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comparison LinkedList.c @ 13:54aa96ae8912

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Added LinkedList class to project. ALmixer now saves ALmixer_Data instances in a private linked list so when Quit is called, this memory can be cleaned up. This is meant to deal with two problems. First, SDL_sound does something similar which means since I wrap SDL_sound structures, I may be left with dangling pointers if. Second is the obvious auto-cleanup when quiting which is convenient for resetting.
author Eric Wing <ewing . public |-at-| gmail . com>
date Sat, 06 Nov 2010 00:37:29 -0700
parents
children b27f7ff5e44b
comparison
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12:bfe90b4f3d87 13:54aa96ae8912
1 #include "LinkedList.h"
2 #include <stddef.h> /* for NULL */
3 #include <stdlib.h> /* for malloc/free */
4 #include <stdio.h> /* for debugging */
5
6 struct LinkedListNode
7 {
8 LinkedListNode* nextNode;
9 LinkedListNode* previousNode;
10 void* dataPtr;
11 };
12
13 struct LinkedList
14 {
15 size_t currentSize;
16 LinkedListNode* headPtr;
17 LinkedListNode* tailPtr;
18 };
19
20
21 LinkedListNode* LinkedListNode_Create()
22 {
23 LinkedListNode* list_node;
24 list_node = (LinkedListNode*)calloc(1, sizeof(LinkedListNode));
25 if(NULL == list_node)
26 {
27 /* Very bad, but not sure what to do here. */
28 return NULL;
29 }
30
31 return list_node;
32 }
33
34
35 void LinkedListNode_Free(LinkedListNode* list_node)
36 {
37 if(NULL == list_node)
38 {
39 return;
40 }
41 free(list_node);
42 }
43
44
45 LinkedList* LinkedList_Create()
46 {
47 LinkedList* linked_list;
48 linked_list = (LinkedList*)calloc(1, sizeof(LinkedList));
49 if(NULL == linked_list)
50 {
51 /* Very bad, but not sure what to do here. */
52 return NULL;
53 }
54
55 return linked_list;
56 }
57
58 void LinkedList_Free(LinkedList* linked_list)
59 {
60 /* Both functions check for NULL */
61 LinkedList_Clear(linked_list);
62 free(linked_list);
63 }
64
65
66 /**
67 * Returns 1 if successful, 0 if failure.
68 */
69 unsigned int LinkedList_PushFront(LinkedList* linked_list, void* new_item)
70 {
71 LinkedListNode* new_node;
72
73 if(NULL == linked_list)
74 {
75 return 0;
76 }
77
78 new_node = LinkedListNode_Create();
79 if(NULL == new_node)
80 {
81 return 0;
82 }
83
84 new_node->dataPtr = new_item;
85
86 if(0 == linked_list->currentSize)
87 {
88 linked_list->tailPtr = new_node;
89 }
90 else
91 {
92 LinkedListNode* head_node = linked_list->headPtr;
93 new_node->nextNode = head_node;
94 head_node->previousNode = new_node;
95 }
96
97 linked_list->headPtr = new_node;
98 linked_list->currentSize++;
99 return 1;
100 }
101
102 unsigned int LinkedList_PushBack(LinkedList* linked_list, void* new_item)
103 {
104 LinkedListNode* new_node;
105
106 if(NULL == linked_list)
107 {
108 return 0;
109 }
110
111 new_node = LinkedListNode_Create();
112 if(NULL == new_node)
113 {
114 return 0;
115 }
116
117 new_node->dataPtr = new_item;
118
119 if(0 == linked_list->currentSize)
120 {
121 linked_list->headPtr = new_node;
122 }
123 else
124 {
125 LinkedListNode* tail_node = linked_list->tailPtr;
126 new_node->previousNode = tail_node;
127 tail_node->nextNode = new_node;
128 }
129
130 linked_list->tailPtr = new_node;
131 linked_list->currentSize++;
132 return 1;
133
134 }
135
136 void* LinkedList_PopFront(LinkedList* linked_list)
137 {
138 LinkedListNode* head_node;
139 void* return_data;
140
141 if(NULL == linked_list)
142 {
143 return 0;
144 }
