feat: [Firestore] publish the pipelines API to the stable branch (#8781)

* feat: publish the pipelines API to the stable branch

PiperOrigin-RevId: 840829013

Source-Link: googleapis/googleapis@534adc5

Source-Link: googleapis/googleapis-gen@38e4d8b
Copy-Tag: eyJwIjoiRmlyZXN0b3JlLy5Pd2xCb3QueWFtbCIsImgiOiIzOGU0ZDhiZjU3NzQ0NDJkZDc3ODkzNTE1NGY1YWU1NjUzN2Y1NGUyIn0=

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: gcf-owl-bot[bot]

Firestore/metadata/V1/Document.php

@@ -0,0 +1,76 @@
+<?php
+/*
+ * Copyright 2025 Google LLC
+ *
+ * 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
+ *
+ *     https://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.
+ */
+
+/*
+ * GENERATED CODE WARNING
+ * This file was automatically generated - do not edit!
+ */
+
+require_once __DIR__ . '/../../../vendor/autoload.php';
+
+// [START firestore_v1_generated_Firestore_ExecutePipeline_sync]
+use Google\ApiCore\ApiException;
+use Google\ApiCore\ServerStream;
+use Google\Cloud\Firestore\V1\Client\FirestoreClient;
+use Google\Cloud\Firestore\V1\ExecutePipelineRequest;
+use Google\Cloud\Firestore\V1\ExecutePipelineResponse;
+
+/**
+ * Executes a pipeline query.
+ *
+ * @param string $database Database identifier, in the form
+ *                         `projects/{project}/databases/{database}`.
+ */
+function execute_pipeline_sample(string $database): void
+{
+    // Create a client.
+    $firestoreClient = new FirestoreClient();
+
+    // Prepare the request message.
+    $request = (new ExecutePipelineRequest())
+        ->setDatabase($database);
+
+    // Call the API and handle any network failures.
+    try {
+        /** @var ServerStream $stream */
+        $stream = $firestoreClient->executePipeline($request);
+
+        /** @var ExecutePipelineResponse $element */
+        foreach ($stream->readAll() as $element) {
+            printf('Element data: %s' . PHP_EOL, $element->serializeToJsonString());
+        }
+    } catch (ApiException $ex) {
+        printf('Call failed with message: %s' . PHP_EOL, $ex->getMessage());
+    }
+}
+
+/**
+ * Helper to execute the sample.
+ *
+ * This sample has been automatically generated and should be regarded as a code
+ * template only. It will require modifications to work:
+ *  - It may require correct/in-range values for request initialization.
+ *  - It may require specifying regional endpoints when creating the service client,
+ *    please see the apiEndpoint client configuration option for more details.
+ */
+function callSample(): void
+{
+    $database = '[DATABASE]';
+
+    execute_pipeline_sample($database);
+}
+// [END firestore_v1_generated_Firestore_ExecutePipeline_sync]

Firestore/metadata/V1/ExplainStats.php

@@ -46,6 +46,8 @@
 use Google\Cloud\Firestore\V1\CreateDocumentRequest;
 use Google\Cloud\Firestore\V1\DeleteDocumentRequest;
 use Google\Cloud\Firestore\V1\Document;
+use Google\Cloud\Firestore\V1\ExecutePipelineRequest;
+use Google\Cloud\Firestore\V1\ExecutePipelineResponse;
 use Google\Cloud\Firestore\V1\GetDocumentRequest;
 use Google\Cloud\Firestore\V1\ListCollectionIdsRequest;
 use Google\Cloud\Firestore\V1\ListDocumentsRequest;
@@ -380,6 +382,28 @@ public function deleteDocument(DeleteDocumentRequest $request, array $callOption
         $this->startApiCall('DeleteDocument', $request, $callOptions)->wait();
     }
 
+    /**
+     * Executes a pipeline query.
+     *
+     * @example samples/V1/FirestoreClient/execute_pipeline.php
+     *
+     * @param ExecutePipelineRequest $request     A request to house fields associated with the call.
+     * @param array                  $callOptions {
+     *     Optional.
+     *
+     *     @type int $timeoutMillis
+     *           Timeout to use for this call.
+     * }
+     *
+     * @return ServerStream<ExecutePipelineResponse>
+     *
+     * @throws ApiException Thrown if the API call fails.
+     */
+    public function executePipeline(ExecutePipelineRequest $request, array $callOptions = []): ServerStream
+    {
+        return $this->startApiCall('ExecutePipeline', $request, $callOptions);
+    }
+
     /**
      * Gets a single document.
      *