service/notification/src/provider/NSProviderMemoryCache.c

   1 //******************************************************************\r
   2 //\r
   3 // Copyright 2016 Samsung Electronics All Rights Reserved.\r
   4 //\r
   5 //-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\r
   6 //\r
   7 // Licensed under the Apache License, Version 2.0 (the "License");\r
   8 // you may not use this file except in compliance with the License.\r
   9 // You may obtain a copy of the License at\r
  10 //\r
  11 //      http://www.apache.org/licenses/LICENSE-2.0\r
  12 //\r
  13 // Unless required by applicable law or agreed to in writing, software\r
  14 // distributed under the License is distributed on an "AS IS" BASIS,\r
  15 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  16 // See the License for the specific language governing permissions and\r
  17 // limitations under the License.\r
  18 //\r
  19 //-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=\r
  20 \r
  21 #include "NSProviderMemoryCache.h"\r
  22 #include <string.h>\r
  23 \r
  24 NSCacheList * NSStorageCreate()\r
  25 {\r
  26     pthread_mutex_lock(&NSCacheMutex);\r
  27     NSCacheList * newList = (NSCacheList *) OICMalloc(sizeof(NSCacheList));\r
  28     if (!newList)\r
  29     {\r
  30         pthread_mutex_unlock(&NSCacheMutex);\r
  31         return NULL;\r
  32     }\r
  33 \r
  34     newList->head = newList->tail = NULL;\r
  35 \r
  36     pthread_mutex_unlock(&NSCacheMutex);\r
  37     NS_LOG(DEBUG, "NSCacheCreate");\r
  38 \r
  39     return newList;\r
  40 }\r
  41 \r
  42 NSCacheElement * NSStorageRead(NSCacheList * list, const char * findId)\r
  43 {\r
  44     pthread_mutex_lock(&NSCacheMutex);\r
  45 \r
  46     NS_LOG(DEBUG, "NSCacheRead - IN");\r
  47 \r
  48     NSCacheElement * iter = list->head;\r
  49     NSCacheElement * next = NULL;\r
  50     NSCacheType type = list->cacheType;\r
  51 \r
  52     NS_LOG_V(DEBUG, "Find ID - %s", findId);\r
  53 \r
  54     while (iter)\r
  55     {\r
  56         next = iter->next;\r
  57 \r
  58         if (NSProviderCompareIdCacheData(type, iter->data, findId))\r
  59         {\r
  60             NS_LOG(DEBUG, "Found in Cache");\r
  61             pthread_mutex_unlock(&NSCacheMutex);\r
  62             return iter;\r
  63         }\r
  64 \r
  65         iter = next;\r
  66     }\r
  67 \r
  68     NS_LOG(DEBUG, "Not found in Cache");\r
  69     NS_LOG(DEBUG, "NSCacheRead - OUT");\r
  70     pthread_mutex_unlock(&NSCacheMutex);\r
  71 \r
  72     return NULL;\r
  73 }\r
  74 \r
  75 NSResult NSCacheUpdateSubScriptionState(NSCacheList * list, char * id, bool state)\r
  76 {\r
  77     pthread_mutex_lock(&NSCacheMutex);\r
  78 \r
  79     NS_LOG(DEBUG, "NSCacheUpdateSubScriptionState - IN");\r
  80 \r
  81     if (id == NULL)\r
  82     {\r
  83         NS_LOG(DEBUG, "id is NULL");\r
  84         pthread_mutex_unlock(&NSCacheMutex);\r
  85         return NS_ERROR;\r
  86     }\r
  87 \r
  88     NSCacheElement * it = NSStorageRead(list, id);\r
  89 \r
  90     if (it)\r
  91     {\r
  92         NSCacheSubData * itData = (NSCacheSubData *) it->data;\r
  93         if (strcmp(itData->id, id) == 0)\r
  94         {\r
  95             NS_LOG(DEBUG, "Update Data - IN");\r
  96 \r
  97             NS_LOG_V(DEBUG, "currData_ID = %s", itData->id);\r
  98             NS_LOG_V(DEBUG, "currData_MsgObID = %d", itData->messageObId);\r
  99             NS_LOG_V(DEBUG, "currData_SyncObID = %d", itData->syncObId);\r