145 if(0 == linked_list->currentSize)
146 {
147 return NULL;
148 }
149
150 head_node = linked_list->headPtr;
151 return_data = head_node->dataPtr;
152
153 if(1 == linked_list->currentSize)
154 {
155 LinkedList_Clear(linked_list);
156 }
157 else
158 {
159 LinkedListNode* next_node = head_node->nextNode;
160 next_node->previousNode = NULL;
161 LinkedListNode_Free(head_node);
162 linked_list->headPtr = next_node;
163 linked_list->currentSize = linked_list->currentSize - 1;
164
165 }
166 return return_data;
167 }
168
169 void* LinkedList_PopBack(LinkedList* linked_list)
170 {
171 LinkedListNode* tail_node;
172 void* return_data;
173
174 if(NULL == linked_list)
175 {
176 return NULL;
177 }
178 if(0 == linked_list->currentSize)
179 {
180 return NULL;
181 }
182
183 tail_node = linked_list->tailPtr;
184 return_data = tail_node->dataPtr;
185
186 if(1 == linked_list->currentSize)
187 {
188 LinkedList_Clear(linked_list);
189 }
190 else
191 {
192 LinkedListNode* previous_node = tail_node->previousNode;
193 previous_node->nextNode = NULL;
194 LinkedListNode_Free(tail_node);
195 linked_list->tailPtr = previous_node;
196 linked_list->currentSize = linked_list->currentSize - 1;
197 }
198 return return_data;
199 }
200
201 size_t LinkedList_Size(LinkedList* linked_list)
202 {
203 if(NULL == linked_list)
204 {
205 return 0;
206 }
207 return linked_list->currentSize;
208 }
209
210 void LinkedList_Clear(LinkedList* linked_list)
211 {
212 if(NULL == linked_list)
213 {
214 return;
215 }
216
217 LinkedListNode* current_node = linked_list->headPtr;
218 LinkedListNode* next_node;
219 while(NULL != current_node)
220 {
221 next_node = current_node->nextNode;
222 LinkedListNode_Free(current_node);
223 current_node = next_node;
224 }
225 linked_list->headPtr = NULL;
226 linked_list->tailPtr = NULL;
227 linked_list->currentSize = 0;
228 }
229
230 void* LinkedListNode_GetData(LinkedListNode* list_node)
231 {
232 if(NULL == list_node)
233 {
234 return NULL;
235 }
236 return list_node->dataPtr;
237 }
238
239 LinkedListNode* LinkedList_Find(LinkedList* linked_list, void* the_data, LinkedListNode* start_node)
240 {
241 LinkedListNode* current_node;
242 if(NULL == linked_list)
243 {
244 return;
245 }
246 if(NULL == start_node)
247 {
248 start_node = linked_list->headPtr;
249 }
250
251 for(current_node = start_node; NULL != current_node; current_node = current_node->nextNode)
252 {
253 if(current_node->dataPtr == the_data)
254 {
255 return current_node;
256 }
257 }
258 return current_node;
259 }
260
261 /* Make sure your LinkedListNode is actually connected to the
262 * LinkedList instance you pass.
263 */
264 unsigned int LinkedList_Remove(LinkedList* linked_list, LinkedListNode* list_node)
265 {
266 LinkedListNode* previous_node;
267 LinkedListNode* next_node;
268 if(NULL == linked_list)
269 {
270 return 0;
271 }
272 if(NULL == list_node)
273 {
274 return 0;
275 }
276
277 if(1 == linked_list->currentSize)
278 {
279 LinkedList_Clear(linked_list);
280 }
281 else if(list_node == linked_list->headPtr)
282 {
283 LinkedList_PopFront(linked_list);
284 }
285 else if(list_node == linked_list->tailPtr)
286 {
287 LinkedList_PopBack(linked_list);
288 }
289 else
290 {
291 previous_node = list_node->previousNode;
292 next_node = list_node->nextNode;
293
294 previous_node->nextNode = next_node;
295 next_node->previousNode = previous_node;
296 LinkedListNode_Free(list_node);
297
298 linked_list->currentSize = linked_list->currentSize - 1;
299 }
300
301 return 1;
302
303 }
304
305
306