chunky-stream

chunky-stream

Buffer up chunks and push them based on certain conditions or if a period of time has passed. chunk-stream is a simple object-mode transform stream that you can pass any number of testable conditions to force a push/flush of the buffered chunks. It also has a interval feature to allow chunks to flush if a certain time has passed and no further chunks have been received.

  fs.createReadStream(file)
    .pipe(split2())
    .pipe(new ChunkyStream({ interval: 1000 }));

chunky-stream takes in the following options:

• interval - The amount of time (in ms) to wait since receiving data (0 to disable)
• ignoreEmpty - If set to true, do not count an empty string as a chunk (i.e. '', default = false)

API

ChunkyStream.use(condition)

This is similar to Express middleware, condition is a function that will run each time a chunk is received to determine whether the buffered chunks should be released. condition should have 1 argument:

• chunks - The array of chunks currently buffered and not yet flushed. condition should return true if you want to release the chunks to the consumer of the stream, false if you want to continue to buffer.

Examples

Buffer 10 text lines at a time

  var ChunkyStream = require('chunky-stream');
  var split = require('split2');
  var stream = fs.createReadStream('./test.txt');
  var chunk = new ChunkyStream();

  chunk.use(function (chunks) {
    return (chunks.length === 10);
  });

  stream.pipe(split()).pipe(chunk).on('data', function (err, lines) {
    console.log(lines);
  });