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more TDB

This commit is contained in:
Hongze Cheng 2022-03-31 03:55:46 +00:00
parent 7f08a2b7c3
commit 839912e4f5
1 changed files with 64 additions and 68 deletions
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46
source/libs/tdb/src/db/tdbBtree.c
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@ -1276,35 +1276,35 @@ static int tdbBtcMoveUpward(SBTC *pBtc) {
static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) { static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) {
int ret; int ret;
SBTree *pBt; SBTree *pBt;
SCell *pCell;
SPager *pPager; SPager *pPager;
SCellDecoder cd = {0};
pBt = pBtc->pBt; pBt = pBtc->pBt;
pPager = pBt->pPager; pPager = pBt->pPager;
if (pBtc->iPage < 0) { if (pBtc->iPage < 0) {
ASSERT(pBtc->iPage == -1); // move from a clear cursor
ASSERT(pBtc->idx == -1);
// Move from the root
ret = tdbPagerFetchPage(pPager, pBt->root, &(pBtc->pPage), tdbBtreeInitPage, pBt); ret = tdbPagerFetchPage(pPager, pBt->root, &(pBtc->pPage), tdbBtreeInitPage, pBt);
if (ret < 0) { if (ret < 0) {
// TODO
ASSERT(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; return 0;
} }
pBtc->iPage = 0;
pBtc->idx = -1;
// for empty tree, just return with an invalid position
if (TDB_PAGE_TOTAL_CELLS(pBtc->pPage) == 0) return 0;
} else {
// move upward to a page that the search key is in the range
ASSERT(0);
}
// search downward to the leaf
for (;;) { for (;;) {
int lidx, ridx, midx, c, nCells; int lidx, ridx, midx, c, nCells;
SCell *pCell;
SPage *pPage; SPage *pPage;
SCellDecoder cd = {0};
pPage = pBtc->pPage; pPage = pBtc->pPage;
nCells = TDB_PAGE_TOTAL_CELLS(pPage); nCells = TDB_PAGE_TOTAL_CELLS(pPage);
@ -1312,7 +1312,9 @@ static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) {
ridx = nCells - 1; ridx = nCells - 1;
ASSERT(nCells > 0); ASSERT(nCells > 0);
ASSERT(pBtc->idx == -1);
// binary search
for (;;) { for (;;) {
if (lidx > ridx) break; if (lidx > ridx) break;
@ -1329,20 +1331,19 @@ static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) {
// Compare the key values // Compare the key values
c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen); c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
if (c < 0) { if (c < 0) {
/* input-key < cell-key */ // pKey < cd.pKey
ridx = midx - 1; ridx = midx - 1;
} else if (c > 0) { } else if (c > 0) {
/* input-key > cell-key */ // pKey > cd.pKey
lidx = midx + 1; lidx = midx + 1;
} else { } else {
/* input-key == cell-key */ // pKey == cd.pKey
break; break;
} }
} }
// Move downward or break // keep search downward or break
u8 leaf = TDB_BTREE_PAGE_IS_LEAF(pPage); if (TDB_BTREE_PAGE_IS_LEAF(pPage)) {
if (leaf) {
pBtc->idx = midx; pBtc->idx = midx;
*pCRst = c; *pCRst = c;
break; break;
@ -1356,11 +1357,6 @@ static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) {
} }
} }
} else {
// TODO: Move the cursor from a some position instead of a clear state
ASSERT(0);
}
return 0; return 0;
} }