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
|
/********************* */
/*! \file stacking_map.h
** \verbatim
** Original author: Morgan Deters
** Major contributors: none
** Minor contributors (to current version): Dejan Jovanovic
** This file is part of the CVC4 project.
** Copyright (c) 2009-2014 New York University and The University of Iowa
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief Backtrackable map using an undo stack
**
** Backtrackable map using an undo stack rather than storing items in
** a CDMap<>.
**/
#include "cvc4_private.h"
#ifndef __CVC4__CONTEXT__STACKING_MAP_H
#define __CVC4__CONTEXT__STACKING_MAP_H
#include <utility>
#include <vector>
#include <ext/hash_map>
#include "expr/node.h"
#include "context/cdo.h"
namespace CVC4 {
namespace context {
template <class T>
struct StackingMapArgType {
typedef T argtype;
};/* struct StackingMapArgType<T> */
template <>
struct StackingMapArgType<Node> {
typedef TNode argtype;
};/* struct StackingMapArgType<Node> */
template <class KeyType, class ValueType, class KeyHash>
struct StackingMapRestoreValue {
typedef typename StackingMapArgType<KeyType>::argtype ArgType;
static void restore(__gnu_cxx::hash_map<KeyType, ValueType, KeyHash>& map, const ArgType& k, const ValueType& v) {
map[k] = v;
}
};/* struct StackingMapRestoreValue<KeyType, ValueType, KeyHash> */
template <class KeyType, class KeyHash>
struct StackingMapRestoreValue<KeyType, Node, KeyHash> {
typedef typename StackingMapArgType<KeyType>::argtype ArgType;
static void restore(__gnu_cxx::hash_map<KeyType, Node, KeyHash>& map, const ArgType& k, TNode v) {
if(v.isNull()) {
map.erase(k);
} else {
map[k] = v;
}
}
};/* struct StackingMapRestoreValue<KeyType, Node, KeyHash> */
template <class KeyType, class KeyHash>
struct StackingMapRestoreValue<KeyType, TNode, KeyHash> {
typedef typename StackingMapArgType<KeyType>::argtype ArgType;
static void restore(__gnu_cxx::hash_map<KeyType, TNode, KeyHash>& map, const ArgType& k, TNode v) {
if(v.isNull()) {
map.erase(k);
} else {
map[k] = v;
}
}
};/* struct StackingMapRestoreValue<KeyType, TNode, KeyHash> */
template <class KeyType, class ValueType, class KeyHash>
class StackingMap : context::ContextNotifyObj {
/** Our underlying map type. */
typedef __gnu_cxx::hash_map<KeyType, ValueType, KeyHash> MapType;
/**
* The type for arguments being passed in. It's the same as
* KeyType, unless KeyType is Node, then it's TNode for efficiency.
*/
typedef typename StackingMapArgType<KeyType>::argtype ArgType;
/** Our map of keys to their values. */
MapType d_map;
/** Our undo stack for changes made to d_map. */
std::vector<std::pair<ArgType, ValueType> > d_trace;
/** Our current offset in the d_trace stack (context-dependent). */
context::CDO<size_t> d_offset;
protected:
/**
* Called by the Context when a pop occurs. Cancels everything to the
* current context level. Overrides ContextNotifyObj::contextNotifyPop().
*/
void contextNotifyPop();
public:
typedef typename MapType::const_iterator const_iterator;
StackingMap(context::Context* ctxt) :
context::ContextNotifyObj(ctxt),
d_offset(ctxt, 0) {
}
~StackingMap() throw() { }
const_iterator find(ArgType n) const { return d_map.find(n); }
const_iterator end() const { return d_map.end(); }
/**
* Return a key's value in the key-value map. If n is not a key in
* the map, this function returns a default-constructed value.
*/
ValueType operator[](ArgType n) const {
const_iterator it = find(n);
if(it == end()) {
return ValueType();
} else {
return (*it).second;
}
}
//ValueType& operator[](ArgType n) { return d_map[n]; }// not permitted--bypasses set() logic
/**
* Set the value in the key-value map for Node n to newValue.
*/
void set(ArgType n, const ValueType& newValue);
};/* class StackingMap<> */
template <class KeyType, class ValueType, class KeyHash>
void StackingMap<KeyType, ValueType, KeyHash>::set(ArgType n, const ValueType& newValue) {
Trace("sm") << "SM setting " << n << " : " << newValue << " @ " << d_trace.size() << std::endl;
ValueType& ref = d_map[n];
d_trace.push_back(std::make_pair(n, ValueType(ref)));
d_offset = d_trace.size();
ref = newValue;
}
template <class KeyType, class ValueType, class KeyHash>
void StackingMap<KeyType, ValueType, KeyHash>::contextNotifyPop() {
Trace("sm") << "SM cancelling : " << d_offset << " < " << d_trace.size() << " ?" << std::endl;
while(d_offset < d_trace.size()) {
std::pair<ArgType, ValueType> p = d_trace.back();
StackingMapRestoreValue<KeyType, ValueType, KeyHash>::restore(d_map, p.first, p.second);
d_trace.pop_back();
}
Trace("sm") << "SM cancelling finished." << std::endl;
}
}/* CVC4::context namespace */
}/* CVC4 namespace */
#endif /*__CVC4__CONTEXT__STACKING_MAP_H */
|
