VOL-1967 move api-server to separate repository

Current with voltha-go acf0adaf2d91ae72b55192cc8a939e0485918d16

Change-Id: I000ea6be0789e20c922bd671562b58a7120892ae
diff --git a/internal/pkg/afrouter/affinity-router.go b/internal/pkg/afrouter/affinity-router.go
new file mode 100644
index 0000000..7a94f7b
--- /dev/null
+++ b/internal/pkg/afrouter/affinity-router.go
@@ -0,0 +1,377 @@
+/*
+ * 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 (
+	"errors"
+	"fmt"
+	"github.com/golang/protobuf/proto"
+	"github.com/opencord/voltha-go/common/log"
+	"google.golang.org/grpc"
+	"regexp"
+	"strconv"
+)
+
+// TODO: Used in multiple routers, should move to common file
+const (
+	PKG_MTHD_PKG  int = 1
+	PKG_MTHD_MTHD int = 2
+)
+
+type AffinityRouter struct {
+	name               string
+	association        associationType
+	routingField       string
+	grpcService        string
+	methodMap          map[string]byte
+	nbBindingMethodMap map[string]byte
+	cluster            *cluster
+	affinity           map[string]*backend
+	currentBackend     **backend
+}
+
+func newAffinityRouter(rconf *RouterConfig, config *RouteConfig) (Router, error) {
+	var err error = nil
+	var rtrn_err = false
+	var pkg_re = regexp.MustCompile(`^(\.[^.]+\.)(.+)$`)
+	// Validate the configuration
+
+	// A name must exist
+	if config.Name == "" {
+		log.Error("A router 'name' must be specified")
+		rtrn_err = true
+	}
+
+	if rconf.ProtoPackage == "" {
+		log.Error("A 'package' must be specified")
+		rtrn_err = true
+	}
+
+	if rconf.ProtoService == "" {
+		log.Error("A 'service' must be specified")
+		rtrn_err = true
+	}
+
+	//if config.RouteField == "" {
+	//	log.Error("A 'routing_field' must be specified")
+	//	rtrn_err = true
+	//}
+
+	// TODO The overrieds section is currently not being used
+	// so the router will route all methods based on the
+	// routing_field. This needs to be added so that methods
+	// can have different routing fields.
+	var bptr *backend
+	bptr = nil
+	dr := AffinityRouter{
+		name:               config.Name,
+		grpcService:        rconf.ProtoService,
+		affinity:           make(map[string]*backend),
+		methodMap:          make(map[string]byte),
+		nbBindingMethodMap: make(map[string]byte),
+		currentBackend:     &bptr,
+	}
+	// An association must exist
+	dr.association = config.Association
+	if dr.association == AssociationUndefined {
+		log.Error("An association must be specified")
+		rtrn_err = true
+	}
+
+	// Build the routing structure based on the loaded protobuf
+	// descriptor file and the config information.
+	type key struct {
+		method string
+		field  string
+	}
+	var fieldNumberLookup = make(map[key]byte)
+	for _, f := range rconf.protoDescriptor.File {
+		// Build a temporary map of message types by name.
+		for _, m := range f.MessageType {
+			for _, fld := range m.Field {
+				log.Debugf("Processing message '%s', field '%s'", *m.Name, *fld.Name)
+				fieldNumberLookup[key{*m.Name, *fld.Name}] = byte(*fld.Number)
+			}
+		}
+	}
+	for _, f := range rconf.protoDescriptor.File {
+		if *f.Package == rconf.ProtoPackage {
+			for _, s := range f.Service {
+				if *s.Name == rconf.ProtoService {
+					log.Debugf("Loading package data '%s' for service '%s' for router '%s'", *f.Package, *s.Name, dr.name)
+					// Now create a map keyed by method name with the value being the
+					// field number of the route selector.
+					var ok bool
+					for _, m := range s.Method {
+						// Find the input type in the messages and extract the
+						// field number and save it for future reference.
+						log.Debugf("Processing method '%s'", *m.Name)
+						// Determine if this is a method we're supposed to be processing.
+						if needMethod(*m.Name, config) {
+							log.Debugf("Enabling method '%s'", *m.Name)
+							pkg_methd := pkg_re.FindStringSubmatch(*m.InputType)
+							if pkg_methd == nil {
+								log.Errorf("Regular expression didn't match input type '%s'", *m.InputType)
+								rtrn_err = true
+							}
+							// The input type has the package name prepended to it. Remove it.
