Create streams lazily when they are read from or written to.
lazystream: 1.0.0
Sometimes you feel the itch to open all the files at once. You want to pass a bunch of streams around, so the consumer does not need to worry where the data comes from.
From a software design point-of-view this sounds entirely reasonable. Then there is that neat little function fs.createReadStream()
that opens a file and gives you a nice fs.ReadStream
to pass around, so you use what the mighty creator deities of node bestowed upon you.
Error: EMFILE, too many open files
─ node
This package provides two classes based on the node’s Streams3 API (courtesy of readable-stream
to ensure a stable version).
A wrapper for readable streams. Extends stream.PassThrough
.
fn
{Function}options
{Object}PassThrough
stream, accessible by fn
.Creates a new readable stream. Once the stream is accessed (for example when you call its read()
method, or attach a data
-event listener) the fn
function is called with the outer lazystream.Readable
instance bound to this
.
If you pass an options
object to the constuctor, you can access it in your fn
function.
new lazystream.Readable(function (options) {
return fs.createReadStream('/dev/urandom');
});
A wrapper for writable streams. Extends stream.PassThrough
.
fn
{Function}options
{Object}PassThrough
stream, accessible by fn
.Creates a new writable stream. Just like the one above but for writable streams.
new lazystream.Writable(function () {
return fs.createWriteStream('/dev/null');
});
$ npm install lazystream --save
lazystream@1.0.0 node_modules/lazystream
└── readable-stream@2.0.5
readable-stream
2.x.Fork it, branch it, send me a pull request. We’ll work out the rest together.
Chris Talkington and his node-archiver for providing a use-case.
Copyright © 2013 J. Pommerening, contributors.
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