diff --git a/mdbx.h b/mdbx.h index c1fdd90e..611efd1e 100644 --- a/mdbx.h +++ b/mdbx.h @@ -4938,6 +4938,13 @@ LIBMDBX_API int mdbx_cursor_scan(MDBX_cursor *cursor, MDBX_cursor_op start_op, MDBX_cursor_op turn_op, void *arg); +/** FIXME */ +LIBMDBX_API int mdbx_cursor_scan_from(MDBX_cursor *cursor, + MDBX_predicate_func *predicate, + void *context, MDBX_cursor_op from_op, + MDBX_val *from_key, MDBX_val *from_value, + MDBX_cursor_op turn_op, void *arg); + /** \brief Retrieve multiple non-dupsort key/value pairs by cursor. * \ingroup c_crud * diff --git a/src/core.c b/src/core.c index 23eaaa92..861c266f 100644 --- a/src/core.c +++ b/src/core.c @@ -17466,6 +17466,50 @@ int mdbx_cursor_scan(MDBX_cursor *mc, MDBX_predicate_func *predicate, } } +int mdbx_cursor_scan_from(MDBX_cursor *mc, MDBX_predicate_func *predicate, + void *context, MDBX_cursor_op from_op, MDBX_val *key, + MDBX_val *value, MDBX_cursor_op turn_op, void *arg) { + if (unlikely(!predicate)) + return MDBX_EINVAL; + + const unsigned valid_start_mask = + 1 << MDBX_GET_BOTH | 1 << MDBX_GET_BOTH_RANGE | 1 << MDBX_SET_KEY | + 1 << MDBX_GET_MULTIPLE | 1 << MDBX_SET_LOWERBOUND | + 1 << MDBX_SET_UPPERBOUND; + ; + if (unlikely(from_op < MDBX_TO_KEY_LESSER_THAN && + ((1 << from_op) & valid_start_mask) == 0)) + return MDBX_EINVAL; + + const unsigned valid_turn_mask = + 1 << MDBX_NEXT | 1 << MDBX_NEXT_DUP | 1 << MDBX_NEXT_NODUP | + 1 << MDBX_PREV | 1 << MDBX_PREV_DUP | 1 << MDBX_PREV_NODUP | + 1 << MDBX_NEXT_MULTIPLE | 1 << MDBX_PREV_MULTIPLE; + if (unlikely(turn_op > 30 || ((1 << turn_op) & valid_turn_mask) == 0)) + return MDBX_EINVAL; + + int rc = mdbx_cursor_get(mc, key, value, from_op); + if (unlikely(MDBX_IS_ERROR(rc))) + return rc; + + cASSERT(mc, key != nullptr); + MDBX_val stub; + if (!value) { + value = &stub; + rc = cursor_get(mc, key, value, MDBX_GET_CURRENT); + if (unlikely(rc != MDBX_SUCCESS)) + return rc; + } + for (;;) { + rc = predicate(context, key, value, arg); + if (rc != MDBX_RESULT_FALSE) + return rc; + rc = cursor_get(mc, key, value, turn_op); + if (rc != MDBX_SUCCESS) + return (rc == MDBX_NOTFOUND) ? MDBX_RESULT_FALSE : rc; + } +} + static int cursor_first_batch(MDBX_cursor *mc) { if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { int err = page_search(mc, NULL, MDBX_PS_FIRST);