ceph/src/rocksdb/include/rocksdb/utilities/checkpoint.h

   1 // Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5 //
   6 // A checkpoint is an openable snapshot of a database at a point in time.
   7
   8 #pragma once
   9 #ifndef ROCKSDB_LITE
  10
  11 #include <string>
  12 #include <vector>
  13 #include "rocksdb/status.h"
  14
  15 namespace ROCKSDB_NAMESPACE {
  16
  17 class DB;
  18 class ColumnFamilyHandle;
  19 struct LiveFileMetaData;
  20 struct ExportImportFilesMetaData;
  21
  22 class Checkpoint {
  23  public:
  24   // Creates a Checkpoint object to be used for creating openable snapshots
  25   static Status Create(DB* db, Checkpoint** checkpoint_ptr);
  26
  27   // Builds an openable snapshot of RocksDB on the same disk, which
  28   // accepts an output directory on the same disk, and under the directory
  29   // (1) hard-linked SST files pointing to existing live SST files
  30   // SST files will be copied if output directory is on a different filesystem
  31   // (2) a copied manifest files and other files
  32   // The directory should not already exist and will be created by this API.
  33   // The directory will be an absolute path
  34   // log_size_for_flush: if the total log file size is equal or larger than
  35   // this value, then a flush is triggered for all the column families. The
  36   // default value is 0, which means flush is always triggered. If you move
  37   // away from the default, the checkpoint may not contain up-to-date data
  38   // if WAL writing is not always enabled.
  39   // Flush will always trigger if it is 2PC.
  40   // sequence_number_ptr: if it is not nullptr, the value it points to will be
  41   // set to the DB's sequence number. The default value of this parameter is
  42   // nullptr.
  43   virtual Status CreateCheckpoint(const std::string& checkpoint_dir,
  44                                   uint64_t log_size_for_flush = 0,
  45                                   uint64_t* sequence_number_ptr = nullptr);
  46
  47   // Exports all live SST files of a specified Column Family onto export_dir,
  48   // returning SST files information in metadata.
  49   // - SST files will be created as hard links when the directory specified
  50   //   is in the same partition as the db directory, copied otherwise.
  51   // - export_dir should not already exist and will be created by this API.
  52   // - Always triggers a flush.
  53   virtual Status ExportColumnFamily(ColumnFamilyHandle* handle,
  54                                     const std::string& export_dir,
  55                                     ExportImportFilesMetaData** metadata);
  56
  57   virtual ~Checkpoint() {}
  58 };
  59
  60 }  // namespace ROCKSDB_NAMESPACE
  61 #endif  // !ROCKSDB_LITE