@zaplify/gcp-pubsub
Version:
Cloud Pub/Sub Client Library for Node.js
444 lines • 15.8 kB
JavaScript
;
/*!
* Copyright 2017 Google Inc. All Rights Reserved.
*
* 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.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.Topic = void 0;
const paginator_1 = require("@google-cloud/paginator");
const iam_1 = require("./iam");
const publisher_1 = require("./publisher");
const flow_publisher_1 = require("./publisher/flow-publisher");
const util_1 = require("./util");
const snakeCase = require("lodash.snakecase");
/**
* A Topic object allows you to interact with a Cloud Pub/Sub topic.
*
* @class
* @param {PubSub} pubsub PubSub object.
* @param {string} name Name of the topic.
* @param {PublishOptions} [options] Publisher configuration object.
*
* @example
* ```
* const {PubSub} = require('@google-cloud/pubsub');
* const pubsub = new PubSub();
*
* const topic = pubsub.topic('my-topic');
*
* ```
* @example To enable message ordering, set `enableMessageOrdering` to true. Please note that this does not persist to an actual topic.
* ```
* const topic = pubsub.topic('ordered-topic', {enableMessageOrdering: true});
* ```
*/
class Topic {
constructor(pubsub, name, options) {
this.getSubscriptionsStream = paginator_1.paginator.streamify('getSubscriptions');
/**
* The fully qualified name of this topic.
* @name Topic#name
* @type {string}
*/
this.name = Topic.formatName_(pubsub.projectId, name);
this.publisher = new publisher_1.Publisher(this, options);
/**
* The parent {@link PubSub} instance of this topic instance.
* @name Topic#pubsub
* @type {PubSub}
*/
/**
* The parent {@link PubSub} instance of this topic instance.
* @name Topic#parent
* @type {PubSub}
*/
this.parent = this.pubsub = pubsub;
this.request = pubsub.request.bind(pubsub);
/**
* [IAM (Identity and Access
* Management)](https://cloud.google.com/pubsub/access_control) allows you
* to set permissions on individual resources and offers a wider range of
* roles: editor, owner, publisher, subscriber, and viewer. This gives you
* greater flexibility and allows you to set more fine-grained access
* control.
*
* *The IAM access control features described in this document are Beta,
* including the API methods to get and set IAM policies, and to test IAM
* permissions. Cloud Pub/Sub's use of IAM features is not covered by
* any SLA or deprecation policy, and may be subject to
* backward-incompatible changes.*
*
* @name Topic#iam
* @mixes IAM
*
* @see [Access Control Overview]{@link https://cloud.google.com/pubsub/access_control}
* @see [What is Cloud IAM?]{@link https://cloud.google.com/iam/}
*
* @example
* ```
* const {PubSub} = require('@google-cloud/pubsub');
* const pubsub = new PubSub();
*
* const topic = pubsub.topic('my-topic');
*
* //-
* // Get the IAM policy for your topic.
* //-
* topic.iam.getPolicy((err, policy) => {
* console.log(policy);
* });
*
* //-
* // If the callback is omitted, we'll return a Promise.
* //-
* topic.iam.getPolicy().then((data) => {
* const policy = data[0];
* const apiResponse = data[1];
* });
* ```
*/
this.iam = new iam_1.IAM(pubsub, this.name);
}
flush(callback) {
// It doesn't matter here if callback is undefined; the Publisher
// flush() will handle it.
