atcheck/lsscanner/new_ubuntu/node_modules/delayed-stream/lib/delayed_stream.js

108 lines
2.3 KiB
JavaScript

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