 100             NS_LOG_V(DEBUG, "currData_Cloud_MsgObID = %d", itData->remote_messageObId);\r
 101             NS_LOG_V(DEBUG, "currData_Cloud_SyncObID = %d", itData->remote_syncObId);\r
 102             NS_LOG_V(DEBUG, "currData_IsWhite = %d", itData->isWhite);\r
 103 \r
 104             NS_LOG_V(DEBUG, "update state = %d", state);\r
 105 \r
 106             itData->isWhite = state;\r
 107 \r
 108             NS_LOG(DEBUG, "Update Data - OUT");\r
 109             pthread_mutex_unlock(&NSCacheMutex);\r
 110             return NS_OK;\r
 111         }\r
 112     }\r
 113     else\r
 114     {\r
 115         NS_LOG(DEBUG, "Not Found Data");\r
 116     }\r
 117 \r
 118     NS_LOG(DEBUG, "NSCacheUpdateSubScriptionState - OUT");\r
 119     pthread_mutex_unlock(&NSCacheMutex);\r
 120     return NS_ERROR;\r
 121 }\r
 122 \r
 123 NSResult NSStorageWrite(NSCacheList * list, NSCacheElement * newObj)\r
 124 {\r
 125     pthread_mutex_lock(&NSCacheMutex);\r
 126 \r
 127     NSCacheType type = list->cacheType;\r
 128 \r
 129     NS_LOG(DEBUG, "NSCacheWrite - IN");\r
 130 \r
 131     if (newObj == NULL)\r
 132     {\r
 133         NS_LOG(DEBUG, "newObj is NULL - IN");\r
 134         pthread_mutex_unlock(&NSCacheMutex);\r
 135         return NS_ERROR;\r
 136     }\r
 137 \r
 138     if (type == NS_PROVIDER_CACHE_SUBSCRIBER)\r
 139     {\r
 140         NS_LOG(DEBUG, "Type is SUBSCRIBER");\r
 141 \r
 142         NSCacheSubData * subData = (NSCacheSubData *) newObj->data;\r
 143         NSCacheElement * it = NSStorageRead(list, subData->id);\r
 144 \r
 145         if (it)\r
 146         {\r
 147             NSCacheSubData * itData = (NSCacheSubData *) it->data;\r
 148 \r
 149             if (strcmp(itData->id, subData->id) == 0)\r
 150             {\r
 151                 NS_LOG(DEBUG, "Update Data - IN");\r
 152 \r
 153                 NS_LOG_V(DEBUG, "currData_ID = %s", itData->id);\r
 154                 NS_LOG_V(DEBUG, "currData_MsgObID = %d", itData->messageObId);\r
 155                 NS_LOG_V(DEBUG, "currData_SyncObID = %d", itData->syncObId);\r
 156                 NS_LOG_V(DEBUG, "currData_Cloud_MsgObID = %d", itData->remote_messageObId);\r
 157                 NS_LOG_V(DEBUG, "currData_Cloud_SyncObID = %d", itData->remote_syncObId);\r
 158                 NS_LOG_V(DEBUG, "currData_IsWhite = %d", itData->isWhite);\r
 159 \r
 160                 NS_LOG_V(DEBUG, "subData_ID = %s", subData->id);\r
 161                 NS_LOG_V(DEBUG, "subData_MsgObID = %d", subData->messageObId);\r
 162                 NS_LOG_V(DEBUG, "subData_SyncObID = %d", subData->syncObId);\r
 163                 NS_LOG_V(DEBUG, "subData_Cloud_MsgObID = %d", subData->remote_messageObId);\r
 164                 NS_LOG_V(DEBUG, "subData_Cloud_SyncObID = %d", subData->remote_syncObId);\r
 165                 NS_LOG_V(DEBUG, "subData_IsWhite = %d", subData->isWhite);\r
 166 \r
 167                 if (subData->messageObId != 0)\r
 168                 {\r
 169                     itData->messageObId = subData->messageObId;\r
 170                 }\r
 171 \r
 172                 if (subData->syncObId != 0)\r
 173                 {\r
 174                     itData->syncObId = subData->syncObId;\r
 175                 }\r
 176 \r
 177                 if (subData->remote_messageObId != 0)\r
 178                 {\r
 179                     itData->remote_messageObId = subData->remote_messageObId;\r
 180                 }\r
 181 \r
