1315 lines
39 KiB
JavaScript
1315 lines
39 KiB
JavaScript
// Copyright Joyent, Inc. and other Node contributors.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a
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// copy of this software and associated documentation files (the
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// "Software"), to deal in the Software without restriction, including
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// without limitation the rights to use, copy, modify, merge, publish,
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// distribute, sublicense, and/or sell copies of the Software, and to permit
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// persons to whom the Software is furnished to do so, subject to the
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// following conditions:
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//
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// The above copyright notice and this permission notice shall be included
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// in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
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// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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// USE OR OTHER DEALINGS IN THE SOFTWARE.
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'use strict'
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const {
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ArrayPrototypeIndexOf,
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NumberIsInteger,
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NumberIsNaN,
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NumberParseInt,
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ObjectDefineProperties,
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ObjectKeys,
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ObjectSetPrototypeOf,
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Promise,
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SafeSet,
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SymbolAsyncIterator,
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Symbol
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} = require('../../ours/primordials')
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module.exports = Readable
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Readable.ReadableState = ReadableState
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const { EventEmitter: EE } = require('events')
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const { Stream, prependListener } = require('./legacy')
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const { addAbortSignal } = require('./add-abort-signal')
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const eos = require('./end-of-stream')
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let debug = require('../../ours/util').debuglog('stream', (fn) => {
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debug = fn
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})
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const BufferList = require('./buffer_list')
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const destroyImpl = require('./destroy')
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const { getHighWaterMark, getDefaultHighWaterMark } = require('./state')
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const {
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aggregateTwoErrors,
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codes: {
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ERR_INVALID_ARG_TYPE,
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ERR_METHOD_NOT_IMPLEMENTED,
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ERR_OUT_OF_RANGE,
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ERR_STREAM_PUSH_AFTER_EOF,
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ERR_STREAM_UNSHIFT_AFTER_END_EVENT
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}
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} = require('../../ours/errors')
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const { validateObject } = require('../validators')
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const kPaused = Symbol('kPaused')
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const { StringDecoder } = require('string_decoder')
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const from = require('./from')
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ObjectSetPrototypeOf(Readable.prototype, Stream.prototype)
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ObjectSetPrototypeOf(Readable, Stream)
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const nop = () => {}
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const { errorOrDestroy } = destroyImpl
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function ReadableState(options, stream, isDuplex) {
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// Duplex streams are both readable and writable, but share
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// the same options object.
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// However, some cases require setting options to different
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// values for the readable and the writable sides of the duplex stream.
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// These options can be provided separately as readableXXX and writableXXX.
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if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof require('./duplex') // Object stream flag. Used to make read(n) ignore n and to
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// make all the buffer merging and length checks go away.
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this.objectMode = !!(options && options.objectMode)
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if (isDuplex) this.objectMode = this.objectMode || !!(options && options.readableObjectMode) // The point at which it stops calling _read() to fill the buffer
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// Note: 0 is a valid value, means "don't call _read preemptively ever"
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this.highWaterMark = options
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? getHighWaterMark(this, options, 'readableHighWaterMark', isDuplex)
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: getDefaultHighWaterMark(false) // A linked list is used to store data chunks instead of an array because the
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// linked list can remove elements from the beginning faster than
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// array.shift().
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this.buffer = new BufferList()
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this.length = 0
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this.pipes = []
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this.flowing = null
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this.ended = false
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this.endEmitted = false
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this.reading = false // Stream is still being constructed and cannot be
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// destroyed until construction finished or failed.
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// Async construction is opt in, therefore we start as
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// constructed.
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this.constructed = true // A flag to be able to tell if the event 'readable'/'data' is emitted
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// immediately, or on a later tick. We set this to true at first, because
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// any actions that shouldn't happen until "later" should generally also
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// not happen before the first read call.
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this.sync = true // Whenever we return null, then we set a flag to say
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// that we're awaiting a 'readable' event emission.
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this.needReadable = false
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this.emittedReadable = false
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this.readableListening = false
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this.resumeScheduled = false
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this[kPaused] = null // True if the error was already emitted and should not be thrown again.
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this.errorEmitted = false // Should close be emitted on destroy. Defaults to true.
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this.emitClose = !options || options.emitClose !== false // Should .destroy() be called after 'end' (and potentially 'finish').
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this.autoDestroy = !options || options.autoDestroy !== false // Has it been destroyed.
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this.destroyed = false // Indicates whether the stream has errored. When true no further
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// _read calls, 'data' or 'readable' events should occur. This is needed
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// since when autoDestroy is disabled we need a way to tell whether the
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// stream has failed.
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this.errored = null // Indicates whether the stream has finished destroying.
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this.closed = false // True if close has been emitted or would have been emitted
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// depending on emitClose.
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this.closeEmitted = false // Crypto is kind of old and crusty. Historically, its default string
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// encoding is 'binary' so we have to make this configurable.
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// Everything else in the universe uses 'utf8', though.
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this.defaultEncoding = (options && options.defaultEncoding) || 'utf8' // Ref the piped dest which we need a drain event on it
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// type: null | Writable | Set<Writable>.
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this.awaitDrainWriters = null
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this.multiAwaitDrain = false // If true, a maybeReadMore has been scheduled.
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this.readingMore = false
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this.dataEmitted = false
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this.decoder = null
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this.encoding = null
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if (options && options.encoding) {
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this.decoder = new StringDecoder(options.encoding)
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this.encoding = options.encoding
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}
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}
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function Readable(options) {
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if (!(this instanceof Readable)) return new Readable(options) // Checking for a Stream.Duplex instance is faster here instead of inside
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// the ReadableState constructor, at least with V8 6.5.
