Merge pull request #304 from binaryfire/add-exponential-backoff

Feature | Add exponential backoff for retry interval

Author: Sammyjo20

src/Traits/Connector/SendsRequests.php

@@ -37,6 +37,7 @@ public function send(Request $request, MockClient $mockClient = null, callable $
         $maxTries = $request->tries ?? $this->tries ?? 1;
         $retryInterval = $request->retryInterval ?? $this->retryInterval ?? 0;
         $throwOnMaxTries = $request->throwOnMaxTries ?? $this->throwOnMaxTries ?? true;
+        $useExponentialBackoff = $request->useExponentialBackoff ?? $this->useExponentialBackoff ?? false;
 
         if ($maxTries <= 0) {
             $maxTries = 1;
@@ -53,7 +54,11 @@ public function send(Request $request, MockClient $mockClient = null, callable $
             // the interval (if it has been provided)
 
             if ($attempts > 1) {
-                usleep($retryInterval * 1000);
+                $sleepTime = $useExponentialBackoff
+                    ? $retryInterval * (2 ** ($attempts - 2)) * 1000
+                    : $retryInterval * 1000;
+
+                usleep($sleepTime);
             }
 
             try {
@@ -151,11 +156,12 @@ public function sendAsync(Request $request, MockClient $mockClient = null): Prom
      *
      * @param callable(\Throwable, \Saloon\Http\Request): (bool)|null $handleRetry
      */
-    public function sendAndRetry(Request $request, int $tries, int $interval = 0, callable $handleRetry = null, bool $throw = true, MockClient $mockClient = null): Response
+    public function sendAndRetry(Request $request, int $tries, int $interval = 0, callable $handleRetry = null, bool $throw = true, MockClient $mockClient = null, bool $useExponentialBackoff = false): Response
     {
         $request->tries = $tries;
         $request->retryInterval = $interval;
         $request->throwOnMaxTries = $throw;
+        $request->useExponentialBackoff = $useExponentialBackoff;
 
         return $this->send($request, $mockClient, $handleRetry);
     }

src/Traits/RequestProperties/HasTries.php

@@ -26,6 +26,13 @@ trait HasTries
      */
     public ?int $retryInterval = null;
 
+    /**
+     * Should Saloon use exponential backoff during retries?
+     *
+     * When true, Saloon will double the retry interval after each attempt.
+     */
+    public bool $useExponentialBackoff = false;
+
     /**
      * Should Saloon throw an exception after exhausting the maximum number of retries?
      *

tests/Feature/SendAndRetryTest.php

@@ -108,6 +108,27 @@
     expect(round(microtime(true) - $start))->toBeGreaterThanOrEqual(2);
 });
 
+test('a failed request can have an interval with exponential backoff between each attempt', function () {
+    $mockClient = new MockClient([
+        MockResponse::make(['name' => 'Sam'], 500), // 1,000
+        MockResponse::make(['name' => 'Gareth'], 500), // 2,000
+        MockResponse::make(['name' => 'Michael'], 500), // 4,000
+        MockResponse::make(['name' => 'Teodor'], 200),
+    ]);
+
+    $connector = new TestConnector;
+    $connector->withMockClient($mockClient);
+
+    $start = microtime(true);
+
+    $connector->sendAndRetry(new UserRequest, 4, 1000, useExponentialBackoff: true);
+
+    // It should be a duration of > 7000ms (7 seconds) because the there are four requests
+    // after the first.
+
+    expect(round(microtime(true) - $start))->toBeGreaterThanOrEqual(7);
+});
+
 test('an exception other than a request exception will not be retried', function () {
     $mockClient = new MockClient([
         MockResponse::make(['name' => 'Sam'], 500),