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mdbx: radix sort for large chunks of PNL and DPL.

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More for https://github.com/erthink/libmdbx/issues/132

Change-Id: I19b253f78069d4ecd4ec360a12121c78f182fc09
This commit is contained in:
Leonid Yuriev 2021-02-01 01:50:27 +03:00
parent 88bdf4b96f
commit 25c4df0d3e
3 changed files with 110 additions and 31 deletions
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1
.github/actions/spelling/expect.txt vendored
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@ -1304,6 +1304,7 @@ quanah
quicksort
Quinteiro
qwest
radixsort
radvisory
RAII
ramdev

139
src/core.c
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@ -2686,6 +2686,68 @@ static int lcklist_detach_locked(MDBX_env *env) {
} \
}
/*------------------------------------------------------------------------------
* LY: radix sort for large chunks */
#define RADIXSORT_IMPL(NAME, TYPE, EXTRACT_KEY) \
\
__hot static bool NAME##_radixsort(TYPE *const begin, \
const unsigned length) { \
TYPE *tmp = mdbx_malloc(sizeof(TYPE) * length); \
if (unlikely(!tmp)) \
return false; \
\
unsigned key_shift = 0, key_diff_mask; \
do { \
struct { \
unsigned a[256], b[256]; \
} counters; \
memset(&counters, 0, sizeof(counters)); \
\
key_diff_mask = 0; \
unsigned prev_key = EXTRACT_KEY(begin) >> key_shift; \
TYPE *r = begin, *end = begin + length; \
do { \
const unsigned key = EXTRACT_KEY(r) >> key_shift; \
counters.a[key & 255]++; \
counters.b[(key >> 8) & 255]++; \
key_diff_mask |= prev_key ^ key; \
prev_key = key; \
} while (++r != end); \
\
unsigned ta = 0, tb = 0; \
for (unsigned i = 0; i < 256; ++i) { \
const unsigned ia = counters.a[i]; \
counters.a[i] = ta; \
ta += ia; \
const unsigned ib = counters.b[i]; \
counters.b[i] = tb; \
tb += ib; \
} \
\
r = begin; \
do { \
const unsigned key = EXTRACT_KEY(r) >> key_shift; \
tmp[counters.a[key & 255]++] = *r; \
} while (++r != end); \
\
if (unlikely(key_diff_mask < 256)) { \
memcpy(begin, tmp, (char *)end - (char *)begin); \
break; \
} \
end = (r = tmp) + length; \
do { \
const unsigned key = EXTRACT_KEY(r) >> key_shift; \
begin[counters.b[(key >> 8) & 255]++] = *r; \
} while (++r != end); \
\
key_shift += 16; \
} while (key_diff_mask >> 16); \
\
mdbx_free(tmp); \
return true; \
}
/*------------------------------------------------------------------------------
* LY: Binary search */
@ -2995,9 +3057,18 @@ static MDBX_PNL mdbx_spill_purge(MDBX_txn *txn) {
return sl;
}
#if MDBX_PNL_ASCENDING
#define MDBX_PNL_EXTRACT_KEY(ptr) (*(ptr))
#else
#define MDBX_PNL_EXTRACT_KEY(ptr) (P_INVALID - *(ptr))
#endif
RADIXSORT_IMPL(pgno, pgno_t, MDBX_PNL_EXTRACT_KEY)
SORT_IMPL(pgno_sort, false, pgno_t, MDBX_PNL_ORDERED)
static __hot void mdbx_pnl_sort(MDBX_PNL pnl) {
pgno_sort(MDBX_PNL_BEGIN(pnl), MDBX_PNL_END(pnl));
if (likely(MDBX_PNL_SIZE(pnl) < MDBX_PNL_RADIXSORT_THRESHOLD) ||
!pgno_radixsort(&MDBX_PNL_FIRST(pnl), MDBX_PNL_SIZE(pnl)))
pgno_sort(MDBX_PNL_BEGIN(pnl), MDBX_PNL_END(pnl));
assert(mdbx_pnl_check(pnl, MAX_PAGENO + 1));
}
