msgpack5 
A msgpack v5 implementation for node.js and the browser, with extension point support.
Install
npm install msgpack5 --save
Usage
var msgpack = require('msgpack5')() // namespace our extensions
, a = new MyType(2, 'a')
, encode = msgpack.encode
, decode = msgpack.decode
msgpack.register(0x42, MyType, mytipeEncode, mytipeDecode)
console.log(encode({ 'hello': 'world' }).toString('hex'))
// 81a568656c6c6fa5776f726c64
console.log(decode(encode({ 'hello': 'world' })))
// { hello: 'world' }
console.log(encode(a).toString('hex'))
// d5426161
console.log(decode(encode(a)) instanceof MyType)
// true
console.log(decode(encode(a)))
// { value: 'a', size: 2 }
function MyType(size, value) {
this.value = value
this.size = size
}
function mytipeEncode(obj) {
var buf = new Buffer(obj.size)
buf.fill(obj.value)
return buf
}
function mytipeDecode(data) {
var result = new MyType(data.length, data.toString('utf8', 0, 1))
, i
for (i = 0; i < data.length; i++) {
if (data.readUInt8(0) != data.readUInt8(i)) {
throw new Error('should all be the same')
}
}
return result
}
In the Browser
This library is compatible with Browserify.
If you want to use standalone, grab the file in the dist folder of
this repo, and use in your own HTML page, the module will expose a
msgpack5 global.
<script type="text/javascript"
src="./msgpack5.min.js">
</script>
To build
npm run build
API
API
- msgpack()
- msgpack().encode()
- msgpack().decode()
- msgpack().registerEncoder()
- msgpack().registerDecoder()
- msgpack().register()
- msgpack().encoder()
- msgpack().decoder()
msgpack(options(obj))
Creates a new instance on which you can register new types for being
encoded.
options:
forceFloat64, a boolean to that forces all floats to be encoded as 64-bits floats. Defaults to false.sortKeys, a boolean to force a determinate keys ordercompatibilityMode, a boolean that enables "compatibility mode" which doesn't use str 8 format. Defaults to false.disableTimestampEncoding, a boolean that when set disables the encoding of Dates into the timestamp extension type. Defaults to false.
encode(object)
Encodes object in msgpack, returns a bl.
decode(buf)
Decodes buf from in msgpack. buf can be a Buffer or a bl instance.
In order to support a stream interface, a user must pass in a bl instance.
registerEncoder(check(obj), encode(obj))
Register a new custom object type for being automatically encoded.
The arguments are:
check, a function that will be called to check if the passed
object should be encoded with theencodefunctionencode, a function that will be called to encode an object in binary
form; this function must return aBufferwhich include the same type
for registerDecoder.
registerDecoder(type, decode(buf))
Register a new custom object type for being automatically decoded.
The arguments are:
type, is a greater than zero integer identificating the type once serializeddecode, a function that will be called to decode the object from
the passedBuffer
register(type, constructor, encode(obj), decode(buf))
Register a new custom object type for being automatically encoded and
decoded. The arguments are:
type, is a greater than zero integer identificating the type once serializedconstructor, the function that will be used to match the objects
withinstanceofencode, a function that will be called to encode an object in binary
form; this function must return aBufferthat can be
deserialized by thedecodefunctiondecode, a function that will be called to decode the object from
the passedBuffer
This is just a commodity that calls
registerEncoder and
registerDecoder internally.
encoder(options)
Builds a stream in object mode that encodes msgpack.
Supported options:
wrap, objects should be passed to encoder in wrapped object {value: data}. Wrap option should be used if you need to pass null to encoder.
decoder(options)
Builds a stream in object mode that decodes msgpack.
Supported options:
wrap, decoded objects returned in wrapped object {value: data}. Wrap option should be used if stream contains msgpack nil.
LevelUp Support
msgpack5 can be used as a LevelUp
valueEncoding straight away:
var level = require('level')
, pack = msgpack()
, db = level('foo', {
valueEncoding: pack
})
, obj = { my: 'obj' }
db.put('hello', obj, function(err) {
db.get('hello', function(err, result) {
console.log(result)
db.close()
})
})
Related projects
- msgpack5rpc: An implementation of the
msgpack-rpc spec
on top of this library.
Disclaimer
This library is built fully on JS and on bl to
simplify the code. Every improvement that keeps the same API is welcome.
Acknowledgements
This project was kindly sponsored by nearForm.
This library was originally built as the data format for
JSChan.
License
MIT