blob: 4d29b83c4ff9d413e75479b40bdfef92724c633d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
|
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#pragma once
#include "rocksdb/types.h"
namespace rocksdb {
enum class SnapshotCheckerResult : int {
kInSnapshot = 0,
kNotInSnapshot = 1,
// In case snapshot is released and the checker has no clue whether
// the given sequence is visible to the snapshot.
kSnapshotReleased = 2,
};
// Callback class that control GC of duplicate keys in flush/compaction.
class SnapshotChecker {
public:
virtual ~SnapshotChecker() {}
virtual SnapshotCheckerResult CheckInSnapshot(
SequenceNumber sequence, SequenceNumber snapshot_sequence) const = 0;
};
class DisableGCSnapshotChecker : public SnapshotChecker {
public:
virtual ~DisableGCSnapshotChecker() {}
virtual SnapshotCheckerResult CheckInSnapshot(
SequenceNumber /*sequence*/,
SequenceNumber /*snapshot_sequence*/) const override {
// By returning kNotInSnapshot, we prevent all the values from being GCed
return SnapshotCheckerResult::kNotInSnapshot;
}
static DisableGCSnapshotChecker* Instance() { return &instance_; }
protected:
static DisableGCSnapshotChecker instance_;
explicit DisableGCSnapshotChecker() {}
};
class WritePreparedTxnDB;
// Callback class created by WritePreparedTxnDB to check if a key
// is visible by a snapshot.
class WritePreparedSnapshotChecker : public SnapshotChecker {
public:
explicit WritePreparedSnapshotChecker(WritePreparedTxnDB* txn_db);
virtual ~WritePreparedSnapshotChecker() {}
virtual SnapshotCheckerResult CheckInSnapshot(
SequenceNumber sequence, SequenceNumber snapshot_sequence) const override;
private:
#ifndef ROCKSDB_LITE
const WritePreparedTxnDB* const txn_db_;
#endif // !ROCKSDB_LITE
};
} // namespace rocksdb
|