+							//in := (*m.InputType)[len(rconf.ProtoPackage)+2:]
+							in := pkg_methd[PKG_MTHD_MTHD]
+							dr.methodMap[*m.Name], ok = fieldNumberLookup[key{in, config.RouteField}]
+							if !ok {
+								log.Errorf("Method '%s' has no field named '%s' in it's parameter message '%s'",
+									*m.Name, config.RouteField, in)
+								rtrn_err = true
+							}
+						}
+						// The sb method is always included in the methods so we can check it here too.
+						if needNbBindingMethod(*m.Name, config) {
+							log.Debugf("Enabling southbound method '%s'", *m.Name)
+							// The output type has the package name prepended to it. Remove it.
+							out := (*m.OutputType)[len(rconf.ProtoPackage)+2:]
+							dr.nbBindingMethodMap[*m.Name], ok = fieldNumberLookup[key{out, config.RouteField}]
+							if !ok {
+								log.Errorf("Method '%s' has no field named '%s' in it's parameter message '%s'",
+									*m.Name, config.RouteField, out)
+								rtrn_err = true
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+
+	// Create the backend cluster or link to an existing one
+	ok := true
+	if dr.cluster, ok = clusters[config.backendCluster.Name]; !ok {
+		if dr.cluster, err = newBackendCluster(config.backendCluster); err != nil {
+			log.Errorf("Could not create a backend for router %s", config.Name)
+			rtrn_err = true
+		}
+	}
+
+	if rtrn_err {
+		return dr, errors.New(fmt.Sprintf("Failed to create a new router '%s'", dr.name))
+	}
+
+	return dr, nil
+}
+
+func needNbBindingMethod(mthd string, conf *RouteConfig) bool {
+	for _, m := range conf.NbBindingMethods {
+		if mthd == m {
+			return true
+		}
+	}
+	return false
+}
+
+// TODO: Used in multiple routers, should move to common file
+func needMethod(mthd string, conf *RouteConfig) bool {
+	for _, m := range conf.Methods {
+		if mthd == m {
+			return true
+		}
+	}
+	return false
+}
+
+func (ar AffinityRouter) Service() string {
+	return ar.grpcService
+}
+
+func (ar AffinityRouter) Name() string {
+	return ar.name
+}
+
+func (ar AffinityRouter) skipField(data *[]byte, idx *int) error {
+	switch (*data)[*idx] & 3 {
+	case 0: // Varint
+		// skip the field number/type
+		*idx++
+		// if the msb is set, then more bytes to follow
+		for (*data)[*idx] >= 128 {
+			*idx++
+		}
+		// the last byte doesn't have the msb set
+		*idx++
+	case 1: // 64 bit
+		*idx += 9
+	case 2: // Length delimited
+		*idx++
+		b := proto.NewBuffer((*data)[*idx:])
+		t, _ := b.DecodeVarint()
+		*idx += int(t) + 1
+	case 3: // Deprecated
+	case 4: // Deprecated
+	case 5: // 32 bit
+		*idx += 5
+	}
+	return nil
+}
+
+func (ar AffinityRouter) decodeProtoField(payload []byte, fieldId byte) (string, error) {
+	idx := 0
+	b := proto.NewBuffer([]byte{})
+	//b.DebugPrint("The Buffer", payload)
+	for { // Find the route selector field
+		log.Debugf("Decoding afinity value attributeNumber: %d from %v at index %d", fieldId, payload, idx)
+		log.Debugf("Attempting match with payload: %d, methodTable: %d", payload[idx], fieldId)
+		if payload[idx]>>3 == fieldId {
+			log.Debugf("Method match with payload: %d, methodTable: %d", payload[idx], fieldId)
+			// TODO: Consider supporting other selector types.... Way, way in the future
+			// ok, the future is now, support strings as well... ugh.
+			var selector string
+			switch payload[idx] & 3 {
+			case 0: // Integer
+				b.SetBuf(payload[idx+1:])
+				v, e := b.DecodeVarint()
+				if e == nil {
+					log.Debugf("Decoded the ing field: %v", v)
+					selector = strconv.Itoa(int(v))
+				} else {
+					log.Errorf("Failed to decode varint %v", e)
+					return "", e
+				}
+			case 2: // Length delimited AKA string
+				b.SetBuf(payload[idx+1:])
+				v, e := b.DecodeStringBytes()
+				if e == nil {
+					log.Debugf("Decoded the string field: %v", v)
+					selector = v
+				} else {
+					log.Errorf("Failed to decode string %v", e)
+					return "", e
+				}
+			default:
+				err := errors.New(fmt.Sprintf("Only integer and string route selectors are permitted"))
+				log.Error(err)
+				return "", err
+			}
+			return selector, nil
+		} else if err := ar.skipField(&payload, &idx); err != nil {
+			log.Errorf("Parsing message failed %v", err)
+			return "", err
+		}
+	}
+}
+
+func (ar AffinityRouter) Route(sel interface{}) (*backend, *connection) {
+	switch sl := sel.(type) {
+	case *requestFrame:
+		log.Debugf("Route called for requestFrame with method %s", sl.methodInfo.method)
+		// Check if this method should be affinity bound from the
+		// reply rather than the request.
