1var once = require('once') 2var eos = require('end-of-stream') 3var fs = require('fs') // we only need fs to get the ReadStream and WriteStream prototypes 4 5var noop = function () {} 6var ancient = /^v?\.0/.test(process.version) 7 8var isFn = function (fn) { 9 return typeof fn === 'function' 10} 11 12var isFS = function (stream) { 13 if (!ancient) return false // newer node version do not need to care about fs is a special way 14 if (!fs) return false // browser 15 return (stream instanceof (fs.ReadStream || noop) || stream instanceof (fs.WriteStream || noop)) && isFn(stream.close) 16} 17 18var isRequest = function (stream) { 19 return stream.setHeader && isFn(stream.abort) 20} 21 22var destroyer = function (stream, reading, writing, callback) { 23 callback = once(callback) 24 25 var closed = false 26 stream.on('close', function () { 27 closed = true 28 }) 29 30 eos(stream, {readable: reading, writable: writing}, function (err) { 31 if (err) return callback(err) 32 closed = true 33 callback() 34 }) 35 36 var destroyed = false 37 return function (err) { 38 if (closed) return 39 if (destroyed) return 40 destroyed = true 41 42 if (isFS(stream)) return stream.close(noop) // use close for fs streams to avoid fd leaks 43 if (isRequest(stream)) return stream.abort() // request.destroy just do .end - .abort is what we want 44 45 if (isFn(stream.destroy)) return stream.destroy() 46 47 callback(err || new Error('stream was destroyed')) 48 } 49} 50 51var call = function (fn) { 52 fn() 53} 54 55var pipe = function (from, to) { 56 return from.pipe(to) 57} 58 59var pump = function () { 60 var streams = Array.prototype.slice.call(arguments) 61 var callback = isFn(streams[streams.length - 1] || noop) && streams.pop() || noop 62 63 if (Array.isArray(streams[0])) streams = streams[0] 64 if (streams.length < 2) throw new Error('pump requires two streams per minimum') 65 66 var error 67 var destroys = streams.map(function (stream, i) { 68 var reading = i < streams.length - 1 69 var writing = i > 0 70 return destroyer(stream, reading, writing, function (err) { 71 if (!error) error = err 72 if (err) destroys.forEach(call) 73 if (reading) return 74 destroys.forEach(call) 75 callback(error) 76 }) 77 }) 78 79 return streams.reduce(pipe) 80} 81 82module.exports = pump 83