ceph/src/rocksdb/db/job_context.h

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under the BSD-style license found in the
   3 //  LICENSE file in the root directory of this source tree. An additional grant
   4 //  of patent rights can be found in the PATENTS file in the same directory.
   5 //
   6 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
   7 // Use of this source code is governed by a BSD-style license that can be
   8 // found in the LICENSE file. See the AUTHORS file for names of contributors.
   9
  10 #pragma once
  11
  12 #include <string>
  13 #include <vector>
  14
  15 #include "db/log_writer.h"
  16
  17 namespace rocksdb {
  18
  19 class MemTable;
  20
  21 struct JobContext {
  22   inline bool HaveSomethingToDelete() const {
  23     return full_scan_candidate_files.size() || sst_delete_files.size() ||
  24            log_delete_files.size() || manifest_delete_files.size() ||
  25            new_superversion != nullptr || superversions_to_free.size() > 0 ||
  26            memtables_to_free.size() > 0 || logs_to_free.size() > 0;
  27   }
  28
  29   // Structure to store information for candidate files to delete.
  30   struct CandidateFileInfo {
  31     std::string file_name;
  32     uint32_t path_id;
  33     CandidateFileInfo(std::string name, uint32_t path)
  34         : file_name(std::move(name)), path_id(path) {}
  35     bool operator==(const CandidateFileInfo& other) const {
  36       return file_name == other.file_name && path_id == other.path_id;
  37     }
  38   };
  39
  40   // Unique job id
  41   int job_id;
  42
  43   // a list of all files that we'll consider deleting
  44   // (every once in a while this is filled up with all files
  45   // in the DB directory)
  46   // (filled only if we're doing full scan)
  47   std::vector<CandidateFileInfo> full_scan_candidate_files;
  48
  49   // the list of all live sst files that cannot be deleted
  50   std::vector<FileDescriptor> sst_live;
  51
  52   // a list of sst files that we need to delete
  53   std::vector<FileMetaData*> sst_delete_files;
  54
  55   // a list of log files that we need to delete
  56   std::vector<uint64_t> log_delete_files;
  57
  58   // a list of log files that we need to preserve during full purge since they
  59   // will be reused later
  60   std::vector<uint64_t> log_recycle_files;
  61
  62   // a list of manifest files that we need to delete
  63   std::vector<std::string> manifest_delete_files;
  64
  65   // a list of memtables to be free
  66   autovector<MemTable*> memtables_to_free;
  67
  68   autovector<SuperVersion*> superversions_to_free;
  69
  70   autovector<log::Writer*> logs_to_free;
  71
  72   SuperVersion* new_superversion;  // if nullptr no new superversion
  73
  74   // the current manifest_file_number, log_number and prev_log_number
  75   // that corresponds to the set of files in 'live'.
  76   uint64_t manifest_file_number;
  77   uint64_t pending_manifest_file_number;
  78   uint64_t log_number;
  79   uint64_t prev_log_number;
  80
  81   uint64_t min_pending_output = 0;
  82   uint64_t prev_total_log_size = 0;
  83   size_t num_alive_log_files = 0;
  84   uint64_t size_log_to_delete = 0;
  85
  86   explicit JobContext(int _job_id, bool create_superversion = false) {
  87     job_id = _job_id;
  88     manifest_file_number = 0;
  89     pending_manifest_file_number = 0;
  90     log_number = 0;
  91     prev_log_number = 0;
  92     new_superversion = create_superversion ? new SuperVersion() : nullptr;
  93   }
  94
  95   // For non-empty JobContext Clean() has to be called at least once before
  96   // before destruction (see asserts in ~JobContext()). Should be called with
  97   // unlocked DB mutex. Destructor doesn't call Clean() to avoid accidentally
  98   // doing potentially slow Clean() with locked DB mutex.
  99   void Clean() {
 100     // free pending memtables
 101     for (auto m : memtables_to_free) {
 102       delete m;
 103     }
 104     // free superversions
 105     for (auto s : superversions_to_free) {
 106       delete s;
 107     }
 108     for (auto l : logs_to_free) {
 109       delete l;
 110     }
 111     // if new_superversion was not used, it will be non-nullptr and needs
 112     // to be freed here
 113     delete new_superversion;
 114
 115     memtables_to_free.clear();
 116     superversions_to_free.clear();
 117     logs_to_free.clear();
 118     new_superversion = nullptr;
 119   }
 120
 121   ~JobContext() {
 122     assert(memtables_to_free.size() == 0);
 123     assert(superversions_to_free.size() == 0);
 124     assert(new_superversion == nullptr);
 125     assert(logs_to_free.size() == 0);
 126   }
 127 };
 128
 129 }  // namespace rocksdb