42 lines
		
	
	
		
			899 B
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
		
		
			
		
	
	
			42 lines
		
	
	
		
			899 B
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
|  | 'use strict'; | ||
|  | 
 | ||
|  | var PassThrough = require('readable-stream/passthrough') | ||
|  | 
 | ||
|  | module.exports = function (/*streams...*/) { | ||
|  |   var sources = [] | ||
|  |   var output  = new PassThrough({objectMode: true}) | ||
|  | 
 | ||
|  |   output.setMaxListeners(0) | ||
|  | 
 | ||
|  |   output.add = add | ||
|  |   output.isEmpty = isEmpty | ||
|  | 
 | ||
|  |   output.on('unpipe', remove) | ||
|  | 
 | ||
|  |   Array.prototype.slice.call(arguments).forEach(add) | ||
|  | 
 | ||
|  |   return output | ||
|  | 
 | ||
|  |   function add (source) { | ||
|  |     if (Array.isArray(source)) { | ||
|  |       source.forEach(add) | ||
|  |       return this | ||
|  |     } | ||
|  | 
 | ||
|  |     sources.push(source); | ||
|  |     source.once('end', remove.bind(null, source)) | ||
|  |     source.once('error', output.emit.bind(output, 'error')) | ||
|  |     source.pipe(output, {end: false}) | ||
|  |     return this | ||
|  |   } | ||
|  | 
 | ||
|  |   function isEmpty () { | ||
|  |     return sources.length == 0; | ||
|  |   } | ||
|  | 
 | ||
|  |   function remove (source) { | ||
|  |     sources = sources.filter(function (it) { return it !== source }) | ||
|  |     if (!sources.length && output.readable) { output.end() } | ||
|  |   } | ||
|  | } |