more code

source/dnode/vnode/src/inc/tsdb.h

@@ -207,7 +207,7 @@ int32_t tsdbDecmprColData(uint8_t *pIn, SBlockCol *pBlockCol, int8_t cmprAlg, in
 int32_t  tsdbMemTableCreate(STsdb *pTsdb, SMemTable **ppMemTable);
 void     tsdbMemTableDestroy(SMemTable *pMemTable);
 STbData *tsdbGetTbDataFromMemTable(SMemTable *pMemTable, tb_uid_t suid, tb_uid_t uid);
-int32_t  tsdbRefMemTable(SMemTable *pMemTable, void *pQueryHandle, SQueryNode **ppNode);
+int32_t  tsdbRefMemTable(SMemTable *pMemTable, void *pQHandle, SQueryNode **ppNode);
 int32_t  tsdbUnrefMemTable(SMemTable *pMemTable, SQueryNode *pNode);
 SArray  *tsdbMemTableGetTbDataArray(SMemTable *pMemTable);
 // STbDataIter
@@ -369,7 +369,7 @@ struct STbData {
 struct SQueryNode {
   SQueryNode  *pNext;
   SQueryNode **ppNext;
-  void        *pQueryHandle;
+  void        *pQHandle;
 };
 
 struct SMemTable {

source/dnode/vnode/src/tsdb/tsdbMemTable.c

@@ -631,19 +631,19 @@ _err:
 
 int32_t tsdbGetNRowsInTbData(STbData *pTbData) { return pTbData->sl.size; }
 
-int32_t tsdbRefMemTable(SMemTable *pMemTable, void *pQueryHandle, SQueryNode **ppNode) {
+int32_t tsdbRefMemTable(SMemTable *pMemTable, void *pQHandle, SQueryNode **ppNode) {
   int32_t code = 0;
 
   int32_t nRef = atomic_fetch_add_32(&pMemTable->nRef, 1);
   ASSERT(nRef > 0);
 
-  // register handle
+  // register handle (todo: take concurrency in consideration)
   *ppNode = taosMemoryMalloc(sizeof(SQueryNode));
   if (*ppNode == NULL) {
     code = TSDB_CODE_OUT_OF_MEMORY;
     goto _exit;
   }
-  (*ppNode)->pQueryHandle = pQueryHandle;
+  (*ppNode)->pQHandle = pQHandle;
   (*ppNode)->pNext = pMemTable->qList.pNext;
   (*ppNode)->ppNext = &pMemTable->qList.pNext;
   pMemTable->qList.pNext->ppNext = &(*ppNode)->pNext;
@@ -656,7 +656,7 @@ _exit:
 int32_t tsdbUnrefMemTable(SMemTable *pMemTable, SQueryNode *pNode) {
   int32_t code = 0;
 
-  // unregister handle
+  // unregister handle (todo: take concurrency in consideration)
   if (pNode) {
     pNode->pNext->ppNext = pNode->ppNext;
     *pNode->ppNext = pNode->pNext;
@@ -708,3 +708,31 @@ SArray *tsdbMemTableGetTbDataArray(SMemTable *pMemTable) {
 _exit:
   return aTbDataP;
 }
+
+extern int32_t tsdbSetQueryReseek(void *pQHandle);
+
+int32_t tsdbRecycleMemTable(SMemTable *pMemTable) {
+  int32_t code = 0;
+
+  SQueryNode *pNode = pMemTable->qList.pNext;
+  while (1) {
+    ASSERT(pNode != &pMemTable->qList);
+    SQueryNode *pNextNode = pNode->pNext;
+
+    if (pNextNode == &pMemTable->qList) {
+      code = tsdbSetQueryReseek(pNode->pQHandle);
+      if (code) goto _exit;
+      break;
+    } else {
+      code = tsdbSetQueryReseek(pNode->pQHandle);
+      if (code) goto _exit;
+      pNode = pMemTable->qList.pNext;
+      ASSERT(pNode == pNextNode);
+    }
+  }
+
+  // NOTE: Take care here, pMemTable is destroyed
+
+_exit:
+  return code;
+}

source/dnode/vnode/src/tsdb/tsdbRead.c

@@ -3925,3 +3925,20 @@ void tsdbUntakeReadSnap(STsdbReader* pReader, STsdbReadSnap* pSnap) {
 
   tsdbTrace("vgId:%d, untake read snapshot", TD_VID(pTsdb->pVnode));
 }
+
+int32_t tsdbSetQueryReseek(void* pQHandle) {
+  int32_t code = 0;
+
+  // lock handle
+
+  // check state (is already in reseek state, skip below)
+
+  // save all state for further restore
+
+  // unref read snapshot
+  // tsdbUntakeReadSnap();
+
+  // unlock handle
+
+  return code;
+}
\ No newline at end of file