blob: 8ab182b2516011a28c9bf3f2fbdece242b5d80c7 [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"
"compress/gzip"
"context"
"github.com/golang/protobuf/proto"
"github.com/google/uuid"
"github.com/opencord/voltha-lib-go/pkg/db/kvstore"
"github.com/opencord/voltha-lib-go/pkg/log"
"reflect"
"strings"
"sync"
)
// PersistedRevision holds information of revision meant to be saved in a persistent storage
type PersistedRevision struct {
Revision
Compress bool
events chan *kvstore.Event
kvStore *Backend
mutex sync.RWMutex
versionMutex sync.RWMutex
Version int64
isStored bool
isWatched bool
}
type watchCache struct {
Cache sync.Map
}
var watchCacheInstance *watchCache
var watchCacheOne sync.Once
func Watches() *watchCache {
watchCacheOne.Do(func() {
watchCacheInstance = &watchCache{Cache: sync.Map{}}
})
return watchCacheInstance
}
// NewPersistedRevision creates a new instance of a PersistentRevision structure
func NewPersistedRevision(branch *Branch, data interface{}, children map[string][]Revision) Revision {
pr := &PersistedRevision{}
pr.kvStore = branch.Node.GetRoot().KvStore
pr.Version = 1
pr.Revision = NewNonPersistedRevision(nil, branch, data, children)
return pr
}
func (pr *PersistedRevision) getVersion() int64 {
pr.versionMutex.RLock()
defer pr.versionMutex.RUnlock()
return pr.Version
}
func (pr *PersistedRevision) setVersion(version int64) {
pr.versionMutex.Lock()
defer pr.versionMutex.Unlock()
pr.Version = version
}
// Finalize is responsible of saving the revision in the persistent storage
func (pr *PersistedRevision) Finalize(skipOnExist bool) {
pr.store(skipOnExist)
}
func (pr *PersistedRevision) store(skipOnExist bool) {
if pr.GetBranch().Txid != "" {
return
}
log.Debugw("ready-to-store-revision", log.Fields{"hash": pr.GetHash(), "name": pr.GetName(), "data": pr.GetData()})
// clone the revision data to avoid any race conditions with processes
// accessing the same data
cloned := proto.Clone(pr.GetConfig().Data.(proto.Message))
if blob, err := proto.Marshal(cloned); err != nil {
log.Errorw("problem-to-marshal", log.Fields{"error": err, "hash": pr.GetHash(), "name": pr.GetName(), "data": pr.GetData()})
} else {
if pr.Compress {
var b bytes.Buffer
w := gzip.NewWriter(&b)
w.Write(blob)
w.Close()
blob = b.Bytes()
}
GetRevCache().Set(pr.GetName(), pr)
if err := pr.kvStore.Put(pr.GetName(), blob); err != nil {
log.Warnw("problem-storing-revision", log.Fields{"error": err, "hash": pr.GetHash(), "name": pr.GetName(), "data": pr.GetConfig().Data})
} else {
log.Debugw("storing-revision", log.Fields{"hash": pr.GetHash(), "name": pr.GetName(), "data": pr.GetConfig().Data, "version": pr.getVersion()})
pr.isStored = true
}
}
}
func (pr *PersistedRevision) SetupWatch(key string) {
if key == "" {
log.Debugw("ignoring-watch", log.Fields{"key": key, "revision-hash": pr.GetHash()})
return
}
if _, exists := Watches().Cache.LoadOrStore(key+"-"+pr.GetHash(), struct{}{}); exists {
return
}
if pr.events == nil {
pr.events = make(chan *kvstore.Event)
log.Debugw("setting-watch-channel", log.Fields{"key": key, "revision-hash": pr.GetHash()})
pr.SetName(key)
pr.events = pr.kvStore.CreateWatch(key)
}
if !pr.isWatched {
pr.isWatched = true
log.Debugw("setting-watch-routine", log.Fields{"key": key, "revision-hash": pr.GetHash()})
// Start watching
go pr.startWatching()
}
}
func (pr *PersistedRevision) startWatching() {
