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
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
content / browser / indexed_db / instance / leveldb_tombstone_sweeper.h [blame]
// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_INDEXED_DB_INSTANCE_LEVELDB_TOMBSTONE_SWEEPER_H_
#define CONTENT_BROWSER_INDEXED_DB_INSTANCE_LEVELDB_TOMBSTONE_SWEEPER_H_
#include <map>
#include <memory>
#include <optional>
#include <vector>
#include "base/feature_list.h"
#include "base/functional/callback.h"
#include "base/memory/raw_ptr.h"
#include "base/memory/weak_ptr.h"
#include "content/browser/indexed_db/indexed_db_leveldb_coding.h"
#include "content/browser/indexed_db/instance/backing_store_pre_close_task_queue.h"
#include "content/browser/indexed_db/status.h"
#include "content/common/content_export.h"
#include "third_party/leveldatabase/src/include/leveldb/write_batch.h"
namespace blink {
struct IndexedDBDatabaseMetadata;
struct IndexedDBIndexMetadata;
struct IndexedDBObjectStoreMetadata;
} // namespace blink
namespace leveldb {
class DB;
class Iterator;
} // namespace leveldb
namespace content::indexed_db {
class BackingStore;
// Facilitates iterating a whole container with an abnormal starting position.
// If the starting position is not 0, then the iteration will wrap to the
// beginning of the container until the starting position is reached again.
template <typename T>
class WrappingIterator {
public:
WrappingIterator();
WrappingIterator(const T* container, size_t start_position);
~WrappingIterator();
WrappingIterator& operator=(const WrappingIterator& other) = default;
void Next();
bool IsValid() const { return valid_; }
const typename T::value_type& Value() const;
private:
bool valid_ = false;
size_t iterations_done_ = 0;
typename T::const_iterator inner_;
raw_ptr<const T> container_ = nullptr;
};
// Sweeps the IndexedDB leveldb database looking for index tombstones. These
// occur when the indexed fields of rows are modified, and stay around if script
// doesn't do a cursor iteration of the database.
//
// Owned by the BackingStore.
//
// TODO(dmurph) Describe this class in a README.md file.
// See bit.ly/idb-tombstone-sweeper for more information.
class CONTENT_EXPORT LevelDbTombstoneSweeper
: public BackingStorePreCloseTaskQueue::PreCloseTask {
public:
// The |database| must outlive this instance.
LevelDbTombstoneSweeper(int round_iterations,
int max_iterations,
leveldb::DB* database);
LevelDbTombstoneSweeper(const LevelDbTombstoneSweeper&) = delete;
LevelDbTombstoneSweeper& operator=(const LevelDbTombstoneSweeper&) = delete;
~LevelDbTombstoneSweeper() override;
bool RequiresMetadata() const override;
void SetMetadata(
const std::vector<blink::IndexedDBDatabaseMetadata>* metadata) override;
bool RunRound() override;
private:
using IndexedDBDatabaseMetadataVector =
std::vector<blink::IndexedDBDatabaseMetadata>;
using ObjectStoreMetadataMap =
std::map<int64_t, blink::IndexedDBObjectStoreMetadata>;
using IndexMetadataMap = std::map<int64_t, blink::IndexedDBIndexMetadata>;
friend class LevelDbTombstoneSweeperTest;
enum class SweepStatus { SWEEPING, DONE_ERROR, DONE };
// Contains the current sweeping state and position for the sweeper.
struct SweepState {
SweepState();
~SweepState();
// Stores the random starting database seed. Not bounded.
size_t start_database_seed = 0;
std::optional<WrappingIterator<IndexedDBDatabaseMetadataVector>>
database_it;
// Stores the random starting object store seed. Not bounded.
size_t start_object_store_seed = 0;
std::optional<WrappingIterator<ObjectStoreMetadataMap>> object_store_it;
// Stores the random starting object store seed. Not bounded.
size_t start_index_seed = 0;
std::optional<WrappingIterator<IndexMetadataMap>> index_it;
std::optional<IndexDataKey> index_it_key;
};
void SetStartSeedsForTesting(size_t database_seed,
size_t object_store_seed,
size_t index_seed) {
sweep_state_.start_database_seed = database_seed;
sweep_state_.start_object_store_seed = object_store_seed;
sweep_state_.start_index_seed = index_seed;
}
Status FlushDeletions();
bool ShouldContinueIteration(SweepStatus* sweep_status,
Status* leveldb_status,
int* round_iters);
SweepStatus DoSweep(Status* status);
// Returns true if sweeper can continue iterating.
bool IterateIndex(int64_t database_id,
int64_t object_store_id,
const blink::IndexedDBIndexMetadata& index,
SweepStatus* sweep_status,
Status* leveldb_status,
int* round_iterations);
int num_iterations_ = 0;
const int max_round_iterations_;
const int max_iterations_;
int indices_scanned_ = 0;
int total_indices_ = 0;
bool has_writes_ = false;
leveldb::WriteBatch round_deletion_batch_;
raw_ptr<const std::vector<blink::IndexedDBDatabaseMetadata>>
database_metadata_ = nullptr;
std::unique_ptr<leveldb::Iterator> iterator_;
SweepState sweep_state_;
base::WeakPtrFactory<LevelDbTombstoneSweeper> ptr_factory_{this};
};
} // namespace content::indexed_db
#endif // CONTENT_BROWSER_INDEXED_DB_INSTANCE_LEVELDB_TOMBSTONE_SWEEPER_H_