546 lines
14 KiB
JavaScript
546 lines
14 KiB
JavaScript
'use strict'
|
|
const EE = require('events')
|
|
const Stream = require('stream')
|
|
const Yallist = require('yallist')
|
|
const SD = require('string_decoder').StringDecoder
|
|
|
|
const EOF = Symbol('EOF')
|
|
const MAYBE_EMIT_END = Symbol('maybeEmitEnd')
|
|
const EMITTED_END = Symbol('emittedEnd')
|
|
const EMITTING_END = Symbol('emittingEnd')
|
|
const CLOSED = Symbol('closed')
|
|
const READ = Symbol('read')
|
|
const FLUSH = Symbol('flush')
|
|
const FLUSHCHUNK = Symbol('flushChunk')
|
|
const ENCODING = Symbol('encoding')
|
|
const DECODER = Symbol('decoder')
|
|
const FLOWING = Symbol('flowing')
|
|
const PAUSED = Symbol('paused')
|
|
const RESUME = Symbol('resume')
|
|
const BUFFERLENGTH = Symbol('bufferLength')
|
|
const BUFFERPUSH = Symbol('bufferPush')
|
|
const BUFFERSHIFT = Symbol('bufferShift')
|
|
const OBJECTMODE = Symbol('objectMode')
|
|
const DESTROYED = Symbol('destroyed')
|
|
|
|
// TODO remove when Node v8 support drops
|
|
const doIter = global._MP_NO_ITERATOR_SYMBOLS_ !== '1'
|
|
const ASYNCITERATOR = doIter && Symbol.asyncIterator
|
|
|| Symbol('asyncIterator not implemented')
|
|
const ITERATOR = doIter && Symbol.iterator
|
|
|| Symbol('iterator not implemented')
|
|
|
|
// events that mean 'the stream is over'
|
|
// these are treated specially, and re-emitted
|
|
// if they are listened for after emitting.
|
|
const isEndish = ev =>
|
|
ev === 'end' ||
|
|
ev === 'finish' ||
|
|
ev === 'prefinish'
|
|
|
|
const isArrayBuffer = b => b instanceof ArrayBuffer ||
|
|
typeof b === 'object' &&
|
|
b.constructor &&
|
|
b.constructor.name === 'ArrayBuffer' &&
|
|
b.byteLength >= 0
|
|
|
|
const isArrayBufferView = b => !Buffer.isBuffer(b) && ArrayBuffer.isView(b)
|
|
|
|
module.exports = class Minipass extends Stream {
|
|
constructor (options) {
|
|
super()
|
|
this[FLOWING] = false
|
|
// whether we're explicitly paused
|
|
this[PAUSED] = false
|
|
this.pipes = new Yallist()
|
|
this.buffer = new Yallist()
|
|
this[OBJECTMODE] = options && options.objectMode || false
|
|
if (this[OBJECTMODE])
|
|
this[ENCODING] = null
|
|
else
|
|
this[ENCODING] = options && options.encoding || null
|
|
if (this[ENCODING] === 'buffer')
|
|
this[ENCODING] = null
|
|
this[DECODER] = this[ENCODING] ? new SD(this[ENCODING]) : null
|
|
this[EOF] = false
|
|
this[EMITTED_END] = false
|
|
this[EMITTING_END] = false
|
|
this[CLOSED] = false
|
|
this.writable = true
|
|
this.readable = true
|
|
this[BUFFERLENGTH] = 0
|
|
this[DESTROYED] = false
|
|
}
|
|
|
|
get bufferLength () { return this[BUFFERLENGTH] }
|
|
|
|
get encoding () { return this[ENCODING] }
|
|
set encoding (enc) {
