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mdbx: incremental/combined linear+binary search for dirty-pages list.

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Change-Id: I20f606a0a5d3729bfc92cb20c9db00cc1971d2ad
This commit is contained in:
Leonid Yuriev 2019-09-23 04:54:56 +03:00
parent f3a51be7ff
commit 3549744f40
1 changed files with 48 additions and 30 deletions
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78
src/elements/core.c
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@ -951,7 +951,7 @@ static int lcklist_detach_locked(MDBX_env *env) {
static __always_inline TYPE_LIST *NAME(TYPE_LIST *first, unsigned length, \
const TYPE_ARG item) { \
while (length > 3) { \
const size_t half = length >> 1; \
const unsigned half = length >> 1; \
TYPE_LIST *const middle = first + half; \
if (CMP(*middle, item)) { \
first = middle + 1; \
@ -1308,20 +1308,55 @@ static __inline MDBX_DPL mdbx_dpl_sort(MDBX_DPL dl) {
/* Returns the index of the first dirty-page whose pgno
* member is greater than or equal to id. */
#define DP_SEARCH_CMP(dp, id) ((dp).pgno < (id))
SEARCH_IMPL(dp_bsearch, MDBX_DP, pgno_t, DP_SEARCH_CMP)
static unsigned __hot mdbx_dpl_search(MDBX_DPL dl, pgno_t id) {
if (dl->sorted < dl->length) {
/* unsorted tail case */
#if MDBX_DEBUG
for (const MDBX_DP *ptr = dl + dl->sorted; --ptr > dl;)
assert(ptr[0].pgno < ptr[1].pgno);
for (const MDBX_DP *ptr = dl + dl->sorted; --ptr > dl;) {
assert(ptr[0].pgno < ptr[1].pgno);
assert(ptr[0].pgno >= NUM_METAS);
}
#endif
dl = mdbx_dpl_sort(dl);
/* binary search of id in array
* 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 = dl->length;
/* try linear search until the threshold */
if (dl->length - dl->sorted < SORT_THRESHOLD / 2) {
unsigned i = dl->length;
while (i - dl->sorted > 7) {
if (dl[i].pgno == id)
return i;
if (dl[i - 1].pgno == id)
return i - 1;
if (dl[i - 2].pgno == id)
return i - 2;
if (dl[i - 3].pgno == id)
return i - 3;
if (dl[i - 4].pgno == id)
return i - 4;
if (dl[i - 5].pgno == id)
return i - 5;
if (dl[i - 6].pgno == id)
return i - 6;
if (dl[i - 7].pgno == id)
return i - 7;
i -= 8;
}
while (i > dl->sorted) {
if (dl[i].pgno == id)
return i;
--i;
}
MDBX_DPL it = dp_bsearch(dl + 1, i, id);
return (unsigned)(it - dl);
}
/* sort a whole */
dl->sorted = dl->length;
dp_sort(dl + 1, dl + dl->length + 1);
}
#if MDBX_DEBUG
for (const MDBX_DP *ptr = dl + dl->length; --ptr > dl;) {
@ -1330,25 +1365,8 @@ static unsigned __hot mdbx_dpl_search(MDBX_DPL dl, pgno_t id) {
}
#endif
while (n > 0) {
unsigned pivot = n >> 1;
cursor = base + pivot + 1;
val = mdbx_cmp2int(id, dl[cursor].pgno);
if (val < 0) {
n = pivot;
} else if (val > 0) {
base = cursor;
n -= pivot + 1;
} else {
return cursor;
}
}
if (val > 0)
++cursor;
return cursor;
MDBX_DPL it = dp_bsearch(dl + 1, dl->length, id);
return (unsigned)(it - dl);
}
static __inline MDBX_page *mdbx_dpl_find(MDBX_DPL dl, pgno_t id) {