75 lines
1.8 KiB
JavaScript
75 lines
1.8 KiB
JavaScript
|
// a duplex stream is just a stream that is both readable and writable.
|
||
|
|
// Since JS doesn't have multiple prototypal inheritance, this class
|
||
|
|
// prototypally inherits from Readable, and then parasitically from
|
||
|
|
// Writable.
|
||
|
|
|
||
|
|
'use strict';
|
||
|
|
|
||
|
|
/*<replacement>*/
|
||
|
|
|
||
|
|
var objectKeys = Object.keys || function (obj) {
|
||
|
|
var keys = [];
|
||
|
|
for (var key in obj) {
|
||
|
|
keys.push(key);
|
||
|
|
}return keys;
|
||
|
|
};
|
||
|
|
/*</replacement>*/
|
||
|
|
|
||
|
|
module.exports = Duplex;
|
||
|
|
|
||
|
|
/*<replacement>*/
|
||
|
|
var processNextTick = require('process-nextick-args');
|
||
|
|
/*</replacement>*/
|
||
|
|
|
||
|
|
/*<replacement>*/
|
||
|
|
var util = require('core-util-is');
|
||
|
|
util.inherits = require('inherits');
|
||
|
|
/*</replacement>*/
|
||
|
|
|
||
|
|
var Readable = require('./_stream_readable');
|
||
|
|
var Writable = require('./_stream_writable');
|
||
|
|
|
||
|
|
util.inherits(Duplex, Readable);
|
||
|
|
|
||
|
|
var keys = objectKeys(Writable.prototype);
|
||
|
|
for (var v = 0; v < keys.length; v++) {
|
||
|
|
var method = keys[v];
|
||
|
|
if (!Duplex.prototype[method]) Duplex.prototype[method] = Writable.prototype[method];
|
||
|
|
}
|
||
|
|
|
||
|
|
function Duplex(options) {
|
||
|
|
if (!(this instanceof Duplex)) return new Duplex(options);
|
||
|
|
|
||
|
|
Readable.call(this, options);
|
||
|
|
Writable.call(this, options);
|
||
|
|
|
||
|
|
if (options && options.readable === false) this.readable = false;
|
||
|
|
|
||
|
|
if (options && options.writable === false) this.writable = false;
|
||
|
|
|
||
|
|
this.allowHalfOpen = true;
|
||
|
|
if (options && options.allowHalfOpen === false) this.allowHalfOpen = false;
|
||
|
|
|
||
|
|
this.once('end', onend);
|
||
|
|
}
|
||
|
|
|
||
|
|
// the no-half-open enforcer
|
||
|
|
function onend() {
|
||
|
|
// if we allow half-open state, or if the writable side ended,
|
||
|
|
// then we're ok.
|
||
|
|
if (this.allowHalfOpen || this._writableState.ended) return;
|
||
|
|
|
||
|
|
// no more data can be written.
|
||
|
|
// But allow more writes to happen in this tick.
|
||
|
|
processNextTick(onEndNT, this);
|
||
|
|
}
|
||
|
|
|
||
|
|
function onEndNT(self) {
|
||
|
|
self.end();
|
||
|
|
}
|
||
|
|
|
||
|
|
function forEach(xs, f) {
|
||
|
|
for (var i = 0, l = xs.length; i < l; i++) {
|
||
|
|
f(xs[i], i);
|
||
|
|
}
|
||
|
|
}
|