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

   1 //  Copyright (c) 2017-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 #pragma once
   7
   8 #ifndef ROCKSDB_LITE
   9
  10 #include "rocksdb/db.h"
  11 #include "rocksdb/types.h"
  12
  13 namespace ROCKSDB_NAMESPACE {
  14
  15 // Data associated with a particular version of a key. A database may internally
  16 // store multiple versions of a same user key due to snapshots, compaction not
  17 // happening yet, etc.
  18 struct KeyVersion {
  19   KeyVersion() : user_key(""), value(""), sequence(0), type(0) {}
  20
  21   KeyVersion(const std::string& _user_key, const std::string& _value,
  22              SequenceNumber _sequence, int _type)
  23       : user_key(_user_key), value(_value), sequence(_sequence), type(_type) {}
  24
  25   std::string user_key;
  26   std::string value;
  27   SequenceNumber sequence;
  28   // TODO(ajkr): we should provide a helper function that converts the int to a
  29   // string describing the type for easier debugging.
  30   int type;
  31 };
  32
  33 // Returns listing of all versions of keys in the provided user key range.
  34 // The range is inclusive-inclusive, i.e., [`begin_key`, `end_key`], or
  35 // `max_num_ikeys` has been reached. Since all those keys returned will be
  36 // copied to memory, if the range covers too many keys, the memory usage
  37 // may be huge. `max_num_ikeys` can be used to cap the memory usage.
  38 // The result is inserted into the provided vector, `key_versions`.
  39 Status GetAllKeyVersions(DB* db, Slice begin_key, Slice end_key,
  40                          size_t max_num_ikeys,
  41                          std::vector<KeyVersion>* key_versions);
  42
  43 Status GetAllKeyVersions(DB* db, ColumnFamilyHandle* cfh, Slice begin_key,
  44                          Slice end_key, size_t max_num_ikeys,
  45                          std::vector<KeyVersion>* key_versions);
  46
  47 }  // namespace ROCKSDB_NAMESPACE
  48
  49 #endif  // ROCKSDB_LITE