blob: b11d1022e62f912e733bb75ae4e56d6b2da23555 [file] [log] [blame]
/*
* Copyright 2018-present Open Networking Foundation
* 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 afrouter
import (
"github.com/golang/protobuf/proto"
"github.com/opencord/voltha-go/common/log"
"google.golang.org/grpc/encoding"
)
/*
* encoding.Codec renamed grpc.Codec's String() method to Name()
*
* grpc.ForceCodec() expects an encoding.Codec, alternative use of grpc.Codec is deprecated
* grpc.CustomCodec() expects a grpc.Codec, has no mechanism to use encoding.Codec
*
* Make an interface that supports them both.
*/
type hybridCodec interface {
encoding.Codec
String() string
}
func Codec() hybridCodec {
return CodecWithParent(&protoCodec{})
}
func CodecWithParent(parent encoding.Codec) hybridCodec {
return &transparentRoutingCodec{parent}
}
type transparentRoutingCodec struct {
parentCodec encoding.Codec
}
// responseFrame is a frame being "returned" to whomever established the connection
type responseFrame struct {
payload []byte
router Router
method string
backend *backend
metaKey string
metaVal string
}
// requestFrame is a frame coming in from whomever established the connection
type requestFrame struct {
payload []byte
router Router
backend *backend
connection *connection // optional, if the router preferred one connection over another
err error
methodInfo methodDetails
serialNo string
metaKey string
metaVal string
}
func (cdc *transparentRoutingCodec) Marshal(v interface{}) ([]byte, error) {
switch t := v.(type) {
case *responseFrame:
return t.payload, nil
case *requestFrame:
return t.payload, nil
default:
return cdc.parentCodec.Marshal(v)
}
}
func (cdc *transparentRoutingCodec) Unmarshal(data []byte, v interface{}) error {
switch t := v.(type) {
case *responseFrame:
t.payload = data
// This is where the affinity is established on a northbound response
/*
* NOTE: Ignoring this error is intentional. MethodRouter returns
* error when a reply is not processed for northbound affinity,
* but we still need to unmarshal it.
*
* TODO: Investigate error-return semantics of ReplyHandler.
*/
_ = t.router.ReplyHandler(v)
return nil
case *requestFrame:
t.payload = data
// This is were the afinity value is pulled from the payload
// and the backend selected.
t.backend, t.connection = t.router.Route(v)
name := "<nil>"
if t.backend != nil {
name = t.backend.name
}
log.Debugf("Routing returned %s for method %s", name, t.methodInfo.method)
return nil
default:
return cdc.parentCodec.Unmarshal(data, v)
}
}
func (cdc *transparentRoutingCodec) Name() string {
return cdc.parentCodec.Name()
}
func (cdc *transparentRoutingCodec) String() string {
return cdc.Name()
}
// protoCodec is a Codec implementation with protobuf. It is the default Codec for gRPC.
type protoCodec struct{}
func (protoCodec) Marshal(v interface{}) ([]byte, error) {
return proto.Marshal(v.(proto.Message))
}
func (protoCodec) Unmarshal(data []byte, v interface{}) error {
return proto.Unmarshal(data, v.(proto.Message))
}
func (protoCodec) Name() string {
return "protoCodec"
}