Created
May 27, 2014 16:33
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| 'use strict'; | |
| var stream = require('stream') | |
| ,util =require('util'); | |
| util.inherits(ConstantStream,stream.Readable); | |
| function ConstantStream(constant){ | |
| stream.Readable.call(this,{objectMode:true}); | |
| this.constant =constant; //get count form Cache | |
| } | |
| ConstantStream.prototype._read = function(){ | |
| var value ={}; | |
| value.name ='constant'; | |
| value.data =this.constant; | |
| this.push([value]); | |
| }; | |
| //simple Console write stream | |
| util.inherits(ConsoleStream,stream.Writable); | |
| function ConsoleStream(){ | |
| stream.Writable.call(this,{objectMode:true}); | |
| } | |
| ConsoleStream.prototype._write = function(chunk,enc,next){ | |
| console.log(chunk); | |
| next(); | |
| }; | |
| var consoleStream = new ConsoleStream(); | |
| //Concats array content | |
| util.inherits(ConcatProcessor,stream.Transform); | |
| function ConcatProcessor(){ | |
| stream.Transform.call(this,{objectMode:true}); | |
| } | |
| ConcatProcessor.prototype._transform = function(chunk,enc,next){ | |
| var result =''; | |
| chunk.forEach(function(item){ | |
| result +='-'+ item[0].data; | |
| }); | |
| this.push(result); | |
| next(); | |
| }; | |
| var concatProcessor = new ConcatProcessor(); | |
| //Combines multiple streams like a Multiplexer | |
| function CombineStreams(){ | |
| var data=[]; | |
| var sources = Array.prototype.slice.call(arguments); | |
| this.pipe =function(target){ | |
| sources.forEach(function(stream){ | |
| //TODO check if readable stream | |
| stream.on('data',function(chunk){ | |
| stream.pause(); | |
| data.push(chunk); | |
| if(data.length ===sources.length){ | |
| target.write(data); | |
| data =[]; | |
| sources.forEach(function(stream){ | |
| stream.resume(); | |
| }) | |
| } | |
| }) | |
| }); | |
| return target; | |
| } | |
| } | |
| var constant= new ConstantStream(3); | |
| var constant2= new ConstantStream(2); | |
| var constant3= new ConstantStream(1); | |
| var test =new CombineStreams(constant,constant2,constant3).pipe(concatProcessor); | |
| test.pipe(consoleStream); |
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