diff options
Diffstat (limited to 'node_modules/duplexify/index.js')
-rw-r--r-- | node_modules/duplexify/index.js | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/node_modules/duplexify/index.js b/node_modules/duplexify/index.js new file mode 100644 index 000000000..377eb60ad --- /dev/null +++ b/node_modules/duplexify/index.js @@ -0,0 +1,227 @@ +var stream = require('readable-stream') +var eos = require('end-of-stream') +var inherits = require('inherits') +var shift = require('stream-shift') + +var SIGNAL_FLUSH = new Buffer([0]) + +var onuncork = function(self, fn) { + if (self._corked) self.once('uncork', fn) + else fn() +} + +var destroyer = function(self, end) { + return function(err) { + if (err) self.destroy(err.message === 'premature close' ? null : err) + else if (end && !self._ended) self.end() + } +} + +var end = function(ws, fn) { + if (!ws) return fn() + if (ws._writableState && ws._writableState.finished) return fn() + if (ws._writableState) return ws.end(fn) + ws.end() + fn() +} + +var toStreams2 = function(rs) { + return new (stream.Readable)({objectMode:true, highWaterMark:16}).wrap(rs) +} + +var Duplexify = function(writable, readable, opts) { + if (!(this instanceof Duplexify)) return new Duplexify(writable, readable, opts) + stream.Duplex.call(this, opts) + + this._writable = null + this._readable = null + this._readable2 = null + + this._forwardDestroy = !opts || opts.destroy !== false + this._forwardEnd = !opts || opts.end !== false + this._corked = 1 // start corked + this._ondrain = null + this._drained = false + this._forwarding = false + this._unwrite = null + this._unread = null + this._ended = false + + this.destroyed = false + + if (writable) this.setWritable(writable) + if (readable) this.setReadable(readable) +} + +inherits(Duplexify, stream.Duplex) + +Duplexify.obj = function(writable, readable, opts) { + if (!opts) opts = {} + opts.objectMode = true + opts.highWaterMark = 16 + return new Duplexify(writable, readable, opts) +} + +Duplexify.prototype.cork = function() { + if (++this._corked === 1) this.emit('cork') +} + +Duplexify.prototype.uncork = function() { + if (this._corked && --this._corked === 0) this.emit('uncork') +} + +Duplexify.prototype.setWritable = function(writable) { + if (this._unwrite) this._unwrite() + + if (this.destroyed) { + if (writable && writable.destroy) writable.destroy() + return + } + + if (writable === null || writable === false) { + this.end() + return + } + + var self = this + var unend = eos(writable, {writable:true, readable:false}, destroyer(this, this._forwardEnd)) + + var ondrain = function() { + var ondrain = self._ondrain + self._ondrain = null + if (ondrain) ondrain() + } + + var clear = function() { + self._writable.removeListener('drain', ondrain) + unend() + } + + if (this._unwrite) process.nextTick(ondrain) // force a drain on stream reset to avoid livelocks + + this._writable = writable + this._writable.on('drain', ondrain) + this._unwrite = clear + + this.uncork() // always uncork setWritable +} + +Duplexify.prototype.setReadable = function(readable) { + if (this._unread) this._unread() + + if (this.destroyed) { + if (readable && readable.destroy) readable.destroy() + return + } + + if (readable === null || readable === false) { + this.push(null) + this.resume() + return + } + + var self = this + var unend = eos(readable, {writable:false, readable:true}, destroyer(this)) + + var onreadable = function() { + self._forward() + } + + var onend = function() { + self.push(null) + } + + var clear = function() { + self._readable2.removeListener('readable', onreadable) + self._readable2.removeListener('end', onend) + unend() + } + + this._drained = true + this._readable = readable + this._readable2 = readable._readableState ? readable : toStreams2(readable) + this._readable2.on('readable', onreadable) + this._readable2.on('end', onend) + this._unread = clear + + this._forward() +} + +Duplexify.prototype._read = function() { + this._drained = true + this._forward() +} + +Duplexify.prototype._forward = function() { + if (this._forwarding || !this._readable2 || !this._drained) return + this._forwarding = true + + var data + + while ((data = shift(this._readable2)) !== null) { + this._drained = this.push(data) + } + + this._forwarding = false +} + +Duplexify.prototype.destroy = function(err) { + if (this.destroyed) return + this.destroyed = true + + var self = this + process.nextTick(function() { + self._destroy(err) + }) +} + +Duplexify.prototype._destroy = function(err) { + if (err) { + var ondrain = this._ondrain + this._ondrain = null + if (ondrain) ondrain(err) + else this.emit('error', err) + } + + if (this._forwardDestroy) { + if (this._readable && this._readable.destroy) this._readable.destroy() + if (this._writable && this._writable.destroy) this._writable.destroy() + } + + this.emit('close') +} + +Duplexify.prototype._write = function(data, enc, cb) { + if (this.destroyed) return cb() + if (this._corked) return onuncork(this, this._write.bind(this, data, enc, cb)) + if (data === SIGNAL_FLUSH) return this._finish(cb) + if (!this._writable) return cb() + + if (this._writable.write(data) === false) this._ondrain = cb + else cb() +} + + +Duplexify.prototype._finish = function(cb) { + var self = this + this.emit('preend') + onuncork(this, function() { + end(self._forwardEnd && self._writable, function() { + // haxx to not emit prefinish twice + if (self._writableState.prefinished === false) self._writableState.prefinished = true + self.emit('prefinish') + onuncork(self, cb) + }) + }) +} + +Duplexify.prototype.end = function(data, enc, cb) { + if (typeof data === 'function') return this.end(null, null, data) + if (typeof enc === 'function') return this.end(data, null, enc) + this._ended = true + if (data) this.write(data) + if (!this._writableState.ending) this.write(SIGNAL_FLUSH) + return stream.Writable.prototype.end.call(this, cb) +} + +module.exports = Duplexify |