clone from danieldin95

vendor/github.com/ovn-org/libovsdb/model/model.go

@@ -0,0 +1,98 @@
+package model
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+
+	"github.com/ovn-org/libovsdb/ovsdb"
+)
+
+// A Model is the base interface used to build Database Models. It is used
+// to express how data from a specific Database Table shall be translated into structs
+// A Model is a struct with at least one (most likely more) field tagged with the 'ovs' tag
+// The value of 'ovs' field must be a valid column name in the OVS Database
+// A field associated with the "_uuid" column mandatory. The rest of the columns are optional
+// The struct may also have non-tagged fields (which will be ignored by the API calls)
+// The Model interface must be implemented by the pointer to such type
+// Example:
+//type MyLogicalRouter struct {
+//	UUID          string            `ovsdb:"_uuid"`
+//	Name          string            `ovsdb:"name"`
+//	ExternalIDs   map[string]string `ovsdb:"external_ids"`
+//	LoadBalancers []string          `ovsdb:"load_balancer"`
+//}
+type Model interface{}
+
+type CloneableModel interface {
+	CloneModel() Model
+	CloneModelInto(Model)
+}
+
+type ComparableModel interface {
+	EqualsModel(Model) bool
+}
+
+// Clone creates a deep copy of a model
+func Clone(a Model) Model {
+	if cloner, ok := a.(CloneableModel); ok {
+		return cloner.CloneModel()
+	}
+
+	val := reflect.Indirect(reflect.ValueOf(a))
+	b := reflect.New(val.Type()).Interface()
+	aBytes, _ := json.Marshal(a)
+	_ = json.Unmarshal(aBytes, b)
+	return b
+}
+
+// CloneInto deep copies a model into another one
+func CloneInto(src, dst Model) {
+	if cloner, ok := src.(CloneableModel); ok {
+		cloner.CloneModelInto(dst)
+		return
+	}
+
+	aBytes, _ := json.Marshal(src)
+	_ = json.Unmarshal(aBytes, dst)
+}
+
+func Equal(l, r Model) bool {
+	if comparator, ok := l.(ComparableModel); ok {
+		return comparator.EqualsModel(r)
+	}
+
+	return reflect.DeepEqual(l, r)
+}
+
+func modelSetUUID(model Model, uuid string) error {
+	modelVal := reflect.ValueOf(model).Elem()
+	for i := 0; i < modelVal.NumField(); i++ {
+		if field := modelVal.Type().Field(i); field.Tag.Get("ovsdb") == "_uuid" &&
+			field.Type.Kind() == reflect.String {
+			modelVal.Field(i).Set(reflect.ValueOf(uuid))
+			return nil
+		}
+	}
+	return fmt.Errorf("model is expected to have a string field mapped to column _uuid")
+}
+
+// Condition is a model-based representation of an OVSDB Condition
+type Condition struct {
+	// Pointer to the field of the model where the operation applies
+	Field interface{}
+	// Condition function
+	Function ovsdb.ConditionFunction
+	// Value to use in the condition
+	Value interface{}
+}
+
+// Mutation is a model-based representation of an OVSDB Mutation
+type Mutation struct {
+	// Pointer to the field of the model that shall be mutated
+	Field interface{}
+	// String representing the mutator (as per RFC7047)
+	Mutator ovsdb.Mutator
+	// Value to use in the mutation
+	Value interface{}
+}