db/model/root.go - voltha-go - Gitiles

 /*
  * 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 (
 	"context"
 	"encoding/hex"
 	"encoding/json"
 	"reflect"
 	"sync"

 	"github.com/golang/protobuf/proto"
 	"github.com/google/uuid"
 	"github.com/opencord/voltha-lib-go/v3/pkg/db"
 	"github.com/opencord/voltha-lib-go/v3/pkg/log"
 )

 // Root is used to provide an abstraction to the base root structure
 type Root interface {
 	Node

 	ExecuteCallbacks(ctx context.Context)
 	AddCallback(callback CallbackFunction, args ...interface{})
 	AddNotificationCallback(callback CallbackFunction, args ...interface{})
 }

 // root points to the top of the data model tree or sub-tree identified by a proxy
 type root struct {
 	*node

 	Callbacks             []CallbackTuple
 	NotificationCallbacks []CallbackTuple

 	DirtyNodes    map[string][]*node
 	KvStore       *db.Backend
 	Loading       bool
 	RevisionClass interface{}

 	mutex sync.RWMutex
 }

 // NewRoot creates an new instance of a root object
 func NewRoot(initialData interface{}, kvStore *db.Backend) Root {
 	root := &root{}

 	root.KvStore = kvStore
 	root.DirtyNodes = make(map[string][]*node)
 	root.Loading = false

 	// If there is no storage in place just revert to
 	// a non persistent mechanism
 	if kvStore != nil {
 		root.RevisionClass = reflect.TypeOf(PersistedRevision{})
 	} else {
 		root.RevisionClass = reflect.TypeOf(NonPersistedRevision{})
 	}

 	root.Callbacks = []CallbackTuple{}
 	root.NotificationCallbacks = []CallbackTuple{}

 	root.node = newNode(root, initialData, false, "")

 	return root
 }

 // MakeTxBranch creates a new transaction branch
 func (r *root) MakeTxBranch() string {
 	txidBin, _ := uuid.New().MarshalBinary()
 	txid := hex.EncodeToString(txidBin)[:12]

 	r.DirtyNodes[txid] = []*node{r.node}
 	r.node.MakeBranch(txid)

 	return txid
 }

 // DeleteTxBranch removes a transaction branch
 func (r *root) DeleteTxBranch(txid string) {
 	for _, dirtyNode := range r.DirtyNodes[txid] {
 		dirtyNode.DeleteBranch(txid)
 	}
 	delete(r.DirtyNodes, txid)
 	r.node.DeleteBranch(txid)
 }

 // FoldTxBranch will merge the contents of a transaction branch with the root object
 func (r *root) FoldTxBranch(ctx context.Context, txid string) {
 	// Start by doing a dry run of the merge
 	// If that fails, it bails out and the branch is deleted
 	if _, err := r.node.MergeBranch(ctx, txid, true); err != nil {
 		// Merge operation fails
 		r.DeleteTxBranch(txid)
 	} else {
 		if _, err = r.node.MergeBranch(ctx, txid, false); err != nil {
 			log.Errorw("Unable to integrate the contents of a transaction branch within the latest branch of a given node", log.Fields{"error": err})
 		}
 		r.node.GetRoot().ExecuteCallbacks(ctx)
 		r.DeleteTxBranch(txid)
 	}
 }

 // ExecuteCallbacks will invoke all the callbacks linked to root object
 func (r *root) ExecuteCallbacks(ctx context.Context) {
 	r.mutex.Lock()
 	defer r.mutex.Unlock()

 	for len(r.Callbacks) > 0 {
 		callback := r.Callbacks[0]
 		r.Callbacks = r.Callbacks[1:]
 		go callback.Execute(ctx, nil)
 	}
 	//for len(r.NotificationCallbacks) > 0 {
 	//	callback := r.NotificationCallbacks[0]
 	//	r.NotificationCallbacks = r.NotificationCallbacks[1:]
 	//	go callback.Execute(nil)
 	//}
 }

 // getCallbacks returns the available callbacks
 func (r *root) GetCallbacks() []CallbackTuple {
 	r.mutex.Lock()
 	defer r.mutex.Unlock()

 	return r.Callbacks
 }

 // getCallbacks returns the available notification callbacks
 func (r *root) GetNotificationCallbacks() []CallbackTuple {
 	r.mutex.Lock()
 	defer r.mutex.Unlock()

 	return r.NotificationCallbacks
 }

 // AddCallback inserts a new callback with its arguments
 func (r *root) AddCallback(callback CallbackFunction, args ...interface{}) {
 	r.mutex.Lock()
 	defer r.mutex.Unlock()

