Added UnmarshalOpt to allow a best effort unmarshal

ytypes/gnmi.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"reflect"
 
+	"github.com/golang/glog"
 	"github.com/openconfig/goyang/pkg/yang"
 	"github.com/openconfig/ygot/util"
 	"github.com/openconfig/ygot/ygot"
@@ -65,6 +66,7 @@ func UnmarshalNotifications(schema *Schema, ns []*gpb.Notification, opts ...Unma
 func UnmarshalSetRequest(schema *Schema, req *gpb.SetRequest, opts ...UnmarshalOpt) error {
 	preferShadowPath := hasPreferShadowPath(opts)
 	ignoreExtraFields := hasIgnoreExtraFields(opts)
+	bestEffortUnmarshal := hasBestEffortUnmarshal(opts)
 	if req == nil {
 		return nil
 	}
@@ -87,10 +89,10 @@ func UnmarshalSetRequest(schema *Schema, req *gpb.SetRequest, opts ...UnmarshalO
 	if err := deletePaths(schema.SchemaTree[nodeName], node, prefix, req.Delete, preferShadowPath); err != nil {
 		return err
 	}
-	if err := replacePaths(schema.SchemaTree[nodeName], node, prefix, req.Replace, preferShadowPath, ignoreExtraFields); err != nil {
+	if err := replacePaths(schema.SchemaTree[nodeName], node, prefix, req.Replace, preferShadowPath, ignoreExtraFields, bestEffortUnmarshal); err != nil {
 		return err
 	}
-	if err := updatePaths(schema.SchemaTree[nodeName], node, prefix, req.Update, preferShadowPath, ignoreExtraFields); err != nil {
+	if err := updatePaths(schema.SchemaTree[nodeName], node, prefix, req.Update, preferShadowPath, ignoreExtraFields, bestEffortUnmarshal); err != nil {
 		return err
 	}
 
@@ -162,7 +164,7 @@ func joinPrefixToUpdate(prefix *gpb.Path, update *gpb.Update) (*gpb.Update, erro
 // replacePaths unmarshals a slice of updates into the given GoStruct. It
 // deletes the values at these paths before unmarshalling them. These updates
 // can either by JSON-encoded or gNMI-encoded values (scalars).
-func replacePaths(schema *yang.Entry, goStruct ygot.GoStruct, prefix *gpb.Path, updates []*gpb.Update, preferShadowPath, ignoreExtraFields bool) error {
+func replacePaths(schema *yang.Entry, goStruct ygot.GoStruct, prefix *gpb.Path, updates []*gpb.Update, preferShadowPath, ignoreExtraField, bestEffortUnmarshal bool) error {
 	var dopts []DelNodeOpt
 	if preferShadowPath {
 		dopts = append(dopts, &PreferShadowPath{})
@@ -177,6 +179,10 @@ func replacePaths(schema *yang.Entry, goStruct ygot.GoStruct, prefix *gpb.Path,
 			return err
 		}
 		if err := setNode(schema, goStruct, update, preferShadowPath, ignoreExtraFields); err != nil {
+			if bestEffortUnmarshal {
+				glog.Infof("error while unmarshalling: %v", err)
+				continue
+			}
 			return err
 		}
 	}
@@ -185,13 +191,17 @@ func replacePaths(schema *yang.Entry, goStruct ygot.GoStruct, prefix *gpb.Path,
 
 // updatePaths unmarshals a slice of updates into the given GoStruct. These
 // updates can either by JSON-encoded or gNMI-encoded values (scalars).
-func updatePaths(schema *yang.Entry, goStruct ygot.GoStruct, prefix *gpb.Path, updates []*gpb.Update, preferShadowPath, ignoreExtraFields bool) error {
+func updatePaths(schema *yang.Entry, goStruct ygot.GoStruct, prefix *gpb.Path, updates []*gpb.Update, preferShadowPath, ignoreExtraFields, bestEffortUnmarshal bool) error {
 	for _, update := range updates {
 		var err error
 		if update, err = joinPrefixToUpdate(prefix, update); err != nil {
 			return err
 		}
 		if err := setNode(schema, goStruct, update, preferShadowPath, ignoreExtraFields); err != nil {
+			if bestEffortUnmarshal {
+				log.Infof("error while unmarshalling: %v", err)
+				continue
+			}
 			return err
 		}
 	}

ytypes/unmarshal.go

@@ -29,6 +29,14 @@ type UnmarshalOpt interface {
 	IsUnmarshalOpt()
 }
 
+// BestEffortUnmarshal is an unmarshal option that 'ignores' errors while unmarshalling,
+// and continues the unmarshaling process. A failing unmarshal will still fail, but it will
+// fail as a series of error reports.
+type BestEffortUnmarshal struct{}
+
+// IsUnmarshalOpt marks BestEffortUnmarshal as a valid UnmarshalOpt.
+func (*BestEffortUnmarshal) IsUnmarshalOpt() {}
+
 // IgnoreExtraFields is an unmarshal option that controls the
 // behaviour of the Unmarshal function when additional fields are
 // found in the input JSON. By default, an error will be returned,
@@ -123,3 +131,15 @@ func hasPreferShadowPath(opts []UnmarshalOpt) bool {
 	}
 	return false
 }
+
+// hasBestEffortUnmarshal determines whether the supplied slice of UnmarshalOpts
+// contains the BestEffortUnmarshal option.
+func hasBestEffortUnmarshal(opts []UnmarshalOpt) bool {
+	for _, o := range opts {
+		if _, ok := o.(*BestEffortUnmarshal); ok {
+			return true
+		}
+	}
+
+	return false
+}