@ -3229,41 +3300,47 @@ static int mdbx_dpl_alloc(MDBX_txn *txn) {
return MDBX_SUCCESS;
}
#define MDBX_DPL_EXTRACT_KEY(ptr) ((ptr)->pgno)
RADIXSORT_IMPL(dpl, MDBX_dp, MDBX_DPL_EXTRACT_KEY)
#define DP_SORT_CMP(first, last) ((first).pgno < (last).pgno)
SORT_IMPL(dp_sort, false, MDBX_dp, DP_SORT_CMP)
__hot static MDBX_dpl *mdbx_dpl_sort_slowpath(MDBX_dpl *dl) {
const unsigned unsorted = dl->length - dl->sorted;
if (dl->sorted > unsorted / 4 + 4 &&
dl->length + unsorted < dl->detent + MDBX_DPL_GAP_FOR_MERGESORT) {
MDBX_dp *const sorted_begin = dl->items + 1;
MDBX_dp *const sorted_end = sorted_begin + dl->sorted;
MDBX_dp *const end = dl->items + dl->detent + MDBX_DPL_RESERVE_GAP;
MDBX_dp *const tmp = end - unsorted;
assert(dl->items + dl->length + 1 < tmp);
/* copy unsorted to the end of allocated space and sort it */
memcpy(tmp, sorted_end, unsorted * sizeof(MDBX_dp));
dp_sort(tmp, tmp + unsorted);
/* merge two parts from end to begin */
MDBX_dp *w = dl->items + dl->length;
MDBX_dp *l = dl->items + dl->sorted;
MDBX_dp *r = end - 1;
do {
const bool cmp = l->pgno > r->pgno;
*w = cmp ? *l : *r;
l -= cmp;
r -= !cmp;
} while (likely(--w > l));
assert(r == tmp - 1);
assert(dl->items[0].pgno == 0 &&
dl->items[dl->length + 1].pgno == P_INVALID);
if (mdbx_assert_enabled())
for (unsigned i = 0; i <= dl->length; ++i)
assert(dl->items[i].pgno < dl->items[i + 1].pgno);
} else {
dp_sort(dl->items + 1, dl->items + dl->length + 1);
assert(dl->items[0].pgno == 0 &&
dl->items[dl->length + 1].pgno == P_INVALID);
if (likely(unsorted < MDBX_PNL_RADIXSORT_THRESHOLD) ||
!dpl_radixsort(dl->items + 1, dl->length)) {
if (dl->sorted > unsorted / 4 + 4 &&
dl->length + unsorted < dl->detent + MDBX_DPL_GAP_FOR_MERGESORT) {
MDBX_dp *const sorted_begin = dl->items + 1;
MDBX_dp *const sorted_end = sorted_begin + dl->sorted;
MDBX_dp *const end = dl->items + dl->detent + MDBX_DPL_RESERVE_GAP;
MDBX_dp *const tmp = end - unsorted;
assert(dl->items + dl->length + 1 < tmp);
/* copy unsorted to the end of allocated space and sort it */
memcpy(tmp, sorted_end, unsorted * sizeof(MDBX_dp));
dp_sort(tmp, tmp + unsorted);
/* merge two parts from end to begin */
MDBX_dp *w = dl->items + dl->length;
MDBX_dp *l = dl->items + dl->sorted;
MDBX_dp *r = end - 1;
do {
const bool cmp = l->pgno > r->pgno;
*w = cmp ? *l : *r;
l -= cmp;
r -= !cmp;
} while (likely(--w > l));
assert(r == tmp - 1);
assert(dl->items[0].pgno == 0 &&
dl->items[dl->length + 1].pgno == P_INVALID);
if (mdbx_assert_enabled())
for (unsigned i = 0; i <= dl->length; ++i)
assert(dl->items[i].pgno < dl->items[i + 1].pgno);
} else {
dp_sort(dl->items + 1, dl->items + dl->length + 1);
assert(dl->items[0].pgno == 0 &&
dl->items[dl->length + 1].pgno == P_INVALID);
}
}
dl->sorted = dl->length;
return dl;

1
src/internals.h
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@ -680,6 +680,7 @@ typedef struct MDBX_dpl {
/* PNL sizes */
#define MDBX_PNL_GRANULATE 1024
#define MDBX_PNL_RADIXSORT_THRESHOLD 1024
#define MDBX_PNL_INITIAL \
(MDBX_PNL_GRANULATE - 2 - MDBX_ASSUME_MALLOC_OVERHEAD / sizeof(pgno_t))