streaming

streaming

A few stream helpers, abiding by the new-style Node.js stream standards ("Streams2").

npm install streaming

streaming.Glob

new Glob(pattern, options) inherits stream.Readable

• _readableState.objectMode: true

streaming.json.Stringifier

new Stringifier(replacer, space) inherits streaming.Splitter

• objectMode: false
  • _writableState.objectMode: false
  • _readableState.objectMode: true

streaming.json.Parser

new Parser() inherits streaming.Splitter

• objectMode: true

streaming.Line

new Line() inherits stream.Transform

• _writableState.objectMode: false
• _readableState.objectMode: true

streaming.Mapper

new Mapper(fn) inherits stream.Transform

• _writableState.objectMode: true
• _readableState.objectMode: true

streaming.Queue

new Queue(concurrency, worker) inherits streaming.Mapper

• _writableState.objectMode: true
• _readableState.objectMode: true

Example:

var streaming = require('streaming');

var lazy_worker = function(task, callback) {
  setTimeout(function() {
    var json = JSON.stringify(task);
    callback(null, json.length + ' after 1s\n');
  }, 1000);
};

process.stdin
.pipe(new streaming.Line())
.pipe(new streaming.Mapper(JSON.parse))
.pipe(new streaming.Queue(5, lazy_worker))
.pipe(process.stdout);

streaming.Splitter

Very similar to streaming.Line, but more configurable.

new Splitter(split, opts) inherits stream.Transform

streaming.Timeout

new Timeout(seconds, opts) inherits stream.Transform

stream.Transform(opts) results:

opts. decodeStrings	opts. objectMode	_writableState. decodeStrings	_writableState. objectMode	_readableState. objectMode
true	true	true	true	true
false	true	false	true	true
undefined	true	true	true	true
true	false	true	false	false
false	false	false	false	false
undefined	false	true	false	false
true	undefined	true	false	false
false	undefined	false	false	false
undefined	undefined	true	false	false

License

Copyright © 2013 Christopher Brown. MIT Licensed.