Matt Jeanneret | cab955f | 2019-04-10 15:45:57 -0400 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2018-present Open Networking Foundation |
| 3 | |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package model |
| 18 | |
| 19 | import ( |
| 20 | "crypto/md5" |
| 21 | "errors" |
| 22 | "fmt" |
| 23 | "github.com/opencord/voltha-go/common/log" |
| 24 | "reflect" |
| 25 | "runtime" |
| 26 | "strings" |
| 27 | "sync" |
| 28 | ) |
| 29 | |
| 30 | // OperationContext holds details on the information used during an operation |
| 31 | type OperationContext struct { |
| 32 | Path string |
| 33 | Data interface{} |
| 34 | FieldName string |
| 35 | ChildKey string |
| 36 | } |
| 37 | |
| 38 | // NewOperationContext instantiates a new OperationContext structure |
| 39 | func NewOperationContext(path string, data interface{}, fieldName string, childKey string) *OperationContext { |
| 40 | oc := &OperationContext{ |
| 41 | Path: path, |
| 42 | Data: data, |
| 43 | FieldName: fieldName, |
| 44 | ChildKey: childKey, |
| 45 | } |
| 46 | return oc |
| 47 | } |
| 48 | |
| 49 | // Update applies new data to the context structure |
| 50 | func (oc *OperationContext) Update(data interface{}) *OperationContext { |
| 51 | oc.Data = data |
| 52 | return oc |
| 53 | } |
| 54 | |
| 55 | // Proxy holds the information for a specific location with the data model |
| 56 | type Proxy struct { |
| 57 | sync.RWMutex |
| 58 | Root *root |
| 59 | Node *node |
| 60 | ParentNode *node |
| 61 | Path string |
| 62 | FullPath string |
| 63 | Exclusive bool |
| 64 | Callbacks map[CallbackType]map[string]*CallbackTuple |
| 65 | Operation ProxyOperation |
| 66 | } |
| 67 | |
| 68 | // NewProxy instantiates a new proxy to a specific location |
| 69 | func NewProxy(root *root, node *node, parentNode *node, path string, fullPath string, exclusive bool) *Proxy { |
| 70 | callbacks := make(map[CallbackType]map[string]*CallbackTuple) |
| 71 | if fullPath == "/" { |
| 72 | fullPath = "" |
| 73 | } |
| 74 | p := &Proxy{ |
| 75 | Root: root, |
| 76 | Node: node, |
| 77 | ParentNode: parentNode, |
| 78 | Exclusive: exclusive, |
| 79 | Path: path, |
| 80 | FullPath: fullPath, |
| 81 | Callbacks: callbacks, |
| 82 | } |
| 83 | return p |
| 84 | } |
| 85 | |
| 86 | // GetRoot returns the root attribute of the proxy |
| 87 | func (p *Proxy) GetRoot() *root { |
| 88 | return p.Root |
| 89 | } |
| 90 | |
| 91 | // getPath returns the path attribute of the proxy |
| 92 | func (p *Proxy) getPath() string { |
| 93 | return p.Path |
| 94 | } |
| 95 | |
| 96 | // getFullPath returns the full path attribute of the proxy |
| 97 | func (p *Proxy) getFullPath() string { |
| 98 | return p.FullPath |
| 99 | } |
| 100 | |
| 101 | // getCallbacks returns the full list of callbacks associated to the proxy |
| 102 | func (p *Proxy) getCallbacks(callbackType CallbackType) map[string]*CallbackTuple { |
| 103 | if cb, exists := p.Callbacks[callbackType]; exists { |
| 104 | return cb |
| 105 | } |
| 106 | return nil |
| 107 | } |
| 108 | |
| 109 | // getCallback returns a specific callback matching the type and function hash |
| 110 | func (p *Proxy) getCallback(callbackType CallbackType, funcHash string) *CallbackTuple { |
| 111 | p.Lock() |
| 112 | defer p.Unlock() |
