mdbx: косметический рефакторинг cursor_shadow() (backport).

This commit is contained in:
Леонид Юрьев (Leonid Yuriev) 2025-03-20 01:12:15 +03:00
parent b6dcdcf2dc
commit 2b6a768750
2 changed files with 19 additions and 23 deletions

View File

@ -184,14 +184,13 @@ __hot int cursor_touch(MDBX_cursor *const mc, const MDBX_val *key, const MDBX_va
/*----------------------------------------------------------------------------*/
int cursor_shadow(MDBX_cursor *parent_cursor, MDBX_txn *nested_txn, const size_t dbi) {
tASSERT(nested_txn, dbi > FREE_DBI && dbi < nested_txn->n_dbi);
const size_t size = parent_cursor->subcur ? sizeof(MDBX_cursor) + sizeof(subcur_t) : sizeof(MDBX_cursor);
for (MDBX_cursor *bk; parent_cursor; parent_cursor = bk->next) {
cASSERT(parent_cursor, parent_cursor != parent_cursor->next);
bk = parent_cursor;
if (parent_cursor->signature != cur_signature_live)
int cursor_shadow(MDBX_cursor *mc, MDBX_txn *nested, const size_t dbi) {
tASSERT(nested, dbi > FREE_DBI && dbi < nested->n_dbi);
const size_t size = mc->subcur ? sizeof(MDBX_cursor) + sizeof(subcur_t) : sizeof(MDBX_cursor);
for (MDBX_cursor *bk; mc; mc = bk->next) {
cASSERT(mc, mc != mc->next);
bk = mc;
if (mc->signature != cur_signature_live)
continue;
bk = osal_malloc(size);
if (unlikely(!bk))
@ -200,22 +199,19 @@ int cursor_shadow(MDBX_cursor *parent_cursor, MDBX_txn *nested_txn, const size_t
memset(bk, 0xCD, size);
VALGRIND_MAKE_MEM_UNDEFINED(bk, size);
#endif /* MDBX_DEBUG */
*bk = *parent_cursor;
parent_cursor->backup = bk;
/* Kill pointers into src to reduce abuse: The
* user may not use mc until dst ends. But we need a valid
* txn pointer here for cursor fixups to keep working. */
parent_cursor->txn = nested_txn;
parent_cursor->tree = &nested_txn->dbs[dbi];
parent_cursor->dbi_state = &nested_txn->dbi_state[dbi];
subcur_t *mx = parent_cursor->subcur;
if (mx != nullptr) {
*bk = *mc;
mc->backup = bk;
mc->txn = nested;
mc->tree = &nested->dbs[dbi];
mc->dbi_state = &nested->dbi_state[dbi];
subcur_t *mx = mc->subcur;
if (mx) {
*(subcur_t *)(bk + 1) = *mx;
mx->cursor.txn = nested_txn;
mx->cursor.dbi_state = parent_cursor->dbi_state;
mx->cursor.txn = nested;
mx->cursor.dbi_state = &nested->dbi_state[dbi];
}
parent_cursor->next = nested_txn->cursors[dbi];
nested_txn->cursors[dbi] = parent_cursor;
mc->next = nested->cursors[dbi];
nested->cursors[dbi] = mc;
}
return MDBX_SUCCESS;
}

View File

@ -293,7 +293,7 @@ MDBX_NOTHROW_PURE_FUNCTION static inline bool check_leaf_type(const MDBX_cursor
}
MDBX_INTERNAL void cursor_eot(MDBX_cursor *mc, const bool merge);
MDBX_INTERNAL int cursor_shadow(MDBX_cursor *parent_cursor, MDBX_txn *nested_txn, const size_t dbi);
MDBX_INTERNAL int cursor_shadow(MDBX_cursor *mc, MDBX_txn *nested, const size_t dbi);
MDBX_INTERNAL MDBX_cursor *cursor_cpstk(const MDBX_cursor *csrc, MDBX_cursor *cdst);