refactor: add tag filter cache.

include/common/tglobal.h

@@ -44,6 +44,8 @@ extern int32_t tsCompatibleModel;
 extern bool    tsPrintAuth;
 extern int64_t tsTickPerMin[3];
 extern int32_t tsCountAlwaysReturnValue;
+extern float   tsSelectivityRatio;
+extern int32_t tsTagFilterResCacheSize;
 
 // queue & threads
 extern int32_t tsNumOfRpcThreads;

include/util/tlist.h

@@ -225,7 +225,7 @@ void      *tdListFree(SList *list);
 void       tdListPrependNode(SList *list, SListNode *node);
 void       tdListAppendNode(SList *list, SListNode *node);
 int32_t    tdListPrepend(SList *list, void *data);
-int32_t    tdListAppend(SList *list, void *data);
+int32_t    tdListAppend(SList *list, const void *data);
 SListNode *tdListPopHead(SList *list);
 SListNode *tdListPopTail(SList *list);
 SListNode *tdListGetHead(SList *list);

source/common/src/tglobal.c

@@ -119,6 +119,9 @@ int32_t tsMinIntervalTime = 1;
 // maximum memory allowed to be allocated for a single csv load (in MB)
 int32_t tsMaxMemUsedByInsert = 1024;
 
+float   tsSelectivityRatio = 1.0;
+int32_t tsTagFilterResCacheSize = 4096;
+
 // the maximum allowed query buffer size during query processing for each data node.
 // -1 no limit (default)
 // 0  no query allowed, queries are disabled

source/dnode/vnode/inc/vnode.h

@@ -108,6 +108,9 @@ int         metaGetTableNameByUid(void *meta, uint64_t uid, char *tbName);
 int         metaGetTableUidByName(void *meta, char *tbName, uint64_t *uid);
 int         metaGetTableTypeByName(void *meta, char *tbName, ETableType *tbType);
 bool        metaIsTableExist(SMeta *pMeta, tb_uid_t uid);
+int32_t     metaGetCachedTableUidList(SMeta *pMeta, tb_uid_t suid, const uint8_t *key, int32_t keyLen, SArray *pList, bool* acquired);
+int32_t     metaUidFilterCachePut(SMeta *pMeta, uint64_t suid, const void *pKey, int32_t keyLen, void *pPayload,
+                                  int32_t payloadLen, double selectivityRatio);
 
 typedef struct SMetaFltParam {
   tb_uid_t suid;

source/dnode/vnode/src/meta/metaCache.c

@@ -33,7 +33,7 @@ typedef struct SMetaStbStatsEntry {
 
 typedef struct STagFilterResEntry {
   uint64_t suid;  // uid for super table
-  SList*   pList; // the linked list of md5 digest, extracted from the serialized tag query condition
+  SList    list; // the linked list of md5 digest, extracted from the serialized tag query condition
   uint32_t qTimes;// queried times for current super table
 } STagFilterResEntry;
 
@@ -56,6 +56,7 @@ struct SMetaCache {
   struct STagFilterResCache {
     SHashObj*  pTableEntry;
     SLRUCache* pUidResCache;
+    uint64_t   keyBuf[3];
   } sTagFilterResCache;
 };
 
@@ -119,9 +120,19 @@ int32_t metaCacheOpen(SMeta* pMeta) {
     goto _err2;
   }
 
-  pMeta->pCache = pCache;
+  pCache->sTagFilterResCache.pUidResCache = taosLRUCacheInit(5*1024*1024, -1, 0.5);
+  if (pCache->sTagFilterResCache.pUidResCache == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _err2;
+  }
 
-_exit:
+  pCache->sTagFilterResCache.pTableEntry = taosHashInit(1024, taosGetDefaultHashFunction(TSDB_DATA_TYPE_VARCHAR), false, HASH_NO_LOCK);
+  if (pCache->sTagFilterResCache.pTableEntry == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _err2;
+  }
+
+  pMeta->pCache = pCache;
   return code;
 
 _err2:
@@ -129,7 +140,6 @@ _err2:
 
 _err:
   taosMemoryFree(pCache);
-
   metaError("vgId:%d, meta open cache failed since %s", TD_VID(pMeta->pVnode), tstrerror(code));
   return code;
 }
@@ -138,6 +148,11 @@ void metaCacheClose(SMeta* pMeta) {
   if (pMeta->pCache) {
     entryCacheClose(pMeta);
     statsCacheClose(pMeta);
+
+    taosHashCleanup(pMeta->pCache->sTagFilterResCache.pTableEntry);
+    taosLRUCacheCleanup(pMeta->pCache->sTagFilterResCache.pUidResCache);
+
+    taosMemoryFree(pMeta->pCache->sTagFilterResCache.keyBuf);
     taosMemoryFree(pMeta->pCache);
     pMeta->pCache = NULL;
   }
@@ -399,38 +414,48 @@ int32_t metaStatsCacheGet(SMeta* pMeta, int64_t uid, SMetaStbStats* pInfo) {
   return code;
 }
 
