e0803ff71e
Used for collecting unsued partition_version objects and freeing them incrementally. Will be used for both cache and memtables.
85 lines
2.8 KiB
C++
85 lines
2.8 KiB
C++
/*
|
|
* Copyright (C) 2018 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 "partition_version.hh"
|
|
#include "partition_version_list.hh"
|
|
|
|
#include "utils/logalloc.hh"
|
|
|
|
// Container for garbage partition_version objects, used for freeing them incrementally.
|
|
class mutation_cleaner final {
|
|
logalloc::region& _region;
|
|
cache_tracker* _tracker;
|
|
partition_version_list _versions;
|
|
public:
|
|
mutation_cleaner(logalloc::region& r, cache_tracker* t) : _region(r), _tracker(t) {}
|
|
~mutation_cleaner();
|
|
|
|
// Frees some of the data. Returns stop_iteration::yes iff all was freed.
|
|
// Must be invoked under owning allocator.
|
|
stop_iteration clear_gently() noexcept;
|
|
|
|
// Must be invoked under owning allocator.
|
|
memory::reclaiming_result clear_some() noexcept;
|
|
|
|
// Must be invoked under owning allocator.
|
|
void clear() noexcept;
|
|
|
|
// Enqueues v for destruction.
|
|
// The object must not be part of any list, and must not be accessed externally any more.
|
|
// In particular, it must not be attached, even indirectly, to any snapshot or partition_entry,
|
|
// and must not be evicted from.
|
|
// Must be invoked under owning allocator.
|
|
void destroy_later(partition_version& v) noexcept;
|
|
|
|
// Destroys v now or later.
|
|
// Same requirements as destroy_later().
|
|
// Must be invoked under owning allocator.
|
|
void destroy_gently(partition_version& v) noexcept;
|
|
|
|
// Transfers objects from other to this.
|
|
// This and other must belong to the same logalloc::region, and the same cache_tracker.
|
|
// After the call bool(other) is false.
|
|
void merge(mutation_cleaner& other) noexcept;
|
|
|
|
// Returns true iff contains no unfreed objects
|
|
bool empty() const noexcept { return _versions.empty(); }
|
|
|
|
// Forces cleaning and returns a future which resolves when there is nothing to clean.
|
|
future<> drain();
|
|
};
|
|
|
|
inline
|
|
void mutation_cleaner::destroy_later(partition_version& v) noexcept {
|
|
_versions.push_back(v);
|
|
}
|
|
|
|
inline
|
|
void mutation_cleaner::destroy_gently(partition_version& v) noexcept {
|
|
if (v.clear_gently(_tracker) == stop_iteration::no) {
|
|
destroy_later(v);
|
|
} else {
|
|
current_allocator().destroy(&v);
|
|
}
|
|
}
|