 182                 if (subData->remote_syncObId != 0)\r
 183                 {\r
 184                     itData->remote_syncObId = subData->remote_syncObId;\r
 185                     NS_LOG_V(DEBUG, "sync id cached: %d", itData->remote_syncObId);\r
 186                 }\r
 187 \r
 188                 NS_LOG(DEBUG, "Update Data - OUT");\r
 189 \r
 190                 pthread_mutex_unlock(&NSCacheMutex);\r
 191                 return NS_OK;\r
 192             }\r
 193         }\r
 194 \r
 195     }\r
 196     else if(type == NS_PROVIDER_CACHE_REGISTER_TOPIC)\r
 197     {\r
 198         NS_LOG(DEBUG, "Type is REGITSTER TOPIC");\r
 199 \r
 200         NSCacheTopicData * topicData = (NSCacheTopicData *) newObj->data;\r
 201         NSCacheElement * it = NSStorageRead(list, topicData->topicName);\r
 202 \r
 203         if (it)\r
 204         {\r
 205             NS_LOG(DEBUG, "already registered for topic name");\r
 206             pthread_mutex_unlock(&NSCacheMutex);\r
 207             return NS_FAIL;\r
 208         }\r
 209     }\r
 210     else if(type == NS_PROVIDER_CACHE_CONSUMER_TOPIC_NAME)\r
 211     {\r
 212         NS_LOG(DEBUG, "Type is REGITSTER TOPIC");\r
 213 \r
 214         NSCacheTopicSubData * topicData = (NSCacheTopicSubData *) newObj->data;\r
 215         NSCacheElement * it = NSStorageRead(list, topicData->topicName);\r
 216 \r
 217         if (it)\r
 218         {\r
 219             NS_LOG(DEBUG, "already registered for topic name");\r
 220             pthread_mutex_unlock(&NSCacheMutex);\r
 221             return NS_FAIL;\r
 222         }\r
 223     }\r
 224 \r
 225     else if(type == NS_PROVIDER_CACHE_CONSUMER_TOPIC_CID)\r
 226     {\r
 227         NS_LOG(DEBUG, "Type is REGITSTER TOPIC");\r
 228 \r
 229         NSCacheTopicSubData * topicData = (NSCacheTopicSubData *) newObj->data;\r
 230         NSCacheElement * it = NSStorageRead(list, topicData->id);\r
 231 \r
 232         if (it)\r
 233         {\r
 234             NS_LOG(DEBUG, "already registered for topic name");\r
 235             pthread_mutex_unlock(&NSCacheMutex);\r
 236             return NS_FAIL;\r
 237         }\r
 238     }\r
 239 \r
 240 \r
 241     if (list->head == NULL)\r
 242     {\r
 243         NS_LOG(DEBUG, "list->head is NULL, Insert First Data");\r
 244         list->head = list->tail = newObj;\r
 245         pthread_mutex_unlock(&NSCacheMutex);\r
 246         return NS_OK;\r
 247     }\r
 248 \r
 249     list->tail = list->tail->next = newObj;\r
 250     NS_LOG(DEBUG, "list->head is not NULL");\r
 251     pthread_mutex_unlock(&NSCacheMutex);\r
 252     return NS_OK;\r
 253 }\r
 254 \r
 255 NSResult NSStorageDestroy(NSCacheList * list)\r
 256 {\r
 257     NSCacheElement * iter = list->head;\r
 258     NSCacheElement * next = NULL;\r
 259     NSCacheType type = list->cacheType;\r
 260 \r
 261     while (iter)\r
 262     {\r
 263         next = (NSCacheElement *) iter->next;\r
 264         NSProviderDeleteCacheData(type, iter->data);\r
 265         OICFree(iter);\r
 266         iter = next;\r
 267     }\r
 268 \r
 269     OICFree(list);\r
 270     return NS_OK;\r
 271 }\r
 272 \r
 273 bool NSProviderCompareIdCacheData(NSCacheType type, void * data, const char * id)\r
 274 {\r
 275     NS_LOG(DEBUG, "NSProviderCompareIdCacheData - IN");\r
 276 \r
 277     if (data == NULL)\r
 278     {\r
 279         return false;\r
 280     }\r
 281 \r
 282     NS_LOG_V(DEBUG, "Data(compData) = [%s]", id);\r
 283 \r
 284     if (type == NS_PROVIDER_CACHE_SUBSCRIBER)\r