+		if _, ok := ar.nbBindingMethodMap[sl.methodInfo.method]; ok {
+			var err error
+			log.Debugf("Method '%s' affinity binds on reply", sl.methodInfo.method)
+			// Just round robin route the southbound request
+			if *ar.currentBackend, err = ar.cluster.nextBackend(*ar.currentBackend, BackendSequenceRoundRobin); err == nil {
+				return *ar.currentBackend, nil
+			} else {
+				sl.err = err
+				return nil, nil
+			}
+		}
+		// Not a south affinity binding method, proceed with north affinity binding.
+		if selector, err := ar.decodeProtoField(sl.payload, ar.methodMap[sl.methodInfo.method]); err == nil {
+			log.Debugf("Establishing affinity for selector: %s", selector)
+			if rtrn, ok := ar.affinity[selector]; ok {
+				return rtrn, nil
+			} else {
+				// The selector isn't in the map, create a new affinity mapping
+				log.Debugf("MUST CREATE A NEW AFFINITY MAP ENTRY!!")
+				var err error
+				if *ar.currentBackend, err = ar.cluster.nextBackend(*ar.currentBackend, BackendSequenceRoundRobin); err == nil {
+					ar.setAffinity(selector, *ar.currentBackend)
+					//ar.affinity[selector] = *ar.currentBackend
+					//log.Debugf("New affinity set to backend %s",(*ar.currentBackend).name)
+					return *ar.currentBackend, nil
+				} else {
+					sl.err = err
+					return nil, nil
+				}
+			}
+		}
+	default:
+		log.Errorf("Internal: invalid data type in Route call %v", sel)
+		return nil, nil
+	}
+	log.Errorf("Bad lookup in affinity map %v", ar.affinity)
+	return nil, nil
+}
+
+func (ar AffinityRouter) GetMetaKeyVal(serverStream grpc.ServerStream) (string, string, error) {
+	return "", "", nil
+}
+
+func (ar AffinityRouter) IsStreaming(_ string) (bool, bool) {
+	panic("not implemented")
+}
+
+func (ar AffinityRouter) BackendCluster(mthd string, metaKey string) (*cluster, error) {
+	return ar.cluster, nil
+}
+
+func (ar AffinityRouter) FindBackendCluster(beName string) *cluster {
+	if beName == ar.cluster.name {
+		return ar.cluster
+	}
+	return nil
+}
+
+func (ar AffinityRouter) ReplyHandler(sel interface{}) error {
+	switch sl := sel.(type) {
+	case *responseFrame:
+		log.Debugf("Reply handler called for responseFrame with method %s", sl.method)
+		// Determine if reply action is required.
+		if fld, ok := ar.nbBindingMethodMap[sl.method]; ok && len(sl.payload) > 0 {
+			// Extract the field value from the frame and
+			// and set affinity accordingly
+			if selector, err := ar.decodeProtoField(sl.payload, fld); err == nil {
+				log.Debug("Settign affinity on reply")
+				if ar.setAffinity(selector, sl.backend) != nil {
+					log.Error("Setting affinity on reply failed")
+				}
+				return nil
+			} else {
+				err := errors.New(fmt.Sprintf("Failed to decode reply field %d for method %s", fld, sl.method))
+				log.Error(err)
+				return err
+			}
+		}
+		return nil
+	default:
+		err := errors.New(fmt.Sprintf("Internal: invalid data type in ReplyHander call %v", sl))
+		log.Error(err)
+		return err
+	}
+}
+
+func (ar AffinityRouter) setAffinity(key string, be *backend) error {
+	if be2, ok := ar.affinity[key]; !ok {
+		ar.affinity[key] = be
+		log.Debugf("New affinity set to backend %s for key %s", be.name, key)
+	} else if be2 != be {
+		err := errors.New(fmt.Sprintf("Attempting multiple sets of affinity for key %s to backend %s from %s on router %s",
+			key, be.name, ar.affinity[key].name, ar.name))
+		log.Error(err)
+		return err
+	}
+	return nil
+}