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mdbx: refactor/refine cursor next/prev.

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Change-Id: I0bfe0fed62e137e933027ba90cec23dbf1a6310b
This commit is contained in:
Leonid Yuriev 2020-11-08 16:15:34 +03:00
parent 5f09ec73c9
commit 9a2dbb845c
1 changed files with 16 additions and 14 deletions
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30
src/core.c
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@ -11274,13 +11274,11 @@ static void mdbx_cursor_adjust(MDBX_cursor *mc, func) {
#endif #endif
/* Pop a page off the top of the cursor's stack. */ /* Pop a page off the top of the cursor's stack. */
static void mdbx_cursor_pop(MDBX_cursor *mc) { static __inline void mdbx_cursor_pop(MDBX_cursor *mc) {
if (mc->mc_snum) { if (mc->mc_snum) {
mdbx_debug("popped page %" PRIaPGNO " off db %d cursor %p", mdbx_debug("popped page %" PRIaPGNO " off db %d cursor %p",
mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *)mc); mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *)mc);
if (--mc->mc_snum) {
mc->mc_snum--;
if (mc->mc_snum) {
mc->mc_top--; mc->mc_top--;
} else { } else {
mc->mc_flags &= ~C_INITIALIZED; mc->mc_flags &= ~C_INITIALIZED;
@ -11290,7 +11288,7 @@ static void mdbx_cursor_pop(MDBX_cursor *mc) {
/* Push a page onto the top of the cursor's stack. /* Push a page onto the top of the cursor's stack.
* Set MDBX_TXN_ERROR on failure. */ * Set MDBX_TXN_ERROR on failure. */
static int mdbx_cursor_push(MDBX_cursor *mc, MDBX_page *mp) { static __inline int mdbx_cursor_push(MDBX_cursor *mc, MDBX_page *mp) {
mdbx_debug("pushing page %" PRIaPGNO " on db %d cursor %p", mp->mp_pgno, mdbx_debug("pushing page %" PRIaPGNO " on db %d cursor %p", mp->mp_pgno,
DDBI(mc), (void *)mc); DDBI(mc), (void *)mc);
@ -11809,7 +11807,7 @@ static int mdbx_cursor_sibling(MDBX_cursor *mc, int dir) {
if ((dir == SIBLING_RIGHT) if ((dir == SIBLING_RIGHT)
? (mc->mc_ki[mc->mc_top] + 1u >= page_numkeys(mc->mc_pg[mc->mc_top])) ? (mc->mc_ki[mc->mc_top] + 1u >= page_numkeys(mc->mc_pg[mc->mc_top]))
: (mc->mc_ki[mc->mc_top] == 0)) { : (mc->mc_ki[mc->mc_top] == 0)) {
mdbx_debug("no more keys left, moving to %s sibling", mdbx_debug("no more keys aside, moving to next %s sibling",
dir ? "right" : "left"); dir ? "right" : "left");
if (unlikely((rc = mdbx_cursor_sibling(mc, dir)) != MDBX_SUCCESS)) { if (unlikely((rc = mdbx_cursor_sibling(mc, dir)) != MDBX_SUCCESS)) {
/* undo cursor_pop before returning */ /* undo cursor_pop before returning */
@ -11837,9 +11835,9 @@ static int mdbx_cursor_sibling(MDBX_cursor *mc, int dir) {
rc = mdbx_cursor_push(mc, mp); rc = mdbx_cursor_push(mc, mp);
if (unlikely(rc != MDBX_SUCCESS)) if (unlikely(rc != MDBX_SUCCESS))
return rc; return rc;
if (dir == SIBLING_LEFT)
mc->mc_ki[mc->mc_top] = (indx_t)page_numkeys(mp) - 1;
mc->mc_ki[mc->mc_top] =
(indx_t)((dir == SIBLING_LEFT) ? page_numkeys(mp) - 1 : 0);
return MDBX_SUCCESS; return MDBX_SUCCESS;
} }
@ -11889,8 +11887,12 @@ static int mdbx_cursor_next(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,
goto skip; goto skip;
} }
if (++mc->mc_ki[mc->mc_top] >= page_numkeys(mp)) { int ki = mc->mc_ki[mc->mc_top];
mc->mc_ki[mc->mc_top] = (indx_t)++ki;
const int numkeys = page_numkeys(mp);
if (unlikely(ki >= numkeys)) {
mdbx_debug("%s", "=====> move to next sibling page"); mdbx_debug("%s", "=====> move to next sibling page");
mc->mc_ki[mc->mc_top] = numkeys - 1;
if (unlikely((rc = mdbx_cursor_sibling(mc, SIBLING_RIGHT)) != if (unlikely((rc = mdbx_cursor_sibling(mc, SIBLING_RIGHT)) !=
MDBX_SUCCESS)) { MDBX_SUCCESS)) {
mc->mc_flags |= C_EOF; mc->mc_flags |= C_EOF;
@ -11981,17 +11983,17 @@ static int mdbx_cursor_prev(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,
mc->mc_flags &= ~(C_EOF | C_DEL); mc->mc_flags &= ~(C_EOF | C_DEL);
if (mc->mc_ki[mc->mc_top] == 0) { int ki = mc->mc_ki[mc->mc_top];
mc->mc_ki[mc->mc_top] = (indx_t)--ki;
if (unlikely(ki < 0)) {
mc->mc_ki[mc->mc_top] = 0;
mdbx_debug("%s", "=====> move to prev sibling page"); mdbx_debug("%s", "=====> move to prev sibling page");
if ((rc = mdbx_cursor_sibling(mc, SIBLING_LEFT)) != MDBX_SUCCESS) if ((rc = mdbx_cursor_sibling(mc, SIBLING_LEFT)) != MDBX_SUCCESS)
return rc; return rc;
mp = mc->mc_pg[mc->mc_top]; mp = mc->mc_pg[mc->mc_top];
mc->mc_ki[mc->mc_top] = (indx_t)page_numkeys(mp) - 1;
mdbx_debug("prev page is %" PRIaPGNO ", key index %u", mp->mp_pgno, mdbx_debug("prev page is %" PRIaPGNO ", key index %u", mp->mp_pgno,
mc->mc_ki[mc->mc_top]); mc->mc_ki[mc->mc_top]);
} else }
mc->mc_ki[mc->mc_top]--;
mdbx_debug("==> cursor points to page %" PRIaPGNO mdbx_debug("==> cursor points to page %" PRIaPGNO
" with %u keys, key index %u", " with %u keys, key index %u",
mp->mp_pgno, page_numkeys(mp), mc->mc_ki[mc->mc_top]); mp->mp_pgno, page_numkeys(mp), mc->mc_ki[mc->mc_top]);