xxq250
/
homework-jianmu
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

more TDB

This commit is contained in:
Hongze Cheng 2022-03-22 02:08:56 +00:00
parent 9250047702
commit e2f1434bf2
1 changed files with 34 additions and 74 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

108
source/libs/tdb/src/db/tdbBtree.c
View File

@ -688,26 +688,33 @@ static int tdbBtreeBalanceNonRoot(SBTree *pBt, SPage *pParent, int idx) {
} }
int nNews = 0; int nNews = 0;
int cntNews[5] = {0}; // TODO: maybe 5 is not enough struct {
int szNews[5] = {0}; int cnt;
int size;
int oPage;
int oIdx;
} infoNews[5] = {0};
{ // Get how many new pages are needed and the new distribution { // Get how many new pages are needed and the new distribution
// loop to find number of pages needed // first loop to find minimum number of pages needed
for (int i = 0; i < nOlds; i++) { for (int oPage = 0; oPage < nOlds; oPage++) {
SPage *pPage = pOlds[i]; SPage *pPage = pOlds[oPage];
SCell *pCell; SCell *pCell;
int cellBytes; int cellBytes;
for (int cIdx = 0; cIdx < TDB_PAGE_TOTAL_CELLS(pPage); cIdx++) { for (int oIdx = 0; oIdx < TDB_PAGE_TOTAL_CELLS(pPage); oIdx++) {
pCell = tdbPageGetCell(pPage, cIdx); pCell = tdbPageGetCell(pPage, oIdx);
cellBytes = TDB_BYTES_CELL_TAKEN(pPage, pCell); cellBytes = TDB_BYTES_CELL_TAKEN(pPage, pCell);
if (szNews[nNews] + cellBytes > TDB_PAGE_USABLE_SIZE(pPage)) { if (infoNews[nNews].size + cellBytes > TDB_PAGE_USABLE_SIZE(pPage)) {
// page is full, use a new page
nNews++; nNews++;
} }
cntNews[nNews]++; infoNews[nNews].cnt++;
szNews[nNews] = szNews[nNews] + cellBytes; infoNews[nNews].size += cellBytes;
infoNews[nNews].oPage = oPage;
infoNews[nNews].oIdx = oIdx;
} }
} }
@ -715,85 +722,38 @@ static int tdbBtreeBalanceNonRoot(SBTree *pBt, SPage *pParent, int idx) {
// back loop to make the distribution even // back loop to make the distribution even
for (int iNew = nNews - 1; iNew > 0; iNew--) { for (int iNew = nNews - 1; iNew > 0; iNew--) {
// TODO: find the last cell of page (iNew-1)
int cIdx;
int iPage;
int cellBytes;
SPage *pPage;
SCell *pCell; SCell *pCell;
SPage *pPage;
int cellBytes;
for (;;) { for (;;) {
pCell = tdbPageGetCell(pPage, cIdx); pPage = pOlds[infoNews[iNew - 1].oPage];
pCell = tdbPageGetCell(pPage, infoNews[iNew - 1].oIdx);
cellBytes = TDB_BYTES_CELL_TAKEN(pPage, pCell); cellBytes = TDB_BYTES_CELL_TAKEN(pPage, pCell);
if (szNews[iNew] + cellBytes >= szNews[iNew - 1] + cellBytes) { infoNews[iNew].cnt++;
break; infoNews[iNew].size += cellBytes;
infoNews[iNew - 1].cnt--;
infoNews[iNew - 1].size -= cellBytes;
if ((infoNews[iNew - 1].oIdx--) == 0) {
infoNews[iNew - 1].oPage--;
infoNews[iNew - 1].oIdx = TDB_PAGE_TOTAL_CELLS(pOlds[infoNews[iNew - 1].oPage]);
} }
// Move the cell right if (infoNews[iNew].size > infoNews[iNew - 1].size) {
szNews[iNew] += cellBytes; break;
cntNews[iNew]++;
szNews[iNew - 1] -= cellBytes;
cntNews[iNew - 1]++;
cIdx--;
if (cIdx < 0) {
pPage = pOlds[--iPage];
cIdx = TDB_PAGE_TOTAL_CELLS(pPage) - 1;
} }
} }
} }
int k = 0;
} }
SPage *pNews[5]; SPage *pNews[5];
{ // Allocate the new pages {
// Allocate the new pages
} }
#if 0
// Step 1: find two sibling pages and get engough info about the old pages
ret = tdbBtreeBalanceStep1(&blh);
if (ret < 0) {
ASSERT(0);
return -1;
}
// Step 2: Load all cells on the old page and the divider cells
ret = tdbBtreeBalanceStep2(&blh);
if (ret < 0) {
ASSERT(0);
return -1;
}
// Step 3: Get the number of pages needed to hold all cells
ret = tdbBtreeBalanceStep3(&blh);
if (ret < 0) {
ASSERT(0);
return -1;
}
// Step 4: Allocate enough new pages. Reuse old pages as much as possible
ret = tdbBtreeBalanceStep4(&blh);
if (ret < 0) {
ASSERT(0);
return -1;
}
// Step 5: Insert new divider cells into pParent
ret = tdbBtreeBalanceStep5(&blh);
if (ret < 0) {
ASSERT(0);
return -1;
}
// Step 6: Update the sibling pages
ret = tdbBtreeBalanceStep6(&blh);
if (ret < 0) {
ASSERT(0);
return -1;
}
#endif
{ {
// TODO: Reset states // TODO: Reset states
} }