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/*
* 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 (
"crypto/md5"
"errors"
"fmt"
"github.com/opencord/voltha-go/common/log"
"reflect"
"runtime"
"strings"
"sync"
)
// OperationContext holds details on the information used during an operation
type OperationContext struct {
Path string
Data interface{}
FieldName string
ChildKey string
}
// NewOperationContext instantiates a new OperationContext structure
func NewOperationContext(path string, data interface{}, fieldName string, childKey string) *OperationContext {
oc := &OperationContext{
Path: path,
Data: data,
FieldName: fieldName,
ChildKey: childKey,
}
return oc
}
// Update applies new data to the context structure
func (oc *OperationContext) Update(data interface{}) *OperationContext {
oc.Data = data
return oc
}
// Proxy holds the information for a specific location with the data model
type Proxy struct {
sync.RWMutex
Root *root
Node *node
ParentNode *node
Path string
FullPath string
Exclusive bool
Callbacks map[CallbackType]map[string]*CallbackTuple
Operation ProxyOperation
}
// NewProxy instantiates a new proxy to a specific location
func NewProxy(root *root, node *node, parentNode *node, path string, fullPath string, exclusive bool) *Proxy {
callbacks := make(map[CallbackType]map[string]*CallbackTuple)
if fullPath == "/" {
fullPath = ""
}
p := &Proxy{
Root: root,
Node: node,
ParentNode: parentNode,
Exclusive: exclusive,
Path: path,
FullPath: fullPath,
Callbacks: callbacks,
}
return p
}
// GetRoot returns the root attribute of the proxy
func (p *Proxy) GetRoot() *root {
return p.Root
}
// getPath returns the path attribute of the proxy
func (p *Proxy) getPath() string {
return p.Path
}
// getFullPath returns the full path attribute of the proxy
func (p *Proxy) getFullPath() string {
return p.FullPath
}
// getCallbacks returns the full list of callbacks associated to the proxy
func (p *Proxy) getCallbacks(callbackType CallbackType) map[string]*CallbackTuple {
if cb, exists := p.Callbacks[callbackType]; exists {
return cb
}
return nil
}
// getCallback returns a specific callback matching the type and function hash
func (p *Proxy) getCallback(callbackType CallbackType, funcHash string) *CallbackTuple {
p.Lock()
defer p.Unlock()
if tuple, exists := p.Callbacks[callbackType][funcHash]; exists {
return tuple
}
return nil
}
// setCallbacks applies a callbacks list to a type
func (p *Proxy) setCallbacks(callbackType CallbackType, callbacks map[string]*CallbackTuple) {
p.Lock()
defer p.Unlock()
p.Callbacks[callbackType] = callbacks
}
// setCallback applies a callback to a type and hash value
func (p *Proxy) setCallback(callbackType CallbackType, funcHash string, tuple *CallbackTuple) {
p.Lock()
defer p.Unlock()
p.Callbacks[callbackType][funcHash] = tuple
}
// DeleteCallback removes a callback matching the type and hash
func (p *Proxy) DeleteCallback(callbackType CallbackType, funcHash string) {
p.Lock()
defer p.Unlock()
delete(p.Callbacks[callbackType], funcHash)
}
// CallbackType is an enumerated value to express when a callback should be executed
type ProxyOperation uint8
// Enumerated list of callback types
const (
PROXY_GET ProxyOperation = iota
PROXY_LIST
PROXY_ADD
PROXY_UPDATE
PROXY_REMOVE
PROXY_CREATE
)
// parseForControlledPath verifies if a proxy path matches a pattern
// for locations that need to be access controlled.
