rocksdb/db/version_builder.h
Yi Wu 3c840d1a6d Allow DB reopen with reduced options.num_levels
Summary:
Allow user to reduce number of levels in LSM by issue a full CompactRange() and put the result in a lower level, and then reopen DB with reduced options.num_levels. Previous this will fail on reopen on when recovery replaying the previous MANIFEST and found a historical file was on a higher level than the new options.num_levels. The workaround was after CompactRange(), reopen the DB with old num_levels, which will create a new MANIFEST, and then reopen the DB again with new num_levels.

This patch relax the check of levels during recovery. It allows DB to open if there was a historical file on level > options.num_levels, but was also deleted.
Closes https://github.com/facebook/rocksdb/pull/2740

Differential Revision: D5629354

Pulled By: yiwu-arbug

fbshipit-source-id: 545903f6b36b6083e8cbaf777176aef2f488021d
2017-08-24 16:10:54 -07:00

46 lines
1.6 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root 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 "rocksdb/env.h"
namespace rocksdb {
class TableCache;
class VersionStorageInfo;
class VersionEdit;
struct FileMetaData;
class InternalStats;
// A helper class so we can efficiently apply a whole sequence
// of edits to a particular state without creating intermediate
// Versions that contain full copies of the intermediate state.
class VersionBuilder {
public:
VersionBuilder(const EnvOptions& env_options, TableCache* table_cache,
VersionStorageInfo* base_vstorage, Logger* info_log = nullptr);
~VersionBuilder();
void CheckConsistency(VersionStorageInfo* vstorage);
void CheckConsistencyForDeletes(VersionEdit* edit, uint64_t number,
int level);
bool CheckConsistencyForNumLevels();
void Apply(VersionEdit* edit);
void SaveTo(VersionStorageInfo* vstorage);
void LoadTableHandlers(InternalStats* internal_stats, int max_threads,
bool prefetch_index_and_filter_in_cache);
void MaybeAddFile(VersionStorageInfo* vstorage, int level, FileMetaData* f);
private:
class Rep;
Rep* rep_;
};
extern bool NewestFirstBySeqNo(FileMetaData* a, FileMetaData* b);
} // namespace rocksdb