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const isDuplex = this instanceof require('./duplex')
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this._readableState = new ReadableState(options, this, isDuplex)
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if (options) {
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if (typeof options.read === 'function') this._read = options.read
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if (typeof options.destroy === 'function') this._destroy = options.destroy
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if (typeof options.construct === 'function') this._construct = options.construct
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if (options.signal && !isDuplex) addAbortSignal(options.signal, this)
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}
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Stream.call(this, options)
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destroyImpl.construct(this, () => {
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if (this._readableState.needReadable) {
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maybeReadMore(this, this._readableState)
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}
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})
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}
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Readable.prototype.destroy = destroyImpl.destroy
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Readable.prototype._undestroy = destroyImpl.undestroy
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Readable.prototype._destroy = function (err, cb) {
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cb(err)
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}
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Readable.prototype[EE.captureRejectionSymbol] = function (err) {
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this.destroy(err)
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} // Manually shove something into the read() buffer.
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// This returns true if the highWaterMark has not been hit yet,
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// similar to how Writable.write() returns true if you should
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// write() some more.
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Readable.prototype.push = function (chunk, encoding) {
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return readableAddChunk(this, chunk, encoding, false)
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} // Unshift should *always* be something directly out of read().
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Readable.prototype.unshift = function (chunk, encoding) {
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return readableAddChunk(this, chunk, encoding, true)
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}
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function readableAddChunk(stream, chunk, encoding, addToFront) {
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debug('readableAddChunk', chunk)
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const state = stream._readableState
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let err
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if (!state.objectMode) {
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if (typeof chunk === 'string') {
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encoding = encoding || state.defaultEncoding
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if (state.encoding !== encoding) {
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if (addToFront && state.encoding) {
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// When unshifting, if state.encoding is set, we have to save
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// the string in the BufferList with the state encoding.
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chunk = Buffer.from(chunk, encoding).toString(state.encoding)
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} else {
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chunk = Buffer.from(chunk, encoding)
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encoding = ''
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}
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}
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} else if (chunk instanceof Buffer) {
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encoding = ''
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} else if (Stream._isUint8Array(chunk)) {
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chunk = Stream._uint8ArrayToBuffer(chunk)
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encoding = ''
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} else if (chunk != null) {
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err = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer', 'Uint8Array'], chunk)
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}
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}
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if (err) {
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errorOrDestroy(stream, err)
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} else if (chunk === null) {
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state.reading = false
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onEofChunk(stream, state)
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} else if (state.objectMode || (chunk && chunk.length > 0)) {
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if (addToFront) {
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if (state.endEmitted) errorOrDestroy(stream, new ERR_STREAM_UNSHIFT_AFTER_END_EVENT())
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else if (state.destroyed || state.errored) return false
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else addChunk(stream, state, chunk, true)
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} else if (state.ended) {
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errorOrDestroy(stream, new ERR_STREAM_PUSH_AFTER_EOF())
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} else if (state.destroyed || state.errored) {
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return false
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} else {
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state.reading = false
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if (state.decoder && !encoding) {
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chunk = state.decoder.write(chunk)
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if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false)
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else maybeReadMore(stream, state)
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} else {
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addChunk(stream, state, chunk, false)
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}
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}
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} else if (!addToFront) {
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state.reading = false
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maybeReadMore(stream, state)
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} // We can push more data if we are below the highWaterMark.
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// Also, if we have no data yet, we can stand some more bytes.
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// This is to work around cases where hwm=0, such as the repl.
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return !state.ended && (state.length < state.highWaterMark || state.length === 0)
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}
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function addChunk(stream, state, chunk, addToFront) {
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if (state.flowing && state.length === 0 && !state.sync && stream.listenerCount('data') > 0) {
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// Use the guard to avoid creating `Set()` repeatedly
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// when we have multiple pipes.
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if (state.multiAwaitDrain) {
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state.awaitDrainWriters.clear()
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} else {
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state.awaitDrainWriters = null
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}
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state.dataEmitted = true
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stream.emit('data', chunk)
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} else {
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// Update the buffer info.
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state.length += state.objectMode ? 1 : chunk.length
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if (addToFront) state.buffer.unshift(chunk)
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else state.buffer.push(chunk)
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if (state.needReadable) emitReadable(stream)
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}
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maybeReadMore(stream, state)
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}
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Readable.prototype.isPaused = function () {
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const state = this._readableState
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return state[kPaused] === true || state.flowing === false
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} // Backwards compatibility.
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Readable.prototype.setEncoding = function (enc) {
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const decoder = new StringDecoder(enc)
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this._readableState.decoder = decoder // If setEncoding(null), decoder.encoding equals utf8.
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this._readableState.encoding = this._readableState.decoder.encoding
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const buffer = this._readableState.buffer // Iterate over current buffer to convert already stored Buffers:
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let content = ''
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for (const data of buffer) {
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content += decoder.write(data)
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}
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buffer.clear()
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if (content !== '') buffer.push(content)
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this._readableState.length = content.length
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return this
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} // Don't raise the hwm > 1GB.
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const MAX_HWM = 0x40000000
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function computeNewHighWaterMark(n) {
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if (n > MAX_HWM) {
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throw new ERR_OUT_OF_RANGE('size', '<= 1GiB', n)
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} else {
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// Get the next highest power of 2 to prevent increasing hwm excessively in
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// tiny amounts.
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n--
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n |= n >>> 1
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n |= n >>> 2
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n |= n >>> 4
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n |= n >>> 8
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n |= n >>> 16
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n++
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}
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return n
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} // This function is designed to be inlinable, so please take care when making
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// changes to the function body.
