path: root/rpc/codec/codec.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package codec

import (
    "net"
    "strconv"

    "github.com/ethereum/go-ethereum/rpc/shared"
)

type Codec int

// (de)serialization support for rpc interface
type ApiCoder interface {
    // Parse message to request from underlying stream
    ReadRequest() ([]*shared.Request, bool, error)
    // Parse response message from underlying stream
    ReadResponse() (interface{}, error)
    // Read raw message from underlying stream
    Recv() (interface{}, error)
    // Encode response to encoded form in underlying stream
    WriteResponse(interface{}) error
    // Decode single message from data
    Decode([]byte, interface{}) error
    // Encode msg to encoded form
    Encode(msg interface{}) ([]byte, error)
    // close the underlying stream
    Close()
}

// supported codecs
const (
    JSON Codec = iota
    nCodecs
)

var (
    // collection with supported coders
    coders = make([]func(net.Conn) ApiCoder, nCodecs)
)

// create a new coder instance
func (c Codec) New(conn net.Conn) ApiCoder {
    switch c {
    case JSON:
        return NewJsonCoder(conn)
    }

    panic("codec: request for codec #" + strconv.Itoa(int(c)) + " is unavailable")
}