Files
scylladb/utils/sequenced_set.hh
Avi Kivity c6a441f9c2 Update seastar submodule
* seastar 3c498abcab...92c488706c (14):
  > dpdk: restore including reactor.hh
  > tests: distributed_test: add missing #include <mutex>
  > reactor: un-static-ify make_pollfn()
  > merge: Reduce inclusions of reactor.hh
A few #includes added to compensate for this
  > sharded: delete move constructor
  > future: Avoid a move constructor call
  > future: Erase types a bit more in then_wrapped
  > memory: Drop a never nullopt optional
  > semaphore: specify get_units and with_semaphore as noexcept
  > spinlock.hh: Add include for <cassert> header
  > dpdk: Avoid a variable sized array
  > future: Add an explicit promise member to continuation
  > net: remove smart pointer wrappers around pollable_fd
  > Merge "cleanup reactor file functions" from Benny
2020-03-23 11:59:30 +02:00

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C++

/*
* Copyright (C) 2014 ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <vector>
#include <unordered_set>
namespace utils {
/**
* This class implements an add-only vector that ensures that the elements are
* unique.
*
* This class provides a similar functionality to the Java's LinkedHashSet
* class.
*/
template<typename T>
struct sequenced_set {
typedef typename std::vector<T>::iterator iterator;
void push_back(const T& val) {
insert(val);
}
std::pair<iterator, bool> insert(const T& t) {
auto r = _set.insert(t);
if (r.second) {
try {
_vec.push_back(t);
return std::make_pair(std::prev(_vec.end()), true);
} catch (...) {
_set.erase(r.first);
throw;
}
}
return std::make_pair(_vec.end(), false);
}
size_t size() {
return _vec.size();
}
iterator begin() {
return _vec.begin();
}
iterator end() {
return _vec.end();
}
const std::vector<T>& get_vector() const {
return _vec;
}
std::vector<T>& get_vector() {
return _vec;
}
void reserve(size_t sz) {
_set.reserve(sz);
_vec.reserve(sz);
}
private:
std::unordered_set<T> _set;
std::vector<T> _vec;
};
} // namespace utils