opusdev/vector-similarity-api

1var Stream = require('stream').Stream;2var util = require('util');3 4module.exports = DelayedStream;5function DelayedStream() {6  this.source = null;7  this.dataSize = 0;8  this.maxDataSize = 1024 * 1024;9  this.pauseStream = true;10 11  this._maxDataSizeExceeded = false;12  this._released = false;13  this._bufferedEvents = [];14}15util.inherits(DelayedStream, Stream);16 17DelayedStream.create = function(source, options) {18  var delayedStream = new this();19 20  options = options || {};21  for (var option in options) {22    delayedStream[option] = options[option];23  }24 25  delayedStream.source = source;26 27  var realEmit = source.emit;28  source.emit = function() {29    delayedStream._handleEmit(arguments);30    return realEmit.apply(source, arguments);31  };32 33  source.on('error', function() {});34  if (delayedStream.pauseStream) {35    source.pause();36  }37 38  return delayedStream;39};40 41Object.defineProperty(DelayedStream.prototype, 'readable', {42  configurable: true,43  enumerable: true,44  get: function() {45    return this.source.readable;46  }47});48 49DelayedStream.prototype.setEncoding = function() {50  return this.source.setEncoding.apply(this.source, arguments);51};52 53DelayedStream.prototype.resume = function() {54  if (!this._released) {55    this.release();56  }57 58  this.source.resume();59};60 61DelayedStream.prototype.pause = function() {62  this.source.pause();63};64 65DelayedStream.prototype.release = function() {66  this._released = true;67 68  this._bufferedEvents.forEach(function(args) {69    this.emit.apply(this, args);70  }.bind(this));71  this._bufferedEvents = [];72};73 74DelayedStream.prototype.pipe = function() {75  var r = Stream.prototype.pipe.apply(this, arguments);76  this.resume();77  return r;78};79 80DelayedStream.prototype._handleEmit = function(args) {81  if (this._released) {82    this.emit.apply(this, args);83    return;84  }85 86  if (args[0] === 'data') {87    this.dataSize += args[1].length;88    this._checkIfMaxDataSizeExceeded();89  }90 91  this._bufferedEvents.push(args);92};93 94DelayedStream.prototype._checkIfMaxDataSizeExceeded = function() {95  if (this._maxDataSizeExceeded) {96    return;97  }98 99  if (this.dataSize <= this.maxDataSize) {100    return;101  }102 103  this._maxDataSizeExceeded = true;104  var message =105    'DelayedStream#maxDataSize of ' + this.maxDataSize + ' bytes exceeded.'106  this.emit('error', new Error(message));107};108