From 1c89972fc6c97ef3a0df57e34eecbeeafb91bdc7 Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Sat, 3 Sep 2022 22:00:24 +0800
Subject: [PATCH] fix(query): add multiple blockdata structure.

---
 source/dnode/vnode/src/tsdb/tsdbMergeTree.c | 63 ++++++++++++++-------
 1 file changed, 42 insertions(+), 21 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbMergeTree.c b/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
index ce36d74467..95f26161c3 100644
--- a/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
+++ b/source/dnode/vnode/src/tsdb/tsdbMergeTree.c
@@ -24,7 +24,8 @@ typedef struct SLDataIter {
   int8_t        backward;
   SArray       *aSstBlk;
   int32_t       iSstBlk;
-  SBlockData    bData;
+  SBlockData    bData[2];
+  int32_t       loadIndex;
   int32_t       iRow;
   SRowInfo      rInfo;
   uint64_t      uid;
@@ -32,6 +33,15 @@ typedef struct SLDataIter {
   SVersionRange verRange;
 } SLDataIter;
 
+static SBlockData* getCurrentBlock(SLDataIter* pIter) {
+  return &pIter->bData[pIter->loadIndex];
+}
+
+static SBlockData* getNextBlock(SLDataIter* pIter) {
+  pIter->loadIndex ^= 1;
+  return getCurrentBlock(pIter);
+}
+
 int32_t tLDataIterOpen(struct SLDataIter **pIter, SDataFReader *pReader, int32_t iSst, int8_t backward, uint64_t uid,
                        STimeWindow *pTimeWindow, SVersionRange *pRange) {
   int32_t code = 0;
@@ -53,7 +63,12 @@ int32_t tLDataIterOpen(struct SLDataIter **pIter, SDataFReader *pReader, int32_t
     goto _exit;
   }
 
-  code = tBlockDataCreate(&(*pIter)->bData);
+  code = tBlockDataCreate(&(*pIter)->bData[0]);
+  if (code) {
+    goto _exit;
+  }
+
+  code = tBlockDataCreate(&(*pIter)->bData[1]);
   if (code) {
     goto _exit;
   }
@@ -95,7 +110,8 @@ _exit:
 }
 
 void tLDataIterClose(SLDataIter *pIter) {
-  tBlockDataDestroy(&pIter->bData, 1);
+  tBlockDataDestroy(&pIter->bData[0], 1);
+  tBlockDataDestroy(&pIter->bData[1], 1);
   taosArrayDestroy(pIter->aSstBlk);
   taosMemoryFree(pIter);
 }
@@ -136,24 +152,26 @@ static void findNextValidRow(SLDataIter *pIter) {
 
   bool    hasVal = false;
   int32_t i = pIter->iRow;
-  for (; i < pIter->bData.nRow && i >= 0; i += step) {
-    if (pIter->bData.aUid != NULL) {
+  SBlockData* pBlockData = getCurrentBlock(pIter);
+
+  for (; i < pBlockData->nRow && i >= 0; i += step) {
+    if (pBlockData->aUid != NULL) {
       if (!pIter->backward) {
-        if (pIter->bData.aUid[i] < pIter->uid) {
+        if (pBlockData->aUid[i] < pIter->uid) {
           continue;
-        } else if (pIter->bData.aUid[i] > pIter->uid) {
+        } else if (pBlockData->aUid[i] > pIter->uid) {
           break;
         }
       } else {
-        if (pIter->bData.aUid[i] > pIter->uid) {
+        if (pBlockData->aUid[i] > pIter->uid) {
           continue;
-        } else if (pIter->bData.aUid[i] < pIter->uid) {
+        } else if (pBlockData->aUid[i] < pIter->uid) {
           break;
         }
       }
     }
 
