forked from rDrama/rDrama
145 lines
3.2 KiB
JavaScript
145 lines
3.2 KiB
JavaScript
|
'use strict'
|
||
|
/*
|
||
|
* merge2
|
||
|
* https://github.com/teambition/merge2
|
||
|
*
|
||
|
* Copyright (c) 2014-2020 Teambition
|
||
|
* Licensed under the MIT license.
|
||
|
*/
|
||
|
const Stream = require('stream')
|
||
|
const PassThrough = Stream.PassThrough
|
||
|
const slice = Array.prototype.slice
|
||
|
|
||
|
module.exports = merge2
|
||
|
|
||
|
function merge2 () {
|
||
|
const streamsQueue = []
|
||
|
const args = slice.call(arguments)
|
||
|
let merging = false
|
||
|
let options = args[args.length - 1]
|
||
|
|
||
|
if (options && !Array.isArray(options) && options.pipe == null) {
|
||
|
args.pop()
|
||
|
} else {
|
||
|
options = {}
|
||
|
}
|
||
|
|
||
|
const doEnd = options.end !== false
|
||
|
const doPipeError = options.pipeError === true
|
||
|
if (options.objectMode == null) {
|
||
|
options.objectMode = true
|
||
|
}
|
||
|
if (options.highWaterMark == null) {
|
||
|
options.highWaterMark = 64 * 1024
|
||
|
}
|
||
|
const mergedStream = PassThrough(options)
|
||
|
|
||
|
function addStream () {
|
||
|
for (let i = 0, len = arguments.length; i < len; i++) {
|
||
|
streamsQueue.push(pauseStreams(arguments[i], options))
|
||
|
}
|
||
|
mergeStream()
|
||
|
return this
|
||
|
}
|
||
|
|
||
|
function mergeStream () {
|
||
|
if (merging) {
|
||
|
return
|
||
|
}
|
||
|
merging = true
|
||
|
|
||
|
let streams = streamsQueue.shift()
|
||
|
if (!streams) {
|
||
|
process.nextTick(endStream)
|
||
|
return
|
||
|
}
|
||
|
if (!Array.isArray(streams)) {
|
||
|
streams = [streams]
|
||
|
}
|
||
|
|
||
|
let pipesCount = streams.length + 1
|
||
|
|
||
|
function next () {
|
||
|
if (--pipesCount > 0) {
|
||
|
return
|
||
|
}
|
||
|
merging = false
|
||
|
mergeStream()
|
||
|
}
|
||
|
|
||
|
function pipe (stream) {
|
||
|
function onend () {
|
||
|
stream.removeListener('merge2UnpipeEnd', onend)
|
||
|
stream.removeListener('end', onend)
|
||
|
if (doPipeError) {
|
||
|
stream.removeListener('error', onerror)
|
||
|
}
|
||
|
next()
|
||
|
}
|
||
|
function onerror (err) {
|
||
|
mergedStream.emit('error', err)
|
||
|
}
|
||
|
// skip ended stream
|
||
|
if (stream._readableState.endEmitted) {
|
||
|
return next()
|
||
|
}
|
||
|
|
||
|
stream.on('merge2UnpipeEnd', onend)
|
||
|
stream.on('end', onend)
|
||
|
|
||
|
if (doPipeError) {
|
||
|
stream.on('error', onerror)
|
||
|
}
|
||
|
|
||
|
stream.pipe(mergedStream, { end: false })
|
||
|
// compatible for old stream
|
||
|
stream.resume()
|
||
|
}
|
||
|
|
||
|
for (let i = 0; i < streams.length; i++) {
|
||
|
pipe(streams[i])
|
||
|
}
|
||
|
|
||
|
next()
|
||
|
}
|
||
|
|
||
|
function endStream () {
|
||
|
merging = false
|
||
|
// emit 'queueDrain' when all streams merged.
|
||
|
mergedStream.emit('queueDrain')
|
||
|
if (doEnd) {
|
||
|
mergedStream.end()
|
||
|
}
|
||
|
}
|
||
|
|
||
|
mergedStream.setMaxListeners(0)
|
||
|
mergedStream.add = addStream
|
||
|
mergedStream.on('unpipe', function (stream) {
|
||
|
stream.emit('merge2UnpipeEnd')
|
||
|
})
|
||
|
|
||
|
if (args.length) {
|
||
|
addStream.apply(null, args)
|
||
|
}
|
||
|
return mergedStream
|
||
|
}
|
||
|
|
||
|
// check and pause streams for pipe.
|
||
|
function pauseStreams (streams, options) {
|
||
|
if (!Array.isArray(streams)) {
|
||
|
// Backwards-compat with old-style streams
|
||
|
if (!streams._readableState && streams.pipe) {
|
||
|
streams = streams.pipe(PassThrough(options))
|
||
|
}
|
||
|
if (!streams._readableState || !streams.pause || !streams.pipe) {
|
||
|
throw new Error('Only readable stream can be merged.')
|
||
|
}
|
||
|
streams.pause()
|
||
|
} else {
|
||
|
for (let i = 0, len = streams.length; i < len; i++) {
|
||
|
streams[i] = pauseStreams(streams[i], options)
|
||
|
}
|
||
|
}
|
||
|
return streams
|
||
|
}
|