 	r.Callbacks = append(r.Callbacks, CallbackTuple{callback, args})
 }

 // AddNotificationCallback inserts a new notification callback with its arguments
 func (r *root) AddNotificationCallback(callback CallbackFunction, args ...interface{}) {
 	r.mutex.Lock()
 	defer r.mutex.Unlock()

 	r.NotificationCallbacks = append(r.NotificationCallbacks, CallbackTuple{callback, args})
 }

 func (r *root) syncParent(ctx context.Context, childRev Revision, txid string) {
 	data := proto.Clone(r.GetProxy().ParentNode.Latest().GetData().(proto.Message))

 	for fieldName := range ChildrenFields(data) {
 		childDataName, childDataHolder := GetAttributeValue(data, fieldName, 0)
 		if reflect.TypeOf(childRev.GetData()) == reflect.TypeOf(childDataHolder.Interface()) {
 			childDataHolder = reflect.ValueOf(childRev.GetData())
 			reflect.ValueOf(data).Elem().FieldByName(childDataName).Set(childDataHolder)
 		}
 	}

 	r.GetProxy().ParentNode.Latest().SetConfig(NewDataRevision(r.GetProxy().ParentNode.GetRoot(), data))
 	r.GetProxy().ParentNode.Latest(txid).Finalize(ctx, false)
 }

 // Update modifies the content of an object at a given path with the provided data
 func (r *root) Update(ctx context.Context, path string, data interface{}, strict bool, txid string, makeBranch MakeBranchFunction) Revision {
 	var result Revision

 	if txid != "" {
 		trackDirty := func(node *node) *Branch {
 			r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
 			return node.MakeBranch(txid)
 		}
 		result = r.node.Update(ctx, path, data, strict, txid, trackDirty)
 	} else {
 		result = r.node.Update(ctx, path, data, strict, "", nil)
 	}

 	if result != nil {
 		if r.GetProxy().FullPath != r.GetProxy().Path {
 			r.syncParent(ctx, result, txid)
 		} else {
 			result.Finalize(ctx, false)
 		}
 	}

 	r.node.GetRoot().ExecuteCallbacks(ctx)

 	return result
 }

 // Add creates a new object at the given path with the provided data
 func (r *root) Add(ctx context.Context, path string, data interface{}, txid string, makeBranch MakeBranchFunction) Revision {
 	var result Revision

 	if txid != "" {
 		trackDirty := func(node *node) *Branch {
 			r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
 			return node.MakeBranch(txid)
 		}
 		result = r.node.Add(ctx, path, data, txid, trackDirty)
 	} else {
 		result = r.node.Add(ctx, path, data, "", nil)
 	}

 	if result != nil {
 		result.Finalize(ctx, true)
 		r.node.GetRoot().ExecuteCallbacks(ctx)
 	}
 	return result
 }

 // Remove discards an object at a given path
 func (r *root) Remove(ctx context.Context, path string, txid string, makeBranch MakeBranchFunction) Revision {
 	var result Revision

 	if txid != "" {
 		trackDirty := func(node *node) *Branch {
 			r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
 			return node.MakeBranch(txid)
 		}
 		result = r.node.Remove(ctx, path, txid, trackDirty)
 	} else {
 		result = r.node.Remove(ctx, path, "", nil)
 	}

 	r.node.GetRoot().ExecuteCallbacks(ctx)

 	return result
 }

 // MakeLatest updates a branch with the latest node revision
 func (r *root) MakeLatest(ctx context.Context, branch *Branch, revision Revision, changeAnnouncement []ChangeTuple) {
 	r.makeLatest(ctx, branch, revision, changeAnnouncement)
 }

 func (r *root) MakeRevision(branch *Branch, data interface{}, children map[string][]Revision) Revision {
 	if r.RevisionClass.(reflect.Type) == reflect.TypeOf(PersistedRevision{}) {
 		return NewPersistedRevision(branch, data, children)
 	}

 	return NewNonPersistedRevision(r, branch, data, children)
 }

 func (r *root) makeLatest(ctx context.Context, branch *Branch, revision Revision, changeAnnouncement []ChangeTuple) {
 	r.node.makeLatest(branch, revision, changeAnnouncement)

 	if r.KvStore != nil && branch.Txid == "" {
 		tags := make(map[string]string)
 		for k, v := range r.node.Tags {
 			tags[k] = v.GetHash()
 		}
 		data := &rootData{
 			Latest: branch.GetLatest().GetHash(),
 			Tags:   tags,
 		}
 		if blob, err := json.Marshal(data); err != nil {
 			// TODO report error
 		} else {
 			log.Debugf("Changing root to : %s", string(blob))
 			if err := r.KvStore.Put(ctx, "root", blob); err != nil {
 				log.Errorf("failed to properly put value in kvstore - err: %s", err.Error())
 			}
 		}
 	}
 }

 type rootData struct {
 	Latest string            `json:"latest"`
 	Tags   map[string]string `json:"tags"`
 }
	/*
	* 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 (
	"context"
	"encoding/hex"
	"encoding/json"
	"reflect"
	"sync"