func (p *Proxy) parseForControlledPath(path string) (pathLock string, controlled bool) {
// TODO: Add other path prefixes that may need control
if strings.HasPrefix(path, "/devices") ||
strings.HasPrefix(path, "/logical_devices") ||
strings.HasPrefix(path, "/adapters") {
split := strings.SplitN(path, "/", -1)
switch len(split) {
case 2:
controlled = false
pathLock = ""
break
case 3:
fallthrough
default:
pathLock = fmt.Sprintf("%s/%s", split[1], split[2])
controlled = true
}
}
return pathLock, controlled
}
// List will retrieve information from the data model at the specified path location
// A list operation will force access to persistence storage
func (p *Proxy) List(path string, depth int, deep bool, txid string) interface{} {
var effectivePath string
if path == "/" {
effectivePath = p.getFullPath()
} else {
effectivePath = p.getFullPath() + path
}
pathLock, controlled := p.parseForControlledPath(effectivePath)
log.Debugf("Path: %s, Effective: %s, PathLock: %s", path, effectivePath, pathLock)
pac := PAC().ReservePath(effectivePath, p, pathLock)
defer PAC().ReleasePath(pathLock)
pac.SetProxy(p)
rv := pac.List(path, depth, deep, txid, controlled)
return rv
}
// Get will retrieve information from the data model at the specified path location
func (p *Proxy) Get(path string, depth int, deep bool, txid string) interface{} {
var effectivePath string
if path == "/" {
effectivePath = p.getFullPath()
} else {
effectivePath = p.getFullPath() + path
}
pathLock, controlled := p.parseForControlledPath(effectivePath)
log.Debugf("Path: %s, Effective: %s, PathLock: %s", path, effectivePath, pathLock)
pac := PAC().ReservePath(effectivePath, p, pathLock)
defer PAC().ReleasePath(pathLock)
pac.SetProxy(p)
rv := pac.Get(path, depth, deep, txid, controlled)
return rv
}
// Update will modify information in the data model at the specified location with the provided data
func (p *Proxy) Update(path string, data interface{}, strict bool, txid string) interface{} {
if !strings.HasPrefix(path, "/") {
log.Errorf("invalid path: %s", path)
return nil
}
var fullPath string
var effectivePath string
if path == "/" {
fullPath = p.getPath()
effectivePath = p.getFullPath()
} else {
fullPath = p.getPath() + path
effectivePath = p.getFullPath() + path
}
pathLock, controlled := p.parseForControlledPath(effectivePath)
log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s, Controlled: %b", path, effectivePath, fullPath, pathLock, controlled)
pac := PAC().ReservePath(effectivePath, p, pathLock)
defer PAC().ReleasePath(pathLock)
p.Operation = PROXY_UPDATE
pac.SetProxy(p)
defer func(op ProxyOperation) {
pac.getProxy().Operation = op
}(PROXY_GET)
log.Debugw("proxy-operation--update", log.Fields{"operation":p.Operation})
return pac.Update(fullPath, data, strict, txid, controlled)
}
// AddWithID will insert new data at specified location.
// This method also allows the user to specify the ID of the data entry to ensure
// that access control is active while inserting the information.
func (p *Proxy) AddWithID(path string, id string, data interface{}, txid string) interface{} {
if !strings.HasPrefix(path, "/") {
log.Errorf("invalid path: %s", path)
return nil
}
var fullPath string
var effectivePath string
if path == "/" {
fullPath = p.getPath()
effectivePath = p.getFullPath()
} else {
fullPath = p.getPath() + path
effectivePath = p.getFullPath() + path + "/" + id
}
pathLock, controlled := p.parseForControlledPath(effectivePath)
log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s", path, effectivePath, fullPath, pathLock)
pac := PAC().ReservePath(path, p, pathLock)
defer PAC().ReleasePath(pathLock)
p.Operation = PROXY_ADD
defer func() {
p.Operation = PROXY_GET
}()
pac.SetProxy(p)
log.Debugw("proxy-operation--add", log.Fields{"operation":p.Operation})
return pac.Add(fullPath, data, txid, controlled)
}
// Add will insert new data at specified location.
func (p *Proxy) Add(path string, data interface{}, txid string) interface{} {
if !strings.HasPrefix(path, "/") {
log.Errorf("invalid path: %s", path)
return nil
}
var fullPath string
var effectivePath string
if path == "/" {
fullPath = p.getPath()
effectivePath = p.getFullPath()
} else {
fullPath = p.getPath() + path
effectivePath = p.getFullPath() + path
}
pathLock, controlled := p.parseForControlledPath(effectivePath)
log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s", path, effectivePath, fullPath, pathLock)
pac := PAC().ReservePath(path, p, pathLock)
defer PAC().ReleasePath(pathLock)
p.Operation = PROXY_ADD
pac.SetProxy(p)
defer func() {
p.Operation = PROXY_GET
}()
log.Debugw("proxy-operation--add", log.Fields{"operation":p.Operation})
return pac.Add(fullPath, data, txid, controlled)
}
// Remove will delete an entry at the specified location
func (p *Proxy) Remove(path string, txid string) interface{} {
if !strings.HasPrefix(path, "/") {
log.Errorf("invalid path: %s", path)