 285     {\r
 286         NSCacheSubData * subData = (NSCacheSubData *) data;\r
 287 \r
 288         NS_LOG_V(DEBUG, "Data(subData) = [%s]", subData->id);\r
 289 \r
 290         if (strcmp(subData->id, id) == 0)\r
 291         {\r
 292             NS_LOG(DEBUG, "SubData is Same");\r
 293             return true;\r
 294         }\r
 295 \r
 296         NS_LOG(DEBUG, "Message Data is Not Same");\r
 297         return false;\r
 298     }\r
 299     else if (type == NS_PROVIDER_CACHE_REGISTER_TOPIC)\r
 300     {\r
 301         NSCacheTopicData * topicData = (NSCacheTopicData *) data;\r
 302 \r
 303         NS_LOG_V(DEBUG, "Data(topicData) = [%s]", topicData->topicName);\r
 304 \r
 305         if (strcmp(topicData->topicName, id) == 0)\r
 306         {\r
 307             NS_LOG(DEBUG, "SubData is Same");\r
 308             return true;\r
 309         }\r
 310 \r
 311         NS_LOG(DEBUG, "Message Data is Not Same");\r
 312         return false;\r
 313     }\r
 314     else if (type == NS_PROVIDER_CACHE_CONSUMER_TOPIC_NAME)\r
 315     {\r
 316         NSCacheTopicSubData * topicData = (NSCacheTopicSubData *) data;\r
 317 \r
 318         NS_LOG_V(DEBUG, "Data(topicData) = [%s]", topicData->topicName);\r
 319 \r
 320         if (strcmp(topicData->topicName, id) == 0)\r
 321         {\r
 322             NS_LOG(DEBUG, "SubData is Same");\r
 323             return true;\r
 324         }\r
 325 \r
 326         NS_LOG(DEBUG, "Message Data is Not Same");\r
 327         return false;\r
 328     }\r
 329     else if (type == NS_PROVIDER_CACHE_CONSUMER_TOPIC_CID)\r
 330     {\r
 331         NSCacheTopicSubData * topicData = (NSCacheTopicSubData *) data;\r
 332 \r
 333         NS_LOG_V(DEBUG, "Data(topicData) = [%s]", topicData->id);\r
 334 \r
 335         if (strcmp(topicData->id, id) == 0)\r
 336         {\r
 337             NS_LOG(DEBUG, "SubData is Same");\r
 338             return true;\r
 339         }\r
 340 \r
 341         NS_LOG(DEBUG, "Message Data is Not Same");\r
 342         return false;\r
 343     }\r
 344 \r
 345 \r
 346     NS_LOG(DEBUG, "NSProviderCompareIdCacheData - OUT");\r
 347     return false;\r
 348 }\r
 349 \r
 350 NSResult NSProviderDeleteCacheData(NSCacheType type, void * data)\r
 351 {\r
 352     if (data == NULL)\r
 353     {\r
 354         return NS_OK;\r
 355     }\r
 356 \r
 357     if (type == NS_PROVIDER_CACHE_SUBSCRIBER)\r
 358     {\r
 359         NSCacheSubData * subData = (NSCacheSubData *) data;\r
 360 \r
 361         (subData->id)[0] = '\0';\r
 362         OICFree(subData);\r
 363 \r
 364         return NS_OK;\r
 365     }\r
 366     else if(type == NS_PROVIDER_CACHE_REGISTER_TOPIC)\r
 367     {\r
 368         NSCacheTopicData * data = (NSCacheTopicData *) data;\r
 369         OICFree(data->topicName);\r
 370     }\r
 371     else if(type == NS_PROVIDER_CACHE_CONSUMER_TOPIC_NAME ||\r
 372             type == NS_PROVIDER_CACHE_CONSUMER_TOPIC_CID)\r
 373     {\r
 374         NSCacheTopicSubData * data = (NSCacheTopicSubData *) data;\r
 375         OICFree(data->topicName);\r
 376     }\r
 377 \r
 378     return NS_OK;\r
 379 }\r
 380 \r
 381 bool NSIsSameObId(NSCacheSubData * data, OCObservationId id)\r
 382 {\r
 383     if (id == data->messageObId || id == data->syncObId || id == data->remote_messageObId ||\r
 384                 id == data->remote_syncObId)\r
 385     {\r
 386         return true;\r
 387     }\r
 388 \r
 389     return false;\r
 390 }\r
 391 \r
