J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 3 | * |
| 4 | * This code is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License version 2 only, as |
| 6 | * published by the Free Software Foundation. Sun designates this |
| 7 | * particular file as subject to the "Classpath" exception as provided |
| 8 | * by Sun in the LICENSE file that accompanied this code. |
| 9 | * |
| 10 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 13 | * version 2 for more details (a copy is included in the LICENSE file that |
| 14 | * accompanied this code). |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License version |
| 17 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 18 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 19 | * |
| 20 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 21 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 22 | * have any questions. |
| 23 | */ |
| 24 | /* $XConsortium: list.c /main/4 1996/10/14 15:03:56 swick $ */ |
| 25 | /** ------------------------------------------------------------------------ |
| 26 | This file contains routines for manipulating generic lists. |
| 27 | Lists are implemented with a "harness". In other words, each |
| 28 | node in the list consists of two pointers, one to the data item |
| 29 | and one to the next node in the list. The head of the list is |
| 30 | the same struct as each node, but the "item" ptr is used to point |
| 31 | to the current member of the list (used by the first_in_list and |
| 32 | next_in_list functions). |
| 33 | |
| 34 | This file is available under and governed by the GNU General Public |
| 35 | License version 2 only, as published by the Free Software Foundation. |
| 36 | However, the following notice accompanied the original version of this |
| 37 | file: |
| 38 | |
| 39 | Copyright (c) 1994 Hewlett-Packard Co. |
| 40 | Copyright (c) 1996 X Consortium |
| 41 | |
| 42 | Permission is hereby granted, free of charge, to any person obtaining |
| 43 | a copy of this software and associated documentation files (the |
| 44 | "Software"), to deal in the Software without restriction, including |
| 45 | without limitation the rights to use, copy, modify, merge, publish, |
| 46 | distribute, sublicense, and sell copies of the Software, and to |
| 47 | permit persons to whom the Software is furnished to do so, subject to |
| 48 | the following conditions: |
| 49 | |
| 50 | The above copyright notice and this permission notice shall be included |
| 51 | in all copies or substantial portions of the Software. |
| 52 | |
| 53 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| 54 | OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 55 | MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 56 | IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR |
| 57 | OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
| 58 | ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| 59 | OTHER DEALINGS IN THE SOFTWARE. |
| 60 | |
| 61 | Except as contained in this notice, the name of the X Consortium shall |
| 62 | not be used in advertising or otherwise to promote the sale, use or |
| 63 | other dealings in this Software without prior written authorization |
| 64 | from the X Consortium. |
| 65 | |
| 66 | ----------------------------------------------------------------------- **/ |
| 67 | |
| 68 | #include <stdio.h> |
| 69 | #include <malloc.h> |
| 70 | #include "list.h" |
| 71 | |
| 72 | |
| 73 | /** ------------------------------------------------------------------------ |
| 74 | Sets the pointers of the specified list to NULL. |
| 75 | --------------------------------------------------------------------- **/ |
| 76 | #if NeedFunctionPrototypes |
| 77 | void zero_list(list_ptr lp) |
| 78 | #else |
| 79 | void zero_list(lp) |
| 80 | list_ptr lp; |
| 81 | #endif |
| 82 | { |
| 83 | lp->next = NULL; |
| 84 | lp->ptr.item = NULL; |
| 85 | } |
| 86 | |
| 87 | |
| 88 | /** ------------------------------------------------------------------------ |