|
|
if (this[OBJECTMODE])
|
|
throw new Error('cannot set encoding in objectMode')
|
|
|
|
if (this[ENCODING] && enc !== this[ENCODING] &&
|
|
(this[DECODER] && this[DECODER].lastNeed || this[BUFFERLENGTH]))
|
|
throw new Error('cannot change encoding')
|
|
|
|
if (this[ENCODING] !== enc) {
|
|
this[DECODER] = enc ? new SD(enc) : null
|
|
if (this.buffer.length)
|
|
this.buffer = this.buffer.map(chunk => this[DECODER].write(chunk))
|
|
}
|
|
|
|
this[ENCODING] = enc
|
|
}
|
|
|
|
setEncoding (enc) {
|
|
this.encoding = enc
|
|
}
|
|
|
|
get objectMode () { return this[OBJECTMODE] }
|
|
set objectMode (om) { this[OBJECTMODE] = this[OBJECTMODE] || !!om }
|
|
|
|
write (chunk, encoding, cb) {
|
|
if (this[EOF])
|
|
throw new Error('write after end')
|
|
|
|
if (this[DESTROYED]) {
|
|
this.emit('error', Object.assign(
|
|
new Error('Cannot call write after a stream was destroyed'),
|
|
{ code: 'ERR_STREAM_DESTROYED' }
|
|
))
|
|
return true
|
|
}
|
|
|
|
if (typeof encoding === 'function')
|
|
cb = encoding, encoding = 'utf8'
|
|
|
|
if (!encoding)
|
|
encoding = 'utf8'
|
|
|
|
// convert array buffers and typed array views into buffers
|
|
// at some point in the future, we may want to do the opposite!
|
|
// leave strings and buffers as-is
|
|
// anything else switches us into object mode
|
|
if (!this[OBJECTMODE] && !Buffer.isBuffer(chunk)) {
|
|
if (isArrayBufferView(chunk))
|
|
chunk = Buffer.from(chunk.buffer, chunk.byteOffset, chunk.byteLength)
|
|
else if (isArrayBuffer(chunk))
|
|
chunk = Buffer.from(chunk)
|
|
else if (typeof chunk !== 'string')
|
|
// use the setter so we throw if we have encoding set
|
|
this.objectMode = true
|
|
}
|
|
|
|
// this ensures at this point that the chunk is a buffer or string
|
|
// don't buffer it up or send it to the decoder
|
|
if (!this.objectMode && !chunk.length) {
|
|
if (this[BUFFERLENGTH] !== 0)
|
|
this.emit('readable')
|
|
if (cb)
|
|
cb()
|
|
return this.flowing
|
|
}
|
|
|
|
// fast-path writing strings of same encoding to a stream with
|
|
// an empty buffer, skipping the buffer/decoder dance
|
|
if (typeof chunk === 'string' && !this[OBJECTMODE] &&
|
|
// unless it is a string already ready for us to use
|
|
!(encoding === this[ENCODING] && !this[DECODER].lastNeed)) {
|
|
chunk = Buffer.from(chunk, encoding)
|
|
}
|
|
|
|
if (Buffer.isBuffer(chunk) && this[ENCODING])
|
|
chunk = this[DECODER].write(chunk)
|
|
|
|
if (this.flowing) {
|
|
// if we somehow have something in the buffer, but we think we're
|
|
// flowing, then we need to flush all that out first, or we get
|
|
// chunks coming in out of order. Can't emit 'drain' here though,
|
|
// because we're mid-write, so that'd be bad.
