[VOL-785,VOL-786,VOL-1315,VOL-1316]
Initial commit of the affinity router's data plane
Change-Id: Iccc93b5526d5d2468b33eff7d8847e22fb88ef2d
diff --git a/afrouter/afrouter/codec.go b/afrouter/afrouter/codec.go
new file mode 100644
index 0000000..20bf354
--- /dev/null
+++ b/afrouter/afrouter/codec.go
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ */
+// gRPC affinity router with active/active backends
+
+package afrouter
+
+import (
+ "fmt"
+ "sync"
+ "google.golang.org/grpc"
+ "github.com/golang/protobuf/proto"
+ "github.com/opencord/voltha-go/common/log"
+)
+
+func Codec() grpc.Codec {
+ return CodecWithParent(&protoCodec{})
+}
+
+func CodecWithParent(fallback grpc.Codec) grpc.Codec {
+ return &rawCodec{fallback}
+}
+
+type rawCodec struct {
+ parentCodec grpc.Codec
+}
+
+type sbFrame struct {
+ payload []byte
+ router Router
+ method string
+ be *backend
+ lck sync.Mutex
+ metaKey string
+ metaVal string
+}
+
+type nbFrame struct {
+ payload []byte
+ router Router
+ be *backend
+ err error
+ mthdSlice []string
+ serNo chan uint64
+ metaKey string
+ metaVal string
+}
+
+func (c *rawCodec) Marshal(v interface{}) ([]byte, error) {
+ switch t := v.(type) {
+ case *sbFrame:
+ return t.payload, nil
+ case *nbFrame:
+ return t.payload, nil
+ default:
+ return c.parentCodec.Marshal(v)
+ }
+
+}
+
+func (c *rawCodec) Unmarshal(data []byte, v interface{}) error {
+ switch t := v.(type) {
+ case *sbFrame:
+ t.payload = data
+ // This is where the affinity is established on a northbound response
+ t.router.ReplyHandler(v)
+ return nil
+ case *nbFrame:
+ t.payload = data
+ // This is were the afinity value is pulled from the payload
+ // and the backend selected.
+ t.be = t.router.Route(v)
+ log.Debugf("Routing returned %v for method %s", t.be, t.mthdSlice[REQ_METHOD])
+ return nil
+ default:
+ return c.parentCodec.Unmarshal(data,v)
+ }
+}
+
+func (c *rawCodec) String() string {
+ return fmt.Sprintf("proxy>%s", c.parentCodec.String())
+}
+
+// protoCodec is a Codec implementation with protobuf. It is the default rawCodec 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) String() string {
+ return "proto"
+}