| 113 | if tuple, exists := p.Callbacks[callbackType][funcHash]; exists { |
| 114 | return tuple |
| 115 | } |
| 116 | return nil |
| 117 | } |
| 118 | |
| 119 | // setCallbacks applies a callbacks list to a type |
| 120 | func (p *Proxy) setCallbacks(callbackType CallbackType, callbacks map[string]*CallbackTuple) { |
| 121 | p.Lock() |
| 122 | defer p.Unlock() |
| 123 | p.Callbacks[callbackType] = callbacks |
| 124 | } |
| 125 | |
| 126 | // setCallback applies a callback to a type and hash value |
| 127 | func (p *Proxy) setCallback(callbackType CallbackType, funcHash string, tuple *CallbackTuple) { |
| 128 | p.Lock() |
| 129 | defer p.Unlock() |
| 130 | p.Callbacks[callbackType][funcHash] = tuple |
| 131 | } |
| 132 | |
| 133 | // DeleteCallback removes a callback matching the type and hash |
| 134 | func (p *Proxy) DeleteCallback(callbackType CallbackType, funcHash string) { |
| 135 | p.Lock() |
| 136 | defer p.Unlock() |
| 137 | delete(p.Callbacks[callbackType], funcHash) |
| 138 | } |
| 139 | |
| 140 | // CallbackType is an enumerated value to express when a callback should be executed |
| 141 | type ProxyOperation uint8 |
| 142 | |
| 143 | // Enumerated list of callback types |
| 144 | const ( |
| 145 | PROXY_GET ProxyOperation = iota |
| 146 | PROXY_LIST |
| 147 | PROXY_ADD |
| 148 | PROXY_UPDATE |
| 149 | PROXY_REMOVE |
| 150 | ) |
| 151 | |
| 152 | // parseForControlledPath verifies if a proxy path matches a pattern |
| 153 | // for locations that need to be access controlled. |
| 154 | func (p *Proxy) parseForControlledPath(path string) (pathLock string, controlled bool) { |
| 155 | // TODO: Add other path prefixes that may need control |
| 156 | if strings.HasPrefix(path, "/devices") || |
| 157 | strings.HasPrefix(path, "/logical_devices") || |
| 158 | strings.HasPrefix(path, "/adapters") { |
| 159 | |
| 160 | split := strings.SplitN(path, "/", -1) |
| 161 | switch len(split) { |
| 162 | case 2: |
| 163 | controlled = false |
| 164 | pathLock = "" |
| 165 | break |
| 166 | case 3: |
| 167 | fallthrough |
| 168 | default: |
| 169 | pathLock = fmt.Sprintf("%s/%s", split[1], split[2]) |
| 170 | controlled = true |
| 171 | } |
| 172 | } |
| 173 | return pathLock, controlled |
| 174 | } |
| 175 | |
| 176 | // List will retrieve information from the data model at the specified path location |
| 177 | // A list operation will force access to persistence storage |
| 178 | func (p *Proxy) List(path string, depth int, deep bool, txid string) interface{} { |
| 179 | var effectivePath string |
| 180 | if path == "/" { |
| 181 | effectivePath = p.getFullPath() |
| 182 | } else { |
| 183 | effectivePath = p.getFullPath() + path |
| 184 | } |
| 185 | |
| 186 | pathLock, controlled := p.parseForControlledPath(effectivePath) |
| 187 | |
| 188 | log.Debugf("Path: %s, Effective: %s, PathLock: %s", path, effectivePath, pathLock) |
| 189 | |
| 190 | pac := PAC().ReservePath(effectivePath, p, pathLock) |
| 191 | defer PAC().ReleasePath(pathLock) |
| 192 | pac.SetProxy(p) |
| 193 | |
| 194 | rv := pac.List(path, depth, deep, txid, controlled) |
| 195 | |
| 196 | return rv |
| 197 | } |
| 198 | |
| 199 | // Get will retrieve information from the data model at the specified path location |
| 200 | func (p *Proxy) Get(path string, depth int, deep bool, txid string) interface{} { |