log.Debugw("starting-watch", log.Fields{"key": pr.GetHash(), "watch": pr.GetName()})
StopWatchLoop:
for {
latestRev := pr.GetBranch().GetLatest()
select {
case event, ok := <-pr.events:
if !ok {
log.Errorw("event-channel-failure: stopping watch loop", log.Fields{"key": latestRev.GetHash(), "watch": latestRev.GetName()})
break StopWatchLoop
}
log.Debugw("received-event", log.Fields{"type": event.EventType, "watch": latestRev.GetName()})
switch event.EventType {
case kvstore.DELETE:
log.Debugw("delete-from-memory", log.Fields{"key": latestRev.GetHash(), "watch": latestRev.GetName()})
// Remove reference from cache
GetRevCache().Delete(latestRev.GetName())
// Remove reference from parent
parent := pr.GetBranch().Node.GetRoot()
parent.GetBranch(NONE).Latest.ChildDropByName(latestRev.GetName())
break StopWatchLoop
case kvstore.PUT:
log.Debugw("update-in-memory", log.Fields{"key": latestRev.GetHash(), "watch": latestRev.GetName()})
if latestRev.getVersion() >= event.Version {
log.Debugw("skipping-matching-or-older-revision", log.Fields{
"watch": latestRev.GetName(),
"watch-version": event.Version,
"latest-version": latestRev.getVersion(),
})
continue
} else {
log.Debugw("watch-revision-is-newer", log.Fields{
"watch": latestRev.GetName(),
"watch-version": event.Version,
"latest-version": latestRev.getVersion(),
})
}
data := reflect.New(reflect.TypeOf(latestRev.GetData()).Elem())
if err := proto.Unmarshal(event.Value.([]byte), data.Interface().(proto.Message)); err != nil {
log.Errorw("failed-to-unmarshal-watch-data", log.Fields{"key": latestRev.GetHash(), "watch": latestRev.GetName(), "error": err})
} else {
log.Debugw("un-marshaled-watch-data", log.Fields{"key": latestRev.GetHash(), "watch": latestRev.GetName(), "data": data.Interface()})
var pathLock string
var blobs map[string]*kvstore.KVPair
// The watch reported new persistence data.
// Construct an object that will be used to update the memory
blobs = make(map[string]*kvstore.KVPair)
key, _ := kvstore.ToString(event.Key)
blobs[key] = &kvstore.KVPair{
Key: key,
Value: event.Value,
Session: "",
Lease: 0,
Version: event.Version,
}
if latestRev.GetNode().GetProxy() != nil {
//
// If a proxy exists for this revision, use it to lock access to the path
// and prevent simultaneous updates to the object in memory
//
//If the proxy already has a request in progress, then there is no need to process the watch
if latestRev.GetNode().GetProxy().GetOperation() != PROXY_NONE {
log.Debugw("operation-in-progress", log.Fields{
"key": latestRev.GetHash(),
"path": latestRev.GetNode().GetProxy().getFullPath(),
"operation": latestRev.GetNode().GetProxy().operation.String(),
})
continue
}
pathLock, _ = latestRev.GetNode().GetProxy().parseForControlledPath(latestRev.GetNode().GetProxy().getFullPath())
// Reserve the path to prevent others to modify while we reload from persistence
latestRev.GetNode().GetProxy().GetRoot().KvStore.Client.Reserve(pathLock+"_", uuid.New().String(), ReservationTTL)
latestRev.GetNode().GetProxy().SetOperation(PROXY_WATCH)
// Load changes and apply to memory
latestRev.LoadFromPersistence(context.Background(), latestRev.GetName(), "", blobs)
// Release path
latestRev.GetNode().GetProxy().GetRoot().KvStore.Client.ReleaseReservation(pathLock + "_")
} else {
// This block should be reached only if coming from a non-proxied request
log.Debugw("revision-with-no-proxy", log.Fields{"key": latestRev.GetHash(), "watch": latestRev.GetName()})