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function howMuchToRead(n, state) {
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if (n <= 0 || (state.length === 0 && state.ended)) return 0
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if (state.objectMode) return 1
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if (NumberIsNaN(n)) {
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// Only flow one buffer at a time.
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if (state.flowing && state.length) return state.buffer.first().length
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return state.length
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}
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if (n <= state.length) return n
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return state.ended ? state.length : 0
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} // You can override either this method, or the async _read(n) below.
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Readable.prototype.read = function (n) {
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debug('read', n) // Same as parseInt(undefined, 10), however V8 7.3 performance regressed
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// in this scenario, so we are doing it manually.
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if (n === undefined) {
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n = NaN
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} else if (!NumberIsInteger(n)) {
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n = NumberParseInt(n, 10)
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}
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const state = this._readableState
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const nOrig = n // If we're asking for more than the current hwm, then raise the hwm.
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if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n)
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if (n !== 0) state.emittedReadable = false // If we're doing read(0) to trigger a readable event, but we
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// already have a bunch of data in the buffer, then just trigger
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// the 'readable' event and move on.
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if (
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n === 0 &&
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state.needReadable &&
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((state.highWaterMark !== 0 ? state.length >= state.highWaterMark : state.length > 0) || state.ended)
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) {
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debug('read: emitReadable', state.length, state.ended)
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if (state.length === 0 && state.ended) endReadable(this)
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else emitReadable(this)
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return null
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}
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n = howMuchToRead(n, state) // If we've ended, and we're now clear, then finish it up.
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if (n === 0 && state.ended) {
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if (state.length === 0) endReadable(this)
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return null
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} // All the actual chunk generation logic needs to be
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// *below* the call to _read. The reason is that in certain
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// synthetic stream cases, such as passthrough streams, _read
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// may be a completely synchronous operation which may change
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// the state of the read buffer, providing enough data when
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// before there was *not* enough.
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//
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// So, the steps are:
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// 1. Figure out what the state of things will be after we do
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// a read from the buffer.
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//
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// 2. If that resulting state will trigger a _read, then call _read.
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// Note that this may be asynchronous, or synchronous. Yes, it is
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// deeply ugly to write APIs this way, but that still doesn't mean
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// that the Readable class should behave improperly, as streams are
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// designed to be sync/async agnostic.
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// Take note if the _read call is sync or async (ie, if the read call
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// has returned yet), so that we know whether or not it's safe to emit
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// 'readable' etc.
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//
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// 3. Actually pull the requested chunks out of the buffer and return.
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// if we need a readable event, then we need to do some reading.
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let doRead = state.needReadable
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debug('need readable', doRead) // If we currently have less than the highWaterMark, then also read some.
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if (state.length === 0 || state.length - n < state.highWaterMark) {
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doRead = true
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debug('length less than watermark', doRead)
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} // However, if we've ended, then there's no point, if we're already
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// reading, then it's unnecessary, if we're constructing we have to wait,
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// and if we're destroyed or errored, then it's not allowed,
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if (state.ended || state.reading || state.destroyed || state.errored || !state.constructed) {
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doRead = false
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debug('reading, ended or constructing', doRead)
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} else if (doRead) {
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debug('do read')
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state.reading = true
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state.sync = true // If the length is currently zero, then we *need* a readable event.
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if (state.length === 0) state.needReadable = true // Call internal read method
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try {
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this._read(state.highWaterMark)
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} catch (err) {
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errorOrDestroy(this, err)
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}
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state.sync = false // If _read pushed data synchronously, then `reading` will be false,
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// and we need to re-evaluate how much data we can return to the user.
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if (!state.reading) n = howMuchToRead(nOrig, state)
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}
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let ret
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if (n > 0) ret = fromList(n, state)
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else ret = null
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if (ret === null) {
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state.needReadable = state.length <= state.highWaterMark
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n = 0
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} else {
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state.length -= n
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if (state.multiAwaitDrain) {
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state.awaitDrainWriters.clear()
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} else {
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state.awaitDrainWriters = null
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}
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}
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if (state.length === 0) {
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// If we have nothing in the buffer, then we want to know
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// as soon as we *do* get something into the buffer.
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if (!state.ended) state.needReadable = true // If we tried to read() past the EOF, then emit end on the next tick.
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if (nOrig !== n && state.ended) endReadable(this)
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}
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if (ret !== null && !state.errorEmitted && !state.closeEmitted) {
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state.dataEmitted = true
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this.emit('data', ret)
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}
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return ret
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}
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function onEofChunk(stream, state) {
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debug('onEofChunk')
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if (state.ended) return
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if (state.decoder) {
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const chunk = state.decoder.end()
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if (chunk && chunk.length) {
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state.buffer.push(chunk)
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state.length += state.objectMode ? 1 : chunk.length
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}
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}
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state.ended = true
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if (state.sync) {
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// If we are sync, wait until next tick to emit the data.
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// Otherwise we risk emitting data in the flow()
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// the readable code triggers during a read() call.
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emitReadable(stream)
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} else {
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// Emit 'readable' now to make sure it gets picked up.
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state.needReadable = false
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state.emittedReadable = true // We have to emit readable now that we are EOF. Modules
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// in the ecosystem (e.g. dicer) rely on this event being sync.
