sc_bool _sc_iterator3_f_a_a_next(sc_iterator3 *it)
{
sc_addr arc_addr;
SC_ADDR_MAKE_EMPTY(arc_addr);
if (it->finished == SC_TRUE)
return SC_FALSE;
it->results[0] = it->params[0].addr;
// try to find first output arc
if (SC_ADDR_IS_EMPTY(it->results[1]))
{
sc_element *el = 0;
STORAGE_CHECK_CALL(sc_storage_element_lock(it->ctx, it->params[0].addr, &el));
g_assert(el != null_ptr);
arc_addr = el->first_out_arc;
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, it->params[0].addr));
}else
{
sc_element *el = 0;
STORAGE_CHECK_CALL(sc_storage_element_lock(it->ctx, it->results[1], &el));
g_assert(el != null_ptr);
arc_addr = el->arc.next_out_arc;
_sc_iterator_unref_element(it->ctx, el, it->results[1]);
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, it->results[1]));
}
// iterate throught output arcs
while (SC_ADDR_IS_NOT_EMPTY(arc_addr))
{
sc_element *el = 0;
// lock required elements to prevent deadlock with deletion
while (el == null_ptr)
STORAGE_CHECK_CALL(sc_storage_element_lock_try(it->ctx, arc_addr, s_max_iterator_lock_attempts, &el));
if (!sc_element_itref_add(sc_storage_get_element_meta(it->ctx, arc_addr)))
{
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, arc_addr));
continue;
}
sc_addr next_out_arc = el->arc.next_out_arc;
if (sc_element_is_request_deletion(el) == SC_FALSE)
{
sc_addr arc_end = el->arc.end;
sc_type arc_type = el->flags.type;
sc_access_levels arc_access = el->flags.access_levels;
sc_access_levels end_access;
if (sc_storage_get_access_levels(it->ctx, arc_end, &end_access) != SC_RESULT_OK)
end_access = sc_access_lvl_make_max;
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, arc_addr));
sc_type el_type;
sc_storage_get_element_type(it->ctx, arc_end, &el_type);
if (sc_iterator_compare_type(arc_type, it->params[1].type) &&
sc_iterator_compare_type(el_type, it->params[2].type) &&
sc_access_lvl_check_read(it->ctx->access_levels, arc_access) &&
sc_access_lvl_check_read(it->ctx->access_levels, end_access)
)
{
// store found result
it->results[1] = arc_addr;
it->results[2] = arc_end;
return SC_TRUE;
}
} else
{
_sc_iterator_unref_element(it->ctx, el, arc_addr);
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, arc_addr));
}
// go to next arc
arc_addr = next_out_arc;
}
it->finished = SC_TRUE;
return SC_FALSE;
}
sc_bool _sc_iterator3_a_a_f_next(sc_iterator3 *it)
{
sc_addr arc_addr;
SC_ADDR_MAKE_EMPTY(arc_addr)
it->results[2] = it->params[2].addr;
// try to find first input arc
if (SC_ADDR_IS_EMPTY(it->results[1]))
{
sc_element *el = 0;
STORAGE_CHECK_CALL(sc_storage_element_lock(it->ctx, it->params[2].addr, &el));
g_assert(el != null_ptr);
arc_addr = el->first_in_arc;
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, it->params[2].addr));
}else
{
sc_element *el = 0;
STORAGE_CHECK_CALL(sc_storage_element_lock(it->ctx, it->results[1], &el));
g_assert(el != null_ptr);
arc_addr = el->arc.next_in_arc;
_sc_iterator_unref_element(it->ctx, el, it->results[1]);
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, it->results[1]));
}
// trying to find input arc, that created before iterator, and wasn't deleted
while (SC_ADDR_IS_NOT_EMPTY(arc_addr))
{
sc_element *el = 0;
while (el == null_ptr)
STORAGE_CHECK_CALL(sc_storage_element_lock_try(it->ctx, arc_addr, s_max_iterator_lock_attempts, &el));
if (!sc_element_itref_add(sc_storage_get_element_meta(it->ctx, arc_addr)))
{
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, arc_addr));
continue;
}
sc_addr next_in_arc = el->arc.next_in_arc;
if (sc_element_is_request_deletion(el) == SC_FALSE)
{
sc_type arc_type = el->flags.type;
sc_addr arc_begin = el->arc.begin;
sc_access_levels arc_access = el->flags.access_levels;
sc_access_levels begin_access;
if (sc_storage_get_access_levels(it->ctx, arc_begin, &begin_access) != SC_RESULT_OK)
begin_access = sc_access_lvl_make_max;
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, arc_addr));
sc_type el_type = 0;
sc_storage_get_element_type(it->ctx, arc_begin, &el_type);
if (sc_iterator_compare_type(arc_type, it->params[1].type) &&
sc_iterator_compare_type(el_type, it->params[0].type) &&
sc_access_lvl_check_read(it->ctx->access_levels, arc_access) &&
sc_access_lvl_check_read(it->ctx->access_levels, begin_access)
)
{
// store found result
it->results[1] = arc_addr;
it->results[0] = arc_begin;
return SC_TRUE;
}
} else
{
_sc_iterator_unref_element(it->ctx, el, arc_addr);
STORAGE_CHECK_CALL(sc_storage_element_unlock(it->ctx, arc_addr));
}
// go to next arc
arc_addr = next_in_arc;
}
it->finished = SC_TRUE;
return SC_FALSE;
}
sc_result sc_memory_get_element_type(sc_memory_context const * ctx, sc_addr addr, sc_type *result)
{
return sc_storage_get_element_type(ctx, addr, result);
}
