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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*
* Copyright (C) 2011 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef LevelDBTransaction_h
#define LevelDBTransaction_h
#if ENABLE(INDEXED_DATABASE)
#if USE(LEVELDB)
#include "LevelDBComparator.h"
#include "LevelDBIterator.h"
#include "LevelDBSlice.h"
#include <wtf/AVLTree.h>
#include <wtf/HashSet.h>
#include <wtf/PassOwnPtr.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>
#include <wtf/Vector.h>
namespace WebCore {
class LevelDBDatabase;
class LevelDBWriteBatch;
using WTF::AVLTree;
class LevelDBTransaction : public RefCounted<LevelDBTransaction> {
public:
static PassRefPtr<LevelDBTransaction> create(LevelDBDatabase*);
~LevelDBTransaction();
void put(const LevelDBSlice& key, const Vector<char>& value);
void remove(const LevelDBSlice& key);
bool get(const LevelDBSlice& key, Vector<char>& value);
bool commit();
void rollback();
PassOwnPtr<LevelDBIterator> createIterator();
private:
LevelDBTransaction(LevelDBDatabase*);
struct AVLTreeNode {
Vector<char> key;
Vector<char> value;
bool deleted;
AVLTreeNode* less;
AVLTreeNode* greater;
int balanceFactor;
};
struct AVLTreeAbstractor {
typedef AVLTreeNode* handle;
typedef size_t size;
typedef LevelDBSlice key;
handle get_less(handle h) { return h->less; }
void set_less(handle h, handle less) { h->less = less; }
handle get_greater(handle h) { return h->greater; }
void set_greater(handle h, handle greater) { h->greater = greater; }
int get_balance_factor(handle h) { return h->balanceFactor; }
void set_balance_factor(handle h, int bf) { h->balanceFactor = bf; }
int compare_key_key(const key& ka, const key& kb) { return m_comparator->compare(ka, kb); }
int compare_key_node(const key& k, handle h) { return compare_key_key(k, h->key); }
int compare_node_node(handle ha, handle hb) { return compare_key_key(ha->key, hb->key); }
static handle null() { return 0; }
const LevelDBComparator* m_comparator;
};
typedef AVLTree<AVLTreeAbstractor> TreeType;
class TreeIterator : public LevelDBIterator {
public:
static PassOwnPtr<TreeIterator> create(LevelDBTransaction*);
~TreeIterator();
virtual bool isValid() const;
virtual void seekToLast();
virtual void seek(const LevelDBSlice&);
virtual void next();
virtual void prev();
virtual LevelDBSlice key() const;
virtual LevelDBSlice value() const;
bool isDeleted() const;
void reset();
private:
TreeIterator(LevelDBTransaction*);
mutable TreeType::Iterator m_iterator; // Dereferencing this is non-const.
TreeType* m_tree;
LevelDBTransaction* m_transaction;
Vector<char> m_key;
};
class TransactionIterator : public LevelDBIterator {
public:
~TransactionIterator();
static PassOwnPtr<TransactionIterator> create(PassRefPtr<LevelDBTransaction>);
virtual bool isValid() const;
virtual void seekToLast();
virtual void seek(const LevelDBSlice& target);
virtual void next();
virtual void prev();
virtual LevelDBSlice key() const;
virtual LevelDBSlice value() const;
void treeChanged();
private:
TransactionIterator(PassRefPtr<LevelDBTransaction>);
void handleConflictsAndDeletes();
void setCurrentIteratorToSmallestKey();
void setCurrentIteratorToLargestKey();
void refreshTreeIterator() const;
bool treeIteratorIsLower() const;
bool treeIteratorIsHigher() const;
RefPtr<LevelDBTransaction> m_transaction;
const LevelDBComparator* m_comparator;
mutable OwnPtr<TreeIterator> m_treeIterator;
OwnPtr<LevelDBIterator> m_dbIterator;
LevelDBIterator* m_current;
enum Direction {
kForward,
kReverse
};
Direction m_direction;
mutable bool m_treeChanged;
};
void set(const LevelDBSlice& key, const Vector<char>& value, bool deleted);
void clearTree();
void registerIterator(TransactionIterator*);
void unregisterIterator(TransactionIterator*);
void notifyIteratorsOfTreeChange();
LevelDBDatabase* m_db;
const LevelDBComparator* m_comparator;
TreeType m_tree;
bool m_finished;
HashSet<TransactionIterator*> m_iterators;
};
class LevelDBWriteOnlyTransaction {
public:
static PassOwnPtr<LevelDBWriteOnlyTransaction> create(LevelDBDatabase*);
~LevelDBWriteOnlyTransaction();
void remove(const LevelDBSlice& key);
bool commit();
private:
LevelDBWriteOnlyTransaction(LevelDBDatabase*);
LevelDBDatabase* m_db;
OwnPtr<LevelDBWriteBatch> m_writeBatch;
bool m_finished;
};
}
#endif // USE(LEVELDB)
#endif // ENABLE(INDEXED_DATABASE)
#endif // LevelDBTransaction_h
|