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emitReadable_(stream)
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}
|
|
} // Don't emit readable right away in sync mode, because this can trigger
|
|
// another read() call => stack overflow. This way, it might trigger
|
|
// a nextTick recursion warning, but that's not so bad.
|
|
|
|
function emitReadable(stream) {
|
|
const state = stream._readableState
|
|
debug('emitReadable', state.needReadable, state.emittedReadable)
|
|
state.needReadable = false
|
|
|
|
if (!state.emittedReadable) {
|
|
debug('emitReadable', state.flowing)
|
|
state.emittedReadable = true
|
|
process.nextTick(emitReadable_, stream)
|
|
}
|
|
}
|
|
|
|
function emitReadable_(stream) {
|
|
const state = stream._readableState
|
|
debug('emitReadable_', state.destroyed, state.length, state.ended)
|
|
|
|
if (!state.destroyed && !state.errored && (state.length || state.ended)) {
|
|
stream.emit('readable')
|
|
state.emittedReadable = false
|
|
} // The stream needs another readable event if:
|
|
// 1. It is not flowing, as the flow mechanism will take
|
|
// care of it.
|
|
// 2. It is not ended.
|
|
// 3. It is below the highWaterMark, so we can schedule
|
|
// another readable later.
|
|
|
|
state.needReadable = !state.flowing && !state.ended && state.length <= state.highWaterMark
|
|
flow(stream)
|
|
} // At this point, the user has presumably seen the 'readable' event,
|
|
// and called read() to consume some data. that may have triggered
|
|
// in turn another _read(n) call, in which case reading = true if
|
|
// it's in progress.
|
|
// However, if we're not ended, or reading, and the length < hwm,
|
|
// then go ahead and try to read some more preemptively.
|
|
|
|
function maybeReadMore(stream, state) {
|
|
if (!state.readingMore && state.constructed) {
|
|
state.readingMore = true
|
|
process.nextTick(maybeReadMore_, stream, state)
|
|
}
|
|
}
|
|
|
|
function maybeReadMore_(stream, state) {
|
|
// Attempt to read more data if we should.
|
|
//
|
|
// The conditions for reading more data are (one of):
|
|
// - Not enough data buffered (state.length < state.highWaterMark). The loop
|
|
// is responsible for filling the buffer with enough data if such data
|
|
// is available. If highWaterMark is 0 and we are not in the flowing mode
|
|
// we should _not_ attempt to buffer any extra data. We'll get more data
|
|
// when the stream consumer calls read() instead.
|
|
// - No data in the buffer, and the stream is in flowing mode. In this mode
|
|
// the loop below is responsible for ensuring read() is called. Failing to
|
|
// call read here would abort the flow and there's no other mechanism for
|
|
// continuing the flow if the stream consumer has just subscribed to the
|
|
// 'data' event.
|
|
//
|
|
// In addition to the above conditions to keep reading data, the following
|
|
// conditions prevent the data from being read:
|
|
// - The stream has ended (state.ended).
|
|
// - There is already a pending 'read' operation (state.reading). This is a
|
|
// case where the stream has called the implementation defined _read()
|
|
// method, but they are processing the call asynchronously and have _not_
|
|
// called push() with new data. In this case we skip performing more
|
|
// read()s. The execution ends in this method again after the _read() ends
|
|
// up calling push() with more data.
|
|
while (
|
|
!state.reading &&
|
|
!state.ended &&
|
|
(state.length < state.highWaterMark || (state.flowing && state.length === 0))
|
|
) {
|
|
const len = state.length
|
|
debug('maybeReadMore read 0')
|
|
stream.read(0)
|
|
if (len === state.length)
|
|
// Didn't get any data, stop spinning.
|
|
break
|
|
}
|
|
|
|
state.readingMore = false
|
|
} // Abstract method. to be overridden in specific implementation classes.
|
|
// call cb(er, data) where data is <= n in length.
|
|
// for virtual (non-string, non-buffer) streams, "length" is somewhat
|
|
// arbitrary, and perhaps not very meaningful.
|
|
|
|
Readable.prototype._read = function (n) {
|
|
throw new ERR_METHOD_NOT_IMPLEMENTED('_read()')
|
|
}
|
|
|
|
Readable.prototype.pipe = function (dest, pipeOpts) {
|
|
const src = this
|
|
const state = this._readableState
|
|
|
|
if (state.pipes.length === 1) {
|
|
if (!state.multiAwaitDrain) {
|
|
state.multiAwaitDrain = true
|
|
state.awaitDrainWriters = new SafeSet(state.awaitDrainWriters ? [state.awaitDrainWriters] : [])
|
|
}
|
|
}
|
|
|
|
state.pipes.push(dest)
|
|
debug('pipe count=%d opts=%j', state.pipes.length, pipeOpts)
|
|
const doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr
|
|
const endFn = doEnd ? onend : unpipe
|
|
if (state.endEmitted) process.nextTick(endFn)
|
|
else src.once('end', endFn)
|
|
dest.on('unpipe', onunpipe)
|
|
|
|
function onunpipe(readable, unpipeInfo) {
|
|
debug('onunpipe')
|
|
|
|
if (readable === src) {
|
|
if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
|
|
unpipeInfo.hasUnpiped = true
|
|
cleanup()
|
|
}
|
|
}
|
|
}
|
|
|
|
function onend() {
|
|
debug('onend')
|
|
dest.end()
|
|
}
|
|
|
|
let ondrain
|
|
let cleanedUp = false
|
|
|
|
function cleanup() {
|
|
debug('cleanup') // Cleanup event handlers once the pipe is broken.
