rocksdb/table/scoped_arena_iterator.h

62 lines
1.6 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
#pragma once
#include "table/internal_iterator.h"
#include "port/port.h"
namespace rocksdb {
class ScopedArenaIterator {
void reset(InternalIterator* iter) ROCKSDB_NOEXCEPT {
if (iter_ != nullptr) {
iter_->~InternalIterator();
}
iter_ = iter;
}
public:
explicit ScopedArenaIterator(InternalIterator* iter = nullptr)
: iter_(iter) {}
ScopedArenaIterator(const ScopedArenaIterator&) = delete;
ScopedArenaIterator& operator=(const ScopedArenaIterator&) = delete;
ScopedArenaIterator(ScopedArenaIterator&& o) ROCKSDB_NOEXCEPT {
iter_ = o.iter_;
o.iter_ = nullptr;
}
ScopedArenaIterator& operator=(ScopedArenaIterator&& o) ROCKSDB_NOEXCEPT {
reset(o.iter_);
o.iter_ = nullptr;
return *this;
}
InternalIterator* operator->() { return iter_; }
InternalIterator* get() { return iter_; }
void set(InternalIterator* iter) { reset(iter); }
InternalIterator* release() {
assert(iter_ != nullptr);
auto* res = iter_;
iter_ = nullptr;
return res;
}
~ScopedArenaIterator() {
reset(nullptr);
}
private:
InternalIterator* iter_;
};
} // namespace rocksdb