//
// 解析Thrift数据的Message Header
//
func ParseThriftMsgBegin(msg []byte) (name string, typeId thrift.TMessageType, seqId int32, err error) {
transport := thrift.NewTMemoryBufferLen(256)
transport.Write(msg)
protocol := thrift.NewTBinaryProtocolTransport(transport)
name, typeId, seqId, err = protocol.ReadMessageBegin()
return
}
//
// 将Request中的SeqNum进行替换（修改Request部分的数据)
//
func (r *Request) ReplaceSeqId(newSeq int32) {
if r.Request.Data != nil {
// log.Printf(Green("Replace SeqNum: %d --> %d"), r.Request.SeqId, newSeq)
if r.Response.SeqId != 0 {
log.Errorf("Unexpected Response SedId")
}
r.Response.SeqId = newSeq
start := 0
if r.ProxyRequest {
start = len(r.Service)
}
if start > 0 {
start += 1 // ":"
// log.Printf("Service: %s, Name: %s\n", r.Service, r.Request.Name)
}
transport := NewTMemoryBufferWithBuf(r.Request.Data[start:start])
protocol := thrift.NewTBinaryProtocolTransport(transport)
protocol.WriteMessageBegin(r.Request.Name, r.Request.TypeId, newSeq)
if start > 0 {
r.Request.DataOrig = r.Request.Data
}
// 将service从name中剥离出去
r.Request.Data = r.Request.Data[start:len(r.Request.Data)]
} else {
log.Errorf("ReplaceSeqId called on processed Data")
}
}
func fakeData(name string, typeId thrift.TMessageType, seqId int32, buf []byte) int {
transport := NewTMemoryBufferWithBuf(buf)
protocol := thrift.NewTBinaryProtocolTransport(transport)
// 切换回原始的SeqId
protocol.WriteMessageBegin(name, typeId, seqId)
return transport.Buffer.Len()
}
func HandleProxyPingRequest(req *Request) {
transport := NewTMemoryBufferLen(30)
protocol := thrift.NewTBinaryProtocolTransport(transport)
protocol.WriteMessageBegin("ping", thrift.REPLY, req.Request.SeqId)
result := services.NewRpcServiceBasePingResult()
result.Write(protocol)
protocol.WriteMessageEnd()
protocol.Flush()
req.Response.Data = transport.Bytes()
}
//
// 后端如何处理一个Request
//
func (p *ThriftRpcServer) Dispatch(r *Request) error {
transport := NewTMemoryBufferWithBuf(r.Request.Data)
ip := thrift.NewTBinaryProtocolTransport(transport)
slice := getSlice(0, DEFAULT_SLICE_LEN)
transport = NewTMemoryBufferWithBuf(slice)
op := thrift.NewTBinaryProtocolTransport(transport)
p.Processor.Process(ip, op)
r.Response.Data = transport.Bytes()
_, _, seqId, _ := DecodeThriftTypIdSeqId(r.Response.Data)
log.Debugf("SeqId: %d vs. %d, Dispatch Over", r.Request.SeqId, seqId)
// // 如果transport重新分配了内存，则立即归还slice
// if cap(r.Response.Data) != DEFAULT_SLICE_LEN {
// returnSlice(slice)
// }
return nil
}
func GetWorkerNotFoundData(req *Request, module string) []byte {
req.Response.TypeId = thrift.EXCEPTION
// 构建thrift的Transport
transport := thrift.NewTMemoryBufferLen(100)
protocol := thrift.NewTBinaryProtocolTransport(transport)
// 构建一个Message, 写入Exception
msg := fmt.Sprintf("Worker FOR %s#%s.%s Not Found", module, req.Service, req.Request.Name)
exc := thrift.NewTApplicationException(thrift.INTERNAL_ERROR, msg)
protocol.WriteMessageBegin(req.Request.Name, thrift.EXCEPTION, req.Request.SeqId)
exc.Write(protocol)
protocol.WriteMessageEnd()
bytes := transport.Bytes()
return bytes
}
func NewPingRequest() *Request {
// 构建thrift的Transport
transport := NewTMemoryBufferLen(30)
protocol := thrift.NewTBinaryProtocolTransport(transport)
protocol.WriteMessageBegin("ping", MESSAGE_TYPE_HEART_BEAT, 0)
protocol.WriteMessageEnd()
protocol.Flush()
r := &Request{}
// 告诉Request, Data中不包含service，在ReplaceSeqId时不需要特别处理
r.ProxyRequest = false
r.Start = microseconds()
r.Request.Data = transport.Bytes()
r.Request.Name = "ping"
r.Request.SeqId = 0 // SeqId在这里无效，因此设置为0
r.Request.TypeId = MESSAGE_TYPE_HEART_BEAT
return r
}
//
// 生成Thrift格式的Exception Message
//
func GetServiceNotFoundData(req *Request) []byte {
req.Response.TypeId = thrift.EXCEPTION
// 构建thrift的Transport
transport := thrift.NewTMemoryBufferLen(100)
protocol := thrift.NewTBinaryProtocolTransport(transport)
// 构建一个Message, 写入Exception
msg := fmt.Sprintf("Service: %s Not Found", req.Service)
exc := thrift.NewTApplicationException(thrift.UNKNOWN_APPLICATION_EXCEPTION, msg)
protocol.WriteMessageBegin(req.Request.Name, thrift.EXCEPTION, req.Request.SeqId)
exc.Write(protocol)
protocol.WriteMessageEnd()
protocol.Flush()
bytes := transport.Bytes()
return bytes
}
func GetThriftException(req *Request, module string) []byte {
req.Response.TypeId = thrift.EXCEPTION
// 构建thrift的Transport
transport := thrift.NewTMemoryBufferLen(256)
protocol := thrift.NewTBinaryProtocolTransport(transport)
msg := fmt.Sprintf("Module: %s, Service: %s, Method: %s, Error: %v", module, req.Service, req.Request.Name, req.Response.Err)
// 构建一个Message, 写入Exception
exc := thrift.NewTApplicationException(thrift.INTERNAL_ERROR, msg)
// 注意消息的格式
protocol.WriteMessageBegin(req.Request.Name, thrift.EXCEPTION, req.Request.SeqId)
exc.Write(protocol)
protocol.WriteMessageEnd()
bytes := transport.Bytes()
return bytes
}
//
// 从Request.Data中读取出 Request的Name, TypeId, SeqId
// RequestName可能和thrift package中的name不一致，Service部分从Name中剔除
//
func (r *Request) DecodeRequest() error {
var err error
transport := NewTMemoryBufferWithBuf(r.Request.Data)
protocol := thrift.NewTBinaryProtocolTransport(transport)
// 如果数据异常，则直接报错
r.Request.Name, r.Request.TypeId, r.Request.SeqId, err = protocol.ReadMessageBegin()
if err != nil {
return err
}
// 参考 ： TMultiplexedProtocol
idx := strings.Index(r.Request.Name, thrift.MULTIPLEXED_SEPARATOR)
if idx == -1 {
r.Service = ""
} else {
r.Service = r.Request.Name[0:idx]
r.Request.Name = r.Request.Name[idx+1 : len(r.Request.Name)]
}
return nil
}