// Load changes and apply to memory
latestRev.LoadFromPersistence(context.Background(), latestRev.GetName(), "", blobs)
}
}
default:
log.Debugw("unhandled-event", log.Fields{"key": latestRev.GetHash(), "watch": latestRev.GetName(), "type": event.EventType})
}
}
}
Watches().Cache.Delete(pr.GetName() + "-" + pr.GetHash())
log.Debugw("exiting-watch", log.Fields{"key": pr.GetHash(), "watch": pr.GetName()})
}
// UpdateData modifies the information in the data model and saves it in the persistent storage
func (pr *PersistedRevision) UpdateData(ctx context.Context, data interface{}, branch *Branch) Revision {
log.Debugw("updating-persisted-data", log.Fields{"hash": pr.GetHash()})
newNPR := pr.Revision.UpdateData(ctx, data, branch)
newPR := &PersistedRevision{
Revision: newNPR,
Compress: pr.Compress,
kvStore: pr.kvStore,
events: pr.events,
Version: pr.getVersion(),
isWatched: pr.isWatched,
}
if newPR.GetHash() != pr.GetHash() {
newPR.isStored = false
pr.Drop(branch.Txid, false)
pr.Drop(branch.Txid, false)
} else {
newPR.isStored = true
}
return newPR
}
// UpdateChildren modifies the children of a revision and of a specific component and saves it in the persistent storage
func (pr *PersistedRevision) UpdateChildren(ctx context.Context, name string, children []Revision, branch *Branch) Revision {
log.Debugw("updating-persisted-children", log.Fields{"hash": pr.GetHash()})
newNPR := pr.Revision.UpdateChildren(ctx, name, children, branch)
newPR := &PersistedRevision{
Revision: newNPR,
Compress: pr.Compress,
kvStore: pr.kvStore,
events: pr.events,
Version: pr.getVersion(),
isWatched: pr.isWatched,
}
if newPR.GetHash() != pr.GetHash() {
newPR.isStored = false
pr.Drop(branch.Txid, false)
} else {
newPR.isStored = true
}
return newPR
}
// UpdateAllChildren modifies the children for all components of a revision and saves it in the peristent storage
func (pr *PersistedRevision) UpdateAllChildren(children map[string][]Revision, branch *Branch) Revision {
log.Debugw("updating-all-persisted-children", log.Fields{"hash": pr.GetHash()})
newNPR := pr.Revision.UpdateAllChildren(children, branch)
newPR := &PersistedRevision{
Revision: newNPR,
Compress: pr.Compress,
kvStore: pr.kvStore,
events: pr.events,
Version: pr.getVersion(),
isWatched: pr.isWatched,
}
if newPR.GetHash() != pr.GetHash() {
newPR.isStored = false
pr.Drop(branch.Txid, false)
} else {
newPR.isStored = true
}
return newPR
}
// Drop takes care of eliminating a revision hash that is no longer needed
// and its associated config when required
func (pr *PersistedRevision) Drop(txid string, includeConfig bool) {
pr.Revision.Drop(txid, includeConfig)
}
// Drop takes care of eliminating a revision hash that is no longer needed
// and its associated config when required
func (pr *PersistedRevision) StorageDrop(txid string, includeConfig bool) {
log.Debugw("dropping-revision", log.Fields{"txid": txid, "hash": pr.GetHash(), "config-hash": pr.GetConfig().Hash})
pr.mutex.Lock()
defer pr.mutex.Unlock()
if pr.kvStore != nil && txid == "" {
if pr.isStored {
if pr.isWatched {
pr.kvStore.DeleteWatch(pr.GetName(), pr.events)
pr.isWatched = false
}
if err := pr.kvStore.Delete(pr.GetName()); err != nil {
log.Errorw("failed-to-remove-revision", log.Fields{"hash": pr.GetHash(), "error": err.Error()})
} else {
pr.isStored = false
}
}
} else {
if includeConfig {
log.Debugw("attempted-to-remove-transacted-revision-config", log.Fields{"hash": pr.GetConfig().Hash, "txid": txid})
