Implement translib backend logic for the gNSI Pathz

Signed-off-by: niranjanivivek <niranjaniv@google.com>

Author: niranjanivivek

models/yang/annotations/openconfig-system-annot.yang

@@ -0,0 +1,29 @@
+module openconfig-system-annot {
+
+    yang-version "1";
+
+    namespace "http://openconfig.net/yang/openconfig-system-annot";
+    prefix "oc-sys-annot";
+
+    import openconfig-system { prefix oc-sys; }
+    import openconfig-yang-types { prefix oc-yang; }
+    import openconfig-system { prefix oc-sys; }
+    import gnsi-credentialz { prefix gnsi-credz; }
+    import gnsi-pathz { prefix gnsi-pathz; }
+    import sonic-extensions {prefix sonic-ext; }
+    import openconfig-system-grpc { prefix oc-sys-grpc; }
+
+    deviation /oc-sys:system/oc-sys-grpc:grpc-servers {
+        deviate add {
+            sonic-ext:key-transformer "grpc_server_key_xfmr";
+            sonic-ext:subtree-transformer "grpc_server_xfmr";
+        }
+    }
+
+    deviation /oc-sys:system/gnsi-pathz:gnmi-pathz-policies {
+      deviate add {
+        sonic-ext:key-transformer "pathz_policies_key_xfmr";
+        sonic-ext:subtree-transformer "pathz_policies_xfmr";
+      }
+    }
+}

translib/tlerr/tlerr.go

@@ -31,7 +31,9 @@ package tlerr
 
 import (
 	//	"fmt"
+	"errors"
 	"github.com/Azure/sonic-mgmt-common/cvl"
+	"github.com/golang/glog"
 	"golang.org/x/text/language"
 	"golang.org/x/text/message"
 	//	"errors"
@@ -190,3 +192,32 @@ type TranslibBusy struct {
 func (e TranslibBusy) Error() string {
 	return p.Sprintf("Translib Busy")
 }
+
+func IsTranslibRedisClientEntryNotExist(err error) bool {
+	switch err.(type) {
+	case *TranslibRedisClientEntryNotExist, TranslibRedisClientEntryNotExist:
+		return true
+	}
+	return false
+}
+
+// isDBEntryNotExistError returns `true` if `err` is (or wraps around) an error
+// of type `TranslibRedisClientEntryNotExist`.
+func isDBEntryNotExistError(err error) bool {
+	if IsTranslibRedisClientEntryNotExist(err) {
+		return true
+	}
+	pdberr := &TranslibRedisClientEntryNotExist{}
+	return errors.As(err, &TranslibRedisClientEntryNotExist{}) || errors.As(err, &pdberr)
+}
+
+// ErrorSeverity based on `err` calculates the VLOG level.
+func ErrorSeverity(err error) glog.Level {
+	if err == nil {
+		return 3
+	}
+	if isDBEntryNotExistError(err) {
+		return 3
+	}
+	return 0
+}

translib/transformer/subscribe_req_xlate.go

@@ -478,7 +478,7 @@ func (pathXltr *subscribePathXlator) handleSubtreeNodeXlate() error {
 		log.Info(pathXltr.subReq.reqLogId, "handleSubtreeNodeXlate: handleSubtreeNodeXlate: uriSubtree: ", uriSubtree)
 	}
 
-	subInParam := XfmrSubscInParams{uriSubtree, pathXltr.subReq.dbs, make(RedisDbMap), TRANSLATE_SUBSCRIBE}
+	subInParam := XfmrSubscInParams{uri: uriSubtree, requestURI: pathXltr.subReq.reqUri, dbs: pathXltr.subReq.dbs, dbDataMap: make(RedisDbMap), subscProc: TRANSLATE_SUBSCRIBE}
 	subOutPram, subErr := xfmrSubscSubtreeHandler(subInParam, ygXpathInfo.xfmrFunc)
 
 	if log.V(dbLgLvl) {

translib/transformer/xfmr_interface.go

@@ -76,10 +76,11 @@ type notificationOpts struct {
 
 // XfmrSubscInParams represents input to subscribe subtree callbacks - request uri, DBs info access-pointers, DB info for request uri and subscription process type from translib.
 type XfmrSubscInParams struct {
-	uri       string
-	dbs       [db.MaxDB]*db.DB
-	dbDataMap RedisDbMap
-	subscProc SubscProcType
+	uri        string
+	requestURI string
+	dbs        [db.MaxDB]*db.DB
+	dbDataMap  RedisDbMap
+	subscProc  SubscProcType
 }
 
 // XfmrSubscOutParams represents output from subscribe subtree callback - DB data for request uri, Need cache, OnChange, subscription preference and interval.