 392 NSResult NSProviderDeleteSubDataFromObId(NSCacheList * list, OCObservationId id)\r
 393 {\r
 394     if(!list || !list->head)\r
 395     {\r
 396         NS_LOG(INFO, "list is NULL");\r
 397         return NS_FAIL;\r
 398     }\r
 399 \r
 400     pthread_mutex_lock(&NSCacheMutex);\r
 401     NSCacheElement * prev = list->head;\r
 402     NSCacheElement * del = list->head;\r
 403 \r
 404     NSCacheType type = list->cacheType;\r
 405 \r
 406     bool isDelete = true;\r
 407 \r
 408     while(isDelete)\r
 409     {\r
 410         NSCacheSubData * curr = (NSCacheSubData *)del->data;\r
 411 \r
 412         isDelete = false;\r
 413 \r
 414         if (NSIsSameObId(curr, id))\r
 415         {\r
 416             if (del == list->head) // first object\r
 417             {\r
 418                 if (del == list->tail) // first object (one object)\r
 419                 {\r
 420                     list->tail = del->next;\r
 421                 }\r
 422 \r
 423                 list->head = del->next;\r
 424 \r
 425                 NSProviderDeleteCacheData(type, del->data);\r
 426                 OICFree(del);\r
 427                 isDelete = true;\r
 428             }\r
 429         }\r
 430         else\r
 431         {\r
 432             del = del->next;\r
 433             while (del)\r
 434             {\r
 435                 if (NSIsSameObId(curr, id))\r
 436                 {\r
 437                     if (del == list->tail) // delete object same to last object\r
 438                     {\r
 439                         list->tail = prev;\r
 440                     }\r
 441 \r
 442                     prev->next = del->next;\r
 443                     NSProviderDeleteCacheData(type, del->data);\r
 444                     OICFree(del);\r
 445                     isDelete = true;\r
 446                     break;\r
 447                 }\r
 448 \r
 449                 prev = del;\r
 450                 del = del->next;\r
 451             }\r
 452         }\r
 453     }\r
 454     pthread_mutex_unlock(&NSCacheMutex);\r
 455     return NS_OK;\r
 456 }\r
 457 \r
 458 NSResult NSStorageDelete(NSCacheList * list, const char * delId)\r
 459 {\r
 460     pthread_mutex_lock(&NSCacheMutex);\r
 461     NSCacheElement * prev = list->head;\r
 462     NSCacheElement * del = list->head;\r
 463 \r
 464     NSCacheType type = list->cacheType;\r
 465 \r
 466     if (NSProviderCompareIdCacheData(type, del->data, delId))\r
 467     {\r
 468         if (del == list->head) // first object\r
 469         {\r
 470             if (del == list->tail) // first object (one object)\r
 471             {\r
 472                 list->tail = del->next;\r
 473             }\r
 474 \r
 475             list->head = del->next;\r
 476 \r
 477             NSProviderDeleteCacheData(type, del->data);\r
 478             OICFree(del);\r
 479             pthread_mutex_unlock(&NSCacheMutex);\r
 480             return NS_OK;\r
 481         }\r
 482     }\r
 483 \r
 484     del = del->next;\r
 485     while (del)\r
 486     {\r
 487         if (NSProviderCompareIdCacheData(type, del->data, delId))\r
 488         {\r
 489             if (del == list->tail) // delete object same to last object\r
 490             {\r
 491                 list->tail = prev;\r
 492             }\r
 493 \r
 494             prev->next = del->next;\r
 495             NSProviderDeleteCacheData(type, del->data);\r
 496             OICFree(del);\r
 497             pthread_mutex_unlock(&NSCacheMutex);\r
 498             return NS_OK;\r