}
log.Debugw("attempted-to-remove-transacted-revision", log.Fields{"hash": pr.GetHash(), "txid": txid})
}
pr.Revision.Drop(txid, includeConfig)
}
// verifyPersistedEntry validates if the provided data is available or not in memory and applies updates as required
func (pr *PersistedRevision) verifyPersistedEntry(ctx context.Context, data interface{}, typeName string, keyName string,
keyValue string, txid string, version int64) (response Revision) {
// Parent which holds the current node entry
parent := pr.GetBranch().Node.GetRoot()
// Get a copy of the parent's children
children := make([]Revision, len(parent.GetBranch(NONE).Latest.GetChildren(typeName)))
copy(children, parent.GetBranch(NONE).Latest.GetChildren(typeName))
// Verify if a child with the provided key value can be found
if childIdx, childRev := pr.GetNode().findRevByKey(children, keyName, keyValue); childRev != nil {
// A child matching the provided key exists in memory
// Verify if the data differs from what was retrieved from persistence
// Also check if we are treating a newer revision of the data or not
if childRev.GetData().(proto.Message).String() != data.(proto.Message).String() && childRev.getVersion() < version {
log.Debugw("revision-data-is-different", log.Fields{
"key": childRev.GetHash(),
"name": childRev.GetName(),
"data": childRev.GetData(),
"in-memory-version": childRev.getVersion(),
"persisted-version": version,
})
//
// Data has changed; replace the child entry and update the parent revision
//
// BEGIN Lock child -- prevent any incoming changes
childRev.GetBranch().LatestLock.Lock()
// Update child
updatedChildRev := childRev.UpdateData(ctx, data, childRev.GetBranch())
updatedChildRev.GetNode().SetProxy(childRev.GetNode().GetProxy())
updatedChildRev.SetupWatch(updatedChildRev.GetName())
updatedChildRev.SetLastUpdate()
updatedChildRev.(*PersistedRevision).setVersion(version)
// Update cache
GetRevCache().Set(updatedChildRev.GetName(), updatedChildRev)
childRev.Drop(txid, false)
childRev.GetBranch().LatestLock.Unlock()
// END lock child
// Update child entry
children[childIdx] = updatedChildRev
// BEGIN lock parent -- Update parent
parent.GetBranch(NONE).LatestLock.Lock()
updatedRev := parent.GetBranch(NONE).GetLatest().UpdateChildren(ctx, typeName, children, parent.GetBranch(NONE))
parent.GetBranch(NONE).Node.makeLatest(parent.GetBranch(NONE), updatedRev, nil)
parent.GetBranch(NONE).LatestLock.Unlock()
// END lock parent
// Drop the previous child revision
parent.GetBranch(NONE).Latest.ChildDrop(typeName, childRev.GetHash())
if updatedChildRev != nil {
log.Debugw("verify-persisted-entry--adding-child", log.Fields{
"key": updatedChildRev.GetHash(),
"name": updatedChildRev.GetName(),
"data": updatedChildRev.GetData(),
})
response = updatedChildRev
}
} else {
if childRev != nil {
log.Debugw("keeping-revision-data", log.Fields{
"key": childRev.GetHash(),
"name": childRev.GetName(),
"data": childRev.GetData(),
"in-memory-version": childRev.getVersion(),
"persistence-version": version,
})
// Update timestamp to reflect when it was last read and to reset tracked timeout
childRev.SetLastUpdate()
if childRev.getVersion() < version {
childRev.(*PersistedRevision).setVersion(version)
}
GetRevCache().Set(childRev.GetName(), childRev)
response = childRev
}
}
} else {
// There is no available child with that key value.