|
|
|
|
dest.removeListener('close', onclose)
|
|
dest.removeListener('finish', onfinish)
|
|
|
|
if (ondrain) {
|
|
dest.removeListener('drain', ondrain)
|
|
}
|
|
|
|
dest.removeListener('error', onerror)
|
|
dest.removeListener('unpipe', onunpipe)
|
|
src.removeListener('end', onend)
|
|
src.removeListener('end', unpipe)
|
|
src.removeListener('data', ondata)
|
|
cleanedUp = true // If the reader is waiting for a drain event from this
|
|
// specific writer, then it would cause it to never start
|
|
// flowing again.
|
|
// So, if this is awaiting a drain, then we just call it now.
|
|
// If we don't know, then assume that we are waiting for one.
|
|
|
|
if (ondrain && state.awaitDrainWriters && (!dest._writableState || dest._writableState.needDrain)) ondrain()
|
|
}
|
|
|
|
function pause() {
|
|
// If the user unpiped during `dest.write()`, it is possible
|
|
// to get stuck in a permanently paused state if that write
|
|
// also returned false.
|
|
// => Check whether `dest` is still a piping destination.
|
|
if (!cleanedUp) {
|
|
if (state.pipes.length === 1 && state.pipes[0] === dest) {
|
|
debug('false write response, pause', 0)
|
|
state.awaitDrainWriters = dest
|
|
state.multiAwaitDrain = false
|
|
} else if (state.pipes.length > 1 && state.pipes.includes(dest)) {
|
|
debug('false write response, pause', state.awaitDrainWriters.size)
|
|
state.awaitDrainWriters.add(dest)
|
|
}
|
|
|
|
src.pause()
|
|
}
|
|
|
|
if (!ondrain) {
|
|
// When the dest drains, it reduces the awaitDrain counter
|
|
// on the source. This would be more elegant with a .once()
|
|
// handler in flow(), but adding and removing repeatedly is
|
|
// too slow.
|
|
ondrain = pipeOnDrain(src, dest)
|
|
dest.on('drain', ondrain)
|
|
}
|
|
}
|
|
|
|
src.on('data', ondata)
|
|
|
|
function ondata(chunk) {
|
|
debug('ondata')
|
|
const ret = dest.write(chunk)
|
|
debug('dest.write', ret)
|
|
|
|
if (ret === false) {
|
|
pause()
|
|
}
|
|
} // If the dest has an error, then stop piping into it.
|
|
// However, don't suppress the throwing behavior for this.
|
|
|
|
function onerror(er) {
|
|
debug('onerror', er)
|
|
unpipe()
|
|
dest.removeListener('error', onerror)
|
|
|
|
if (dest.listenerCount('error') === 0) {
|
|
const s = dest._writableState || dest._readableState
|
|
|
|
if (s && !s.errorEmitted) {
|
|
// User incorrectly emitted 'error' directly on the stream.
|
|
errorOrDestroy(dest, er)
|
|
} else {
|
|
dest.emit('error', er)
|
|
}
|
|
}
|
|
} // Make sure our error handler is attached before userland ones.
|
|
|
|
prependListener(dest, 'error', onerror) // Both close and finish should trigger unpipe, but only once.
|
|
|
|
function onclose() {
|
|
dest.removeListener('finish', onfinish)
|
|
unpipe()
|
|
}
|
|
|
|
dest.once('close', onclose)
|
|
|
|
function onfinish() {
|
|
debug('onfinish')
|
|
dest.removeListener('close', onclose)
|
|
unpipe()
|
|
}
|
|
|
|
dest.once('finish', onfinish)
|
|
|
|
function unpipe() {
|
|
debug('unpipe')
|
|
src.unpipe(dest)
|
|
} // Tell the dest that it's being piped to.
|
|
|
|
dest.emit('pipe', src) // Start the flow if it hasn't been started already.
|
|
|
|
if (dest.writableNeedDrain === true) {
|
|
if (state.flowing) {
|
|
pause()
|
|
}
|
|
} else if (!state.flowing) {
|
|
debug('pipe resume')
|
|
src.resume()
|
|
}
|
|
|
|
return dest
|
|
}
|
|
|
|
function pipeOnDrain(src, dest) {
|
|
return function pipeOnDrainFunctionResult() {
|
|
const state = src._readableState // `ondrain` will call directly,
|
|
// `this` maybe not a reference to dest,
|
|
// so we use the real dest here.
|
|
|
|
if (state.awaitDrainWriters === dest) {
|
|
debug('pipeOnDrain', 1)
|
|
state.awaitDrainWriters = null
|
|
} else if (state.multiAwaitDrain) {
|
|
debug('pipeOnDrain', state.awaitDrainWriters.size)
|
|
state.awaitDrainWriters.delete(dest)
|
|
}
|
|
|
|
if ((!state.awaitDrainWriters || state.awaitDrainWriters.size === 0) && src.listenerCount('data')) {
|
|
src.resume()
|
|
}
|
|
}
|
|
}
|
|
|
|
Readable.prototype.unpipe = function (dest) {
|
|
const state = this._readableState
|
|
const unpipeInfo = {
|
|
hasUnpiped: false
|
|
} // If we're not piping anywhere, then do nothing.
|
|
|
|
if (state.pipes.length === 0) return this
|
|
|
|
if (!dest) {
|
|
// remove all.
|
|
const dests = state.pipes
|
|
state.pipes = []
|
|
this.pause()
|
|
|
|
for (let i = 0; i < dests.length; i++)
|
|
dests[i].emit('unpipe', this, {
|
|
hasUnpiped: false
|
|
})
|
|
|
|
return this
|
|
} // Try to find the right one.
