ceph/src/rocksdb/include/rocksdb/utilities/memory_util.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 #ifndef ROCKSDB_LITE
   7
   8 #pragma once
   9
  10 #include <map>
  11 #include <string>
  12 #include <unordered_set>
  13 #include <vector>
  14
  15 #include "rocksdb/cache.h"
  16 #include "rocksdb/db.h"
  17
  18 namespace rocksdb {
  19
  20 // Returns the current memory usage of the specified DB instances.
  21 class MemoryUtil {
  22  public:
  23   enum UsageType : int {
  24     // Memory usage of all the mem-tables.
  25     kMemTableTotal = 0,
  26     // Memory usage of those un-flushed mem-tables.
  27     kMemTableUnFlushed = 1,
  28     // Memory usage of all the table readers.
  29     kTableReadersTotal = 2,
  30     // Memory usage by Cache.
  31     kCacheTotal = 3,
  32     kNumUsageTypes = 4
  33   };
  34
  35   // Returns the approximate memory usage of different types in the input
  36   // list of DBs and Cache set.  For instance, in the output map
  37   // usage_by_type, usage_by_type[kMemTableTotal] will store the memory
  38   // usage of all the mem-tables from all the input rocksdb instances.
  39   //
  40   // Note that for memory usage inside Cache class, we will
  41   // only report the usage of the input "cache_set" without
  42   // including those Cache usage inside the input list "dbs"
  43   // of DBs.
  44   static Status GetApproximateMemoryUsageByType(
  45       const std::vector<DB*>& dbs,
  46       const std::unordered_set<const Cache*> cache_set,
  47       std::map<MemoryUtil::UsageType, uint64_t>* usage_by_type);
  48 };
  49 }  // namespace rocksdb
  50 #endif  // !ROCKSDB_LITE