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1 | /* |
2 | suPHP - (c)2002-2005 Sebastian Marsching <sebastian@marsching.com> |
3 | |
4 | This file is part of suPHP. |
5 | |
6 | suPHP is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published by |
8 | the Free Software Foundation; either version 2 of the License, or |
9 | (at your option) any later version. |
10 | |
11 | suPHP is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | GNU General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with suPHP; if not, write to the Free Software |
18 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | */ |
20 | |
21 | #ifndef SUPHP_SMARTPTR_H |
22 | |
23 | namespace suPHP { |
24 | class Environment; |
25 | }; |
26 | |
27 | #define SUPHP_SMARTPTR_H |
28 | |
29 | #include <map> |
30 | #include <cstdlib> |
31 | #include "PointerException.hpp" |
32 | |
33 | namespace suPHP { |
34 | /** |
35 | * Class template encapsulating pointers. |
36 | */ |
37 | template<class T> |
38 | class SmartPtr { |
39 | private: |
40 | static std::map<T*, int> *counter; |
41 | T* ptr; |
42 | |
43 | void increment(T* key_ptr); |
44 | void decrement(T* key_ptr); |
45 | |
46 | public: |
47 | /** |
48 | * Constructor using NULL pointer |
49 | */ |
50 | SmartPtr(); |
51 | |
52 | /** |
53 | * Constructor taking T* as argument |
54 | */ |
55 | SmartPtr(T* obj_ptr); |
56 | |
57 | /** |
58 | * Copy constructor |
59 | */ |
60 | SmartPtr(const SmartPtr<T>& ref); |
61 | |
62 | /** |
63 | * Destructor |
64 | */ |
65 | ~SmartPtr(); |
66 | |
67 | /** |
68 | * Copy operator |
69 | */ |
70 | const SmartPtr& operator=(const SmartPtr<T>& ref); |
71 | |
72 | /** |
73 | * Dereference operator. |
74 | * Returns reference to object hold by smart pointer |
75 | */ |
76 | T& operator*() const throw(PointerException); |
77 | |
78 | /** |
79 | * Member access operator |
80 | */ |
81 | T* operator->() const throw(PointerException); |
82 | |
83 | /** |
84 | * Returns underlying pointer |
85 | */ |
86 | T* get() const; |
87 | |
88 | /** |
89 | * Returns underlying pointer and releases it |
90 | * from management by the SmartPtr. |
91 | * Throws an exception if underlying pointer is |
92 | * hold by more than one SmartPtr. |
93 | */ |
94 | T* release() throw (PointerException); |
95 | |
96 | /** |
97 | * Resets SmartPtr to point to another object |
98 | */ |
99 | void reset(T* obj_ptr); |
100 | |
101 | /** |
102 | * Compares to pointers. |
103 | * Returns true, if both point to the same object, |
104 | * false otherwise |
105 | */ |
106 | bool operator==(const SmartPtr<T>& ref); |
107 | |
108 | }; |
109 | |
110 | template<class T> |
111 | std::map<T*, int> *suPHP::SmartPtr<T>::counter; |
112 | |
113 | template<class T> |
114 | suPHP::SmartPtr<T>::SmartPtr() { |
115 | if (SmartPtr<T>::counter == NULL) { |
116 | SmartPtr<T>::counter = new std::map<T*, int>; |
117 | } |
118 | this->ptr = NULL; |
119 | } |
120 | |
121 | template<class T> |
122 | suPHP::SmartPtr<T>::SmartPtr(T* obj_ptr) { |
123 | if (SmartPtr<T>::counter == NULL) { |
124 | SmartPtr<T>::counter = new std::map<T*, int>; |
125 | } |
126 | this->ptr = obj_ptr; |
127 | this->increment(obj_ptr); |
128 | } |
129 | |
130 | template<class T> |
131 | suPHP::SmartPtr<T>::SmartPtr(const SmartPtr<T>& ref) { |
