From e9fc109edf06d48c8677ee2b751938c335e90f5d Mon Sep 17 00:00:00 2001
From: Haojun Liao <hjliao@taosdata.com>
Date: Wed, 11 Jan 2023 18:47:45 +0800
Subject: [PATCH] enh(query): opt query perf.

---
 source/libs/executor/inc/executil.h           |  5 +---
 source/libs/executor/src/executil.c           | 27 ++++++++++---------
 source/libs/executor/src/timewindowoperator.c |  5 ++--
 3 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/source/libs/executor/inc/executil.h b/source/libs/executor/inc/executil.h
index e0d2276e6f..523957b54d 100644
--- a/source/libs/executor/inc/executil.h
+++ b/source/libs/executor/inc/executil.h
@@ -44,6 +44,7 @@
 typedef struct SGroupResInfo {
   int32_t index;
   SArray* pRows;  // SArray<SResKeyPos>
+  char*   pBuf;
 } SGroupResInfo;
 
 typedef struct SResultRow {
@@ -115,10 +116,6 @@ struct SResultRowEntryInfo* getResultEntryInfo(const SResultRow* pRow, int32_t i
 
 static FORCE_INLINE SResultRow* getResultRowByPos(SDiskbasedBuf* pBuf, SResultRowPosition* pos, bool forUpdate) {
   SFilePage* bufPage = (SFilePage*)getBufPage(pBuf, pos->pageId);
-  if (NULL == bufPage) {
-    return NULL;
-  }
-  
   if (forUpdate) {
     setBufPageDirty(bufPage, true);
   }
diff --git a/source/libs/executor/src/executil.c b/source/libs/executor/src/executil.c
index 857d57c6b1..06c90481aa 100644
--- a/source/libs/executor/src/executil.c
+++ b/source/libs/executor/src/executil.c
@@ -89,13 +89,7 @@ size_t getResultRowSize(SqlFunctionCtx* pCtx, int32_t numOfOutput) {
 }
 
 void cleanupGroupResInfo(SGroupResInfo* pGroupResInfo) {
-  assert(pGroupResInfo != NULL);
-
-  for (int32_t i = 0; i < taosArrayGetSize(pGroupResInfo->pRows); ++i) {
-    SResKeyPos* pRes = taosArrayGetP(pGroupResInfo->pRows, i);
-    taosMemoryFree(pRes);
-  }
-
+  taosMemoryFreeClear(pGroupResInfo->pBuf);
   pGroupResInfo->pRows = taosArrayDestroy(pGroupResInfo->pRows);
   pGroupResInfo->index = 0;
 }
@@ -126,20 +120,28 @@ void initGroupedResultInfo(SGroupResInfo* pGroupResInfo, SSHashObj* pHashmap, in
   }
 
   // extract the result rows information from the hash map
-  void* pData = NULL;
-  pGroupResInfo->pRows = taosArrayInit(10, POINTER_BYTES);
+  int32_t size = tSimpleHashGetSize(pHashmap);
+
+  void* pData = NULL;
+  pGroupResInfo->pRows = taosArrayInit(size, POINTER_BYTES);
 
-  // todo avoid repeated malloc memory
   size_t  keyLen = 0;
-  int32_t iter = 0;
+  int32_t num = 0, iter = 0, itemSize = 0;
+
   while ((pData = tSimpleHashIterate(pHashmap, pData, &iter)) != NULL) {
     void* key = tSimpleHashGetKey(pData, &keyLen);
 
-    SResKeyPos* p = taosMemoryMalloc(keyLen + sizeof(SResultRowPosition));
+    if (pGroupResInfo->pBuf == NULL) {
+      itemSize = keyLen + sizeof(SResultRowPosition);
+      pGroupResInfo->pBuf = taosMemoryMalloc(size * itemSize);
+    }
+
+    SResKeyPos* p = (SResKeyPos*)(pGroupResInfo->pBuf + num * itemSize);
 
     p->groupId = *(uint64_t*)key;
     p->pos = *(SResultRowPosition*)pData;
     memcpy(p->key, (char*)key + sizeof(uint64_t), keyLen - sizeof(uint64_t));
+
     taosArrayPush(pGroupResInfo->pRows, &p);
   }
 
@@ -172,7 +174,6 @@ bool hasRemainResults(SGroupResInfo* pGroupResInfo) {
 }
 
 int32_t getNumOfTotalRes(SGroupResInfo* pGroupResInfo) {
-  assert(pGroupResInfo != NULL);
   if (pGroupResInfo->pRows == 0) {
     return 0;
   }
diff --git a/source/libs/executor/src/timewindowoperator.c b/source/libs/executor/src/timewindowoperator.c
index d78e9c4edf..4cac29cec8 100644
--- a/source/libs/executor/src/timewindowoperator.c
+++ b/source/libs/executor/src/timewindowoperator.c
@@ -3392,9 +3392,11 @@ static void copyDeleteWindowInfo(SArray* pResWins, SSHashObj* pStDeleted) {
   }
 }
 
+// the allocated memory comes from outer function.
 void initGroupResInfoFromArrayList(SGroupResInfo* pGroupResInfo, SArray* pArrayList) {
   pGroupResInfo->pRows = pArrayList;
   pGroupResInfo->index = 0;
+  pGroupResInfo->pBuf = NULL;
 }
 
 void doBuildSessionResult(SOperatorInfo* pOperator, SStreamState* pState, SGroupResInfo* pGroupResInfo,
@@ -3405,8 +3407,7 @@ void doBuildSessionResult(SOperatorInfo* pOperator, SStreamState* pState, SGroup
 
   blockDataCleanup(pBlock);
   if (!hasRemainResults(pGroupResInfo)) {
-    taosArrayDestroy(pGroupResInfo->pRows);
-    pGroupResInfo->pRows = NULL;
+    cleanupGroupResInfo(pGroupResInfo);
     return;
   }