mdbx: добавление в API mdbx_txn_release_all_cursors_ex() и изменение семантики результата mdbx_txn_release_all_cursors() (backport).

По недосмотру в выпусках остался предварительный/черновой вариант
функции mdbx_txn_release_all_cursors(), который смешивает в возвращаемом
значении информацию об ошибке/успехе и количество обработанных курсоров.
За-за чего невозможно отличить одно от другого, например ошибку EPERM на
Linux от одного успешно закрытого курсора.

Теперь mdbx_txn_release_all_cursors() возвращает только код ошибки,
а для получения кол-ва закрытых курсоров в API добавлена функция mdbx_txn_release_all_cursors_ex().
This commit is contained in:
Леонид Юрьев (Leonid Yuriev) 2025-03-04 14:45:13 +03:00
parent 0604accecf
commit 94a2abaf31
2 changed files with 36 additions and 9 deletions

37
mdbx.h
View File

@ -5227,17 +5227,42 @@ LIBMDBX_API void mdbx_cursor_close(MDBX_cursor *cursor);
* \see mdbx_cursor_unbind()
* \see mdbx_cursor_close()
*
* \param [in] txn A transaction handle returned by \ref mdbx_txn_begin().
* \param [in] unbind If non-zero, unbinds cursors and leaves ones reusable.
* Otherwise close and dispose cursors.
* \param [in] txn A transaction handle returned by \ref mdbx_txn_begin().
* \param [in] unbind If non-zero, unbinds cursors and leaves ones reusable.
* Otherwise close and dispose cursors.
* \param [in,out] count An optional pointer to return the number of cursors
* processed by the requested operation.
*
* \returns A negative error value on failure or the number of closed cursors
* on success, some possible errors are:
* \returns A non-zero error value on failure and 0 on success,
* some possible errors are:
* \retval MDBX_THREAD_MISMATCH Given transaction is not owned
* by current thread.
* \retval MDBX_BAD_TXN Given transaction is invalid or has
* a child/nested transaction transaction. */
LIBMDBX_API int mdbx_txn_release_all_cursors(const MDBX_txn *txn, bool unbind);
LIBMDBX_API int mdbx_txn_release_all_cursors_ex(const MDBX_txn *txn, bool unbind, size_t *count);
/** \brief Unbind or closes all cursors of a given transaction.
* \ingroup c_cursors
*
* Unbinds either closes all cursors associated (opened or renewed) with
* a given transaction in a bulk with minimal overhead.
*
* \see mdbx_cursor_unbind()
* \see mdbx_cursor_close()
*
* \param [in] txn A transaction handle returned by \ref mdbx_txn_begin().
* \param [in] unbind If non-zero, unbinds cursors and leaves ones reusable.
* Otherwise close and dispose cursors.
*
* \returns A non-zero error value on failure and 0 on success,
* some possible errors are:
* \retval MDBX_THREAD_MISMATCH Given transaction is not owned
* by current thread.
* \retval MDBX_BAD_TXN Given transaction is invalid or has
* a child/nested transaction transaction. */
LIBMDBX_INLINE_API(int, mdbx_txn_release_all_cursors, (const MDBX_txn *txn, bool unbind)) {
return mdbx_txn_release_all_cursors_ex(txn, unbind, NULL);
}
/** \brief Renew a cursor handle for use within the given transaction.
* \ingroup c_cursors

View File

@ -216,14 +216,15 @@ again:
return MDBX_SUCCESS;
}
int mdbx_txn_release_all_cursors(const MDBX_txn *txn, bool unbind) {
int mdbx_txn_release_all_cursors_ex(const MDBX_txn *txn, bool unbind, size_t *count) {
int rc = check_txn(txn, MDBX_TXN_FINISHED | MDBX_TXN_HAS_CHILD);
size_t n = 0;
if (likely(rc == MDBX_SUCCESS)) {
TXN_FOREACH_DBI_FROM(txn, i, MAIN_DBI) {
while (txn->cursors[i]) {
++n;
MDBX_cursor *mc = txn->cursors[i];
ENSURE(nullptr, mc->signature == cur_signature_live && (mc->next != mc) && !mc->backup);
rc = likely(rc < INT_MAX) ? rc + 1 : rc;
txn->cursors[i] = mc->next;
mc->next = mc;
if (unbind) {
@ -236,9 +237,10 @@ int mdbx_txn_release_all_cursors(const MDBX_txn *txn, bool unbind) {
}
}
} else {
eASSERT(nullptr, rc < 0);
LOG_IFERR(rc);
}
if (count)
*count = n;
return rc;
}