JarCastinglength-prefixed-stream
Streaming equivalent of length-prefixed-message. This module allow you to send Buffers with a varint length prefix to ensure that they will arrive unpartioned
npm install length-prefixed-stream
Usage
var lpstream = require('length-prefixed-stream')
var encode = lpstream.encode() // create an encode stream to send data
var decode = lpstream.decode() // create an decode stream to receive data
encode.write('hello world') // send "hello world"
decode.on('data', function(data) {
console.log(data.toString()) // will always print "hello world"
})
encode.pipe(decode) // for testing just pipe to our selves
Encoding format
This library encodes each chunks as follows:
<length-of-chunk-1> <chunk-1> <length-of-chunk-2> <chunk-2> …
The length of the following chunk is encoded using varint, which follows the protobuf-style varint encoding.
As an example, we're going to encode two ASCII chunks:
1st chunk:
68 65 79 hey
2nd chunk:
68 65 6c 6c 6f 20 77 6f 72 6c 64 hello world
Encoded using length-prefixed-stream, they look like this:
03 varint-encoded length of 1st chunk
68 65 79 1st chunk (3 bytes)
0b varint-encoded length ()of 2nd chunk
68 65 6c 6c 6f 20 77 6f 72 6c 64 2nd chunk (11 bytes)
API
transformStream = lpstream.encode()
Creates a new encoder transform stream.
transformStream = lpstream.decode()
Creates a new decoder transform stream.
License
MIT