mphandler

Documentation

Overview

Package mphandler implements a MsgPack/TCP interface to the Archiver API at http://godoc.org/github.com/gtfierro/giles/archiver

Overview

The MsgPack format for sMAP is designed to look very similar to the JSON format, while also making it possible to handle different commands (e.g. not just reads) as well as permissions including an API key.

type MsgPackSmap struct {
	Path       string
	UUID       string `codec:"uuid"`
	Key        string `codec:"key"`
	Properties map[string]interface{}
	Metadata   map[string]interface{}
	Readings   [][2]interface{}
}

We need to augment this struct with some information in a simple packet header that gives us the ability to describe packet length and packet command.

Header:

+----------------------+----------------------+----
| packet len (2 bytes) | packet type (1 byte) | packet contents...
+----------------------+----------------------+----

Packet length is 2 bytes. Afterwards comes a single byte that contains the packet type (this will be a value from a predetermined Enum that will be described below. Following this header comes the actual packet contents

Index

• Constants
• func AddReadings(a *archiver.Archiver, md map[string]interface{})
• func HandleTCP(a *archiver.Archiver, port int)
• func HandleUDP(a *archiver.Archiver, port int)
• type MessageType
  • func ParseHeader(input *[]byte, offset int) (MessageType, int)

Constants

const (
	DATA_WRITE = iota
	DATA_PREV
	DATA_NEXT
	DATA_RANGE
	TAG_GET
	TAG_SET
	QUERY
)

const (
	BUFFER_SIZE = 65536
)

Functions

func AddReadings

func AddReadings(a *archiver.Archiver, md map[string]interface{})

TODO: check for malformed

func HandleTCP

func HandleTCP(a *archiver.Archiver, port int)

func HandleUDP

func HandleUDP(a *archiver.Archiver, port int)

Types

type MessageType

type MessageType uint

func ParseHeader

func ParseHeader(input *[]byte, offset int) (MessageType, int)

Given a reference to a byte slice (probably your incoming buffer) and an offset into that slice, decode the header and return the MessageType and the total packet length