commit 3a4b04c1ecec5f63980af13e3ae6c7c20e22c621
Author: Sergio Álvarez <code@sergio.am>
Date:   Fri Nov 22 20:34:10 2019 +0100

    testing promises with php

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..d1502b0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+vendor/
+composer.lock
diff --git a/promises/composer.json b/promises/composer.json
new file mode 100644
index 0000000..70b41a8
--- /dev/null
+++ b/promises/composer.json
@@ -0,0 +1,8 @@
+{
+    "require": {
+        "guzzlehttp/guzzle": "^6.4"
+    },
+    "autoload": {
+        "files": ["lib.php"]
+    }
+}
diff --git a/promises/index.php b/promises/index.php
new file mode 100644
index 0000000..c64cba2
--- /dev/null
+++ b/promises/index.php
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+<?php
+
+// https://xrg.io/tests/promises
+
+require_once(dirname(__FILE__) .'/vendor/autoload.php');
+
+// lib.php, helper functions
+Lib\plain();
+Lib\printf('load');
+
+use GuzzleHttp\Client;
+use GuzzleHttp\Promise;
+use GuzzleHttp\Pool;
+use GuzzleHttp\Psr7\Response;
+use GuzzleHttp\Promise\EachPromise;
+
+Lib\printf('client');
+
+$client = new Client();
+
+Lib\printf('requests');
+
+$requests = function ($n) use ($client) {
+    $uri = 'https://xrg.io/tests/promises/sleep.php?';
+
+    for ($i = 0; $i < $n; $i++) {
+        yield function() use ($client, $uri, $i) {
+            return $client->getAsync($uri . http_build_query(['o' => $i, 's' => random_int(1, 5)]));
+        };
+    }
+};
+
+Lib\printf('pool');
+
+$pool = new Pool($client, $requests(3), [
+    'concurrency' => 5,
+    'fulfilled' => function ($response, $index) {
+        Lib\printf('  i='. $index .' '. $response->getBody());
+    },
+    'rejected' => function ($reason, $index) {
+        Lib\printf('  '. $index .' '. $reason);
+    },
+]);
+
+Lib\printf('promise');
+// Initiate the transfers and create a promise
+$promise = $pool->promise();
+
+Lib\printf('wait');
+// Force the pool of requests to complete.
+$promise->wait();
+
+Lib\printf('end');
diff --git a/promises/lib.php b/promises/lib.php
new file mode 100644
index 0000000..463cd16
--- /dev/null
+++ b/promises/lib.php
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+<?php
+
+namespace Lib;
+
+function microtime_calc(): array
+{
+    static $last = null; // 1st time
+    static $sum = 0.0; // 1st time
+    $mt = microtime(true);
+    $diff = is_null($last)? 0.0: bcsub($mt, $last);
+    $sum = bcadd($sum, $diff);
+    $last = $mt;
+    return [$sum, $diff];
+}
+
+function printf(string $str, ...$args): int
+{
+    return \printf("∑%.6f +%.6f | ". $str."\n", ...microtime_calc(), ...$args);
+}
+
+function plain(): void
+{
+    header('Content-Type: text/plain');
+}
diff --git a/promises/sleep.php b/promises/sleep.php
new file mode 100644
index 0000000..5786993
--- /dev/null
+++ b/promises/sleep.php
@@ -0,0 +1,6 @@
+<?php
+
+$s = ((int)$_GET['s']?: random_int(2, 5));// * 1000000;
+sleep($s);
+//printf("\$µs=%d", $s);
+printf("\$s=%d", $s);