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

refact more TDB

This commit is contained in:
Hongze Cheng 2022-03-30 08:01:49 +00:00
parent cbd0d74d51
commit 75a0216a00
1 changed files with 128 additions and 102 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

228
source/libs/tdb/src/db/tdbBtree.c
View File

@ -988,105 +988,6 @@ int tdbBtcOpen(SBTC *pBtc, SBTree *pBt) {
return 0; return 0;
} }
static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) {
int ret;
SBTree *pBt;
SPager *pPager;
pBt = pBtc->pBt;
pPager = pBt->pPager;
if (pBtc->iPage < 0) {
ASSERT(pBtc->iPage == -1);
ASSERT(pBtc->idx == -1);
// Move from the root
ret = tdbPagerFetchPage(pPager, pBt->root, &(pBtc->pPage), tdbBtreeInitPage, pBt);
if (ret < 0) {
ASSERT(0);
return -1;
}
pBtc->iPage = 0;
if (TDB_PAGE_TOTAL_CELLS(pBtc->pPage) == 0) {
// Current page is empty
// ASSERT(TDB_FLAG_IS(TDB_PAGE_FLAGS(pBtc->pPage), TDB_BTREE_ROOT | TDB_BTREE_LEAF));
return 0;
}
for (;;) {
int lidx, ridx, midx, c, nCells;
SCell *pCell;
SPage *pPage;
SCellDecoder cd = {0};
pPage = pBtc->pPage;
nCells = TDB_PAGE_TOTAL_CELLS(pPage);
lidx = 0;
ridx = nCells - 1;
ASSERT(nCells > 0);
for (;;) {
if (lidx > ridx) break;
midx = (lidx + ridx) >> 1;
pCell = tdbPageGetCell(pPage, midx);
ret = tdbBtreeDecodeCell(pPage, pCell, &cd);
if (ret < 0) {
// TODO: handle error
ASSERT(0);
return -1;
}
// Compare the key values
c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
if (c < 0) {
/* input-key < cell-key */
ridx = midx - 1;
} else if (c > 0) {
/* input-key > cell-key */
lidx = midx + 1;
} else {
/* input-key == cell-key */
break;
}
}
// Move downward or break
u8 leaf = TDB_BTREE_PAGE_IS_LEAF(pPage);
if (leaf) {
pBtc->idx = midx;
*pCRst = c;
break;
} else {
if (c <= 0) {
pBtc->idx = midx;
tdbBtcMoveDownward(pBtc, cd.pgno);
} else {
pBtc->idx = midx + 1;
if (midx == nCells - 1) {
/* Move to right-most child */
tdbBtcMoveDownward(pBtc, ((SIntHdr *)pBtc->pPage->pData)->pgno);
} else {
pCell = tdbPageGetCell(pPage, pBtc->idx);
tdbBtreeDecodeCell(pPage, pCell, &cd);
tdbBtcMoveDownward(pBtc, cd.pgno);
}
}
}
}
} else {
// TODO: Move the cursor from a some position instead of a clear state
ASSERT(0);
}
return 0;
}
int tdbBtcMoveToFirst(SBTC *pBtc) { int tdbBtcMoveToFirst(SBTC *pBtc) {
int ret; int ret;
SBTree *pBt; SBTree *pBt;
@ -1105,11 +1006,36 @@ int tdbBtcMoveToFirst(SBTC *pBtc) {
return -1; return -1;
} }
ASSERT(TDB_BTREE_PAGE_IS_ROOT(pBtc->pPage));
pBtc->iPage = 0; pBtc->iPage = 0;
if (TDB_PAGE_TOTAL_CELLS(pBtc->pPage) > 0) {
pBtc->idx = 0; pBtc->idx = 0;
} else {
// no any data, point is invalid
ASSERT(TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage));
pBtc->idx = -1;
return 0;
}
} else { } else {
// move from a position // move from a position
ASSERT(0); int iPage = 0;
for (; iPage < pBtc->iPage; iPage++) {
ASSERT(pBtc->idxStack[iPage] >= 0);
if (pBtc->idxStack[iPage]) break;
}
// move upward
for (;;) {
