readable stream test

readable_test.js

var readstream = require('fs').createReadStream('./data.json')
  , buffer = []
  , len = 0;

readstream.on('data', function(data) {
  buffer.push(data);
  len += data.length;
});
readstream.on('end', function() {
  buffer = Buffer.concat(buffer, len);
  console.log(buffer.toString());
});


var readstream = require('fs').createReadStream('./data.json')
  , buffer = []
  , len = 0;

// hook to readable so you can restart your processing
readstream.on('readable', function process() {
  var data;

  // People are going to adopt this weird assign and check pattern
  // from C code. Gross.
  while((data = readstream.read()) !== null) {
    buffer.push(data);
    len += data.length;
  }
});
readstream.on('end', function() {
  buffer = Buffer.concat(buffer, len);
  console.log(buffer.toString());
});



var readstream = require('fs').createReadStream('./data.json')
  , Collector = require('data-collector-stream')
  , collector = new Collector();


readstream.pipe(collector)
  .on('end', function() {
    console.log(collector.getData().toString());
  });





var readstream = require('fs').createReadStream('./data.json')
  , FilterStream = require('stream').FilterStream;

var filter = new FilterStream(function(data) {
  if(data === null) {
    this.emit('end');
  }

  this.emit('data', data.toString().toUpperCase());
});

readstream.pipe(filter)
  .on('end', function() {

  });

// If filtering was supported by stream, maybe something like this.
readstream.filter(gzipper);






// foo protocol =
// 2 bytes = msgpack length
// n bytes = filename (n = msgpack length as int)
// the rest = file contents
// end

function FooParser (options) {
  // hook up to underlying stream somehow
  Readable.call(this, options)
  this.process()
  this.state = 'start'
}
util.inherits(FooParser, Readable)
FooParser.prototype.process = function () {
  var data;
  switch (this.state) {
    case 'start': 
      if((data = this.read(2)) !== null) {
        this.length = parseInt(data.toString(), 16)
        this.state = 'filename'
      }
      break
    case 'filename':
      if((data = this.read(this.length)) !== null) {
        this.filename = data
        this.state = 'file'
        return
      }
      break
    case 'file':
      this.emit('ready')
      break
  }
}


var parser = new FooParser();
req.pipe(parser).on('ready', function() {
  var file = fs.createWriteStream(this.filename);
  this.pipe(file);
});