| 89 | Adds item to the list pointed to by lp. Finds the end of the |
| 90 | list, then mallocs a new list node onto the end of the list. |
| 91 | The item pointer in the new node is set to "item" passed in, |
| 92 | and the next pointer in the new node is set to NULL. |
| 93 | Returns 1 if successful, 0 if the malloc failed. |
| 94 | -------------------------------------------------------------------- **/ |
| 95 | #if NeedFunctionPrototypes |
| 96 | int32_t add_to_list(list_ptr lp, void *item) |
| 97 | #else |
| 98 | int32_t add_to_list(lp, item) |
| 99 | list_ptr lp; |
| 100 | void *item; |
| 101 | #endif |
| 102 | { |
| 103 | while (lp->next) { |
| 104 | lp = lp->next; |
| 105 | } |
| 106 | if ((lp->next = (list_ptr) malloc( sizeof( list_item))) == NULL) { |
| 107 | |
| 108 | return 0; |
| 109 | } |
| 110 | lp->next->ptr.item = item; |
| 111 | lp->next->next = NULL; |
| 112 | |
| 113 | return 1; |
| 114 | } |
| 115 | |
| 116 | |
| 117 | /** ------------------------------------------------------------------------ |
| 118 | Creates a new list and sets its pointers to NULL. |
| 119 | Returns a pointer to the new list. |
| 120 | -------------------------------------------------------------------- **/ |
| 121 | list_ptr new_list () |
| 122 | { |
| 123 | list_ptr lp; |
| 124 | |
| 125 | if (lp = (list_ptr) malloc( sizeof( list_item))) { |
| 126 | lp->next = NULL; |
| 127 | lp->ptr.item = NULL; |
| 128 | } |
| 129 | |
| 130 | return lp; |
| 131 | } |
| 132 | |
| 133 | |
| 134 | /** ------------------------------------------------------------------------ |
| 135 | Creates a new list head, pointing to the same list as the one |
| 136 | passed in. If start_at_curr is TRUE, the new list's first item |
| 137 | is the "current" item (as set by calls to first/next_in_list()). |
| 138 | If start_at_curr is FALSE, the first item in the new list is the |
| 139 | same as the first item in the old list. In either case, the |
| 140 | curr pointer in the new list is the same as in the old list. |
| 141 | Returns a pointer to the new list head. |
| 142 | -------------------------------------------------------------------- **/ |
| 143 | #if NeedFunctionPrototypes |
| 144 | list_ptr dup_list_head(list_ptr lp, int32_t start_at_curr) |
| 145 | #else |
| 146 | list_ptr dup_list_head(lp, start_at_curr) |
| 147 | list_ptr lp; |
| 148 | int32_t start_at_curr; |
| 149 | #endif |
| 150 | { |
| 151 | list_ptr new_list; |
| 152 | |
| 153 | if ((new_list = (list_ptr) malloc( sizeof( list_item))) == NULL) { |
| 154 | |
| 155 | return (list_ptr)NULL; |
| 156 | } |
| 157 | new_list->next = start_at_curr ? lp->ptr.curr : lp->next; |
| 158 | new_list->ptr.curr = lp->ptr.curr; |
| 159 | |
| 160 | return new_list; |
| 161 | } |
| 162 | |
| 163 | |
| 164 | /** ------------------------------------------------------------------------ |
| 165 | Returns the number of items in the list. |
| 166 | -------------------------------------------------------------------- **/ |
| 167 | #if NeedFunctionPrototypes |
| 168 | uint32_t list_length(list_ptr lp) |
| 169 | #else |
| 170 | uint32_t list_length(lp) |
| 171 | list_ptr lp; |
| 172 | #endif |
| 173 | { |
| 174 | uint32_t count = 0; |
| 175 | |
| 176 | while (lp->next) { |
| 177 | count++; |
| 178 | lp = lp->next; |
| 179 | } |
| 180 | |
| 181 | return count; |
| 182 | } |
| 183 | |
| 184 | |
| 185 | /** ------------------------------------------------------------------------ |
| 186 | Scans thru list, looking for a node whose ptr.item is equal to |
| 187 | the "item" passed in. "Equal" here means the same address - no |
| 188 | attempt is made to match equivalent values stored in different |
| 189 | locations. If a match is found, that node is deleted from the |
| 190 | list. Storage for the node is freed, but not for the item itself. |
| 191 | Returns a pointer to the item, so the caller can free it if it |
| 192 | so desires. If a match is not found, returns NULL. |
| 193 | -------------------------------------------------------------------- **/ |
