From b8954ae1c5036a91293b385c80fc69501a8e5e82 Mon Sep 17 00:00:00 2001
From: Hongze Cheng <hzcheng@taosdata.com>
Date: Mon, 21 Mar 2022 07:55:56 +0000
Subject: [PATCH] more TDB

---
 source/libs/tdb/src/db/tdbBtree.c  | 28 +---------------------------
 source/libs/tdb/src/page/tdbPage.c | 12 ++++++++++++
 2 files changed, 13 insertions(+), 27 deletions(-)

diff --git a/source/libs/tdb/src/db/tdbBtree.c b/source/libs/tdb/src/db/tdbBtree.c
index 4c7cddf311..9e6ea91a4c 100644
--- a/source/libs/tdb/src/db/tdbBtree.c
+++ b/source/libs/tdb/src/db/tdbBtree.c
@@ -462,29 +462,6 @@ typedef struct {
   SPage  *pNewPages[5];
 } SBtreeBalanceHelper;
 
-static int tdbBtreeCopyPageContent(SPage *pFrom, SPage *pTo) {
-#if 0
-  int nCells = TDB_PAGE_TOTAL_CELLS(pFrom);
-  int cCells = TDB_PAGE_CCELLS(pFrom);
-  int fCell = TDB_PAGE_FCELL(pFrom);
-  int nFree = TDB_PAGE_NFREE(pFrom);
-
-  pTo->pFreeStart = pTo->pCellIdx + nCells * pFrom->pPageMethods->szOffset;
-  memcpy(pTo->pCellIdx, pFrom->pCellIdx, nCells * pFrom->pPageMethods->szOffset);
-  pTo->pFreeEnd = (u8 *)pTo->pPageFtr - (u8 *)(pFrom->pPageFtr) + pFrom->pFreeEnd;
-  memcpy(pTo->pFreeEnd, pFrom->pFreeEnd, (u8 *)pFrom->pPageFtr - pFrom->pFreeEnd);
-
-  TDB_PAGE_NCELLS_SET(pTo, nCells);
-  TDB_PAGE_CCELLS_SET(pTo, cCells);
-  TDB_PAGE_FCELL_SET(pTo, fCell);
-  TDB_PAGE_NFREE_SET(pTo, nFree);
-
-  // TODO: update other fields
-#endif
-
-  return 0;
-}
-
 static int tdbBtreeBalanceDeeper(SBTree *pBt, SPage *pRoot, SPage **ppChild) {
   SPager           *pPager;
   SPage            *pChild;
@@ -503,10 +480,7 @@ static int tdbBtreeBalanceDeeper(SBTree *pBt, SPage *pRoot, SPage **ppChild) {
   }
 
   // Copy the root page content to the child page
-  ret = tdbBtreeCopyPageContent(pRoot, pChild);
-  if (ret < 0) {
-    return -1;
-  }
+  tdbPageCopy(pRoot, pChild);
 
   pChild->nOverflow = pRoot->nOverflow;
   for (int i = 0; i < pChild->nOverflow; i++) {
diff --git a/source/libs/tdb/src/page/tdbPage.c b/source/libs/tdb/src/page/tdbPage.c
index c3fec25d81..803bf168cf 100644
--- a/source/libs/tdb/src/page/tdbPage.c
+++ b/source/libs/tdb/src/page/tdbPage.c
@@ -208,6 +208,8 @@ int tdbPageDropCell(SPage *pPage, int idx) {
 }
 
 void tdbPageCopy(SPage *pFromPage, SPage *pToPage) {
+  int delta, nFree;
+
   pToPage->pFreeStart = pToPage->pPageHdr + (pFromPage->pFreeStart - pFromPage->pPageHdr);
   pToPage->pFreeEnd = (u8 *)(pToPage->pPageFtr) - ((u8 *)pFromPage->pPageFtr - pFromPage->pFreeEnd);
 
@@ -215,6 +217,16 @@ void tdbPageCopy(SPage *pFromPage, SPage *pToPage) {
 
   memcpy(pToPage->pPageHdr, pFromPage->pPageHdr, pFromPage->pFreeStart - pFromPage->pPageHdr);
   memcpy(pToPage->pFreeEnd, pFromPage->pFreeEnd, (u8 *)pFromPage->pPageFtr - pFromPage->pFreeEnd);
+
+  ASSERT(TDB_PAGE_CCELLS(pToPage) == pToPage->pFreeEnd - pToPage->pData);
+
+  delta = (pToPage->pPageHdr - pToPage->pAmHdr) - (pFromPage->pPageHdr - pFromPage->pAmHdr);
+  if (delta != 0) {
+    nFree = TDB_PAGE_NFREE(pFromPage);
+    TDB_PAGE_NFREE_SET(pToPage, nFree - delta);
+  }
+
+  // TODO: do we need to copy the overflow part ???
 }
 
 static int tdbPageAllocate(SPage *pPage, int szCell, SCell **ppCell) {