228 lines
5.5 KiB
JavaScript
228 lines
5.5 KiB
JavaScript
![]() |
var stream = require('readable-stream')
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var eos = require('end-of-stream')
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var inherits = require('inherits')
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var SIGNAL_FLUSH = new Buffer([0])
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var onuncork = function(self, fn) {
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if (self._corked) self.once('uncork', fn)
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else fn()
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}
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var destroyer = function(self, end) {
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return function(err) {
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if (err) self.destroy(err.message === 'premature close' ? null : err)
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else if (end && !self._ended) self.end()
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}
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}
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var end = function(ws, fn) {
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if (!ws) return fn()
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if (ws._writableState && ws._writableState.finished) return fn()
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if (ws._writableState) return ws.end(fn)
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ws.end()
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fn()
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}
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var toStreams2 = function(rs) {
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return new (stream.Readable)({objectMode:true, highWaterMark:16}).wrap(rs)
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}
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var Duplexify = function(writable, readable, opts) {
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if (!(this instanceof Duplexify)) return new Duplexify(writable, readable, opts)
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stream.Duplex.call(this, opts)
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this._writable = null
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this._readable = null
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this._readable2 = null
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this._forwardDestroy = !opts || opts.destroy !== false
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this._forwardEnd = !opts || opts.end !== false
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this._corked = 1 // start corked
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this._ondrain = null
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this._drained = false
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this._forwarding = false
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this._unwrite = null
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this._unread = null
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this._ended = false
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this.destroyed = false
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if (writable) this.setWritable(writable)
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if (readable) this.setReadable(readable)
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}
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inherits(Duplexify, stream.Duplex)
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Duplexify.obj = function(writable, readable, opts) {
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if (!opts) opts = {}
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opts.objectMode = true
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opts.highWaterMark = 16
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return new Duplexify(writable, readable, opts)
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}
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Duplexify.prototype.cork = function() {
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if (++this._corked === 1) this.emit('cork')
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}
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Duplexify.prototype.uncork = function() {
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if (this._corked && --this._corked === 0) this.emit('uncork')
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}
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Duplexify.prototype.setWritable = function(writable) {
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if (this._unwrite) this._unwrite()
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if (this.destroyed) {
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if (writable && writable.destroy) writable.destroy()
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return
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}
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if (writable === null || writable === false) {
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this.end()
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return
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}
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var self = this
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var unend = eos(writable, {writable:true, readable:false}, destroyer(this, this._forwardEnd))
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var ondrain = function() {
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var ondrain = self._ondrain
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self._ondrain = null
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if (ondrain) ondrain()
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}
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var clear = function() {
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self._writable.removeListener('drain', ondrain)
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unend()
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}
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if (this._unwrite) process.nextTick(ondrain) // force a drain on stream reset to avoid livelocks
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this._writable = writable
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this._writable.on('drain', ondrain)
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this._unwrite = clear
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this.uncork() // always uncork setWritable
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}
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Duplexify.prototype.setReadable = function(readable) {
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if (this._unread) this._unread()
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if (this.destroyed) {
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if (readable && readable.destroy) readable.destroy()
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return
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}
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if (readable === null || readable === false) {
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this.push(null)
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this.resume()
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return
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}
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var self = this
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var unend = eos(readable, {writable:false, readable:true}, destroyer(this))
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var onreadable = function() {
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self._forward()
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}
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var onend = function() {
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self.push(null)
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}
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var clear = function() {
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self._readable2.removeListener('readable', onreadable)
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self._readable2.removeListener('end', onend)
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unend()
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}
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this._drained = true
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this._readable = readable
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this._readable2 = readable._readableState ? readable : toStreams2(readable)
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this._readable2.on('readable', onreadable)
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this._readable2.on('end', onend)
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this._unread = clear
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this._forward()
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}
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Duplexify.prototype._read = function() {
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this._drained = true
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this._forward()
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}
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Duplexify.prototype._forward = function() {
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if (this._forwarding || !this._readable2 || !this._drained) return
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this._forwarding = true
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var data
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var state = this._readable2._readableState
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while ((data = this._readable2.read(state.buffer.length ? state.buffer[0].length : state.length)) !== null) {
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this._drained = this.push(data)
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}
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this._forwarding = false
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}
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Duplexify.prototype.destroy = function(err) {
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if (this.destroyed) return
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this.destroyed = true
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var self = this
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process.nextTick(function() {
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self._destroy(err)
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})
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}
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Duplexify.prototype._destroy = function(err) {
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if (err) {
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var ondrain = this._ondrain
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this._ondrain = null
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if (ondrain) ondrain(err)
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else this.emit('error', err)
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}
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if (this._forwardDestroy) {
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if (this._readable && this._readable.destroy) this._readable.destroy()
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if (this._writable && this._writable.destroy) this._writable.destroy()
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}
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this.emit('close')
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}
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Duplexify.prototype._write = function(data, enc, cb) {
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if (this.destroyed) return cb()
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if (this._corked) return onuncork(this, this._write.bind(this, data, enc, cb))
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if (data === SIGNAL_FLUSH) return this._finish(cb)
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if (!this._writable) return cb()
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if (this._writable.write(data) === false) this._ondrain = cb
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else cb()
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}
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Duplexify.prototype._finish = function(cb) {
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var self = this
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this.emit('preend')
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onuncork(this, function() {
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end(self._forwardEnd && self._writable, function() {
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// haxx to not emit prefinish twice
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if (self._writableState.prefinished === false) self._writableState.prefinished = true
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self.emit('prefinish')
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onuncork(self, cb)
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})
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})
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}
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Duplexify.prototype.end = function(data, enc, cb) {
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if (typeof data === 'function') return this.end(null, null, data)
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if (typeof enc === 'function') return this.end(data, null, enc)
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this._ended = true
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if (data) this.write(data)
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if (!this._writableState.ending) this.write(SIGNAL_FLUSH)
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return stream.Writable.prototype.end.call(this, cb)
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}
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module.exports = Duplexify
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