107 lines
2.3 KiB
JavaScript
107 lines
2.3 KiB
JavaScript
var Stream = require('stream').Stream;
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var util = require('util');
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module.exports = DelayedStream;
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function DelayedStream() {
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this.source = null;
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this.dataSize = 0;
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this.maxDataSize = 1024 * 1024;
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this.pauseStream = true;
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this._maxDataSizeExceeded = false;
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this._released = false;
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this._bufferedEvents = [];
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}
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util.inherits(DelayedStream, Stream);
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DelayedStream.create = function(source, options) {
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var delayedStream = new this();
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options = options || {};
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for (var option in options) {
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delayedStream[option] = options[option];
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}
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delayedStream.source = source;
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var realEmit = source.emit;
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source.emit = function() {
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delayedStream._handleEmit(arguments);
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return realEmit.apply(source, arguments);
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};
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source.on('error', function() {});
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if (delayedStream.pauseStream) {
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source.pause();
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}
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return delayedStream;
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};
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Object.defineProperty(DelayedStream.prototype, 'readable', {
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configurable: true,
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enumerable: true,
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get: function() {
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return this.source.readable;
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}
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});
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DelayedStream.prototype.setEncoding = function() {
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return this.source.setEncoding.apply(this.source, arguments);
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};
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DelayedStream.prototype.resume = function() {
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if (!this._released) {
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this.release();
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}
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this.source.resume();
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};
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DelayedStream.prototype.pause = function() {
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this.source.pause();
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};
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DelayedStream.prototype.release = function() {
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this._released = true;
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this._bufferedEvents.forEach(function(args) {
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this.emit.apply(this, args);
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}.bind(this));
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this._bufferedEvents = [];
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};
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DelayedStream.prototype.pipe = function() {
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var r = Stream.prototype.pipe.apply(this, arguments);
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this.resume();
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return r;
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};
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DelayedStream.prototype._handleEmit = function(args) {
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if (this._released) {
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this.emit.apply(this, args);
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return;
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}
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if (args[0] === 'data') {
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this.dataSize += args[1].length;
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this._checkIfMaxDataSizeExceeded();
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}
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this._bufferedEvents.push(args);
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};
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DelayedStream.prototype._checkIfMaxDataSizeExceeded = function() {
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if (this._maxDataSizeExceeded) {
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return;
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}
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if (this.dataSize <= this.maxDataSize) {
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return;
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}
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this._maxDataSizeExceeded = true;
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var message =
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'DelayedStream#maxDataSize of ' + this.maxDataSize + ' bytes exceeded.'
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this.emit('error', new Error(message));
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};
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