132 | if (SmartPtr<T>::counter == NULL) { |
133 | SmartPtr<T>::counter = new std::map<T*, int>; |
134 | } |
135 | this->ptr = ref.ptr; |
136 | if (ref.ptr != NULL) |
137 | this->increment(ref.ptr); |
138 | } |
139 | |
140 | template<class T> |
141 | suPHP::SmartPtr<T>::~SmartPtr() { |
142 | if (this->ptr != NULL) |
143 | this->decrement(this->ptr); |
144 | if (SmartPtr<T>::counter != NULL && SmartPtr<T>::counter->size() == 0) { |
145 | delete SmartPtr<T>::counter; |
146 | SmartPtr<T>::counter = NULL; |
147 | } |
148 | } |
149 | |
150 | template<class T> |
151 | const SmartPtr<T>& suPHP::SmartPtr<T>::operator=( |
152 | const SmartPtr<T>& ref) { |
153 | this.reset(ref.ptr); |
154 | return *this; |
155 | } |
156 | |
157 | template<class T> |
158 | T& suPHP::SmartPtr<T>::operator*() const throw (PointerException) { |
159 | if (this->ptr == NULL) |
160 | throw PointerException("Cannot dereference NULL pointer", |
161 | __FILE__, __LINE__); |
162 | return *(this->ptr); |
163 | } |
164 | |
165 | template<class T> |
166 | T* suPHP::SmartPtr<T>::operator->() const throw (PointerException) { |
167 | if (this->ptr == NULL) |
168 | throw PointerException("Cannot access member of NULL pointer", |
169 | __FILE__, __LINE__); |
170 | return this->ptr; |
171 | } |
172 | |
173 | template<class T> |
174 | T* suPHP::SmartPtr<T>::get() const { |
175 | return this->ptr; |
176 | } |
177 | |
178 | template<class T> |
179 | T* suPHP::SmartPtr<T>::release() throw (PointerException) { |
180 | T* obj_ptr = this->ptr; |
181 | if (obj_ptr == NULL) |
182 | return NULL; |
183 | |
184 | int& c = SmartPtr<T>::counter->find(obj_ptr)->second; |
185 | |
186 | if (c > 1) { |
187 | throw PointerException( |
188 | "Cannot release object hold by more than one SmartPointer.", |
189 | __FILE__, __LINE__); |
190 | } else { |
191 | SmartPtr<T>::counter->erase(obj_ptr); |
192 | } |
193 | this->ptr = NULL; |
194 | return obj_ptr; |
195 | } |
196 | |
197 | template<class T> |
198 | void suPHP::SmartPtr<T>::reset(T* obj_ptr) { |
199 | if (obj_ptr != this->ptr) { |
200 | this->decrement(this->ptr); |
201 | this->ptr = obj_ptr; |
202 | this->increment(obj_ptr); |
203 | } |
204 | } |
205 | |
206 | template<class T> |
207 | void suPHP::SmartPtr<T>::increment(T* key_ptr) { |
208 | if (key_ptr == NULL) |
209 | return; |
210 | |
211 | if (SmartPtr<T>::counter->find(key_ptr) |
212 | != SmartPtr<T>::counter->end()) { |
213 | (SmartPtr<T>::counter->find(key_ptr)->second)++; |
214 | } else { |
215 | std::pair<T*, int> p; |
216 | p.first = key_ptr; |
217 | p.second = 1; |
218 | SmartPtr<T>::counter->insert(p); |
219 | } |
220 | } |
221 | |
222 | template<class T> |
223 | void suPHP::SmartPtr<T>::decrement(T* key_ptr) { |
224 | if (key_ptr == NULL) |
225 | return; |
226 | |
227 | int& c = SmartPtr<T>::counter->find(key_ptr)->second; |
228 | c--; |
229 | if (c < 1) { |
230 | delete key_ptr; |
231 | SmartPtr<T>::counter->erase(key_ptr); |
232 | } |
233 | } |
234 | |
235 | template<class T> |
236 | bool suPHP::SmartPtr<T>::operator==(const SmartPtr<T>& ref) { |
237 | if (this->get() == ref.get()) |
238 | return true; |
239 | else |
240 | return false; |
241 | } |
242 | |
243 | }; |
244 | |
245 | #endif // SUPHP_SMARTPTR_H |