| 201 | var effectivePath string |
| 202 | if path == "/" { |
| 203 | effectivePath = p.getFullPath() |
| 204 | } else { |
| 205 | effectivePath = p.getFullPath() + path |
| 206 | } |
| 207 | |
| 208 | pathLock, controlled := p.parseForControlledPath(effectivePath) |
| 209 | |
| 210 | log.Debugf("Path: %s, Effective: %s, PathLock: %s", path, effectivePath, pathLock) |
| 211 | |
| 212 | pac := PAC().ReservePath(effectivePath, p, pathLock) |
| 213 | defer PAC().ReleasePath(pathLock) |
| 214 | pac.SetProxy(p) |
| 215 | |
| 216 | rv := pac.Get(path, depth, deep, txid, controlled) |
| 217 | |
| 218 | return rv |
| 219 | } |
| 220 | |
| 221 | // Update will modify information in the data model at the specified location with the provided data |
| 222 | func (p *Proxy) Update(path string, data interface{}, strict bool, txid string) interface{} { |
| 223 | if !strings.HasPrefix(path, "/") { |
| 224 | log.Errorf("invalid path: %s", path) |
| 225 | return nil |
| 226 | } |
| 227 | var fullPath string |
| 228 | var effectivePath string |
| 229 | if path == "/" { |
| 230 | fullPath = p.getPath() |
| 231 | effectivePath = p.getFullPath() |
| 232 | } else { |
| 233 | fullPath = p.getPath() + path |
| 234 | effectivePath = p.getFullPath() + path |
| 235 | } |
| 236 | |
| 237 | pathLock, controlled := p.parseForControlledPath(effectivePath) |
| 238 | |
| 239 | log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s, Controlled: %b", path, effectivePath, fullPath, pathLock, controlled) |
| 240 | |
| 241 | pac := PAC().ReservePath(effectivePath, p, pathLock) |
| 242 | defer PAC().ReleasePath(pathLock) |
| 243 | |
| 244 | p.Operation = PROXY_UPDATE |
| 245 | pac.SetProxy(p) |
| 246 | |
| 247 | log.Debugw("proxy-operation--update", log.Fields{"operation":p.Operation}) |
| 248 | |
| 249 | return pac.Update(fullPath, data, strict, txid, controlled) |
| 250 | } |
| 251 | |
| 252 | // AddWithID will insert new data at specified location. |
| 253 | // This method also allows the user to specify the ID of the data entry to ensure |
| 254 | // that access control is active while inserting the information. |
| 255 | func (p *Proxy) AddWithID(path string, id string, data interface{}, txid string) interface{} { |
| 256 | if !strings.HasPrefix(path, "/") { |
| 257 | log.Errorf("invalid path: %s", path) |
| 258 | return nil |
| 259 | } |
| 260 | var fullPath string |
| 261 | var effectivePath string |
| 262 | if path == "/" { |
| 263 | fullPath = p.getPath() |
| 264 | effectivePath = p.getFullPath() |
| 265 | } else { |
| 266 | fullPath = p.getPath() + path |
| 267 | effectivePath = p.getFullPath() + path + "/" + id |
| 268 | } |
| 269 | |
| 270 | pathLock, controlled := p.parseForControlledPath(effectivePath) |
| 271 | |
| 272 | log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s", path, effectivePath, fullPath, pathLock) |
| 273 | |
| 274 | pac := PAC().ReservePath(path, p, pathLock) |
| 275 | defer PAC().ReleasePath(pathLock) |
| 276 | |
| 277 | p.Operation = PROXY_ADD |
| 278 | pac.SetProxy(p) |
| 279 | |
| 280 | log.Debugw("proxy-operation--add", log.Fields{"operation":p.Operation}) |
| 281 | |
| 282 | return pac.Add(fullPath, data, txid, controlled) |
| 283 | } |
| 284 | |
| 285 | // Add will insert new data at specified location. |
