blob: b930ae148dd646341264b6ea02cd859264a4db8f [file] [log] [blame]
/*
* 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 model
import (
"bytes"
"crypto/md5"
"encoding/json"
"fmt"
"github.com/golang/protobuf/proto"
"github.com/opencord/voltha-lib-go/pkg/log"
"reflect"
)
// DataRevision stores the data associated to a revision along with its calculated checksum hash value
type DataRevision struct {
Data interface{}
Hash string
}
// NewDataRevision creates a new instance of a DataRevision structure
func NewDataRevision(root *root, data interface{}) *DataRevision {
dr := DataRevision{}
dr.Data = data
dr.Hash = dr.hashData(root, data)
return &dr
}
func (dr *DataRevision) hashData(root *root, data interface{}) string {
var buffer bytes.Buffer
if IsProtoMessage(data) {
if pbdata, err := proto.Marshal(data.(proto.Message)); err != nil {
log.Debugf("problem to marshal protobuf data --> err: %s", err.Error())
} else {
buffer.Write(pbdata)
// To ensure uniqueness in case data is nil, also include data type
buffer.Write([]byte(reflect.TypeOf(data).String()))
}
} else if reflect.ValueOf(data).IsValid() {
dataObj := reflect.New(reflect.TypeOf(data).Elem())
if json, err := json.Marshal(dataObj.Interface()); err != nil {
log.Debugf("problem to marshal data --> err: %s", err.Error())
} else {
buffer.Write(json)
}
} else {
dataObj := reflect.New(reflect.TypeOf(data).Elem())
buffer.Write(dataObj.Bytes())
}
// Add the root pointer that owns the current data for extra uniqueness
rootPtr := fmt.Sprintf("%p", root)
buffer.Write([]byte(rootPtr))
return fmt.Sprintf("%x", md5.Sum(buffer.Bytes()))[:12]
}