// Create a new child and update the parent revision.
log.Debugw("no-such-revision-entry", log.Fields{
"key": keyValue,
"name": typeName,
"data": data,
"version": version,
})
// BEGIN child lock
pr.GetBranch().LatestLock.Lock()
// Construct a new child node with the retrieved persistence data
childRev = pr.GetBranch().Node.MakeNode(data, txid).Latest(txid)
// We need to start watching this entry for future changes
childRev.SetName(typeName + "/" + keyValue)
childRev.SetupWatch(childRev.GetName())
childRev.(*PersistedRevision).setVersion(version)
// Add entry to cache
GetRevCache().Set(childRev.GetName(), childRev)
pr.GetBranch().LatestLock.Unlock()
// END child lock
//
// Add the child to the parent revision
//
// BEGIN parent lock
parent.GetBranch(NONE).LatestLock.Lock()
children = append(children, childRev)
updatedRev := parent.GetBranch(NONE).GetLatest().UpdateChildren(ctx, typeName, children, parent.GetBranch(NONE))
updatedRev.GetNode().SetProxy(parent.GetBranch(NONE).Node.GetProxy())
parent.GetBranch(NONE).Node.makeLatest(parent.GetBranch(NONE), updatedRev, nil)
parent.GetBranch(NONE).LatestLock.Unlock()
// END parent lock
// Child entry is valid and can be included in the response object
if childRev != nil {
log.Debugw("adding-revision-to-response", log.Fields{
"key": childRev.GetHash(),
"name": childRev.GetName(),
"data": childRev.GetData(),
})
response = childRev
}
}
return response
}
// LoadFromPersistence retrieves data from kv store at the specified location and refreshes the memory
// by adding missing entries, updating changed entries and ignoring unchanged ones
func (pr *PersistedRevision) LoadFromPersistence(ctx context.Context, path string, txid string, blobs map[string]*kvstore.KVPair) []Revision {
pr.mutex.Lock()
defer pr.mutex.Unlock()
log.Debugw("loading-from-persistence", log.Fields{"path": path, "txid": txid})
var response []Revision
for strings.HasPrefix(path, "/") {
path = path[1:]
}
if pr.kvStore != nil && path != "" {
if blobs == nil || len(blobs) == 0 {
log.Debugw("retrieve-from-kv", log.Fields{"path": path, "txid": txid})
blobs, _ = pr.kvStore.List(path)
}
partition := strings.SplitN(path, "/", 2)
name := partition[0]
var nodeType interface{}
if len(partition) < 2 {
path = ""
nodeType = pr.GetBranch().Node.Type
} else {
path = partition[1]
nodeType = pr.GetBranch().Node.GetRoot().Type
}
field := ChildrenFields(nodeType)[name]
if field != nil && field.IsContainer {
log.Debugw("parsing-data-blobs", log.Fields{
"path": path,
"name": name,
"size": len(blobs),
})
for _, blob := range blobs {
output := blob.Value.([]byte)
data := reflect.New(field.ClassType.Elem())
if err := proto.Unmarshal(output, data.Interface().(proto.Message)); err != nil {
log.Errorw("failed-to-unmarshal", log.Fields{
"path": path,
"txid": txid,
"error": err,
})
} else if path == "" {
if field.Key != "" {
log.Debugw("no-path-with-container-key", log.Fields{
"path": path,
"txid": txid,
"data": data.Interface(),
})
// Retrieve the key identifier value from the data structure
// based on the field's key attribute
_, key := GetAttributeValue(data.Interface(), field.Key, 0)
if entry := pr.verifyPersistedEntry(ctx, data.Interface(), name, field.Key, key.String(), txid, blob.Version); entry != nil {
response = append(response, entry)
}
} else {
log.Debugw("path-with-no-container-key", log.Fields{
"path": path,
"txid": txid,
"data": data.Interface(),
})
}
} else if field.Key != "" {
log.Debugw("path-with-container-key", log.Fields{
"path": path,
"txid": txid,
"data": data.Interface(),
})
// The request is for a specific entry/id
partition := strings.SplitN(path, "/", 2)
key := partition[0]
if len(partition) < 2 {
path = ""
} else {
path = partition[1]
}
keyValue := field.KeyFromStr(key)
if entry := pr.verifyPersistedEntry(ctx, data.Interface(), name, field.Key, keyValue.(string), txid, blob.Version); entry != nil {
response = append(response, entry)
}
}
}
log.Debugw("no-more-data-blobs", log.Fields{"path": path, "name": name})
} else {
log.Debugw("cannot-process-field", log.Fields{
"type": pr.GetBranch().Node.Type,
"name": name,
})
}
}
return response
}