| // Copyright Joyent, Inc. and other Node contributors. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a |
| // copy of this software and associated documentation files (the |
| // "Software"), to deal in the Software without restriction, including |
| // without limitation the rights to use, copy, modify, merge, publish, |
| // distribute, sublicense, and/or sell copies of the Software, and to permit |
| // persons to whom the Software is furnished to do so, subject to the |
| // following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included |
| // in all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN |
| // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, |
| // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
| // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
| // USE OR OTHER DEALINGS IN THE SOFTWARE. |
| |
| // 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. |
| |
| module.exports = Duplex; |
| var util = require('util'); |
| var Readable = require('_stream_readable'); |
| var Writable = require('_stream_writable'); |
| |
| util.inherits(Duplex, Readable); |
| |
| Object.keys(Writable.prototype).forEach(function(method) { |
| 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. |
| process.nextTick(this.end.bind(this)); |
| } |