| 286 | func (p *Proxy) Add(path string, data interface{}, txid string) interface{} { |
| 287 | if !strings.HasPrefix(path, "/") { |
| 288 | log.Errorf("invalid path: %s", path) |
| 289 | return nil |
| 290 | } |
| 291 | var fullPath string |
| 292 | var effectivePath string |
| 293 | if path == "/" { |
| 294 | fullPath = p.getPath() |
| 295 | effectivePath = p.getFullPath() |
| 296 | } else { |
| 297 | fullPath = p.getPath() + path |
| 298 | effectivePath = p.getFullPath() + path |
| 299 | } |
| 300 | |
| 301 | pathLock, controlled := p.parseForControlledPath(effectivePath) |
| 302 | |
| 303 | log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s", path, effectivePath, fullPath, pathLock) |
| 304 | |
| 305 | pac := PAC().ReservePath(path, p, pathLock) |
| 306 | defer PAC().ReleasePath(pathLock) |
| 307 | |
| 308 | p.Operation = PROXY_ADD |
| 309 | pac.SetProxy(p) |
| 310 | |
| 311 | log.Debugw("proxy-operation--add", log.Fields{"operation":p.Operation}) |
| 312 | |
| 313 | return pac.Add(fullPath, data, txid, controlled) |
| 314 | } |
| 315 | |
| 316 | // Remove will delete an entry at the specified location |
| 317 | func (p *Proxy) Remove(path string, txid string) interface{} { |
| 318 | if !strings.HasPrefix(path, "/") { |
| 319 | log.Errorf("invalid path: %s", path) |
| 320 | return nil |
| 321 | } |
| 322 | var fullPath string |
| 323 | var effectivePath string |
| 324 | if path == "/" { |
| 325 | fullPath = p.getPath() |
| 326 | effectivePath = p.getFullPath() |
| 327 | } else { |
| 328 | fullPath = p.getPath() + path |
| 329 | effectivePath = p.getFullPath() + path |
| 330 | } |
| 331 | |
| 332 | pathLock, controlled := p.parseForControlledPath(effectivePath) |
| 333 | |
| 334 | log.Debugf("Path: %s, Effective: %s, Full: %s, PathLock: %s", path, effectivePath, fullPath, pathLock) |
| 335 | |
| 336 | pac := PAC().ReservePath(effectivePath, p, pathLock) |
| 337 | defer PAC().ReleasePath(pathLock) |
| 338 | |
| 339 | p.Operation = PROXY_REMOVE |
| 340 | pac.SetProxy(p) |
| 341 | |
| 342 | log.Debugw("proxy-operation--remove", log.Fields{"operation":p.Operation}) |
| 343 | |
| 344 | return pac.Remove(fullPath, txid, controlled) |
| 345 | } |
| 346 | |
| 347 | // OpenTransaction creates a new transaction branch to isolate operations made to the data model |
| 348 | func (p *Proxy) OpenTransaction() *Transaction { |
| 349 | txid := p.GetRoot().MakeTxBranch() |
| 350 | return NewTransaction(p, txid) |
| 351 | } |
| 352 | |
| 353 | // commitTransaction will apply and merge modifications made in the transaction branch to the data model |
| 354 | func (p *Proxy) commitTransaction(txid string) { |
| 355 | p.GetRoot().FoldTxBranch(txid) |
| 356 | } |
| 357 | |
| 358 | // cancelTransaction will terminate a transaction branch along will all changes within it |
| 359 | func (p *Proxy) cancelTransaction(txid string) { |
| 360 | p.GetRoot().DeleteTxBranch(txid) |
| 361 | } |
| 362 | |
| 363 | // CallbackFunction is a type used to define callback functions |
| 364 | type CallbackFunction func(args ...interface{}) interface{} |
| 365 | |
| 366 | // CallbackTuple holds the function and arguments details of a callback |
| 367 | type CallbackTuple struct { |
| 368 | callback CallbackFunction |
| 369 | args []interface{} |
| 370 | } |
| 371 | |
