.494900 Took: 8.01

client-reactive.php

2019-06-05 17:35:58.445000 Receiving...
2019-06-05 17:35:59.639100  <<< RECEIVED
2019-06-05 17:35:59.639200  Transformation started
2019-06-05 17:35:59.639300    Result: data: 0
2019-06-05 17:36:00.139500  Transformation finished
2019-06-05 17:36:00.639200  <<< RECEIVED
2019-06-05 17:36:00.639300  Transformation started
2019-06-05 17:36:00.639400    Result: data: 1
2019-06-05 17:36:01.139500  Transformation finished
2019-06-05 17:36:01.639600  <<< RECEIVED
2019-06-05 17:36:01.639800  Transformation started
2019-06-05 17:36:01.639900    Result: data: 2
2019-06-05 17:36:02.140100  Transformation finished
2019-06-05 17:36:02.639800  <<< RECEIVED
2019-06-05 17:36:02.640000  Transformation started
2019-06-05 17:36:02.640000    Result: data: 3
2019-06-05 17:36:03.140200  Transformation finished
2019-06-05 17:36:03.640200  <<< RECEIVED
2019-06-05 17:36:03.640400  Transformation started
2019-06-05 17:36:03.640600    Result: data: 4
2019-06-05 17:36:04.140800  Transformation finished
2019-06-05 17:36:04.141200 Received
2019-06-05 17:36:04.141400 Closed
2019-06-05 17:36:04.141500 Took: 5.7

client-reactive.php

<?php
function debug($message)
{
    $now = DateTime::createFromFormat('U.u', microtime(true));
    print $now->format("Y-m-d H:i:s.u") . ' ' . $message . PHP_EOL;
    flush();
    ob_flush();
}

function transform($data)
{
    debug(" Transformation started");
    debug("   Result: " . trim($data));
    usleep(500000);
    debug(" Transformation finished");
}

$reader = function ($curl, $data) {
    debug(" <<< RECEIVED");
    transform($data);
    return strlen($data);
};

function receive($url, $reader)
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_WRITEFUNCTION, $reader);

    debug("Receiving...");
    $output = curl_exec($ch);

    debug("Received");
    curl_close($ch);
    debug("Closed");

    return explode("\n\n", $output);
}

header('Content-type: text/plain');
$started = microtime(true);
$result = receive('http://example.nginx/sse.php', $reader);

$took = microtime(true) - $started;
debug("Took: " . round($took, 2));

client-simple.php

<?php

function debug($message)
{
    $now = DateTime::createFromFormat('U.u', microtime(true));
    print $now->format("Y-m-d H:i:s.u") . ' ' . $message . PHP_EOL;
    flush();
    ob_flush();
}

function transform($data)
{
    debug(" Transformation started");
    debug("   Result: " . trim($data));
    usleep(500000);
    debug(" Transformation finished");
}

function receive($url)
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

    debug("Receiving...");
    $output = curl_exec($ch);

    debug("Received");
    curl_close($ch);
    debug("Closed");

    return explode("\n\n", $output);
}

header('Content-type: text/plain');
$started = microtime(true);
$result = receive('http://example.nginx/sse.php');

foreach ($result as $item) {
    transform($item);
}

$took = microtime(true) - $started;
debug("Took: " . round($took, 2));

docker-compose.yml

version: '2.1'

services:
  example.nginx:
    container_name: example.nginx
    image: nginx:1.14.0
    ports:
      - "127.0.0.1:8000:80"
    volumes:
      - ./nginx-site.conf:/etc/nginx/conf.d/site.conf:ro
      - ./:/code

  example.php:
    container_name: example.php
    image: php:7.3.3-fpm
    volumes:
      - ./:/code

index.php

<a href="sse.php">Input service</a>
<br/>
<a href="client-simple.php">Simple</a>
<br/>
<a href="client-reactive.php">Reactive</a>

nginx-site.conf

server {
    listen 80 default_server;
    server_name _;

    index index.php index.html;
    root /code;

    location / {
        # try to serve file directly, fallback to index.php
        try_files $uri /index.php$is_args$args;
    }

    location ~ \.php$ {
        # Links to other container by its name
        resolver 127.0.0.11 valid=10s;
        set $upstream_example_php example.php;

        try_files $uri =404;
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        fastcgi_pass $upstream_example_php:9000;
        fastcgi_index index.php;
        include fastcgi_params;

        fastcgi_buffering off;
        proxy_buffering off;

        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
}

sse.php

<?php

//header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');

for ($i = 0; $i < 5; $i++) {
    print "data: $i\n\n";
    usleep(1000000);
    flush();
    ob_flush();
}