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
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
// 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
#ifndef ROCKSDB_LITE
#include <string>
#include <unordered_map>
#include "db/dbformat.h"
#include "db/read_callback.h"
#include "rocksdb/db.h"
#include "rocksdb/slice.h"
#include "rocksdb/status.h"
#include "rocksdb/types.h"
#include "utilities/transactions/lock/lock_tracker.h"
namespace ROCKSDB_NAMESPACE {
class DBImpl;
struct SuperVersion;
class WriteBatchWithIndex;
class TransactionUtil {
public:
// Verifies there have been no commits to this key in the db since this
// sequence number. If user-defined timestamp is enabled, then also check
// no commits to this key in the db since the given ts.
//
// If cache_only is true, then this function will not attempt to read any
// SST files. This will make it more likely this function will
// return an error if it is unable to determine if there are any conflicts.
//
// See comment of CheckKey() for explanation of `snap_seq`, `ts`,
// `snap_checker` and `min_uncommitted`.
//
// Returns OK on success, BUSY if there is a conflicting write, or other error
// status for any unexpected errors.
static Status CheckKeyForConflicts(
DBImpl* db_impl, ColumnFamilyHandle* column_family,
const std::string& key, SequenceNumber snap_seq,
const std::string* const ts, bool cache_only,
ReadCallback* snap_checker = nullptr,
SequenceNumber min_uncommitted = kMaxSequenceNumber);
// For each key,SequenceNumber pair tracked by the LockTracker, this function
// will verify there have been no writes to the key in the db since that
// sequence number.
//
// Returns OK on success, BUSY if there is a conflicting write, or other error
// status for any unexpected errors.
//
// REQUIRED:
// This function should only be called on the write thread or if the
// mutex is held.
// tracker must support point lock.
static Status CheckKeysForConflicts(DBImpl* db_impl,
const LockTracker& tracker,
bool cache_only);
private:
// If `snap_checker` == nullptr, writes are always commited in sequence number
// order. All sequence number <= `snap_seq` will not conflict with any
// write, and all keys > `snap_seq` of `key` will trigger conflict.
// If `snap_checker` != nullptr, writes may not commit in sequence number
// order. In this case `min_uncommitted` is a lower bound.
// seq < `min_uncommitted`: no conflict
// seq > `snap_seq`: applicable to conflict
// `min_uncommitted` <= seq <= `snap_seq`: call `snap_checker` to determine.
//
// If user-defined timestamp is enabled, a write conflict is detected if an
// operation for `key` with timestamp greater than `ts` exists.
static Status CheckKey(DBImpl* db_impl, SuperVersion* sv,
SequenceNumber earliest_seq, SequenceNumber snap_seq,
const std::string& key, const std::string* const ts,
bool cache_only, ReadCallback* snap_checker = nullptr,
SequenceNumber min_uncommitted = kMaxSequenceNumber);
};
} // namespace ROCKSDB_NAMESPACE
#endif // ROCKSDB_LITE
|