|
|
|
|
const index = ArrayPrototypeIndexOf(state.pipes, dest)
|
|
if (index === -1) return this
|
|
state.pipes.splice(index, 1)
|
|
if (state.pipes.length === 0) this.pause()
|
|
dest.emit('unpipe', this, unpipeInfo)
|
|
return this
|
|
} // Set up data events if they are asked for
|
|
// Ensure readable listeners eventually get something.
|
|
|
|
Readable.prototype.on = function (ev, fn) {
|
|
const res = Stream.prototype.on.call(this, ev, fn)
|
|
const state = this._readableState
|
|
|
|
if (ev === 'data') {
|
|
// Update readableListening so that resume() may be a no-op
|
|
// a few lines down. This is needed to support once('readable').
|
|
state.readableListening = this.listenerCount('readable') > 0 // Try start flowing on next tick if stream isn't explicitly paused.
|
|
|
|
if (state.flowing !== false) this.resume()
|
|
} else if (ev === 'readable') {
|
|
if (!state.endEmitted && !state.readableListening) {
|
|
state.readableListening = state.needReadable = true
|
|
state.flowing = false
|
|
state.emittedReadable = false
|
|
debug('on readable', state.length, state.reading)
|
|
|
|
if (state.length) {
|
|
emitReadable(this)
|
|
} else if (!state.reading) {
|
|
process.nextTick(nReadingNextTick, this)
|
|
}
|
|
}
|
|
}
|
|
|
|
return res
|
|
}
|
|
|
|
Readable.prototype.addListener = Readable.prototype.on
|
|
|
|
Readable.prototype.removeListener = function (ev, fn) {
|
|
const res = Stream.prototype.removeListener.call(this, ev, fn)
|
|
|
|
if (ev === 'readable') {
|
|
// We need to check if there is someone still listening to
|
|
// readable and reset the state. However this needs to happen
|
|
// after readable has been emitted but before I/O (nextTick) to
|
|
// support once('readable', fn) cycles. This means that calling
|
|
// resume within the same tick will have no
|
|
// effect.
|
|
process.nextTick(updateReadableListening, this)
|
|
}
|
|
|
|
return res
|
|
}
|
|
|
|
Readable.prototype.off = Readable.prototype.removeListener
|
|
|
|
Readable.prototype.removeAllListeners = function (ev) {
|
|
const res = Stream.prototype.removeAllListeners.apply(this, arguments)
|
|
|
|
if (ev === 'readable' || ev === undefined) {
|
|
// We need to check if there is someone still listening to
|
|
// readable and reset the state. However this needs to happen
|
|
// after readable has been emitted but before I/O (nextTick) to
|
|
// support once('readable', fn) cycles. This means that calling
|
|
// resume within the same tick will have no
|
|
// effect.
|
|
process.nextTick(updateReadableListening, this)
|
|
}
|
|
|
|
return res
|
|
}
|
|
|
|
function updateReadableListening(self) {
|
|
const state = self._readableState
|
|
state.readableListening = self.listenerCount('readable') > 0
|
|
|
|
if (state.resumeScheduled && state[kPaused] === false) {
|
|
// Flowing needs to be set to true now, otherwise
|
|
// the upcoming resume will not flow.
|
|
state.flowing = true // Crude way to check if we should resume.
|
|
} else if (self.listenerCount('data') > 0) {
|
|
self.resume()
|
|
} else if (!state.readableListening) {
|
|
state.flowing = null
|
|
}
|
|
}
|
|
|
|
function nReadingNextTick(self) {
|
|
debug('readable nexttick read 0')
|
|
self.read(0)
|
|
} // pause() and resume() are remnants of the legacy readable stream API
|
|
// If the user uses them, then switch into old mode.
|
|
|
|
Readable.prototype.resume = function () {
|
|
const state = this._readableState
|
|
|
|
if (!state.flowing) {
|
|
debug('resume') // We flow only if there is no one listening
|
|
// for readable, but we still have to call
|
|
// resume().
|
|
|
|
state.flowing = !state.readableListening
|
|
resume(this, state)
|
|
}
|
|
|
|
state[kPaused] = false
|
|
return this
|
|
}
|
|
|
|
function resume(stream, state) {
|
|
if (!state.resumeScheduled) {
|
|
state.resumeScheduled = true
|
|
process.nextTick(resume_, stream, state)
|
|
}
|
|
}
|
|
|
|
function resume_(stream, state) {
|
|
debug('resume', state.reading)
|
|
|
|
if (!state.reading) {
|
|
stream.read(0)
|
|
}
|
|
|
|
state.resumeScheduled = false
|
|
stream.emit('resume')
|
|
flow(stream)
|
|
if (state.flowing && !state.reading) stream.read(0)
|
|
}
|
|
|
|
Readable.prototype.pause = function () {
|
|
debug('call pause flowing=%j', this._readableState.flowing)
|
|
|
|
if (this._readableState.flowing !== false) {
|
|
debug('pause')
|
|
this._readableState.flowing = false
|
|
this.emit('pause')
|
|
}
|
|
|
|
this._readableState[kPaused] = true
|
|
return this
|
|
}
|
|
|
|
function flow(stream) {
|
|
const state = stream._readableState
|
|
debug('flow', state.flowing)
|
|
|
|
while (state.flowing && stream.read() !== null);
|
|
} // Wrap an old-style stream as the async data source.
|
|
// This is *not* part of the readable stream interface.
|
|
// It is an ugly unfortunate mess of history.
|
|
|
|
Readable.prototype.wrap = function (stream) {
|
|
let paused = false // TODO (ronag): Should this.destroy(err) emit
|
|
// 'error' on the wrapped stream? Would require
|
|
// a static factory method, e.g. Readable.wrap(stream).
