frp/vendor/github.com/fatedier/golib/msg/json/process.go

94 lines
2.1 KiB
Go

// Copyright 2018 fatedier, fatedier@gmail.com
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package json
import (
"encoding/binary"
"errors"
"io"
)
var (
ErrMsgType = errors.New("message type error")
ErrMaxMsgLength = errors.New("message length exceed the limit")
ErrMsgLength = errors.New("message length error")
ErrMsgFormat = errors.New("message format error")
)
func (msgCtl *MsgCtl) readMsg(c io.Reader) (typeByte byte, buffer []byte, err error) {
buffer = make([]byte, 1)
_, err = c.Read(buffer)
if err != nil {
return
}
typeByte = buffer[0]
if _, ok := msgCtl.typeMap[typeByte]; !ok {
err = ErrMsgType
return
}
var length int64
err = binary.Read(c, binary.BigEndian, &length)
if err != nil {
return
}
if length > msgCtl.maxMsgLength {
err = ErrMaxMsgLength
return
} else if length < 0 {
err = ErrMsgLength
return
}
buffer = make([]byte, length)
n, err := io.ReadFull(c, buffer)
if err != nil {
return
}
if int64(n) != length {
err = ErrMsgFormat
}
return
}
func (msgCtl *MsgCtl) ReadMsg(c io.Reader) (msg Message, err error) {
typeByte, buffer, err := msgCtl.readMsg(c)
if err != nil {
return
}
return msgCtl.UnPack(typeByte, buffer)
}
func (msgCtl *MsgCtl) ReadMsgInto(c io.Reader, msg Message) (err error) {
_, buffer, err := msgCtl.readMsg(c)
if err != nil {
return
}
return msgCtl.UnPackInto(buffer, msg)
}
func (msgCtl *MsgCtl) WriteMsg(c io.Writer, msg interface{}) (err error) {
buffer, err := msgCtl.Pack(msg)
if err != nil {
return
}
if _, err = c.Write(buffer); err != nil {
return
}
return nil
}