Socket.IO stream


This is the module for bidirectional binary data transfer with Stream API through Socket.IO.

Installation

npm install socket.io-stream

Usage

If you are not familiar with Stream API, be sure to check out the docs.
I also recommend checking out the awesome Stream Handbook.

For streaming between server and client, you will send stream instances first.
To receive streams, you just wrap socket with socket.io-stream, then listen any events as usual.

Server:

``js
var io = require('socket.io').listen(80);
var ss = require('socket.io-stream');
var path = require('path');

io.of('/user').on('connection', function(socket) {
ss(socket).on('profile-image', function(stream, data) {
var filename = path.basename(data.name);
stream.pipe(fs.createWriteStream(filename));
});
});
`

createStream() returns a new stream which can be sent by emit().

Client:

`js
var io = require('socket.io-client');
var ss = require('socket.io-stream');

var socket = io.connect('http://example.com/user');
var stream = ss.createStream();
var filename = 'profile.jpg';

ss(socket).emit('profile-image', stream, {name: filename});
fs.createReadStream(filename).pipe(stream);
`

You can stream data from a client to server, and vice versa.

`js
// send data
ss(socket).on('file', function(stream) {
fs.createReadStream('/path/to/file').pipe(stream);
});

// receive data
ss(socket).emit('file', stream);
stream.pipe(fs.createWriteStream('file.txt'));
`

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This module can be used on the browser. To do so, just copy a file to a public directory.

$ cp node_modules/socket.io-stream/socket.io-stream.js somewhere/public/

You can also use browserify to create your own bundle.

$ npm install browserify -g
$ cd node_modules/socket.io-stream
$ browserify index.js -s ss > socket.io-stream.js

`html






`

#### Upload progress

You can track upload progress like the following:

`js
var blobStream = ss.createBlobReadStream(file);
var size = 0;

blobStream.on('data', function(chunk) {
size += chunk.length;
console.log(Math.floor(size / file.size * 100) + '%');
// -> e.g. '42%'
});

blobStream.pipe(stream);
`

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You have to set forceBase64 option true when using the library with socket.io v0.9.x.

`js
ss.forceBase64 = true;
`

Documentation

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- sio socket.io Socket A socket of Socket.IO, both for client and server
- return Socket

Look up an existing Socket instance based on sio (a socket of Socket.IO), or create one if it doesn't exist.

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- event String The event name

Emit an event with variable number of arguments including at least a stream.

`js
ss(socket).emit('myevent', stream, {name: 'thefilename'}, function() { ... });

// send some streams at a time.
ss(socket).emit('multiple-streams', stream1, stream2);

// as members of array or object.
ss(socket).emit('flexible', [stream1, { foo: stream2 }]);

// get streams through the ack callback
ss(socket).emit('ack', function(stream1, stream2) { ... });
`

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- event String The event name
- listener Function The event handler function

Add a listener for event. listener will take stream(s) with any data as arguments.

`js
ss(socket).on('myevent', function(stream, data, callback) { ... });

// access stream options
ss(socket).on('foo', function(stream) {
if (stream.options && stream.options.highWaterMark > 1024) {
console.error('Too big highWaterMark.');
return;
}
});
`

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- options Object
- highWaterMark Number
- encoding String
- decodeStrings Boolean
- objectMode Boolean
- allowHalfOpen Boolean if true, then the stream won't automatically close when the other endpoint ends. Default to false.
- return Duplex Stream

Create a new duplex stream. See the docs for the details of stream and options.

`js
var stream = ss.createStream();

// with options
var stream = ss.createStream({
highWaterMark: 1024,
objectMode: true,
allowHalfOpen: true
});
`

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- options Object
- highWaterMark Number
- encoding String
- objectMode Boolean
- return Readable Stream

Create a new readable stream for Blob and File on browser. See the docs for the details of stream and options.

`js
var stream = ss.createBlobReadStream(new Blob([1, 2, 3]));
`

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Node Buffer class to use on browser, which is exposed for convenience. On Node environment, you should just use normal Buffer.

`js
var stream = ss.createStream();
stream.write(new ss.Buffer([0, 1, 2]));
``

License

MIT