if (pBtc->iPage == 0) {
pBtc->idx = 0;
break;
}
if (pBtc->iPage < iPage) break;
tdbBtcMoveUpward(pBtc);
}
} }
// move downward // move downward
@ -1284,6 +1210,7 @@ static int tdbBtcMoveDownward(SBTC *pBtc, SPgno pgno) {
ret = tdbPagerFetchPage(pBtc->pBt->pPager, pgno, &pBtc->pPage, tdbBtreeInitPage, pBtc->pBt); ret = tdbPagerFetchPage(pBtc->pBt->pPager, pgno, &pBtc->pPage, tdbBtreeInitPage, pBtc->pBt);
if (ret < 0) { if (ret < 0) {
ASSERT(0); ASSERT(0);
return -1;
} }
return 0; return 0;
@ -1292,7 +1219,7 @@ static int tdbBtcMoveDownward(SBTC *pBtc, SPgno pgno) {
static int tdbBtcMoveUpward(SBTC *pBtc) { static int tdbBtcMoveUpward(SBTC *pBtc) {
if (pBtc->iPage == 0) return -1; if (pBtc->iPage == 0) return -1;
// tdbPagerReturnPage(pBtc->pBt->pPager, pBtc->pPage); tdbPagerReturnPage(pBtc->pBt->pPager, pBtc->pPage);
pBtc->iPage--; pBtc->iPage--;
pBtc->pPage = pBtc->pgStack[pBtc->iPage]; pBtc->pPage = pBtc->pgStack[pBtc->iPage];
@ -1301,6 +1228,105 @@ static int tdbBtcMoveUpward(SBTC *pBtc) {
return 0; return 0;
} }
static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) {
int ret;
SBTree *pBt;
SPager *pPager;
pBt = pBtc->pBt;
pPager = pBt->pPager;
if (pBtc->iPage < 0) {
ASSERT(pBtc->iPage == -1);
ASSERT(pBtc->idx == -1);
// Move from the root
ret = tdbPagerFetchPage(pPager, pBt->root, &(pBtc->pPage), tdbBtreeInitPage, pBt);
if (ret < 0) {
ASSERT(0);
return -1;
}
pBtc->iPage = 0;
if (TDB_PAGE_TOTAL_CELLS(pBtc->pPage) == 0) {
// Current page is empty
// ASSERT(TDB_FLAG_IS(TDB_PAGE_FLAGS(pBtc->pPage), TDB_BTREE_ROOT | TDB_BTREE_LEAF));
return 0;
}
for (;;) {
int lidx, ridx, midx, c, nCells;
SCell *pCell;
SPage *pPage;
SCellDecoder cd = {0};
pPage = pBtc->pPage;
nCells = TDB_PAGE_TOTAL_CELLS(pPage);
lidx = 0;
ridx = nCells - 1;
ASSERT(nCells > 0);
for (;;) {
if (lidx > ridx) break;
midx = (lidx + ridx) >> 1;
pCell = tdbPageGetCell(pPage, midx);
ret = tdbBtreeDecodeCell(pPage, pCell, &cd);
if (ret < 0) {
// TODO: handle error
ASSERT(0);
return -1;
}
// Compare the key values
c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
if (c < 0) {
/* input-key < cell-key */
ridx = midx - 1;
} else if (c > 0) {
/* input-key > cell-key */
lidx = midx + 1;
} else {
/* input-key == cell-key */
break;
}
}
// Move downward or break
u8 leaf = TDB_BTREE_PAGE_IS_LEAF(pPage);
if (leaf) {
pBtc->idx = midx;
*pCRst = c;
break;
} else {
if (c <= 0) {
pBtc->idx = midx;
tdbBtcMoveDownward(pBtc, cd.pgno);
} else {
pBtc->idx = midx + 1;
if (midx == nCells - 1) {
/* Move to right-most child */
tdbBtcMoveDownward(pBtc, ((SIntHdr *)pBtc->pPage->pData)->pgno);
} else {
pCell = tdbPageGetCell(pPage, pBtc->idx);
tdbBtreeDecodeCell(pPage, pCell, &cd);
tdbBtcMoveDownward(pBtc, cd.pgno);
}
}
}
}
} else {
// TODO: Move the cursor from a some position instead of a clear state
ASSERT(0);
}
return 0;
}
int tdbBtcClose(SBTC *pBtc) { int tdbBtcClose(SBTC *pBtc) {
if (pBtc->iPage < 0) return 0; if (pBtc->iPage < 0) return 0;