Express_Crud_Example/node_modules/pump/index.js

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2022-01-28 22:33:42 +01:00
var once = require('once')
var eos = require('end-of-stream')
var fs = require('fs') // we only need fs to get the ReadStream and WriteStream prototypes
var noop = function () {}
var ancient = /^v?\.0/.test(process.version)
var isFn = function (fn) {
return typeof fn === 'function'
}
var isFS = function (stream) {
if (!ancient) return false // newer node version do not need to care about fs is a special way
if (!fs) return false // browser
return (stream instanceof (fs.ReadStream || noop) || stream instanceof (fs.WriteStream || noop)) && isFn(stream.close)
}
var isRequest = function (stream) {
return stream.setHeader && isFn(stream.abort)
}
var destroyer = function (stream, reading, writing, callback) {
callback = once(callback)
var closed = false
stream.on('close', function () {
closed = true
})
eos(stream, {readable: reading, writable: writing}, function (err) {
if (err) return callback(err)
closed = true
callback()
})
var destroyed = false
return function (err) {
if (closed) return
if (destroyed) return
destroyed = true
if (isFS(stream)) return stream.close(noop) // use close for fs streams to avoid fd leaks
if (isRequest(stream)) return stream.abort() // request.destroy just do .end - .abort is what we want
if (isFn(stream.destroy)) return stream.destroy()
callback(err || new Error('stream was destroyed'))
}
}
var call = function (fn) {
fn()
}
var pipe = function (from, to) {
return from.pipe(to)
}
var pump = function () {
var streams = Array.prototype.slice.call(arguments)
var callback = isFn(streams[streams.length - 1] || noop) && streams.pop() || noop
if (Array.isArray(streams[0])) streams = streams[0]
if (streams.length < 2) throw new Error('pump requires two streams per minimum')
var error
var destroys = streams.map(function (stream, i) {
var reading = i < streams.length - 1
var writing = i > 0
return destroyer(stream, reading, writing, function (err) {
if (!error) error = err
if (err) destroys.forEach(call)
if (reading) return
destroys.forEach(call)
callback(error)
})
})
return streams.reduce(pipe)
}
module.exports = pump