dat-replication-protocol

dat-replication-protocol

Streaming implementation of the dat replication protocol

npm install dat-replication-protocol

Usage

var protocol = require('dat-replication-protocol')

var p = protocol(function(type, stream) {
  if (type === protocol.CHANGES) {
    // receiving the changes stream
    stream.on('data', function(change) {
      console.log('change:', change)
    })
  }
  if (type === protocol.BLOB) {
    // receiving a blob stream
    stream.pipe(process.stdout)
  }
})

var changes = p.createChangesStream()

// write changes data to this stream
changes.write({
  key: 'some-row-key',
  change: 0,
  from: 0,
  to: 1,
  value: new Buffer('some binary value')
})

var blob = p.createBlobStream(12) // 12 is the length of the blob

blob.write('hello ')
blob.write('world\n')
blob.end()

// for testing lets just pipe it to ourselves
p.pipe(p)

This works similarly to the multiplex module except this uses length prefixed streams for the blobs streams

Wire format

Basically all changes and blobs are sent as multibuffers (varint prefixed).

--------------------------------------------------
|  varint length  |  single byte id  |  payload  |
--------------------------------------------------

Since blobs can be large they are treated as streams.

License

MIT