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mdbx: rewrite internal bsearch for pages-lists.

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Change-Id: I77615a2146d83d4304c05c3bafb8bfc89a1a4fd0
This commit is contained in:
Leonid Yuriev 2019-09-23 00:38:31 +03:00
parent aceab9be44
commit f3a51be7ff
1 changed files with 50 additions and 31 deletions
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81
src/elements/core.c
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@ -944,6 +944,42 @@ static int lcklist_detach_locked(MDBX_env *env) {
SORT_SHELLPASS(TYPE, CMP, begin, end, 1); \
}
/*------------------------------------------------------------------------------
* LY: Binary search */
#define SEARCH_IMPL(NAME, TYPE_LIST, TYPE_ARG, CMP) \
static __always_inline TYPE_LIST *NAME(TYPE_LIST *first, unsigned length, \
const TYPE_ARG item) { \
while (length > 3) { \
const size_t half = length >> 1; \
TYPE_LIST *const middle = first + half; \
if (CMP(*middle, item)) { \
first = middle + 1; \
length -= half + 1; \
} else \
length = half; \
} \
\
switch (length) { \
case 3: \
if (!CMP(*first, item)) \
break; \
++first; \
/* fall through */ \
__fallthrough; \
case 2: \
if (!CMP(*first, item)) \
break; \
++first; \
/* fall through */ \
__fallthrough; \
case 1: \
if (CMP(*first, item)) \
++first; \
} \
return first; \
}
/*----------------------------------------------------------------------------*/
static __inline size_t pnl2bytes(const size_t size) {
@ -1132,37 +1168,19 @@ static __hot void mdbx_pnl_sort(MDBX_PNL pnl) {
* [in] pl The PNL to search.
* [in] id The ID to search for.
* Returns The index of the first ID greater than or equal to id. */
static unsigned __hot mdbx_pnl_search(MDBX_PNL pnl, pgno_t id) {
SEARCH_IMPL(pgno_bsearch, pgno_t, pgno_t, MDBX_PNL_ORDERED)
static __noinline __hot unsigned mdbx_pnl_search(MDBX_PNL pnl, pgno_t id) {
assert(mdbx_pnl_check(pnl, true));
/* binary search of id in pl
* if found, returns position of id
* if not found, returns first position greater than id */
unsigned base = 0;
unsigned cursor = 1;
int val = 0;
unsigned n = MDBX_PNL_SIZE(pnl);
while (n > 0) {
unsigned pivot = n >> 1;
cursor = base + pivot + 1;
val = MDBX_PNL_ASCENDING ? mdbx_cmp2int(id, pnl[cursor])
: mdbx_cmp2int(pnl[cursor], id);
if (val < 0) {
n = pivot;
} else if (val > 0) {
base = cursor;
n -= pivot + 1;
} else {
return cursor;
}
}
if (val > 0)
++cursor;
return cursor;
pgno_t *begin = MDBX_PNL_BEGIN(pnl);
pgno_t *it = pgno_bsearch(begin, MDBX_PNL_SIZE(pnl), id);
pgno_t *end = begin + MDBX_PNL_SIZE(pnl);
assert(it >= begin && it <= end);
if (it != begin)
assert(it[-1] < id);
if (it != end)
assert(it[0] >= id);
return (unsigned)(it - begin);
}
/*----------------------------------------------------------------------------*/
@ -8896,7 +8914,8 @@ int mdbx_cursor_get(MDBX_cursor *mc, MDBX_val *key, MDBX_val *data,
return MDBX_EINVAL;
if (unlikely(mc->mc_xcursor == NULL))
return MDBX_INCOMPATIBLE;
/* FALLTHRU */
/* fall through */
__fallthrough;
case MDBX_SET:
case MDBX_SET_KEY:
case MDBX_SET_RANGE: