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// 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.
'use strict';
module.exports = Duplex;
const Readable = require('_stream_readable');
const Writable = require('_stream_writable');
Object.setPrototypeOf(Duplex.prototype, Readable.prototype);
Object.setPrototypeOf(Duplex, Readable);
{
// Allow the keys array to be GC'ed.
const keys = Object.keys(Writable.prototype);
for (var v = 0; v < keys.length; v++) {
const 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);
this.allowHalfOpen = true;
if (options) {
if (options.readable === false)
this.readable = false;
if (options.writable === false)
this.writable = false;
if (options.allowHalfOpen === false) {
this.allowHalfOpen = false;
this.once('end', onend);
}
}
}
Object.defineProperty(Duplex.prototype, 'writableHighWaterMark', {
// Making it explicit this property is not enumerable
// because otherwise some prototype manipulation in
// userland will fail
enumerable: false,
get() {
return this._writableState.highWaterMark;
}
});
Object.defineProperty(Duplex.prototype, 'writableBuffer', {
// Making it explicit this property is not enumerable
// because otherwise some prototype manipulation in
// userland will fail
enumerable: false,
get: function() {
return this._writableState && this._writableState.getBuffer();
}
});
Object.defineProperty(Duplex.prototype, 'writableLength', {
// Making it explicit this property is not enumerable
// because otherwise some prototype manipulation in
// userland will fail
enumerable: false,
get() {
return this._writableState.length;
}
});
// the no-half-open enforcer
function onend() {
// If the writable side ended, then we're ok.
if (this._writableState.ended)
return;
// no more data can be written.
// But allow more writes to happen in this tick.
process.nextTick(onEndNT, this);
}
function onEndNT(self) {
self.end();
}
Object.defineProperty(Duplex.prototype, 'destroyed', {
// Making it explicit this property is not enumerable
// because otherwise some prototype manipulation in
// userland will fail
enumerable: false,
get() {
if (this._readableState === undefined ||
this._writableState === undefined) {
return false;
}
return this._readableState.destroyed && this._writableState.destroyed;
},
set(value) {
// we ignore the value if the stream
// has not been initialized yet
if (this._readableState === undefined ||
this._writableState === undefined) {
return;
}
// backward compatibility, the user is explicitly
// managing destroyed
this._readableState.destroyed = value;
this._writableState.destroyed = value;
}
});
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