	"github.com/golang/protobuf/proto"
	"github.com/google/uuid"
	"github.com/opencord/voltha-lib-go/v3/pkg/db"
	"github.com/opencord/voltha-lib-go/v3/pkg/log"
	)

	// Root is used to provide an abstraction to the base root structure
	type Root interface {
	Node

	ExecuteCallbacks(ctx context.Context)
	AddCallback(callback CallbackFunction, args ...interface{})
	AddNotificationCallback(callback CallbackFunction, args ...interface{})
	}

	// root points to the top of the data model tree or sub-tree identified by a proxy
	type root struct {
	*node

	Callbacks []CallbackTuple
	NotificationCallbacks []CallbackTuple

	DirtyNodes map[string][]*node
	KvStore *db.Backend
	Loading bool
	RevisionClass interface{}

	mutex sync.RWMutex
	}

	// NewRoot creates an new instance of a root object
	func NewRoot(initialData interface{}, kvStore *db.Backend) Root {
	root := &root{}

	root.KvStore = kvStore
	root.DirtyNodes = make(map[string][]*node)
	root.Loading = false

	// If there is no storage in place just revert to
	// a non persistent mechanism
	if kvStore != nil {
	root.RevisionClass = reflect.TypeOf(PersistedRevision{})
	} else {
	root.RevisionClass = reflect.TypeOf(NonPersistedRevision{})
	}

	root.Callbacks = []CallbackTuple{}
	root.NotificationCallbacks = []CallbackTuple{}

	root.node = newNode(root, initialData, false, "")

	return root
	}

	// MakeTxBranch creates a new transaction branch
	func (r *root) MakeTxBranch() string {
	txidBin, _ := uuid.New().MarshalBinary()
	txid := hex.EncodeToString(txidBin)[:12]

	r.DirtyNodes[txid] = []*node{r.node}
	r.node.MakeBranch(txid)

	return txid
	}

	// DeleteTxBranch removes a transaction branch
	func (r *root) DeleteTxBranch(txid string) {
	for _, dirtyNode := range r.DirtyNodes[txid] {
	dirtyNode.DeleteBranch(txid)
	}
	delete(r.DirtyNodes, txid)
	r.node.DeleteBranch(txid)
	}

	// FoldTxBranch will merge the contents of a transaction branch with the root object
	func (r *root) FoldTxBranch(ctx context.Context, txid string) {
	// Start by doing a dry run of the merge
	// If that fails, it bails out and the branch is deleted
	if _, err := r.node.MergeBranch(ctx, txid, true); err != nil {
	// Merge operation fails
	r.DeleteTxBranch(txid)
	} else {
	if _, err = r.node.MergeBranch(ctx, txid, false); err != nil {
	log.Errorw("Unable to integrate the contents of a transaction branch within the latest branch of a given node", log.Fields{"error": err})
	}
	r.node.GetRoot().ExecuteCallbacks(ctx)
	r.DeleteTxBranch(txid)
	}
	}

	// ExecuteCallbacks will invoke all the callbacks linked to root object
	func (r *root) ExecuteCallbacks(ctx context.Context) {
	r.mutex.Lock()
	defer r.mutex.Unlock()

	for len(r.Callbacks) > 0 {
	callback := r.Callbacks[0]
	r.Callbacks = r.Callbacks[1:]
	go callback.Execute(ctx, nil)
	}
	//for len(r.NotificationCallbacks) > 0 {
	// callback := r.NotificationCallbacks[0]
	// r.NotificationCallbacks = r.NotificationCallbacks[1:]
	// go callback.Execute(nil)
	//}
	}

