feat(Storage): add retry configuration example. (#2149)

Author: piotrgradzinski

storage/composer.json

@@ -1,6 +1,6 @@
 {
     "require": {
-        "google/cloud-storage": "^1.28.0",
+        "google/cloud-storage": "^1.48.3",
         "paragonie/random_compat": "^9.0.0"
     },
     "require-dev": {

storage/src/configure_retries.php

@@ -0,0 +1,127 @@
+<?php
+
+/**
+ * Copyright 2025 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * For instructions on how to run the full sample:
+ *
+ * @see https://github.com/GoogleCloudPlatform/php-docs-samples/tree/main/storage/README.md
+ */
+
+namespace Google\Cloud\Samples\Storage;
+
+# [START storage_configure_retries]
+use Google\Cloud\Storage\StorageClient;
+
+/**
+ * Configures retries with customizations.
+ *
+ * @param string $bucketName The name of your Cloud Storage bucket.
+ *        (e.g. 'my-bucket')
+ */
+function configure_retries(string $bucketName): void
+{
+    $storage = new StorageClient([
+        // The maximum number of automatic retries attempted before returning
+        // the error.
+        // Default: 3
+        'retries' => 10,
+
+        // Exponential backoff settings
+        // Retry strategy to signify that we never want to retry an operation
+        // even if the error is retryable.
+        // Default: StorageClient::RETRY_IDEMPOTENT
+        'retryStrategy' => StorageClient::RETRY_ALWAYS,
+
+        // Executes a delay
+        // Defaults to utilizing `usleep`.
+        // Function signature should match: `function (int $delay) : void`.
+        // This function is mostly used internally, so the tests don't wait
+        // the time of the delay to run.
+        'restDelayFunction' => function ($delay) {
+            usleep($delay);
+        },
+
+        // Sets the conditions for determining how long to wait between attempts to retry.
+        // Function signature should match: `function (int $attempt) : int`.
+        // Allows to change the initial retry delay, retry delay multiplier and maximum retry delay.
+        'restCalcDelayFunction' => fn ($attempt) => ($attempt + 1) * 100,
+
+        // Sets the conditions for whether or not a request should attempt to retry.
+        // Function signature should match: `function (\Exception $ex) : bool`.
+        'restRetryFunction' => function (\Exception $e) {
+            // Custom logic: ex. only retry if the error code is 404.
+            return $e->getCode() === 404;
+        },
+
+        // Runs after the restRetryFunction. This might be used to simply consume the
+        // exception and $arguments b/w retries. This returns the new $arguments thus allowing
+        // modification on demand for $arguments. For ex: changing the headers in b/w retries.
+        'restRetryListener' => function (\Exception $e, $retryAttempt, &$arguments) {
+            // logic
+        },
+    ]);
+    $bucket = $storage->bucket($bucketName);
+    $operationRetriesOverrides = [
+        // The maximum number of automatic retries attempted before returning
+        // the error.
+        // Default: 3
+        'retries' => 10,
+
+        // Exponential backoff settings
+        // Retry strategy to signify that we never want to retry an operation
+        // even if the error is retryable.
+        // Default: StorageClient::RETRY_IDEMPOTENT
+        'retryStrategy' => StorageClient::RETRY_ALWAYS,
+
+        // Executes a delay
+        // Defaults to utilizing `usleep`.
+        // Function signature should match: `function (int $delay) : void`.
+        // This function is mostly used internally, so the tests don't wait
+        // the time of the delay to run.
+        'restDelayFunction' => function ($delay) {
+            usleep($delay);
+        },
+
+        // Sets the conditions for determining how long to wait between attempts to retry.
+        // Function signature should match: `function (int $attempt) : int`.
+        // Allows to change the initial retry delay, retry delay multiplier and maximum retry delay.
+        'restCalcDelayFunction' => fn ($attempt) => ($attempt + 1) * 100,
+
+        // Sets the conditions for whether or not a request should attempt to retry.
+        // Function signature should match: `function (\Exception $ex) : bool`.
+        'restRetryFunction' => function (\Exception $e) {
+            // Custom logic: ex. only retry if the error code is 404.
+            return $e->getCode() === 404;
+        },
+
+        // Runs after the restRetryFunction. This might be used to simply consume the
+        // exception and $arguments b/w retries. This returns the new $arguments thus allowing
+        // modification on demand for $arguments. For ex: changing the headers in b/w retries.
+        'restRetryListener' => function (\Exception $e, $retryAttempt, &$arguments) {
+            // logic
+        },
+    ];
+    foreach ($bucket->objects($operationRetriesOverrides) as $object) {
+        printf('Object: %s' . PHP_EOL, $object->name());
+    }
+}
+# [END storage_configure_retries]
+
+// The following 2 lines are only needed to run the samples
+require_once __DIR__ . '/../../testing/sample_helpers.php';
+\Google\Cloud\Samples\execute_sample(__FILE__, __NAMESPACE__, $argv);