|
|
|
|
stream.on('data', (chunk) => {
|
|
if (!this.push(chunk) && stream.pause) {
|
|
paused = true
|
|
stream.pause()
|
|
}
|
|
})
|
|
stream.on('end', () => {
|
|
this.push(null)
|
|
})
|
|
stream.on('error', (err) => {
|
|
errorOrDestroy(this, err)
|
|
})
|
|
stream.on('close', () => {
|
|
this.destroy()
|
|
})
|
|
stream.on('destroy', () => {
|
|
this.destroy()
|
|
})
|
|
|
|
this._read = () => {
|
|
if (paused && stream.resume) {
|
|
paused = false
|
|
stream.resume()
|
|
}
|
|
} // Proxy all the other methods. Important when wrapping filters and duplexes.
|
|
|
|
const streamKeys = ObjectKeys(stream)
|
|
|
|
for (let j = 1; j < streamKeys.length; j++) {
|
|
const i = streamKeys[j]
|
|
|
|
if (this[i] === undefined && typeof stream[i] === 'function') {
|
|
this[i] = stream[i].bind(stream)
|
|
}
|
|
}
|
|
|
|
return this
|
|
}
|
|
|
|
Readable.prototype[SymbolAsyncIterator] = function () {
|
|
return streamToAsyncIterator(this)
|
|
}
|
|
|
|
Readable.prototype.iterator = function (options) {
|
|
if (options !== undefined) {
|
|
validateObject(options, 'options')
|
|
}
|
|
|
|
return streamToAsyncIterator(this, options)
|
|
}
|
|
|
|
function streamToAsyncIterator(stream, options) {
|
|
if (typeof stream.read !== 'function') {
|
|
stream = Readable.wrap(stream, {
|
|
objectMode: true
|
|
})
|
|
}
|
|
|
|
const iter = createAsyncIterator(stream, options)
|
|
iter.stream = stream
|
|
return iter
|
|
}
|
|
|
|
async function* createAsyncIterator(stream, options) {
|
|
let callback = nop
|
|
|
|
function next(resolve) {
|
|
if (this === stream) {
|
|
callback()
|
|
callback = nop
|
|
} else {
|
|
callback = resolve
|
|
}
|
|
}
|
|
|
|
stream.on('readable', next)
|
|
let error
|
|
const cleanup = eos(
|
|
stream,
|
|
{
|
|
writable: false
|
|
},
|
|
(err) => {
|
|
error = err ? aggregateTwoErrors(error, err) : null
|
|
callback()
|
|
callback = nop
|
|
}
|
|
)
|
|
|
|
try {
|
|
while (true) {
|
|
const chunk = stream.destroyed ? null : stream.read()
|
|
|
|
if (chunk !== null) {
|
|
yield chunk
|
|
} else if (error) {
|
|
throw error
|
|
} else if (error === null) {
|
|
return
|
|
} else {
|
|
await new Promise(next)
|
|
}
|
|
}
|
|
} catch (err) {
|
|
error = aggregateTwoErrors(error, err)
|
|
throw error
|
|
} finally {
|
|
if (
|
|
(error || (options === null || options === undefined ? undefined : options.destroyOnReturn) !== false) &&
|
|
(error === undefined || stream._readableState.autoDestroy)
|
|
) {
|
|
destroyImpl.destroyer(stream, null)
|
|
} else {
|
|
stream.off('readable', next)
|
|
cleanup()
|
|
}
|
|
}
|
|
} // Making it explicit these properties are not enumerable
|
|
// because otherwise some prototype manipulation in
|
|
// userland will fail.
|
|
|
|
ObjectDefineProperties(Readable.prototype, {
|
|
readable: {
|
|
get() {
|
|
const r = this._readableState // r.readable === false means that this is part of a Duplex stream
|
|
// where the readable side was disabled upon construction.
|
|
// Compat. The user might manually disable readable side through
|
|
// deprecated setter.
|
|
|
|
return !!r && r.readable !== false && !r.destroyed && !r.errorEmitted && !r.endEmitted
|
|
},
|
|
|
|
set(val) {
|
|
// Backwards compat.
|
|
if (this._readableState) {
|
|
this._readableState.readable = !!val
|
|
}
|
|
}
|
|
},
|
|
readableDidRead: {
|
|
enumerable: false,
|
|
get: function () {
|
|
return this._readableState.dataEmitted
|
|
}
|
|
},
|
|
readableAborted: {
|
|
enumerable: false,
|
|
get: function () {
|
|
return !!(
|
|
this._readableState.readable !== false &&
|
|
(this._readableState.destroyed || this._readableState.errored) &&
|
|
!this._readableState.endEmitted
|
|
)
|
|
}
|
|
},
|
|
readableHighWaterMark: {
|
|
enumerable: false,
|
|
get: function () {
|
|
return this._readableState.highWaterMark
|
|
}
|
|
},
|
|
readableBuffer: {
|
|
enumerable: false,
|
|
get: function () {
|
|
return this._readableState && this._readableState.buffer
|
|
}
|
|
},
|
|
readableFlowing: {
|
|
enumerable: false,
|
|
get: function () {
|
|
return this._readableState.flowing
|
|
},
|
|
set: function (state) {
|
|
if (this._readableState) {
|
|
this._readableState.flowing = state
|
|
}
|
|
}
|
|
},
|
|
readableLength: {
|
|
enumerable: false,
|
|
|
|
get() {
|
|
return this._readableState.length
|
|
}
|
|
},
|
|
readableObjectMode: {
|
|
enumerable: false,
|
|
|
|
get() {
|
|
return this._readableState ? this._readableState.objectMode : false
|
|
}
|
|
},
|
|
readableEncoding: {
|
|
enumerable: false,
|
|
|
|
get() {
|
|
return this._readableState ? this._readableState.encoding : null
|
|
}
|
|
},
|
|
errored: {
|
|
enumerable: false,
|
|
|
|
get() {
|
|
return this._readableState ? this._readableState.errored : null
|
|
}
|
|
},
|
|
closed: {
|
|
get() {
|
|
return this._readableState ? this._readableState.closed : false
|
|
}
|
|
},
|
|
destroyed: {
|
|
enumerable: false,
|
|
|
|
get() {
|
|
return this._readableState ? this._readableState.destroyed : false
|
|
},
|
|
|
|
set(value) {
|
|
// We ignore the value if the stream
|
|
// has not been initialized yet.