this.publisher.flush(callback);
}
create(optsOrCallback, callback) {
const gaxOpts = typeof optsOrCallback === 'object' ? optsOrCallback : {};
callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
this.pubsub.createTopic(this.name, gaxOpts, callback);
}
createSubscription(name, optsOrCallback, callback) {
const options = typeof optsOrCallback === 'object' ? optsOrCallback : {};
callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
this.pubsub.createSubscription(this, name, options, callback);
}
delete(optsOrCallback, callback) {
const gaxOpts = typeof optsOrCallback === 'object' ? optsOrCallback : {};
callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
const reqOpts = {
topic: this.name,
};
this.request({
client: 'PublisherClient',
method: 'deleteTopic',
reqOpts,
gaxOpts: gaxOpts,
}, callback);
}
exists(callback) {
this.getMetadata(err => {
if (!err) {
callback(null, true);
return;
}
if (err.code === 5) {
callback(null, false);
return;
}
callback(err);
});
}
get(optsOrCallback, callback) {
const gaxOpts = typeof optsOrCallback === 'object' ? optsOrCallback : {};
callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
const autoCreate = !!gaxOpts.autoCreate;
delete gaxOpts.autoCreate;
this.getMetadata(gaxOpts, (err, apiResponse) => {
if (!err) {
callback(null, this, apiResponse);
return;
}
if (err.code !== 5 || !autoCreate) {
callback(err, null, apiResponse);
return;
}
this.create(gaxOpts, callback);
});
}
getMetadata(optsOrCallback, callback) {
const gaxOpts = typeof optsOrCallback === 'object' ? optsOrCallback : {};
callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
const reqOpts = {
topic: this.name,
};
this.request({
client: 'PublisherClient',
method: 'getTopic',
reqOpts,
gaxOpts: gaxOpts,
}, (err, apiResponse) => {
if (!err) {
this.metadata = apiResponse;
}
callback(err, apiResponse);
});
}
getSubscriptions(optsOrCallback, callback) {
const options = typeof optsOrCallback === 'object' ? optsOrCallback : {};
callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
const reqOpts = Object.assign({
topic: this.name,
}, options);
delete reqOpts.gaxOpts;
delete reqOpts.autoPaginate;
const gaxOpts = Object.assign({
autoPaginate: options.autoPaginate,
}, options.gaxOpts);
this.request({
client: 'PublisherClient',
method: 'listTopicSubscriptions',
reqOpts,
gaxOpts,
}, (err, subNames, ...args) => {
let subscriptions;
if (subNames) {
subscriptions = subNames.map((sub) => this.subscription(sub));
}
callback(err, subscriptions, ...args);
});
}
publish(data, attrsOrCb, callback) {
const attributes = typeof attrsOrCb === 'object' ? attrsOrCb : {};
callback = typeof attrsOrCb === 'function' ? attrsOrCb : callback;
return this.publishMessage({ data, attributes }, callback);
}
publishJSON(json, attrsOrCb, callback) {
if (!json || typeof json !== 'object') {
throw new Error('First parameter should be an object.');
}
const attributes = typeof attrsOrCb === 'object' ? attrsOrCb : {};
callback = typeof attrsOrCb === 'function' ? attrsOrCb : callback;
return this.publishMessage({ json, attributes }, callback);
}
publishMessage(message, callback) {
// Make a copy to ensure that any changes we make to it will not
// propagate up to the user's data.
message = Object.assign({}, message);
if (message.json && typeof message.json === 'object') {
message.data = Buffer.from(JSON.stringify(message.json));
delete message.json;
}
return this.publisher.publishMessage(message, callback);
}
/**
* Creates a FlowControlledPublisher for this Topic.
*
* FlowControlledPublisher is a helper that lets you control how many messages
* are simultaneously queued to send, to avoid ballooning memory usage on
* a low bandwidth connection to Pub/Sub.
*
* Note that it's perfectly fine to create more than one on the same Topic.
* The actual flow control settings on the Topic will apply across all
* FlowControlledPublisher objects on that Topic.
*
* @returns {FlowControlledPublisher} The flow control helper.
*/
flowControlled() {
return new flow_publisher_1.FlowControlledPublisher(this.publisher);
}
/**
* In the event that the client fails to publish an ordered message, all
* subsequent publish calls using the same ordering key will fail. Calling
* this method will disregard the publish failure, allowing the supplied
* ordering key to be used again in the future.
*
* @param {string} orderingKey The ordering key in question.
*
* @example
* ```
* const {PubSub} = require('@google-cloud/pubsub');
* const pubsub = new PubSub();
* const topic = pubsub.topic('my-topic', {messageOrdering: true});
*
* const orderingKey = 'foo';
* const data = Buffer.from('Hello, order!');
*
* topic.publishMessage({data, orderingKey}, err => {
* if (err) {
* topic.resumePublishing(orderingKey);
* }
* });
* ```
*/
resumePublishing(orderingKey) {
this.publisher.resumePublishing(orderingKey);
}
setMetadata(options, optsOrCallback, callback) {
const gaxOpts = typeof optsOrCallback === 'object' ? optsOrCallback : {};
callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
const topic = Object.assign({ name: this.name }, options);
const updateMask = { paths: Object.keys(options).map(snakeCase) };
const reqOpts = { topic, updateMask };
this.request({
client: 'PublisherClient',
method: 'updateTopic',
reqOpts,
gaxOpts,
}, callback);
}
/**
* Set the publisher options.
