Refactoring: Remove Connection::consume, add NsqException, add tests, allow dynamic change timeout in subscriber

src/Subscriber.php

@@ -5,37 +5,85 @@ declare(strict_types=1);
 namespace Nsq;
 
 use Generator;
+use function get_debug_type;
+use function microtime;
+use function sprintf;
 
 final class Subscriber extends Reader
 {
-    public const STOP = true;
+    public const STOP = 0;
+    public const CHANGE_TIMEOUT = 1;
 
     /**
-     * @psalm-return Generator<int, Envelope|null, true|null, void>
+     * @psalm-return Generator<int, Envelope|null, int|float|null, void>
      */
-    public function subscribe(string $topic, string $channel, ?float $timeout = 0): Generator
+    public function subscribe(string $topic, string $channel, float $timeout = 0): Generator
     {
         $this->sub($topic, $channel);
-        $this->rdy(1);
 
         while (true) {
+            $this->rdy(1);
+
             $message = $this->consume($timeout);
 
-            if (null === $message) {
-                if (self::STOP === yield null) {
-                    break;
-                }
+            $command = yield null === $message ? null : new Envelope($message, $this);
 
-                continue;
-            }
-
-            if (self::STOP === yield new Envelope($message, $this)) {
+            if (self::STOP === $command) {
                 break;
             }
 
-            $this->rdy(1);
+            if (self::CHANGE_TIMEOUT === $command) {
+                $newTimeout = yield null;
+
+                if (!\is_float($newTimeout)) {
+                    throw new Exception(sprintf('Timeout must be float, "%s" given.', get_debug_type($newTimeout)));
+                }
+
+                $timeout = $newTimeout;
+            }
         }
 
         $this->disconnect();
     }
+
+    private function consume(float $timeout): ?Message
+    {
+        $deadline = microtime(true) + $timeout;
+
+        $buffer = $this->receive($timeout);
+        if (null === $buffer) {
+            return null;
+        }
+
+        $type = $buffer->consumeUint32();
+
+        if (self::TYPE_RESPONSE === $type) {
+            $response = $buffer->flush();
+
+            if (self::HEARTBEAT === $response) {
+                $this->send('NOP'.PHP_EOL);
+
+                return $this->consume(
+                    ($currentTime = microtime(true)) > $deadline ? 0 : $deadline - $currentTime
+                );
+            }
+
+            throw new Exception(sprintf('Unexpected response: %s', $response));
+        }
+
+        if (self::TYPE_ERROR === $type) {
+            throw new Exception(sprintf('NSQ return error: "%s"', $buffer->flush()));
+        }
+
+        if (self::TYPE_MESSAGE !== $type) {
+            throw new Exception(sprintf('Expecting "%s" type, but NSQ return: "%s"', self::TYPE_MESSAGE, $type));
+        }
+
+        $timestamp = $buffer->consumeInt64();
+        $attempts = $buffer->consumeUint16();
+        $id = $buffer->consume(self::BYTES_ID);
+        $body = $buffer->flush();
+
+        return new Message($timestamp, $attempts, $id, $body);
+    }
 }