-    int64_t ts = pIter->bData.aTSKEY[i];
+    int64_t ts = pBlockData->aTSKEY[i];
     if (!pIter->backward) {               // asc
       if (ts > pIter->timeWindow.ekey) {  // no more data
         break;
@@ -168,7 +186,7 @@ static void findNextValidRow(SLDataIter *pIter) {
       }
     }
 
-    int64_t ver = pIter->bData.aVersion[i];
+    int64_t ver = pBlockData->aVersion[i];
     if (ver < pIter->verRange.minVer) {
       continue;
     }
@@ -203,14 +221,16 @@ bool tLDataIterNextRow(SLDataIter *pIter) {
   }
 
   int32_t iBlockL = pIter->iSstBlk;
+  SBlockData* pBlockData = getCurrentBlock(pIter);
 
-  if (pIter->bData.nRow == 0 && pIter->pSstBlk != NULL) {  // current block not loaded yet
-    code = tsdbReadSstBlockEx(pIter->pReader, pIter->iSst, pIter->pSstBlk, &pIter->bData);
+  if (pBlockData->nRow == 0 && pIter->pSstBlk != NULL) {  // current block not loaded yet
+    pBlockData = getNextBlock(pIter);
+    code = tsdbReadSstBlockEx(pIter->pReader, pIter->iSst, pIter->pSstBlk, pBlockData);
     if (code != TSDB_CODE_SUCCESS) {
       goto _exit;
     }
 
-    pIter->iRow = (pIter->backward) ? pIter->bData.nRow : -1;
+    pIter->iRow = (pIter->backward) ? pBlockData->nRow : -1;
   }
 
   pIter->iRow += step;
@@ -218,7 +238,7 @@ bool tLDataIterNextRow(SLDataIter *pIter) {
   while (1) {
     findNextValidRow(pIter);
 
-    if (pIter->iRow >= pIter->bData.nRow || pIter->iRow < 0) {
+    if (pIter->iRow >= pBlockData->nRow || pIter->iRow < 0) {
       tLDataIterNextBlock(pIter);
       if (pIter->pSstBlk == NULL) {  // no more data
         goto _exit;
@@ -228,17 +248,18 @@ bool tLDataIterNextRow(SLDataIter *pIter) {
     }
 
     if (iBlockL != pIter->iSstBlk) {
-      code = tsdbReadSstBlockEx(pIter->pReader, pIter->iSst, pIter->pSstBlk, &pIter->bData);
+      pBlockData = getNextBlock(pIter);
+      code = tsdbReadSstBlockEx(pIter->pReader, pIter->iSst, pIter->pSstBlk, pBlockData);
       if (code) {
         goto _exit;
       }
-      pIter->iRow = pIter->backward ? (pIter->bData.nRow - 1) : 0;
+      pIter->iRow = pIter->backward ? (pBlockData->nRow - 1) : 0;
     }
   }
 
-  pIter->rInfo.suid = pIter->bData.suid;
-  pIter->rInfo.uid = pIter->bData.uid;
-  pIter->rInfo.row = tsdbRowFromBlockData(&pIter->bData, pIter->iRow);
+  pIter->rInfo.suid = pBlockData->suid;
+  pIter->rInfo.uid = pBlockData->uid;
+  pIter->rInfo.row = tsdbRowFromBlockData(pBlockData, pIter->iRow);
 
 _exit:
   if (code != TSDB_CODE_SUCCESS) {
@@ -322,7 +343,7 @@ bool tMergeTreeNext(SMergeTree *pMTree) {
     // compare with min in RB Tree
     pIter = (SLDataIter *)tRBTreeMin(&pMTree->rbt);
     if (pMTree->pIter && pIter) {
-      int32_t c = pMTree->rbt.cmprFn(pMTree->pIter->node.payload, &pIter->node.payload);
+      int32_t c = pMTree->rbt.cmprFn(pMTree->pIter->node.payload, pIter->node.payload);
       if (c > 0) {
         tRBTreePut(&pMTree->rbt, (SRBTreeNode *)pMTree->pIter);
         pMTree->pIter = NULL;