	// getCallbacks returns the available callbacks
	func (r *root) GetCallbacks() []CallbackTuple {
	r.mutex.Lock()
	defer r.mutex.Unlock()

	return r.Callbacks
	}

	// getCallbacks returns the available notification callbacks
	func (r *root) GetNotificationCallbacks() []CallbackTuple {
	r.mutex.Lock()
	defer r.mutex.Unlock()

	return r.NotificationCallbacks
	}

	// AddCallback inserts a new callback with its arguments
	func (r *root) AddCallback(callback CallbackFunction, args ...interface{}) {
	r.mutex.Lock()
	defer r.mutex.Unlock()

	r.Callbacks = append(r.Callbacks, CallbackTuple{callback, args})
	}

	// AddNotificationCallback inserts a new notification callback with its arguments
	func (r *root) AddNotificationCallback(callback CallbackFunction, args ...interface{}) {
	r.mutex.Lock()
	defer r.mutex.Unlock()

	r.NotificationCallbacks = append(r.NotificationCallbacks, CallbackTuple{callback, args})
	}

	func (r *root) syncParent(ctx context.Context, childRev Revision, txid string) {
	data := proto.Clone(r.GetProxy().ParentNode.Latest().GetData().(proto.Message))

	for fieldName := range ChildrenFields(data) {
	childDataName, childDataHolder := GetAttributeValue(data, fieldName, 0)
	if reflect.TypeOf(childRev.GetData()) == reflect.TypeOf(childDataHolder.Interface()) {
	childDataHolder = reflect.ValueOf(childRev.GetData())
	reflect.ValueOf(data).Elem().FieldByName(childDataName).Set(childDataHolder)
	}
	}

	r.GetProxy().ParentNode.Latest().SetConfig(NewDataRevision(r.GetProxy().ParentNode.GetRoot(), data))
	r.GetProxy().ParentNode.Latest(txid).Finalize(ctx, false)
	}

	// Update modifies the content of an object at a given path with the provided data
	func (r *root) Update(ctx context.Context, path string, data interface{}, strict bool, txid string, makeBranch MakeBranchFunction) Revision {
	var result Revision

	if txid != "" {
	trackDirty := func(node node) Branch {
	r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
	return node.MakeBranch(txid)
	}
	result = r.node.Update(ctx, path, data, strict, txid, trackDirty)
	} else {
	result = r.node.Update(ctx, path, data, strict, "", nil)
	}

	if result != nil {
	if r.GetProxy().FullPath != r.GetProxy().Path {
	r.syncParent(ctx, result, txid)
	} else {
	result.Finalize(ctx, false)
	}
	}

	r.node.GetRoot().ExecuteCallbacks(ctx)

	return result
	}

	// Add creates a new object at the given path with the provided data
	func (r *root) Add(ctx context.Context, path string, data interface{}, txid string, makeBranch MakeBranchFunction) Revision {
	var result Revision

	if txid != "" {
	trackDirty := func(node node) Branch {
	r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
	return node.MakeBranch(txid)
	}
	result = r.node.Add(ctx, path, data, txid, trackDirty)
	} else {
	result = r.node.Add(ctx, path, data, "", nil)
	}

	if result != nil {
	result.Finalize(ctx, true)
	r.node.GetRoot().ExecuteCallbacks(ctx)
	}
	return result
	}

	// Remove discards an object at a given path
	func (r *root) Remove(ctx context.Context, path string, txid string, makeBranch MakeBranchFunction) Revision {
	var result Revision

	if txid != "" {
	trackDirty := func(node node) Branch {
	r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
	return node.MakeBranch(txid)
	}
	result = r.node.Remove(ctx, path, txid, trackDirty)
	} else {
	result = r.node.Remove(ctx, path, "", nil)
	}

	r.node.GetRoot().ExecuteCallbacks(ctx)

	return result
	}

	// MakeLatest updates a branch with the latest node revision
	func (r root) MakeLatest(ctx context.Context, branch Branch, revision Revision, changeAnnouncement []ChangeTuple) {
	r.makeLatest(ctx, branch, revision, changeAnnouncement)
	}

	func (r root) MakeRevision(branch Branch, data interface{}, children map[string][]Revision) Revision {
	if r.RevisionClass.(reflect.Type) == reflect.TypeOf(PersistedRevision{}) {
	return NewPersistedRevision(branch, data, children)
	}

	return NewNonPersistedRevision(r, branch, data, children)
	}

	func (r root) makeLatest(ctx context.Context, branch Branch, revision Revision, changeAnnouncement []ChangeTuple) {
	r.node.makeLatest(branch, revision, changeAnnouncement)

	if r.KvStore != nil && branch.Txid == "" {
	tags := make(map[string]string)
	for k, v := range r.node.Tags {
	tags[k] = v.GetHash()
	}
	data := &rootData{
	Latest: branch.GetLatest().GetHash(),
	Tags: tags,
	}
	if blob, err := json.Marshal(data); err != nil {
	// TODO report error
	} else {
	log.Debugf("Changing root to : %s", string(blob))
	if err := r.KvStore.Put(ctx, "root", blob); err != nil {
	log.Errorf("failed to properly put value in kvstore - err: %s", err.Error())
	}
	}
	}
	}

	type rootData struct {
	Latest string `json:"latest"`
	Tags map[string]string `json:"tags"`
	}