nodejs流可读卡在第一个可读对象上

Question

I have a NodeJS stream.Readable :

var async = require('async'),
    util = require('util'),
    ReadableStream = require('readable-stream').Readable;

function ArticleReader() {
  ReadableStream.call(this, { objectMode: true });
}

util.inherits(ArticleReader, ReadableStream);

ArticleReader.prototype._read = function() {
    var articles = ['article1', 'article2'];
    var self = this;
    async.each(articles, function(link, callback) {
       self.push(article);
       callback();
    }, function(err) {
        if (err) {
            self.emit('error', err);
        } else {
            self.push(null);
        }
    });
};

And this is the consumer:

var article = new ArticleReader();

  article.on('readable', function() {
  var buf = article.read();
  console.log(buf);
});

article.on('end', function() {
  console.log('end');
});

Here's the output:

'article1'

The problem is program is stuck at 'article1' , it never reads 'article2' , and it never reaches end event too.

Answer 1

Note that the event end fires when there will be no more data to read.

Also the end event will not fire unless the data is completely consumed. This can be done by switching into flowing mode , or by calling read() repeatedly until you get to the end.

The solution, was to keep reading until the end of the stream is reached.

var readable = getReadableStreamSomehow();

readable.on('readable', function() {
  while ((buf = readable.read()) != null) {
    console.log(buf);
  }
}

readable.on('data', function(chunk) {
  console.log('got %d bytes of data', chunk.length);
})
readable.on('end', function() {
  console.log('there will be no more data.');
});