void Ardb::Walk(KeyObject& key, bool reverse, WalkHandler* handler)
{
bool isFirstElement = true;
Iterator* iter = FindValue(key);
if (NULL != iter && !iter->Valid() && reverse)
{
iter->SeekToLast();
isFirstElement = false;
}
uint32 cursor = 0;
while (NULL != iter && iter->Valid())
{
Slice tmpkey = iter->Key();
KeyObject* kk = decode_key(tmpkey, &key);
if (NULL == kk || kk->type != key.type
|| kk->key.compare(key.key) != 0)
{
DELETE(kk);
if (reverse && isFirstElement)
{
iter->Prev();
isFirstElement = false;
continue;
}
break;
}
ValueObject v;
Buffer readbuf(const_cast<char*>(iter->Value().data()), 0,
iter->Value().size());
decode_value(readbuf, v, false);
int ret = handler->OnKeyValue(kk, &v, cursor++);
DELETE(kk);
if (ret < 0)
{
break;
}
if (reverse)
{
iter->Prev();
}
else
{
iter->Next();
}
}
DELETE(iter);
}
int Ardb::LastDB(DBID& db)
{
int ret = -1;
Iterator* iter = NewIterator(ARDB_GLOBAL_DB);
if (NULL != iter && iter->Valid())
{
//Skip last KEY_END entry
iter->Prev();
}
if (NULL != iter && iter->Valid())
{
Slice tmpkey = iter->Key();
KeyObject* kk = decode_key(tmpkey, NULL);
if (NULL != kk)
{
db = kk->db;
ret = 0;
}
DELETE(kk);
}
DELETE(iter);
return ret;
}
int Ardb::Randomkey(Context& ctx, RedisCommandFrame& cmd)
{
ctx.reply.type = REDIS_REPLY_NIL;
KeyObject from;
from.db = ctx.currentDB;
from.type = KEY_META;
std::string min_key, max_key, randkey;
Iterator* iter = IteratorKeyValue(from, false);
if (iter->Valid())
{
KeyObject kk;
if (!decode_key(iter->Key(), kk) || kk.db != ctx.currentDB || kk.type != KEY_META)
{
goto _end;
}
min_key.assign(kk.key.data(), kk.key.size());
max_key = min_key;
from.type = SET_ELEMENT; //Refer comparator.cpp
from.encode_buf.Clear();
IteratorSeek(iter, from);
if (!iter->Valid())
{
iter->SeekToLast();
}
if (iter->Valid())
{
iter->Prev();
if (iter->Valid())
{
if (decode_key(iter->Key(), kk) && kk.db == ctx.currentDB && kk.type == KEY_META)
{
max_key.assign(kk.key.data(), kk.key.size());
}
}
}
randkey = min_key;
if (min_key < max_key)
{
randkey = random_between_string(min_key, max_key);
from.type = KEY_META;
from.db = ctx.currentDB;
from.key = randkey;
IteratorSeek(iter, from);
if (iter->Valid())
{
KeyObject kk;
if (!decode_key(iter->Key(), kk) || kk.db != ctx.currentDB || kk.type != KEY_META)
{
goto _end;
}
randkey.assign(kk.key.data(), kk.key.size());
}
}
}
if (!randkey.empty())
{
fill_str_reply(ctx.reply, randkey);
}
_end:
DELETE(iter);
return 0;
}
