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
|
/*
* Copyright (C) 2013 Apple 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 INC. ``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 INC. OR
* 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.
*/
#pragma once
#include "SQLTransactionState.h"
#include <wtf/Forward.h>
#ifndef NDEBUG
#include <array>
#endif
namespace WebCore {
template<typename T>
class SQLTransactionStateMachine {
public:
virtual ~SQLTransactionStateMachine() = default;
protected:
SQLTransactionStateMachine();
typedef void (T::*StateFunction)();
virtual StateFunction stateFunctionFor(SQLTransactionState) = 0;
void setStateToRequestedState();
void runStateMachine();
SQLTransactionState m_nextState;
SQLTransactionState m_requestedState;
#ifndef NDEBUG
// The state audit trail (i.e. bread crumbs) keeps track of up to the last
// s_sizeOfStateAuditTrail states that the state machine enters. The audit
// trail is updated before entering each state. This is for debugging use
// only.
static constexpr size_t s_sizeOfStateAuditTrail = 20;
int m_nextStateAuditEntry;
std::array<SQLTransactionState, s_sizeOfStateAuditTrail> m_stateAuditTrail;
#endif
};
#if !LOG_DISABLED
extern ASCIILiteral nameForSQLTransactionState(SQLTransactionState);
#endif
template<typename T>
SQLTransactionStateMachine<T>::SQLTransactionStateMachine()
: m_nextState(SQLTransactionState::Idle)
, m_requestedState(SQLTransactionState::Idle)
#ifndef NDEBUG
, m_nextStateAuditEntry(0)
#endif
{
#ifndef NDEBUG
for (size_t i = 0; i < s_sizeOfStateAuditTrail; ++i)
m_stateAuditTrail[i] = SQLTransactionState::NumberOfStates;
#endif
}
template<typename T>
void SQLTransactionStateMachine<T>::setStateToRequestedState()
{
ASSERT(m_nextState == SQLTransactionState::Idle);
ASSERT(m_requestedState != SQLTransactionState::Idle);
m_nextState = m_requestedState;
m_requestedState = SQLTransactionState::Idle;
}
template<typename T>
void SQLTransactionStateMachine<T>::runStateMachine()
{
ASSERT(SQLTransactionState::End < SQLTransactionState::Idle);
if (m_nextState <= SQLTransactionState::Idle)
return;
ASSERT(m_nextState < SQLTransactionState::NumberOfStates);
StateFunction stateFunction = stateFunctionFor(m_nextState);
ASSERT(stateFunction);
#ifndef NDEBUG
m_stateAuditTrail[m_nextStateAuditEntry] = m_nextState;
m_nextStateAuditEntry = (m_nextStateAuditEntry + 1) % s_sizeOfStateAuditTrail;
#endif
(static_cast<T*>(this)->*stateFunction)();
m_nextState = SQLTransactionState::Idle;
}
} // namespace WebCore
|