-int32_t metaUidFilterCacheGet(SMeta* pMeta, uint64_t suid, const void* pKey, int32_t keyLen, LRUHandle** pHandle) {
+int32_t metaGetCachedTableUidList(SMeta* pMeta, tb_uid_t suid, const uint8_t* pKey, int32_t keyLen, SArray* pList1, bool* acquireRes) {
+  uint64_t* pBuf = pMeta->pCache->sTagFilterResCache.keyBuf;
+
   // generate the composed key for LRU cache
-  char* p = taosMemoryMalloc(keyLen + sizeof(uint64_t));
+  SLRUCache* pCache = pMeta->pCache->sTagFilterResCache.pUidResCache;
-  *(uint64_t*) p = suid;
+
-  memcpy(p + sizeof(suid), pKey, keyLen);
+  pBuf[0] = suid;
+  memcpy(&pBuf[1], pKey, keyLen);
 
   int32_t len = keyLen + sizeof(uint64_t);
-  *pHandle = taosLRUCacheLookup(pMeta->pCache->sTagFilterResCache.pUidResCache, p, len);
+  LRUHandle *pHandle = taosLRUCacheLookup(pCache, pBuf, len);
-  if (*pHandle == NULL) {
+  if (pHandle == NULL) {
-    taosMemoryFree(p);
+    *acquireRes = 0;
     return TSDB_CODE_SUCCESS;
   } else {  // do some book mark work after acquiring the filter result from cache
     STagFilterResEntry* pEntry = taosHashGet(pMeta->pCache->sTagFilterResCache.pTableEntry, &suid, sizeof(uint64_t));
     ASSERT(pEntry != NULL);
+    *acquireRes = 1;
+
+    const char* p = taosLRUCacheValue(pMeta->pCache->sTagFilterResCache.pUidResCache, pHandle);
+    int32_t size = *(int32_t*) p;
+    taosArrayAddBatch(pList1, p + sizeof(int32_t), size);
 
     pEntry->qTimes += 1;
 
     // check if scanning all items are necessary or not
-    if (pEntry->qTimes > 5000 && TD_DLIST_NELES(pEntry->pList) > 10) {
+    if (pEntry->qTimes >= 5000 && TD_DLIST_NELES(&pEntry->list) > 10) {
       SArray* pList = taosArrayInit(64, POINTER_BYTES);
 
       SListIter iter = {0};
-      tdListInitIter(pEntry->pList, &iter, TD_LIST_FORWARD);
+      tdListInitIter(&pEntry->list, &iter, TD_LIST_FORWARD);
 
       SListNode* pNode = NULL;
       while ((pNode = tdListNext(&iter)) != NULL) {
-        memcpy(p + sizeof(suid), pNode->data, keyLen);
+        memcpy(pBuf + sizeof(suid), pNode->data, keyLen);
 
         // check whether it is existed in LRU cache, and remove it from linked list if not.
-        void* pRes = taosLRUCacheLookup(pMeta->pCache->sTagFilterResCache.pUidResCache, p, len);
+        LRUHandle* pRes = taosLRUCacheLookup(pCache, pBuf, len);
         if (pRes == NULL) {  // remove the item in the linked list
           taosArrayPush(pList, &pNode);
+        } else {
+          taosLRUCacheRelease(pCache, pRes, false);
         }
       }
 
@@ -438,19 +463,49 @@ int32_t metaUidFilterCacheGet(SMeta* pMeta, uint64_t suid, const void* pKey, int
       size_t s = taosArrayGetSize(pList);
       for(int32_t i = 0; i < s; ++i) {
         SListNode** p1 = taosArrayGet(pList, i);
-        tdListPopNode(pEntry->pList, *p1);
+        tdListPopNode(&pEntry->list, *p1);
-      }
       }
 
-    taosMemoryFree(p);
+      pEntry->qTimes = 0; // reset the query times
+    }
   }
 
   return TSDB_CODE_SUCCESS;
 }
 
 // check both the payload size and selectivity ratio
-int32_t metaUidFilterCachePut(SMeta* pMeta, uint64_t suid, const void* pKey, int32_t keyLen, void* pPayload) {
+int32_t metaUidFilterCachePut(SMeta* pMeta, uint64_t suid, const void* pKey, int32_t keyLen, void* pPayload, int32_t payloadLen, double selectivityRatio) {
+  if (selectivityRatio > tsSelectivityRatio) {
+    return TSDB_CODE_SUCCESS;
+  }
 
