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comparison array.c @ 22:ecdf21f1d0c6

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Added a new function array_swap() that swap elements by index
author David Demelier <markand@malikania.fr>
date Wed, 14 Sep 2011 20:24:14 +0200
parents e9a7b671d707
children 216b6e6a539c
comparison
equal deleted inserted replaced
21:ae4128d16c92 22:ecdf21f1d0c6
32 struct array *arr; 32 struct array *arr;
33 33
34 if (unit == 0 || !(arr = malloc(sizeof (struct array)))) 34 if (unit == 0 || !(arr = malloc(sizeof (struct array))))
35 return NULL; 35 return NULL;
36 36
37 arr->tmp = NULL;
38 arr->length = 0;
39 arr->flags = flags;
37 arr->bsize = (bsize == 0) ? ARRAY_DEFAULT_BSIZE : bsize; 40 arr->bsize = (bsize == 0) ? ARRAY_DEFAULT_BSIZE : bsize;
38 arr->flags = flags;
39 arr->unit = unit; 41 arr->unit = unit;
40 arr->size = SIZE(bsize); 42 arr->size = SIZE(arr->bsize);
41 arr->length = 0;
42 43
43 if (!(arr->data = malloc(arr->size))) { 44 if (!(arr->data = malloc(arr->size))) {
44 free(arr); 45 free(arr);
45 return NULL; 46 return NULL;
46 } 47 }
161 SIZE(arr->length - index)); 162 SIZE(arr->length - index));
162 memset(arr->data + SIZE(--arr->length), 0, arr->unit); 163 memset(arr->data + SIZE(--arr->length), 0, arr->unit);
163 164
164 return data; 165 return data;
165 } 166 }
167
168 /*
169 * Swap the two elements referenced by index `i1' and `i2'. This function needs
170 * to allocate data to swap elements thus if the functions fails it returns -1
171 * otherwise 0 is returned.
172 */
173
174 int
175 array_swap(struct array *arr, int i1, int i2)
176 {
177 /* Out of bounds */
178 if (i1 > arr->length - 1|| i1 < 0 || i2 > arr->length - 1|| i2 < 0)
179 return -1;
180
181 /*
182 * Only allocate at this time, the user may do not want to use this
183 * function.
184 */
185
186 if (!arr->tmp && !(arr->tmp = malloc(arr->unit)))
187 return -1;
188
189 memcpy(arr->tmp, arr->data + SIZE(i1), arr->unit);
190 memcpy(arr->data + SIZE(i1), arr->data + SIZE(i2), arr->unit);
191 memcpy(arr->data + SIZE(i2), arr->tmp, arr->unit);
192
193 return 0;
194 }
195
166 196
167 /* 197 /*
168 * Apply the function `fn' on each object and give the optional `udata' 198 * Apply the function `fn' on each object and give the optional `udata'
169 * argument to the function too. 199 * argument to the function too.
170 */ 200 */
223 void 253 void
224 array_free(struct array *arr) 254 array_free(struct array *arr)
225 { 255 {
226 array_clear(arr); 256 array_clear(arr);
227 257
228 free(arr->data); 258 if (arr->data)
259 free(arr->data);
260 if (arr->tmp)
261 free(arr->tmp);
262
229 free(arr); 263 free(arr);
230 } 264 }
231 265
232 /* 266 /*
233 * Increate the array storage when it is full. If the buffer is fixed size 267 * Increate the array storage when it is full. If the buffer is fixed size