59 lines
1.1 KiB
JavaScript
59 lines
1.1 KiB
JavaScript
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'use strict';
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/*!
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* Module dependencies.
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*/
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const EventEmitter = require('events').EventEmitter;
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/*!
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* ignore
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*/
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class ChangeStream extends EventEmitter {
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constructor(model, pipeline, options) {
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super();
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this.driverChangeStream = null;
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this.closed = false;
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// This wrapper is necessary because of buffering.
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if (model.collection.buffer) {
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model.collection.addQueue(() => {
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if (this.closed) {
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return;
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}
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this.driverChangeStream = model.collection.watch(pipeline, options);
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this._bindEvents();
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this.emit('ready');
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});
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} else {
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this.driverChangeStream = model.collection.watch(pipeline, options);
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this._bindEvents();
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this.emit('ready');
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}
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}
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_bindEvents() {
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['close', 'change', 'end', 'error'].forEach(ev => {
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this.driverChangeStream.on(ev, data => this.emit(ev, data));
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});
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}
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_queue(cb) {
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this.once('ready', () => cb());
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}
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close() {
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this.closed = true;
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if (this.driverChangeStream) {
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this.driverChangeStream.close();
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}
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}
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}
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/*!
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* ignore
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*/
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module.exports = ChangeStream;
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