feat(subscription): ordered messages (#560)

callmehiphop · web-flow · commit 38502ad87c9b · 2019-03-27T09:23:44.000-07:00
diff --git a/proto/pubsub.d.ts b/proto/pubsub.d.ts
@@ -767,6 +767,9 @@ export namespace google {
 
                 /** PubsubMessage publishTime */
                 publishTime?: (google.protobuf.ITimestamp|null);
+
+                /** PubsubMessage orderingKey */
+                orderingKey?: (string|null);
             }
 
             /** Represents a PubsubMessage. */
@@ -790,6 +793,9 @@ export namespace google {
                 /** PubsubMessage publishTime. */
                 public publishTime?: (google.protobuf.ITimestamp|null);
 
+                /** PubsubMessage orderingKey. */
+                public orderingKey: string;
+
                 /**
                  * Creates a new PubsubMessage instance using the specified properties.
                  * @param [properties] Properties to set
@@ -1941,6 +1947,9 @@ export namespace google {
                 /** Subscription labels */
                 labels?: ({ [k: string]: string }|null);
 
+                /** Subscription enableMessageOrdering */
+                enableMessageOrdering?: (boolean|null);
+
                 /** Subscription expirationPolicy */
                 expirationPolicy?: (google.pubsub.v1.IExpirationPolicy|null);
             }
@@ -1975,6 +1984,9 @@ export namespace google {
                 /** Subscription labels. */
                 public labels: { [k: string]: string };
 
+                /** Subscription enableMessageOrdering. */
+                public enableMessageOrdering: boolean;
+
                 /** Subscription expirationPolicy. */
                 public expirationPolicy?: (google.pubsub.v1.IExpirationPolicy|null);
 
diff --git a/src/subscriber.ts b/src/subscriber.ts
@@ -21,31 +21,15 @@ import {EventEmitter} from 'events';
 import {ClientStub} from 'google-gax';
 import {common as protobuf} from 'protobufjs';
 
+import {google} from '../proto/pubsub';
+
 import {Histogram} from './histogram';
 import {FlowControlOptions, LeaseManager} from './lease-manager';
 import {AckQueue, BatchOptions, ModAckQueue} from './message-queues';
 import {MessageStream, MessageStreamOptions} from './message-stream';
 import {Subscription} from './subscription';
 
-/**
- * @see https://cloud.google.com/pubsub/docs/reference/rest/v1/projects.subscriptions/pull#ReceivedMessage
- */
-interface ReceivedMessage {
-  ackId: string;
-  message: {
-    attributes: {},
-    data: Buffer,
-    messageId: string,
-    publishTime: protobuf.ITimestamp
-  };
-}
-
-/**
- * @see https://cloud.google.com/pubsub/docs/reference/rest/v1/projects.subscriptions/pull#body.PullResponse
- */
-export interface PullResponse {
-  receivedMessages: ReceivedMessage[];
-}
+export type PullResponse = google.pubsub.v1.IPullResponse;
 
 /**
  * Date object with nanosecond precision. Supports all standard Date arguments
@@ -65,6 +49,7 @@ export interface PullResponse {
  *   //   attributes: {key: 'value'},
  *   //   data: Buffer.from('Hello, world!),
  *   //   id: '1551297743043',
+ *   //   orderingKey: 'ordering-key',
  *   //   publishTime: new PreciseDate('2019-02-27T20:02:19.029534186Z'),
  *   //   received: 1551297743043,
  *   //   length: 13
@@ -76,6 +61,7 @@ export class Message {
   attributes: {};
   data: Buffer;
   id: string;
+  orderingKey?: string;
   publishTime: PreciseDate;
   received: number;
   private _handled: boolean;
@@ -87,43 +73,59 @@ export class Message {
    * @param {Subscriber} sub The parent subscriber.
    * @param {object} message The raw message response.
    */
-  constructor(sub: Subscriber, {ackId, message}: ReceivedMessage) {
+  constructor(sub: Subscriber, {ackId,
+                                message}: google.pubsub.v1.IReceivedMessage) {
     /**
      * This ID is used to acknowledge the message.
      *
      * @name Message#ackId
      * @type {string}
      */
-    this.ackId = ackId;
+    this.ackId = ackId!;
     /**
      * Optional attributes for this message.
      *
      * @name Message#attributes
      * @type {object}
      */
-    this.attributes = message.attributes || {};
+    this.attributes = message!.attributes || {};
     /**
      * The message data as a Buffer.
      *
      * @name Message#data
      * @type {Buffer}
      */
-    this.data = message.data;
+    this.data = message!.data as Buffer;
     /**
      * ID of the message, assigned by the server when the message is published.
      * Guaranteed to be unique within the topic.
      *
      * @name Message#id
      * @type {string}
      */
-    this.id = message.messageId;
+    this.id = message!.messageId!;
+    /**
+     * Identifies related messages for which publish order should be respected.
+     * If a `Subscription` has `enableMessageOrdering` set to `true`, messages
+     * published with the same `orderingKey` value will be delivered to
+     * subscribers in the order in which they are received by the Pub/Sub
+     * system.
+     *
+     * **EXPERIMENTAL:** This feature is part of a closed alpha release. This
+     * API might be changed in backward-incompatible ways and is not recommended
+     * for production use. It is not subject to any SLA or deprecation policy.
+     *
+     * @name Message#orderingKey
+     * @type {string}
+     */
+    this.orderingKey = message!.orderingKey!;
     /**
      * The time at which the message was published.
      *
      * @name Message#publishTime
      * @type {external:PreciseDate}
      */
-    this.publishTime = new PreciseDate(message.publishTime as DateStruct);
+    this.publishTime = new PreciseDate(message!.publishTime as DateStruct);
     /**
      * The time at which the message was recieved by the subscription.
      *
@@ -424,7 +426,7 @@ export class Subscriber extends EventEmitter {
    * @private
    */
   private _onData({receivedMessages}: PullResponse): void {
-    for (const data of receivedMessages) {
+    for (const data of receivedMessages!) {
       const message = new Message(this, data);
 
       if (this.isOpen) {
diff --git a/test/subscriber.ts b/test/subscriber.ts
@@ -130,6 +130,7 @@ const RECEIVED_MESSAGE = {
     attributes: {},
     data: Buffer.from('Hello, world!'),
     messageId: uuid.v4(),
+    orderingKey: 'ordering-key',
     publishTime: {seconds: 12, nanos: 32}
   }
 };
@@ -608,6 +609,11 @@ describe('Subscriber', () => {
         assert.strictEqual(message.id, RECEIVED_MESSAGE.message.messageId);
       });
 
+      it('should localize orderingKey', () => {
+        assert.strictEqual(
+            message.orderingKey, RECEIVED_MESSAGE.message.orderingKey);
+      });
+
       it('should localize publishTime', () => {
         const m = new Message(subscriber, RECEIVED_MESSAGE);
         const timestamp = m.publishTime as unknown as FakePreciseDate;