*
* @param {PublishOptions} options The publisher options.
*
* @example
* ```
* const {PubSub} = require('@google-cloud/pubsub');
* const pubsub = new PubSub();
*
* const topic = pubsub.topic('my-topic');
*
* topic.setPublishOptions({
* batching: {
* maxMilliseconds: 10
* }
* });
* ```
*/
setPublishOptions(options) {
this.publisher.setOptions(options);
}
/**
* Get the default publisher options. These may be modified and passed
* back into {@link Topic#setPublishOptions}.
*
* @example
* ```
* const {PubSub} = require('@google-cloud/pubsub');
* const pubsub = new PubSub();
*
* const topic = pubsub.topic('my-topic');
*
* const defaults = topic.getPublishOptionDefaults();
* defaults.batching.maxMilliseconds = 10;
* topic.setPublishOptions(defaults);
* ```
*/
getPublishOptionDefaults() {
// Generally I'd leave this as a static, but it'll be easier for users to
// get at when they're using the veneer objects.
return this.publisher.getOptionDefaults();
}
/**
* Create a Subscription object. This command by itself will not run any API
* requests. You will receive a {module:pubsub/subscription} object,
* which will allow you to interact with a subscription.
*
* @throws {Error} If subscription name is omitted.
*
* @param {string} name Name of the subscription.
* @param {SubscriberOptions} [options] Configuration object.
* @return {Subscription}
*
* @example
* ```
* const {PubSub} = require('@google-cloud/pubsub');
* const pubsub = new PubSub();
*
* const topic = pubsub.topic('my-topic');
* const subscription = topic.subscription('my-subscription');
*
* // Register a listener for `message` events.
* subscription.on('message', (message) => {
* // Called every time a message is received.
* // message.id = ID of the message.
* // message.ackId = ID used to acknowledge the message receival.
* // message.data = Contents of the message.
* // message.attributes = Attributes of the message.
* // message.publishTime = Timestamp when Pub/Sub received the message.
* });
* ```
*/
subscription(name, options) {
options = options || {};
options.topic = this;
return this.pubsub.subscription(name, options);
}
/**
* Format the name of a topic. A Topic's full name is in the format of
* 'projects/{projectId}/topics/{topicName}'.
*
* @private
*
* @return {string}
*/
static formatName_(projectId, name) {
// Simple check if the name is already formatted.
if (name.indexOf('/') > -1) {
return name;
}
return 'projects/' + projectId + '/topics/' + name;
}
}
exports.Topic = Topic;
/**
* Get a list of the {module:pubsub/subscription} objects registered to this
* topic as a readable object stream.
*
* @method PubSub#getSubscriptionsStream
* @param {GetSubscriptionsRequest} [options] Configuration object. See
* {@link PubSub#getSubscriptions} for a complete list of options.
* @returns {ReadableStream} A readable stream of {@link Subscription} instances.
*
* @example
* ```
* const {PubSub} = require('@google-cloud/pubsub');
* const pubsub = new PubSub();
*
* const topic = pubsub.topic('my-topic');
*
* topic.getSubscriptionsStream()
* .on('error', console.error)
* .on('data', (subscription) => {
* // subscription is a Subscription object.
* })
* .on('end', () => {
* // All subscriptions retrieved.
* });
*
* //-
* // If you anticipate many results, you can end a stream early to prevent
* // unnecessary processing and API requests.
* //-
* topic.getSubscriptionsStream()
* .on('data', function(subscription) {
* this.end();
* });
* ```
*/
/*! Developer Documentation
*
* These methods can be agto-paginated.
*/
paginator_1.paginator.extend(Topic, ['getSubscriptions']);
/*! Developer Documentation
*
* Existing async methods (except for streams) will return a Promise in the event
* that a callback is omitted. Future methods will not allow for a callback.
* (Use .then() on the returned Promise instead.)
*/
(0, util_1.promisifySome)(Topic, Topic.prototype, [
'flush',
'create',
'createSubscription',
'delete',
'exists',
'get',
'getMetadata',
'getSubscriptions',
'setMetadata',
]);
//# sourceMappingURL=topic.js.map