|
|
if (this[BUFFERLENGTH] !== 0)
|
|
this[FLUSH](true)
|
|
this.emit('data', chunk)
|
|
} else
|
|
this[BUFFERPUSH](chunk)
|
|
|
|
if (this[BUFFERLENGTH] !== 0)
|
|
this.emit('readable')
|
|
|
|
if (cb)
|
|
cb()
|
|
|
|
return this.flowing
|
|
}
|
|
|
|
read (n) {
|
|
if (this[DESTROYED])
|
|
return null
|
|
|
|
try {
|
|
if (this[BUFFERLENGTH] === 0 || n === 0 || n > this[BUFFERLENGTH])
|
|
return null
|
|
|
|
if (this[OBJECTMODE])
|
|
n = null
|
|
|
|
if (this.buffer.length > 1 && !this[OBJECTMODE]) {
|
|
if (this.encoding)
|
|
this.buffer = new Yallist([
|
|
Array.from(this.buffer).join('')
|
|
])
|
|
else
|
|
this.buffer = new Yallist([
|
|
Buffer.concat(Array.from(this.buffer), this[BUFFERLENGTH])
|
|
])
|
|
}
|
|
|
|
return this[READ](n || null, this.buffer.head.value)
|
|
} finally {
|
|
this[MAYBE_EMIT_END]()
|
|
}
|
|
}
|
|
|
|
[READ] (n, chunk) {
|
|
if (n === chunk.length || n === null)
|
|
this[BUFFERSHIFT]()
|
|
else {
|
|
this.buffer.head.value = chunk.slice(n)
|
|
chunk = chunk.slice(0, n)
|
|
this[BUFFERLENGTH] -= n
|
|
}
|
|
|
|
this.emit('data', chunk)
|
|
|
|
if (!this.buffer.length && !this[EOF])
|
|
this.emit('drain')
|
|
|
|
return chunk
|
|
}
|
|
|
|
end (chunk, encoding, cb) {
|
|
if (typeof chunk === 'function')
|
|
cb = chunk, chunk = null
|
|
if (typeof encoding === 'function')
|
|
cb = encoding, encoding = 'utf8'
|
|
if (chunk)
|
|
this.write(chunk, encoding)
|
|
if (cb)
|
|
this.once('end', cb)
|
|
this[EOF] = true
|
|
this.writable = false
|
|
|
|
// if we haven't written anything, then go ahead and emit,
|
|
// even if we're not reading.
|
|
// we'll re-emit if a new 'end' listener is added anyway.
|
|
// This makes MP more suitable to write-only use cases.
|
|
if (this.flowing || !this[PAUSED])
|
|
this[MAYBE_EMIT_END]()
|
|
return this
|
|
}
|
|
|
|
// don't let the internal resume be overwritten
|
|
[RESUME] () {
|
|
if (this[DESTROYED])
|
|
return
|
|
|
|
this[PAUSED] = false
|
|
this[FLOWING] = true
|
|
this.emit('resume')
|
|
if (this.buffer.length)
|
|
this[FLUSH]()
|
|
else if (this[EOF])
|
|
this[MAYBE_EMIT_END]()
|
|
else
|
|
this.emit('drain')
|
|
}
|
|
|
|
resume () {
|
|
return this[RESUME]()
|
|
}
|
|
|
|
pause () {
|
|
this[FLOWING] = false
|
|
this[PAUSED] = true
|
|
}
|
|
|
|
get destroyed () {
|
|
return this[DESTROYED]
|
|
}
|
|
|
|
get flowing () {
|
|
return this[FLOWING]
|
|
}
|
|
|
|
get paused () {
|
|
return this[PAUSED]
|
|
}
|
|
|
|
[BUFFERPUSH] (chunk) {
|
|
if (this[OBJECTMODE])
|
|
this[BUFFERLENGTH] += 1
|
|
else
|
|
this[BUFFERLENGTH] += chunk.length
|
|
return this.buffer.push(chunk)
|
|
}
|
|
|
|
[BUFFERSHIFT] () {
|
|
if (this.buffer.length) {
|
|
if (this[OBJECTMODE])
|
|
this[BUFFERLENGTH] -= 1
|
|
else
|
|
this[BUFFERLENGTH] -= this.buffer.head.value.length
|
|
}
|
|
return this.buffer.shift()
|
|
}
|
|
|
|
[FLUSH] (noDrain) {
|
|
do {} while (this[FLUSHCHUNK](this[BUFFERSHIFT]()))
|
|
|
|
if (!noDrain && !this.buffer.length && !this[EOF])
|
|
this.emit('drain')
|
|
}
|
|
|
|
[FLUSHCHUNK] (chunk) {
