std::pair<std::string, int> cht::find_predecessor(const std::string& key) {
std::vector<std::string> hlist;
get_hashlist_(key, hlist);
std::string hash = make_hash(key);
std::string path;
build_actor_path(path, type_, name_);
path += "/cht";
std::vector<std::string>::iterator node0 = std::lower_bound(hlist.begin(),
hlist.end(),
hash);
size_t idx = (static_cast<int>(node0 - hlist.begin()) + hlist.size() - 1)
% hlist.size();
std::string ip;
int port;
std::string loc;
if (lock_service_->read(path + "/" + hlist[idx], loc)) {
revert(loc, ip, port);
return make_pair(ip, port);
} else {
throw JUBATUS_EXCEPTION(core::common::not_found(path));
// TODO(kuenishi): output log and throw exception
}
}
// return at most n nodes, if theres nodes less than n, return size is also less
// than n.
// find(hash) :: lock_service -> key -> [node]
// where hash(node0) <= hash(key) < hash(node1)
bool cht::find(
const std::string& key,
std::vector<std::pair<std::string, int> >& out,
size_t n) {
out.clear();
std::vector<std::string> hlist;
if (!get_hashlist_(key, hlist)) {
throw JUBATUS_EXCEPTION(core::common::not_found(key));
}
std::string hash = make_hash(key);
std::string path;
build_actor_path(path, type_, name_);
path += "/cht";
std::vector<std::string>::iterator node0 = std::lower_bound(hlist.begin(),
hlist.end(),
hash);
size_t idx = static_cast<int>(node0 - hlist.begin()) % hlist.size();
std::string loc;
for (size_t i = 0; i < n; ++i) {
std::string ip;
int port;
if (lock_service_->read(path + "/" + hlist[idx], loc)) {
revert(loc, ip, port);
out.push_back(make_pair(ip, port));
} else {
// TODO(kuenishi): output log
throw JUBATUS_EXCEPTION(core::common::not_found(path));
}
idx++;
idx %= hlist.size();
}
return !hlist.size();
}
// return at most n nodes, if theres nodes less than n, return size is also less than n.
// find(hash) :: lock_service -> key -> [node] where hash(node0) <= hash(key) < hash(node1)
bool cht::find(const std::string& key, std::vector<std::pair<std::string,int> >& out, size_t n){
out.clear();
std::vector<std::string> hlist;
if(! get_hashlist_(key, hlist)){
throw JUBATUS_EXCEPTION(not_found(key));
}
std::string hash = make_hash(key);
std::string path = ACTOR_BASE_PATH + "/" + name_ + "/cht";
std::vector<std::string>::iterator node0 = std::lower_bound(hlist.begin(), hlist.end(), hash);
size_t idx = int(node0 - hlist.begin()) % hlist.size();
std::string loc;
for(size_t i=0; i<n; ++i){
std::string ip;
int port;
if(lock_service_->read(path + "/" + hlist[idx], loc)){
revert(loc, ip, port);
out.push_back(make_pair(ip,port));
}else{
// TODO: output log
throw JUBATUS_EXCEPTION(not_found(path));
}
idx++;
idx %= hlist.size();
}
return !hlist.size();
}
std::pair<std::string,int> cht::find_predecessor(const std::string& key){
std::vector<std::string> hlist;
get_hashlist_(key, hlist);
std::string hash = make_hash(key);
std::string path = ACTOR_BASE_PATH + "/" + name_ + "/cht";
std::vector<std::string>::iterator node0 = std::lower_bound(hlist.begin(), hlist.end(), hash);
size_t idx = (int(node0 - hlist.begin())+ hlist.size() -1) % hlist.size();
std::string ip;
int port;
std::string loc;
if(lock_service_->read(path + "/" + hlist[idx], loc)){
revert(loc, ip, port);
return make_pair(ip, port);
}else{
throw JUBATUS_EXCEPTION(not_found(path));
// TODO: output log and throw exception
}
}
