fix(query): do some internal refactor.

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

@@ -29,12 +29,14 @@ typedef struct SCacheRowsReader {
   SArray*   pTableList;  // table id list
 } SCacheRowsReader;
 
+#define HASTYPE(_type, _t)  (((_type) & (_t)) == (_t))
+
 static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pReader, const int32_t* slotIds,
                        void** pRes) {
   ASSERT(pReader->numOfCols <= taosArrayGetSize(pBlock->pDataBlock));
   int32_t numOfRows = pBlock->info.rows;
 
-  if ((pReader->type & CACHESCAN_RETRIEVE_LAST) == CACHESCAN_RETRIEVE_LAST) {
+  if (HASTYPE(pReader->type, CACHESCAN_RETRIEVE_LAST)) {
     for (int32_t i = 0; i < pReader->numOfCols; ++i) {
       SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
       SFirstLastRes*   p = (SFirstLastRes*)varDataVal(pRes[i]);
@@ -54,7 +56,7 @@ static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
           if (IS_VAR_DATA_TYPE(pColVal->colVal.type)) {
             varDataSetLen(p->buf, pColVal->colVal.value.nData);
             memcpy(varDataVal(p->buf), pColVal->colVal.value.pData, pColVal->colVal.value.nData);
-            p->bytes = pColVal->colVal.value.nData + VARSTR_HEADER_SIZE;
+            p->bytes = pColVal->colVal.value.nData + VARSTR_HEADER_SIZE;   // binary needs to plus the header size
           } else {
             memcpy(p->buf, &pColVal->colVal.value, pReader->pSchema->columns[slotId].bytes);
             p->bytes = pReader->pSchema->columns[slotId].bytes;
@@ -62,12 +64,13 @@ static void saveOneRow(SArray* pRow, SSDataBlock* pBlock, SCacheRowsReader* pRea
         }
       }
 
+      // pColInfoData->info.bytes includes the VARSTR_HEADER_SIZE, need to substruct it
       p->hasResult = true;
-      varDataSetLen(pRes[i], pColInfoData->info.bytes);
+      varDataSetLen(pRes[i], pColInfoData->info.bytes - VARSTR_HEADER_SIZE);
       colDataAppend(pColInfoData, numOfRows, (const char*)pRes[i], false);
     }
   } else {
-    ASSERT((pReader->type & CACHESCAN_RETRIEVE_LAST_ROW) == CACHESCAN_RETRIEVE_LAST_ROW);
+    ASSERT(HASTYPE(pReader->type, CACHESCAN_RETRIEVE_LAST_ROW));
 
     for (int32_t i = 0; i < pReader->numOfCols; ++i) {
       SColumnInfoData* pColInfoData = taosArrayGet(pBlock->pDataBlock, i);
@@ -177,6 +180,13 @@ static int32_t doExtractCacheRow(SCacheRowsReader* pr, SLRUCache* lruCache, uint
   return code;
 }
 
+static void freeItem(void* pItem) {
+  SLastCol* pCol = (SLastCol*) pItem;
+  if (IS_VAR_DATA_TYPE(pCol->colVal.type)) {
+    taosMemoryFree(pCol->colVal.value.pData);
+  }
+}
+
 int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32_t* slotIds, SArray* pTableUidList) {
   if (pReader == NULL || pResBlock == NULL) {
     return TSDB_CODE_INVALID_PARA;
@@ -217,7 +227,6 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
     if (IS_VAR_DATA_TYPE(pCol->type)) {
       p.colVal.value.pData = taosMemoryCalloc(pCol->bytes, sizeof(char));
     }
-
     taosArrayPush(pLastCols, &p);
   }
 
@@ -237,19 +246,25 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
 
       {
         for (int32_t k = 0; k < pr->numOfCols; ++k) {
-          SLastCol* p = taosArrayGet(pLastCols, k);
-          if (slotIds[k] == -1) {  // the primary timestamp
-            SLastCol* pCol = (SLastCol*)taosArrayGet(pRow, k);
+          int32_t slotId = slotIds[k];
+
+          if (slotId == -1) {  // the primary timestamp
+            SLastCol* p = taosArrayGet(pLastCols, 0);
+            SLastCol* pCol = (SLastCol*)taosArrayGet(pRow, 0);
             if (pCol->ts > p->ts) {
               hasRes = true;
               p->ts = pCol->ts;
               p->colVal = pCol->colVal;
             }
           } else {
-            int32_t   slotId = slotIds[k];
+            SLastCol* p = taosArrayGet(pLastCols, slotId);
             SLastCol* pColVal = (SLastCol*)taosArrayGet(pRow, slotId);
 
             if (pColVal->ts > p->ts) {
+              if (!COL_VAL_IS_VALUE(&pColVal->colVal) && HASTYPE(pr->type, CACHESCAN_RETRIEVE_LAST)) {
+                continue;
+              }
+
               hasRes = true;
               p->ts = pColVal->ts;
 
@@ -308,6 +323,6 @@ int32_t tsdbRetrieveCacheRows(void* pReader, SSDataBlock* pResBlock, const int32
   }
 
   taosMemoryFree(pRes);
-  taosArrayDestroy(pLastCols);
+  taosArrayDestroyEx(pLastCols, freeItem);
   return code;
 }

tests/script/tsim/parser/last_cache_query.sim

@@ -39,6 +39,7 @@ if $data02 != 5.000000000 then
   return -1
 endi
 if $data03 != 3 then
+  print expect 3, actual: $data03
   return -1
 endi
 if $data04 != @70-01-01 07:59:57.000@ then
@@ -210,7 +211,7 @@ if $data01 != 6 then
   return -1
 endi
 if $data02 != 37.000000000 then
-  print $data02
+  print expect 37.000000000 actual: $data02
   return -1
 endi
 if $data03 != 27 then
@@ -233,7 +234,7 @@ if $data01 != 6 then
   return -1
 endi
 if $data02 != 37.000000000 then
-  print $data02
+  print expect 37.000000000, acutal: $data02
   return -1
 endi
 if $data03 != 27 then