|
|
return chunk ? (this.emit('data', chunk), this.flowing) : false
|
|
}
|
|
|
|
pipe (dest, opts) {
|
|
if (this[DESTROYED])
|
|
return
|
|
|
|
const ended = this[EMITTED_END]
|
|
opts = opts || {}
|
|
if (dest === process.stdout || dest === process.stderr)
|
|
opts.end = false
|
|
else
|
|
opts.end = opts.end !== false
|
|
|
|
const p = { dest: dest, opts: opts, ondrain: _ => this[RESUME]() }
|
|
this.pipes.push(p)
|
|
|
|
dest.on('drain', p.ondrain)
|
|
this[RESUME]()
|
|
// piping an ended stream ends immediately
|
|
if (ended && p.opts.end)
|
|
p.dest.end()
|
|
return dest
|
|
}
|
|
|
|
addListener (ev, fn) {
|
|
return this.on(ev, fn)
|
|
}
|
|
|
|
on (ev, fn) {
|
|
try {
|
|
return super.on(ev, fn)
|
|
} finally {
|
|
if (ev === 'data' && !this.pipes.length && !this.flowing)
|
|
this[RESUME]()
|
|
else if (isEndish(ev) && this[EMITTED_END]) {
|
|
super.emit(ev)
|
|
this.removeAllListeners(ev)
|
|
}
|
|
}
|
|
}
|
|
|
|
get emittedEnd () {
|
|
return this[EMITTED_END]
|
|
}
|
|
|
|
[MAYBE_EMIT_END] () {
|
|
if (!this[EMITTING_END] &&
|
|
!this[EMITTED_END] &&
|
|
!this[DESTROYED] &&
|
|
this.buffer.length === 0 &&
|
|
this[EOF]) {
|
|
this[EMITTING_END] = true
|
|
this.emit('end')
|
|
this.emit('prefinish')
|
|
this.emit('finish')
|
|
if (this[CLOSED])
|
|
this.emit('close')
|
|
this[EMITTING_END] = false
|
|
}
|
|
}
|
|
|
|
emit (ev, data) {
|
|
// error and close are only events allowed after calling destroy()
|
|
if (ev !== 'error' && ev !== 'close' && ev !== DESTROYED && this[DESTROYED])
|
|
return
|
|
else if (ev === 'data') {
|
|
if (!data)
|
|
return
|
|
|
|
if (this.pipes.length)
|
|
this.pipes.forEach(p =>
|
|
p.dest.write(data) === false && this.pause())
|
|
} else if (ev === 'end') {
|
|
// only actual end gets this treatment
|
|
if (this[EMITTED_END] === true)
|
|
return
|
|
|
|
this[EMITTED_END] = true
|
|
this.readable = false
|
|
|
|
if (this[DECODER]) {
|
|
data = this[DECODER].end()
|
|
if (data) {
|
|
this.pipes.forEach(p => p.dest.write(data))
|
|
super.emit('data', data)
|
|
}
|
|
}
|
|
|
|
this.pipes.forEach(p => {
|
|
p.dest.removeListener('drain', p.ondrain)
|
|
if (p.opts.end)
|
|
p.dest.end()
|
|
})
|
|
} else if (ev === 'close') {
|
|
this[CLOSED] = true
|
|
// don't emit close before 'end' and 'finish'
|
|
if (!this[EMITTED_END] && !this[DESTROYED])
|
|
return
|
|
}
|
|
|
|
// TODO: replace with a spread operator when Node v4 support drops
|
|
const args = new Array(arguments.length)
|
|
args[0] = ev
|
|
args[1] = data
|
|
if (arguments.length > 2) {
|
|
for (let i = 2; i < arguments.length; i++) {
|
|
args[i] = arguments[i]
|
|
}
|
|
}
|
|
|
|
try {
|
|
return super.emit.apply(this, args)
|
|
} finally {
|
|
if (!isEndish(ev))
|
|
this[MAYBE_EMIT_END]()
|
|
else
|
|
this.removeAllListeners(ev)
|
|
}
|
|
}
|
|
|
|
// const all = await stream.collect()
|
|
collect () {
|
|
const buf = []
|
|
if (!this[OBJECTMODE])
|
|
buf.dataLength = 0
|
|
// set the promise first, in case an error is raised
|
|
// by triggering the flow here.