| 194 | #if NeedFunctionPrototypes |
| 195 | void *delete_from_list(list_ptr lp, void *item) |
| 196 | #else |
| 197 | void *delete_from_list(lp, item) |
| 198 | list_ptr lp; |
| 199 | void *item; |
| 200 | #endif |
| 201 | { |
| 202 | list_ptr new_next; |
| 203 | |
| 204 | while (lp->next) { |
| 205 | if (lp->next->ptr.item == item) { |
| 206 | new_next = lp->next->next; |
| 207 | free (lp->next); |
| 208 | lp->next = new_next; |
| 209 | |
| 210 | return item; |
| 211 | } |
| 212 | lp = lp->next; |
| 213 | } |
| 214 | |
| 215 | return NULL; |
| 216 | } |
| 217 | |
| 218 | |
| 219 | /** ------------------------------------------------------------------------ |
| 220 | Deletes each node in the list *except the head*. This allows |
| 221 | the deletion of lists where the head is not malloced or created |
| 222 | with new_list(). If free_items is true, each item pointed to |
| 223 | from the node is freed, in addition to the node itself. |
| 224 | -------------------------------------------------------------------- **/ |
| 225 | #if NeedFunctionPrototypes |
| 226 | void delete_list(list_ptr lp, int32_t free_items) |
| 227 | #else |
| 228 | void delete_list(lp, free_items) |
| 229 | list_ptr lp; |
| 230 | int32_t free_items; |
| 231 | #endif |
| 232 | { |
| 233 | list_ptr del_node; |
| 234 | void *item; |
| 235 | |
| 236 | while (lp->next) { |
| 237 | del_node = lp->next; |
| 238 | item = del_node->ptr.item; |
| 239 | lp->next = del_node->next; |
| 240 | free (del_node); |
| 241 | if (free_items) { |
| 242 | free( item); |
| 243 | } |
| 244 | } |
| 245 | } |
| 246 | |
| 247 | #if NeedFunctionPrototypes |
| 248 | void delete_list_destroying(list_ptr lp, void destructor(void *item)) |
| 249 | #else |
| 250 | void delete_list_destroying(lp, destructor) |
| 251 | list_ptr lp; |
| 252 | void (*destructor)(); |
| 253 | #endif |
| 254 | { |
| 255 | list_ptr del_node; |
| 256 | void *item; |
| 257 | |
| 258 | while (lp->next) { |
| 259 | del_node = lp->next; |
| 260 | item = del_node->ptr.item; |
| 261 | lp->next = del_node->next; |
| 262 | free( del_node); |
| 263 | if (destructor) { |
| 264 | destructor( item); |
| 265 | } |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | |
| 270 | /** ------------------------------------------------------------------------ |
| 271 | Returns a ptr to the first *item* (not list node) in the list. |
| 272 | Sets the list head node's curr ptr to the first node in the list. |
| 273 | Returns NULL if the list is empty. |
| 274 | -------------------------------------------------------------------- **/ |
| 275 | #if NeedFunctionPrototypes |
| 276 | void * first_in_list(list_ptr lp) |
| 277 | #else |
| 278 | void * first_in_list(lp) |
| 279 | list_ptr lp; |
| 280 | #endif |
| 281 | { |
| 282 | if (! lp) { |
| 283 | |
| 284 | return NULL; |
| 285 | } |
| 286 | lp->ptr.curr = lp->next; |
| 287 | |
| 288 | return lp->ptr.curr ? lp->ptr.curr->ptr.item : NULL; |
| 289 | } |
| 290 | |
| 291 | /** ------------------------------------------------------------------------ |
| 292 | Returns a ptr to the next *item* (not list node) in the list. |
| 293 | Sets the list head node's curr ptr to the next node in the list. |
| 294 | first_in_list must have been called prior. |
| 295 | Returns NULL if no next item. |
| 296 | -------------------------------------------------------------------- **/ |
| 297 | #if NeedFunctionPrototypes |
| 298 | void * next_in_list(list_ptr lp) |
| 299 | #else |
| 300 | void * next_in_list(lp) |
| 301 | list_ptr lp; |
| 302 | #endif |
| 303 | { |
| 304 | if (! lp) { |
| 305 | |
| 306 | return NULL; |
| 307 | } |
| 308 | if (lp->ptr.curr) { |
| 309 | lp->ptr.curr = lp->ptr.curr->next; |
| 310 | } |
| 311 | |
| 312 | return lp->ptr.curr ? lp->ptr.curr->ptr.item : NULL; |
| 313 | } |
| 314 | |
| 315 | #if NeedFunctionPrototypes |
| 316 | int32_t list_is_empty(list_ptr lp) |
| 317 | #else |
| 318 | int32_t list_is_empty(lp) |
| 319 | list_ptr lp; |
| 320 | #endif |
| 321 | { |
| 322 | return (lp == NULL || lp->next == NULL); |
| 323 | } |