+  if (payloadLen > tsTagFilterResCacheSize) {
+    return TSDB_CODE_SUCCESS;
+  }
+
+  SLRUCache* pCache = pMeta->pCache->sTagFilterResCache.pUidResCache;
+  SHashObj* pTableEntry = pMeta->pCache->sTagFilterResCache.pTableEntry;
+
+  void* pEntry = taosHashGet(pMeta->pCache->sTagFilterResCache.pTableEntry, &suid, sizeof(uint64_t));
+  if (pEntry == NULL) {
+    STagFilterResEntry* p = taosMemoryMalloc(sizeof(STagFilterResEntry));
+    p->qTimes = 0;
+    tdListInit(&p->list, keyLen);
+    taosHashPut(pTableEntry, &suid, sizeof(uint64_t), pEntry, POINTER_BYTES);
+
+    pEntry = &p;
+  }
+
+  tdListAppend(&(*(STagFilterResEntry**)pEntry)->list, pKey);
+
+  uint64_t* pBuf = pMeta->pCache->sTagFilterResCache.keyBuf;
+  pBuf[0] = suid;
+
+  memcpy(&pBuf[1], pKey, keyLen);
+  ASSERT(sizeof(uint64_t) + keyLen == 24);
+
+  // add to cache.
+  taosLRUCacheInsert(pCache, pBuf, sizeof(uint64_t) + keyLen, pPayload, payloadLen, NULL, NULL, TAOS_LRU_PRIORITY_LOW);
   return TSDB_CODE_SUCCESS;
 }
 
@@ -466,7 +521,7 @@ int32_t metaUidCacheClear(SMeta* pMeta, uint64_t suid) {
   *(uint64_t*)p = pEntry->suid;
 
   SListIter iter = {0};
-  tdListInitIter(pEntry->pList, &iter, TD_LIST_FORWARD);
+  tdListInitIter(&pEntry->list, &iter, TD_LIST_FORWARD);
 
   SListNode* pNode = NULL;
   while ((pNode = tdListNext(&iter)) != NULL) {
@@ -474,6 +529,8 @@ int32_t metaUidCacheClear(SMeta* pMeta, uint64_t suid) {
     taosLRUCacheErase(pMeta->pCache->sTagFilterResCache.pUidResCache, p, keyLen);
   }
 
+  pEntry->qTimes = 0;
+  tdListEmpty(&pEntry->list);
+
   return TSDB_CODE_SUCCESS;
 }
-

source/libs/executor/src/executil.c

@@ -973,11 +973,28 @@ int32_t getTableList(void* metaHandle, void* pVnode, SScanPhysiNode* pScanNode,
   SArray* res = taosArrayInit(8, sizeof(uint64_t));
 
   if (pScanNode->tableType == TSDB_SUPER_TABLE) {
+    // try to retrieve the result from meta cache
+    // generate the cache key
+    T_MD5_CTX context = {0};
+
+    if (pTagIndexCond) {
+      char*   payload = NULL;
+      int32_t len = 0;
+      nodesNodeToMsg(pTagCond, &payload, &len);
+
+      tMD5Init(&context);
+      tMD5Update(&context, (uint8_t*)payload, (uint32_t)len);
+      tMD5Final(&context);
+    }
+
+    bool acquired = false;
+    metaGetCachedTableUidList(metaHandle, pScanNode->suid, context.digest, tListLen(context.digest), res, &acquired);
+    if (!acquired) {
+      // failed to find the result in the cache, let try to calculate the results
       if (pTagIndexCond) {
         SIndexMetaArg metaArg = {
             .metaEx = metaHandle, .idx = tsdbGetIdx(metaHandle), .ivtIdx = tsdbGetIvtIdx(metaHandle), .suid = tableUid};
 
-      //      int64_t stt = taosGetTimestampUs();
         SIdxFltStatus status = SFLT_NOT_INDEX;
         code = doFilterTag(pTagIndexCond, &metaArg, res, &status);
         if (code != 0 || status == SFLT_NOT_INDEX) {
@@ -987,6 +1004,17 @@ int32_t getTableList(void* metaHandle, void* pVnode, SScanPhysiNode* pScanNode,
       } else if (!pTagCond) {
         vnodeGetCtbIdList(pVnode, pScanNode->suid, res);
       }
+
+      // let's add the filter results into meta-cache
+      size_t numOfTables = taosArrayGetSize(res);
+      size_t size = numOfTables * sizeof(uint64_t) + sizeof(int32_t);
+      char*  pPayload = taosMemoryMalloc(size);
+      *(int32_t*)pPayload = numOfTables;
+      memcpy(pPayload + sizeof(int32_t), taosArrayGet(res, 0), numOfTables * sizeof(uint64_t));
+
+      metaUidFilterCachePut(metaHandle, pScanNode->suid, context.digest, tListLen(context.digest), pPayload,
+          size, 1);
+    }
   } else {  // Create one table group.
     if (metaIsTableExist(metaHandle, tableUid)) {
       taosArrayPush(res, &tableUid);

source/util/src/tlist.c

@@ -60,7 +60,7 @@ int32_t tdListPrepend(SList *list, void *data) {
   return 0;
 }
 
-int32_t tdListAppend(SList *list, void *data) {
+int32_t tdListAppend(SList *list, const void *data) {
   SListNode *node = (SListNode *)taosMemoryCalloc(1, sizeof(SListNode) + list->eleSize);
   if (node == NULL) return -1;