 499         }\r
 500 \r
 501         prev = del;\r
 502         del = del->next;\r
 503     }\r
 504     pthread_mutex_unlock(&NSCacheMutex);\r
 505     return NS_FAIL;\r
 506 }\r
 507 \r
 508 NSTopics * NSProviderGetTopicsCacheData(NSCacheList * regTopicList)\r
 509 {\r
 510     NS_LOG(DEBUG, "NSProviderGetTopicsCache - IN");\r
 511     pthread_mutex_lock(&NSCacheMutex);\r
 512 \r
 513     NSCacheElement * iter = regTopicList->head;\r
 514 \r
 515     if(!iter)\r
 516     {\r
 517         pthread_mutex_unlock(&NSCacheMutex);\r
 518         return NULL;\r
 519     }\r
 520 \r
 521     NSTopics * iterTopic = NULL;\r
 522     NSTopics * newTopic = NULL;\r
 523     NSTopics * topics = NULL;\r
 524 \r
 525     while (iter)\r
 526     {\r
 527         NSCacheTopicData * curr = (NSCacheTopicData *) iter->data;\r
 528 \r
 529         newTopic = (NSTopics *) OICMalloc(sizeof(NSTopics));\r
 530         newTopic->state = curr->state;\r
 531         newTopic->next = NULL;\r
 532         newTopic->topicName = OICStrdup(curr->topicName);\r
 533 \r
 534         if(!topics)\r
 535         {\r
 536             iterTopic = topics = newTopic;\r
 537         }\r
 538         else\r
 539         {\r
 540             iterTopic->next = newTopic;\r
 541             iterTopic = newTopic;\r
 542         }\r
 543 \r
 544         iter = iter->next;\r
 545     }\r
 546 \r
 547     pthread_mutex_unlock(&NSCacheMutex);\r
 548     NS_LOG(DEBUG, "NSProviderGetTopicsCache - OUT");\r
 549 \r
 550     return topics;\r
 551 }\r
 552 \r
 553 NSTopics * NSProviderGetConsumerTopicsCacheData(NSCacheList * conTopicList, char *consumerId)\r
 554 {\r
 555     NS_LOG(DEBUG, "NSProviderGetConsumerTopics - IN");\r
 556 \r
 557     pthread_mutex_lock(&NSCacheMutex);\r
 558     NSTopics * topics = NSProviderGetTopics();\r
 559 \r
 560     if(!topics)\r
 561     {\r
 562         pthread_mutex_unlock(&NSCacheMutex);\r
 563         return NULL;\r
 564     }\r
 565 \r
 566     NSCacheElement * iter = conTopicList->head;\r
 567     conTopicList->cacheType = NS_PROVIDER_CACHE_CONSUMER_TOPIC_CID;\r
 568 \r
 569     while(iter)\r
 570     {\r
 571         NSCacheElement * curr = NSStorageRead(iter, consumerId);\r
 572 \r
 573         if(!curr)\r
 574         {\r
 575             NSTopics * topicIter = topics;\r
 576             while(!topicIter)\r
 577             {\r
 578                 NSCacheTopicSubData * topicSubData = (NSCacheTopicSubData *) curr->data;\r
 579                 if(strcmp(topicIter->topicName, topicSubData->topicName) == 0)\r
 580                 {\r
 581                     topicIter->state = NS_TOPIC_SUBSCRIBED;\r
 582                     break;\r
 583                 }\r
 584                 topicIter = topicIter->next;\r
 585             }\r
 586         }\r
 587 \r
 588         iter = iter->next;\r
 589     }\r
 590 \r
 591     conTopicList->cacheType = NS_PROVIDER_CACHE_CONSUMER_TOPIC_NAME;\r
 592     pthread_mutex_unlock(&NSCacheMutex);\r
 593     NS_LOG(DEBUG, "NSProviderGetConsumerTopics - OUT");\r
 594 \r
 595     return topics;\r
 596 }\r
 597 \r
 598 size_t NSProviderGetListSize(NSCacheElement * firstElement)\r
 599 {\r
 600     if(!firstElement)\r
 601     {\r
 602         return 0;\r
 603     }\r
 604 \r
 605     int cnt = 0;\r
 606 \r
 607     NSCacheElement * iter = firstElement;\r
 608 \r
 609     while(iter)\r
 610     {\r
 611         cnt++;\r
 612         iter = iter->next;\r
 613     }\r
 614 \r
 615     return cnt;\r
 616 }\r