Improve HTTP/2 flow control parameters

examples/streaming/2-http1-http2.php

@@ -0,0 +1,79 @@
+<?php
+
+
+use Amp\File\File;
+use Amp\File\StatCache;
+use Amp\Http\Client\HttpClientBuilder;
+use Amp\Http\Client\HttpException;
+use Amp\Http\Client\Request;
+use Amp\Http\Client\Response;
+use Amp\Loop;
+use function Amp\getCurrentTime;
+
+require __DIR__ . '/../.helper/functions.php';
+
+// https://stackoverflow.com/a/2510540/2373138
+function formatBytes(int $size, int $precision = 2)
+{
+    $base = \log($size, 1024);
+    $suffixes = ['bytes', 'kB', 'MB', 'GB', 'TB'];
+
+    return \round(1024 ** ($base - \floor($base)), $precision) . ' ' . $suffixes[(int) $base];
+}
+
+function fetch(string $uri, array $protocolVersions): \Generator
+{
+    try {
+        $start = getCurrentTime();
+
+        // Instantiate the HTTP client
+        $client = HttpClientBuilder::buildDefault();
+
+        $request = new Request($uri);
+        $request->setProtocolVersions($protocolVersions);
+        $request->setBodySizeLimit(16 * 1024 * 1024); // 128 MB
+        $request->setTransferTimeout(120 * 1000); // 120 seconds
+
+        /** @var Response $response */
+        $response = yield $client->request($request);
+
+        print "\n";
+
+        $path = \tempnam(\sys_get_temp_dir(), "artax-streaming-");
+
+        /** @var File $file */
+        $file = yield Amp\File\open($path, "w");
+
+        $bytes = 0;
+
+        while (null !== $chunk = yield $response->getBody()->read()) {
+            yield $file->write($chunk);
+            $bytes += \strlen($chunk);
+
+            print "\r" . formatBytes($bytes) . '    '; // blanks to remove previous output
+        }
+
+        yield $file->close();
+
+        print \sprintf(
+            "\rDone in %.2f seconds with peak memory usage of %.2fMB.\n",
+            (getCurrentTime() - $start) / 1000,
+            (float) \memory_get_peak_usage(true) / 1024 / 1024
+        );
+
+        // We need to clear the stat cache, as we have just written to the file
+        StatCache::clear($path);
+        $size = yield Amp\File\size($path);
+
+        print \sprintf("%s has a size of %.2fMB\r\n", $path, (float) $size / 1024 / 1024);
+    } catch (HttpException $error) {
+        // If something goes wrong Amp will throw the exception where the promise was yielded.
+        // The HttpClient::request() method itself will never throw directly, but returns a promise.
+        echo $error;
+    }
+}
+
+Loop::run(static function () {
+    yield from fetch('http://1153288396.rsc.cdn77.org//img/cdn77-test-14mb.jpg', ['1.1']);
+    yield from fetch('https://1906714720.rsc.cdn77.org/img/cdn77-test-14mb.jpg', ['2']);
+});

src/Connection/Internal/Http2ConnectionProcessor.php

@@ -42,8 +42,8 @@ final class Http2ConnectionProcessor implements Http2Processor
     private const DEFAULT_MAX_FRAME_SIZE = 1 << 14;
     private const DEFAULT_WINDOW_SIZE = (1 << 16) - 1;
 
-    private const MINIMUM_WINDOW = (1 << 15) - 1;
-    private const MAX_INCREMENT = (1 << 16) - 1;
+    private const MINIMUM_WINDOW = 128 * 1024;
+    private const WINDOW_INCREMENT = 128 * 1024;
 
     // Milliseconds to wait for pong (PING with ACK) frame before closing the connection.
     private const PONG_TIMEOUT = 500;
@@ -448,15 +448,14 @@ public function handleHeaders(int $streamId, array $pseudo, array $headers): voi
             return $response;
         }));
 
-        if ($this->serverWindow <= self::MINIMUM_WINDOW) {
-            $this->serverWindow += self::MAX_INCREMENT;
-            $this->writeFrame(self::WINDOW_UPDATE, 0, 0, \pack("N", self::MAX_INCREMENT));
+        while ($this->serverWindow <= self::MINIMUM_WINDOW) {
+            $this->serverWindow += self::WINDOW_INCREMENT;
+            $this->writeFrame(self::WINDOW_UPDATE, 0, 0, \pack("N", self::WINDOW_INCREMENT));
         }
 
-        if ($stream->serverWindow <= self::MINIMUM_WINDOW) {
-            $stream->serverWindow += self::MAX_INCREMENT;
-
-            $this->writeFrame(self::WINDOW_UPDATE, self::NO_FLAG, $streamId, \pack("N", self::MAX_INCREMENT));
+        while ($stream->serverWindow <= self::MINIMUM_WINDOW) {
+            $stream->serverWindow += self::WINDOW_INCREMENT;
+            $this->writeFrame(self::WINDOW_UPDATE, self::NO_FLAG, $streamId, \pack("N", self::WINDOW_INCREMENT));
         }
 
         if (isset($headers["content-length"])) {
@@ -739,9 +738,9 @@ public function handleData(int $streamId, string $data): void
             return;
         }
 
-        if ($this->serverWindow <= self::MINIMUM_WINDOW) {
-            $this->serverWindow += self::MAX_INCREMENT;
-            $this->writeFrame(self::WINDOW_UPDATE, 0, 0, \pack("N", self::MAX_INCREMENT));
+        while ($this->serverWindow <= self::MINIMUM_WINDOW) {
+            $this->serverWindow += self::WINDOW_INCREMENT;
+            $this->writeFrame(self::WINDOW_UPDATE, 0, 0, \pack("N", self::WINDOW_INCREMENT));
         }
 
         $promise = $stream->body->emit($data);
@@ -753,10 +752,9 @@ public function handleData(int $streamId, string $data): void
 
             $stream = $this->streams[$streamId];
 
-            if ($stream->serverWindow <= self::MINIMUM_WINDOW) {
-                $stream->serverWindow += self::MAX_INCREMENT;
-
-                $this->writeFrame(self::WINDOW_UPDATE, self::NO_FLAG, $streamId, \pack("N", self::MAX_INCREMENT));
+            while ($stream->serverWindow <= self::MINIMUM_WINDOW) {
+                $stream->serverWindow += self::WINDOW_INCREMENT;
+                $this->writeFrame(self::WINDOW_UPDATE, self::NO_FLAG, $streamId, \pack("N", self::WINDOW_INCREMENT));
             }
         });
     }