return nil
}
var fullPath string
var effectivePath string
if path == "/" {
fullPath = p.getPath()
effectivePath = p.getFullPath()
} else {
fullPath = p.getPath() + path
effectivePath = p.getFullPath() + path
}
pathLock, controlled := p.parseForControlledPath(effectivePath)
log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s", path, effectivePath, fullPath, pathLock)
pac := PAC().ReservePath(effectivePath, p, pathLock)
defer PAC().ReleasePath(pathLock)
p.Operation = PROXY_REMOVE
pac.SetProxy(p)
defer func() {
p.Operation = PROXY_GET
}()
log.Debugw("proxy-operation--remove", log.Fields{"operation":p.Operation})
return pac.Remove(fullPath, txid, controlled)
}
// CreateProxy to interact with specific path directly
func (p *Proxy) CreateProxy(path string, exclusive bool) *Proxy {
if !strings.HasPrefix(path, "/") {
log.Errorf("invalid path: %s", path)
return nil
}
var fullPath string
var effectivePath string
if path == "/" {
fullPath = p.getPath()
effectivePath = p.getFullPath()
} else {
fullPath = p.getPath() + path
effectivePath = p.getFullPath() + path
}
pathLock, controlled := p.parseForControlledPath(effectivePath)
log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s", path, effectivePath, fullPath, pathLock)
pac := PAC().ReservePath(path, p, pathLock)
defer PAC().ReleasePath(pathLock)
p.Operation = PROXY_CREATE
pac.SetProxy(p)
defer func() {
p.Operation = PROXY_GET
}()
log.Debugw("proxy-operation--create-proxy", log.Fields{"operation":p.Operation})
return pac.CreateProxy(fullPath, exclusive, controlled)
}
// OpenTransaction creates a new transaction branch to isolate operations made to the data model
func (p *Proxy) OpenTransaction() *Transaction {
txid := p.GetRoot().MakeTxBranch()
return NewTransaction(p, txid)
}
// commitTransaction will apply and merge modifications made in the transaction branch to the data model
func (p *Proxy) commitTransaction(txid string) {
p.GetRoot().FoldTxBranch(txid)
}
// cancelTransaction will terminate a transaction branch along will all changes within it
func (p *Proxy) cancelTransaction(txid string) {
p.GetRoot().DeleteTxBranch(txid)
}
// CallbackFunction is a type used to define callback functions
type CallbackFunction func(args ...interface{}) interface{}
// CallbackTuple holds the function and arguments details of a callback
type CallbackTuple struct {
callback CallbackFunction
args []interface{}
}
// Execute will process the a callback with its provided arguments
func (tuple *CallbackTuple) Execute(contextArgs []interface{}) interface{} {
args := []interface{}{}
for _, ta := range tuple.args {
args = append(args, ta)
}
if contextArgs != nil {
for _, ca := range contextArgs {
args = append(args, ca)
}
}
return tuple.callback(args...)
}
// RegisterCallback associates a callback to the proxy
func (p *Proxy) RegisterCallback(callbackType CallbackType, callback CallbackFunction, args ...interface{}) {
if p.getCallbacks(callbackType) == nil {
p.setCallbacks(callbackType, make(map[string]*CallbackTuple))
}
funcName := runtime.FuncForPC(reflect.ValueOf(callback).Pointer()).Name()
log.Debugf("value of function: %s", funcName)
funcHash := fmt.Sprintf("%x", md5.Sum([]byte(funcName)))[:12]
p.setCallback(callbackType, funcHash, &CallbackTuple{callback, args})
}
// UnregisterCallback removes references to a callback within a proxy
func (p *Proxy) UnregisterCallback(callbackType CallbackType, callback CallbackFunction, args ...interface{}) {
if p.getCallbacks(callbackType) == nil {
log.Errorf("no such callback type - %s", callbackType.String())
return
}
funcName := runtime.FuncForPC(reflect.ValueOf(callback).Pointer()).Name()
funcHash := fmt.Sprintf("%x", md5.Sum([]byte(funcName)))[:12]
log.Debugf("value of function: %s", funcName)
if p.getCallback(callbackType, funcHash) == nil {
log.Errorf("function with hash value: '%s' not registered with callback type: '%s'", funcHash, callbackType)
return
}
p.DeleteCallback(callbackType, funcHash)
}
func (p *Proxy) invoke(callback *CallbackTuple, context []interface{}) (result interface{}, err error) {
defer func() {
if r := recover(); r != nil {
errStr := fmt.Sprintf("callback error occurred: %+v", r)
err = errors.New(errStr)
log.Error(errStr)
}
}()
result = callback.Execute(context)
return result, err
}
// InvokeCallbacks executes all callbacks associated to a specific type
func (p *Proxy) InvokeCallbacks(args ...interface{}) (result interface{}) {
callbackType := args[0].(CallbackType)
proceedOnError := args[1].(bool)
context := args[2:]
var err error
if callbacks := p.getCallbacks(callbackType); callbacks != nil {
p.Lock()
for _, callback := range callbacks {
if result, err = p.invoke(callback, context); err != nil {
if !proceedOnError {
log.Info("An error occurred. Stopping callback invocation")
break
}
log.Info("An error occurred. Invoking next callback")
}
}
p.Unlock()
}
return result
}