|
|
if (!this._readableState) {
|
|
return
|
|
} // Backward compatibility, the user is explicitly
|
|
// managing destroyed.
|
|
|
|
this._readableState.destroyed = value
|
|
}
|
|
},
|
|
readableEnded: {
|
|
enumerable: false,
|
|
|
|
get() {
|
|
return this._readableState ? this._readableState.endEmitted : false
|
|
}
|
|
}
|
|
})
|
|
ObjectDefineProperties(ReadableState.prototype, {
|
|
// Legacy getter for `pipesCount`.
|
|
pipesCount: {
|
|
get() {
|
|
return this.pipes.length
|
|
}
|
|
},
|
|
// Legacy property for `paused`.
|
|
paused: {
|
|
get() {
|
|
return this[kPaused] !== false
|
|
},
|
|
|
|
set(value) {
|
|
this[kPaused] = !!value
|
|
}
|
|
}
|
|
}) // Exposed for testing purposes only.
|
|
|
|
Readable._fromList = fromList // Pluck off n bytes from an array of buffers.
|
|
// Length is the combined lengths of all the buffers in the list.
|
|
// This function is designed to be inlinable, so please take care when making
|
|
// changes to the function body.
|
|
|
|
function fromList(n, state) {
|
|
// nothing buffered.
|
|
if (state.length === 0) return null
|
|
let ret
|
|
if (state.objectMode) ret = state.buffer.shift()
|
|
else if (!n || n >= state.length) {
|
|
// Read it all, truncate the list.
|
|
if (state.decoder) ret = state.buffer.join('')
|
|
else if (state.buffer.length === 1) ret = state.buffer.first()
|
|
else ret = state.buffer.concat(state.length)
|
|
state.buffer.clear()
|
|
} else {
|
|
// read part of list.
|
|
ret = state.buffer.consume(n, state.decoder)
|
|
}
|
|
return ret
|
|
}
|
|
|
|
function endReadable(stream) {
|
|
const state = stream._readableState
|
|
debug('endReadable', state.endEmitted)
|
|
|
|
if (!state.endEmitted) {
|
|
state.ended = true
|
|
process.nextTick(endReadableNT, state, stream)
|
|
}
|
|
}
|
|
|
|
function endReadableNT(state, stream) {
|
|
debug('endReadableNT', state.endEmitted, state.length) // Check that we didn't get one last unshift.
|
|
|
|
if (!state.errored && !state.closeEmitted && !state.endEmitted && state.length === 0) {
|
|
state.endEmitted = true
|
|
stream.emit('end')
|
|
|
|
if (stream.writable && stream.allowHalfOpen === false) {
|
|
process.nextTick(endWritableNT, stream)
|
|
} else if (state.autoDestroy) {
|
|
// In case of duplex streams we need a way to detect
|
|
// if the writable side is ready for autoDestroy as well.
|
|
const wState = stream._writableState
|
|
const autoDestroy =
|
|
!wState ||
|
|
(wState.autoDestroy && // We don't expect the writable to ever 'finish'
|
|
// if writable is explicitly set to false.
|
|
(wState.finished || wState.writable === false))
|
|
|
|
if (autoDestroy) {
|
|
stream.destroy()
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
function endWritableNT(stream) {
|
|
const writable = stream.writable && !stream.writableEnded && !stream.destroyed
|
|
|
|
if (writable) {
|
|
stream.end()
|
|
}
|
|
}
|
|
|
|
Readable.from = function (iterable, opts) {
|
|
return from(Readable, iterable, opts)
|
|
}
|
|
|
|
let webStreamsAdapters // Lazy to avoid circular references
|
|
|
|
function lazyWebStreams() {
|
|
if (webStreamsAdapters === undefined) webStreamsAdapters = {}
|
|
return webStreamsAdapters
|
|
}
|
|
|
|
Readable.fromWeb = function (readableStream, options) {
|
|
return lazyWebStreams().newStreamReadableFromReadableStream(readableStream, options)
|
|
}
|
|
|
|
Readable.toWeb = function (streamReadable) {
|
|
return lazyWebStreams().newReadableStreamFromStreamReadable(streamReadable)
|
|
}
|
|
|
|
Readable.wrap = function (src, options) {
|
|
var _ref, _src$readableObjectMo
|
|
|
|
return new Readable({
|
|
objectMode:
|
|
(_ref =
|
|
(_src$readableObjectMo = src.readableObjectMode) !== null && _src$readableObjectMo !== undefined
|
|
? _src$readableObjectMo
|
|
: src.objectMode) !== null && _ref !== undefined
|
|
? _ref
|
|
: true,
|
|
...options,
|
|
|
|
destroy(err, callback) {
|
|
destroyImpl.destroyer(src, err)
|
|
callback(err)
|
|
}
|
|
}).wrap(src)
|
|
}
|