|
|
const p = this.promise()
|
|
this.on('data', c => {
|
|
buf.push(c)
|
|
if (!this[OBJECTMODE])
|
|
buf.dataLength += c.length
|
|
})
|
|
return p.then(() => buf)
|
|
}
|
|
|
|
// const data = await stream.concat()
|
|
concat () {
|
|
return this[OBJECTMODE]
|
|
? Promise.reject(new Error('cannot concat in objectMode'))
|
|
: this.collect().then(buf =>
|
|
this[OBJECTMODE]
|
|
? Promise.reject(new Error('cannot concat in objectMode'))
|
|
: this[ENCODING] ? buf.join('') : Buffer.concat(buf, buf.dataLength))
|
|
}
|
|
|
|
// stream.promise().then(() => done, er => emitted error)
|
|
promise () {
|
|
return new Promise((resolve, reject) => {
|
|
this.on(DESTROYED, () => reject(new Error('stream destroyed')))
|
|
this.on('end', () => resolve())
|
|
this.on('error', er => reject(er))
|
|
})
|
|
}
|
|
|
|
// for await (let chunk of stream)
|
|
[ASYNCITERATOR] () {
|
|
const next = () => {
|
|
const res = this.read()
|
|
if (res !== null)
|
|
return Promise.resolve({ done: false, value: res })
|
|
|
|
if (this[EOF])
|
|
return Promise.resolve({ done: true })
|
|
|
|
let resolve = null
|
|
let reject = null
|
|
const onerr = er => {
|
|
this.removeListener('data', ondata)
|
|
this.removeListener('end', onend)
|
|
reject(er)
|
|
}
|
|
const ondata = value => {
|
|
this.removeListener('error', onerr)
|
|
this.removeListener('end', onend)
|
|
this.pause()
|
|
resolve({ value: value, done: !!this[EOF] })
|
|
}
|
|
const onend = () => {
|
|
this.removeListener('error', onerr)
|
|
this.removeListener('data', ondata)
|
|
resolve({ done: true })
|
|
}
|
|
const ondestroy = () => onerr(new Error('stream destroyed'))
|
|
return new Promise((res, rej) => {
|
|
reject = rej
|
|
resolve = res
|
|
this.once(DESTROYED, ondestroy)
|
|
this.once('error', onerr)
|
|
this.once('end', onend)
|
|
this.once('data', ondata)
|
|
})
|
|
}
|
|
|
|
return { next }
|
|
}
|
|
|
|
// for (let chunk of stream)
|
|
[ITERATOR] () {
|
|
const next = () => {
|
|
const value = this.read()
|
|
const done = value === null
|
|
return { value, done }
|
|
}
|
|
return { next }
|
|
}
|
|
|
|
destroy (er) {
|
|
if (this[DESTROYED]) {
|
|
if (er)
|
|
this.emit('error', er)
|
|
else
|
|
this.emit(DESTROYED)
|
|
return this
|
|
}
|
|
|
|
this[DESTROYED] = true
|
|
|
|
// throw away all buffered data, it's never coming out
|
|
this.buffer = new Yallist()
|
|
this[BUFFERLENGTH] = 0
|
|
|
|
if (typeof this.close === 'function' && !this[CLOSED])
|
|
this.close()
|
|
|
|
if (er)
|
|
this.emit('error', er)
|
|
else // if no error to emit, still reject pending promises
|
|
this.emit(DESTROYED)
|
|
|
|
return this
|
|
}
|
|
|
|
static isStream (s) {
|
|
return !!s && (s instanceof Minipass || s instanceof Stream ||
|
|
s instanceof EE && (
|
|
typeof s.pipe === 'function' || // readable
|
|
(typeof s.write === 'function' && typeof s.end === 'function') // writable
|
|
))
|
|
}
|
|
}
|