| 372 | // Execute will process the a callback with its provided arguments |
| 373 | func (tuple *CallbackTuple) Execute(contextArgs []interface{}) interface{} { |
| 374 | args := []interface{}{} |
| 375 | |
| 376 | for _, ta := range tuple.args { |
| 377 | args = append(args, ta) |
| 378 | } |
| 379 | |
| 380 | if contextArgs != nil { |
| 381 | for _, ca := range contextArgs { |
| 382 | args = append(args, ca) |
| 383 | } |
| 384 | } |
| 385 | |
| 386 | return tuple.callback(args...) |
| 387 | } |
| 388 | |
| 389 | // RegisterCallback associates a callback to the proxy |
| 390 | func (p *Proxy) RegisterCallback(callbackType CallbackType, callback CallbackFunction, args ...interface{}) { |
| 391 | if p.getCallbacks(callbackType) == nil { |
| 392 | p.setCallbacks(callbackType, make(map[string]*CallbackTuple)) |
| 393 | } |
| 394 | funcName := runtime.FuncForPC(reflect.ValueOf(callback).Pointer()).Name() |
| 395 | log.Debugf("value of function: %s", funcName) |
| 396 | funcHash := fmt.Sprintf("%x", md5.Sum([]byte(funcName)))[:12] |
| 397 | |
| 398 | p.setCallback(callbackType, funcHash, &CallbackTuple{callback, args}) |
| 399 | } |
| 400 | |
| 401 | // UnregisterCallback removes references to a callback within a proxy |
| 402 | func (p *Proxy) UnregisterCallback(callbackType CallbackType, callback CallbackFunction, args ...interface{}) { |
| 403 | if p.getCallbacks(callbackType) == nil { |
| 404 | log.Errorf("no such callback type - %s", callbackType.String()) |
| 405 | return |
| 406 | } |
| 407 | |
| 408 | funcName := runtime.FuncForPC(reflect.ValueOf(callback).Pointer()).Name() |
| 409 | funcHash := fmt.Sprintf("%x", md5.Sum([]byte(funcName)))[:12] |
| 410 | |
| 411 | log.Debugf("value of function: %s", funcName) |
| 412 | |
| 413 | if p.getCallback(callbackType, funcHash) == nil { |
| 414 | log.Errorf("function with hash value: '%s' not registered with callback type: '%s'", funcHash, callbackType) |
| 415 | return |
| 416 | } |
| 417 | |
| 418 | p.DeleteCallback(callbackType, funcHash) |
| 419 | } |
| 420 | |
| 421 | func (p *Proxy) invoke(callback *CallbackTuple, context []interface{}) (result interface{}, err error) { |
| 422 | defer func() { |
| 423 | if r := recover(); r != nil { |
| 424 | errStr := fmt.Sprintf("callback error occurred: %+v", r) |
| 425 | err = errors.New(errStr) |
| 426 | log.Error(errStr) |
| 427 | } |
| 428 | }() |
| 429 | |
| 430 | result = callback.Execute(context) |
| 431 | |
| 432 | return result, err |
| 433 | } |
| 434 | |
| 435 | // InvokeCallbacks executes all callbacks associated to a specific type |
| 436 | func (p *Proxy) InvokeCallbacks(args ...interface{}) (result interface{}) { |
| 437 | callbackType := args[0].(CallbackType) |
| 438 | proceedOnError := args[1].(bool) |
| 439 | context := args[2:] |
| 440 | |
| 441 | var err error |
| 442 | |
| 443 | if callbacks := p.getCallbacks(callbackType); callbacks != nil { |
| 444 | p.Lock() |
| 445 | for _, callback := range callbacks { |
| 446 | if result, err = p.invoke(callback, context); err != nil { |
| 447 | if !proceedOnError { |
| 448 | log.Info("An error occurred. Stopping callback invocation") |
| 449 | break |
| 450 | } |
| 451 | log.Info("An error occurred. Invoking next callback") |
| 452 | } |
| 453 | } |
| 454 | p.Unlock() |
| 455 | } |
| 456 | |
| 457 | return result |
| 458 | } |