int MMKVImpl::SRandMember(DBID db, const Data& key, const StringArrayResult& members, int count)
{
int err = 0;
RWLockGuard<MemorySegmentManager, READ_LOCK> keylock_guard(m_segment);
StringSet* set = GetObject<StringSet>(db, key, V_TYPE_SET, false, err)();
if (IS_NOT_EXISTS(err))
{
return 0;
}
if (0 != err)
{
return err;
}
if (set->empty())
{
return 0;
}
//return whole set
if (count > 0 && count > set->size())
{
StringSet::iterator it = set->begin();
while (it != set->end())
{
it->ToString(members.Get());
it++;
}
return 0;
}
int rand = 0;
for (int i = 0; i < std::abs(count); i++)
{
if (count > 0)
{
if (i == 0)
{
rand = random_between_int32(0, set->size() - 1);
}
else
{
rand += i;
if (rand >= set->size())
{
rand -= set->size();
}
}
}
else
{
rand = random_between_int32(0, set->size() - 1);
}
StringSet::iterator it = set->begin();
it.increment_by(rand);
it->ToString(members.Get());
}
return 0;
}
int64_t MMKVImpl::SScan(DBID db, const Data& key, int64_t cursor, const std::string& pattern, int32_t limit_count,
const StringArrayResult& results)
{
int err = 0;
RWLockGuard<MemorySegmentManager, READ_LOCK> keylock_guard(m_segment);
StringSet* set = GetObject<StringSet>(db, key, V_TYPE_SET, false, err)();
if (NULL == set || 0 != err)
{
return err;
}
StringSet::iterator it = set->begin();
if (cursor >= set->size())
{
return 0;
}
it.increment_by(cursor);
int match_count = 0;
while (it != set->end())
{
std::string key_str;
it->ToString(key_str);
if (pattern == ""
|| stringmatchlen(pattern.c_str(), pattern.size(), key_str.c_str(), key_str.size(), 0) == 1)
{
std::string& ss = results.Get();
ss = key_str;
match_count++;
if (limit_count > 0 && match_count >= limit_count)
{
break;
}
}
cursor++;
it++;
}
return it != set->end() ? cursor : 0;
}