| var once = require('once') | |
| var eos = require('end-of-stream') | |
| var fs | |
| 
 | |
| try { | |
|   fs = require('fs') // we only need fs to get the ReadStream and WriteStream prototypes | |
| } catch (e) {} | |
| 
 | |
| 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
 |