ceph/src/rocksdb/monitoring/in_memory_stats_history.cc

   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 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
   6 // Use of this source code is governed by a BSD-style license that can be
   7 // found in the LICENSE file. See the AUTHORS file for names of contributors.
   8
   9 #include "monitoring/in_memory_stats_history.h"
  10 #include "db/db_impl/db_impl.h"
  11
  12 namespace ROCKSDB_NAMESPACE {
  13
  14 InMemoryStatsHistoryIterator::~InMemoryStatsHistoryIterator() {}
  15
  16 bool InMemoryStatsHistoryIterator::Valid() const { return valid_; }
  17
  18 Status InMemoryStatsHistoryIterator::status() const { return status_; }
  19
  20 // Because of garbage collection, the next stats snapshot may or may not be
  21 // right after the current one. When reading from DBImpl::stats_history_, this
  22 // call will be protected by DB Mutex so it will not return partial or
  23 // corrupted results.
  24 void InMemoryStatsHistoryIterator::Next() {
  25   // increment start_time by 1 to avoid infinite loop
  26   AdvanceIteratorByTime(GetStatsTime() + 1, end_time_);
  27 }
  28
  29 uint64_t InMemoryStatsHistoryIterator::GetStatsTime() const { return time_; }
  30
  31 const std::map<std::string, uint64_t>&
  32 InMemoryStatsHistoryIterator::GetStatsMap() const {
  33   return stats_map_;
  34 }
  35
  36 // advance the iterator to the next time between [start_time, end_time)
  37 // if success, update time_ and stats_map_ with new_time and stats_map
  38 void InMemoryStatsHistoryIterator::AdvanceIteratorByTime(uint64_t start_time,
  39                                                          uint64_t end_time) {
  40   // try to find next entry in stats_history_ map
  41   if (db_impl_ != nullptr) {
  42     valid_ =
  43         db_impl_->FindStatsByTime(start_time, end_time, &time_, &stats_map_);
  44   } else {
  45     valid_ = false;
  46   }
  47 }
  48
  49 }  // namespace ROCKSDB_NAMESPACE