From c0a0e075978224f6fd39c3c2263aec79f5466015 Mon Sep 17 00:00:00 2001
From: Minglei Jin <mljin@taosdata.com>
Date: Tue, 1 Aug 2023 16:02:09 +0800
Subject: [PATCH] cache/read: lazy init uidList when laoding from tsdb

---
 source/dnode/vnode/src/tsdb/tsdbCache.c     | 29 ++++++++++++++++++++-
 source/dnode/vnode/src/tsdb/tsdbCacheRead.c | 23 ----------------
 2 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/source/dnode/vnode/src/tsdb/tsdbCache.c b/source/dnode/vnode/src/tsdb/tsdbCache.c
index 5a384c6bb5..62c61dd397 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCache.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCache.c
@@ -1615,10 +1615,37 @@ static STableLoadInfo *getTableLoadInfo(SCacheRowsReader *pReader, uint64_t uid)
   return pInfo;
 }
 
+static int32_t uidComparFunc(const void *p1, const void *p2) {
+  uint64_t pu1 = *(uint64_t *)p1;
+  uint64_t pu2 = *(uint64_t *)p2;
+  if (pu1 == pu2) {
+    return 0;
+  } else {
+    return (pu1 < pu2) ? -1 : 1;
+  }
+}
+
+static uint64_t *getUidList(SCacheRowsReader *pReader) {
+  if (!pReader->uidList) {
+    int32_t numOfTables = pReader->numOfTables;
+
+    pReader->uidList = taosMemoryMalloc(numOfTables * sizeof(uint64_t));
+
+    for (int32_t i = 0; i < numOfTables; ++i) {
+      uint64_t uid = pReader->pTableList[i].uid;
+      pReader->uidList[i] = uid;
+    }
+
+    taosSort(pReader->uidList, numOfTables, sizeof(uint64_t), uidComparFunc);
+  }
+
+  return pReader->uidList;
+}
+
 static int32_t loadTombFromBlk(const TTombBlkArray *pTombBlkArray, SCacheRowsReader *pReader, void *pFileReader,
                                bool isFile) {
   int32_t   code = 0;
-  uint64_t *uidList = pReader->uidList;
+  uint64_t *uidList = getUidList(pReader);
   int32_t   numOfTables = pReader->numOfTables;
   int64_t   suid = pReader->info.suid;
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
index eb899fb82c..d51305f446 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCacheRead.c
@@ -133,16 +133,6 @@ int32_t tsdbReuseCacherowsReader(void* reader, void* pTableIdList, int32_t numOf
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t uidComparFunc(const void* p1, const void* p2) {
-  uint64_t pu1 = *(uint64_t*)p1;
-  uint64_t pu2 = *(uint64_t*)p2;
-  if (pu1 == pu2) {
-    return 0;
-  } else {
-    return (pu1 < pu2) ? -1 : 1;
-  }
-}
-
 int32_t tsdbCacherowsReaderOpen(void* pVnode, int32_t type, void* pTableIdList, int32_t numOfTables, int32_t numOfCols,
                                 SArray* pCidList, int32_t* pSlotIds, uint64_t suid, void** pReader, const char* idstr) {
   *pReader = NULL;
@@ -168,19 +158,6 @@ int32_t tsdbCacherowsReaderOpen(void* pVnode, int32_t type, void* pTableIdList,
   p->pTableList = pTableIdList;
   p->numOfTables = numOfTables;
 
-  p->uidList = taosMemoryMalloc(numOfTables * sizeof(uint64_t));
-  if (p->uidList == NULL) {
-    tsdbCacherowsReaderClose(p);
-    return TSDB_CODE_OUT_OF_MEMORY;
-  }
-
-  for (int32_t i = 0; i < numOfTables; ++i) {
-    uint64_t uid = p->pTableList[i].uid;
-    p->uidList[i] = uid;
-  }
-
-  taosSort(p->uidList, numOfTables, sizeof(uint64_t), uidComparFunc);
-
   int32_t code = setTableSchema(p, suid, idstr);
   if (code != TSDB_CODE_SUCCESS) {
     tsdbCacherowsReaderClose(p);