[98] | 1 | /* |
---|
| 2 | * Copyright (C) 2008 Timothy D. Morgan |
---|
| 3 | * |
---|
| 4 | * This program is free software; you can redistribute it and/or modify |
---|
| 5 | * it under the terms of the GNU General Public License as published by |
---|
| 6 | * the Free Software Foundation; version 3 of the License. |
---|
| 7 | * |
---|
| 8 | * This program is distributed in the hope that it will be useful, |
---|
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
---|
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
---|
| 11 | * GNU General Public License for more details. |
---|
| 12 | * |
---|
| 13 | * You should have received a copy of the GNU General Public License |
---|
| 14 | * along with this program; if not, write to the Free Software |
---|
| 15 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
---|
| 16 | * |
---|
| 17 | * $Id: $ |
---|
| 18 | */ |
---|
| 19 | |
---|
| 20 | #include <math.h> |
---|
| 21 | #include "../include/range_list.h" |
---|
| 22 | |
---|
| 23 | |
---|
| 24 | /*******************/ |
---|
| 25 | /* Private symbols */ |
---|
| 26 | /*******************/ |
---|
| 27 | #define RANGE_LIST_ALLOC_SIZE 256 |
---|
| 28 | |
---|
| 29 | /* |
---|
| 30 | * Inserts elem into rl at the specified index and updates rl->size. |
---|
| 31 | * Memory reallocation of rl->elements is handled when necessary, and |
---|
| 32 | * rl->elem_alloced is updated in this case.. Returns false if memory |
---|
| 33 | * could not be allocated. |
---|
| 34 | */ |
---|
| 35 | static bool range_list_insert(range_list* rl, range_list_element* elem, uint32_t index) |
---|
| 36 | { |
---|
| 37 | uint32_t i; |
---|
| 38 | range_list_element** tmp; |
---|
| 39 | |
---|
| 40 | if(rl->size == rl->elem_alloced) |
---|
| 41 | { |
---|
| 42 | tmp = (range_list_element**)realloc(rl->elements, rl->elem_alloced+RANGE_LIST_ALLOC_SIZE); |
---|
| 43 | if(tmp == NULL) |
---|
| 44 | return false; |
---|
| 45 | rl->elements = tmp; |
---|
| 46 | rl->elem_alloced += RANGE_LIST_ALLOC_SIZE; |
---|
| 47 | } |
---|
| 48 | |
---|
| 49 | /* Do the shuffle to the right. */ |
---|
| 50 | for(i=rl->size; i > index; i--) |
---|
| 51 | rl->elements[i] = rl->elements[i-1]; |
---|
| 52 | rl->elements[index] = elem; |
---|
| 53 | |
---|
| 54 | rl->size++; |
---|
| 55 | return true; |
---|
| 56 | } |
---|
| 57 | |
---|
| 58 | /* |
---|
| 59 | * Finds the element with the closest offset to that provided, such that |
---|
| 60 | * the element's offset <= the provided offset. If no such element |
---|
| 61 | * exists, this returns -1 which indicates that the provided offset |
---|
| 62 | * appears before all elements. |
---|
| 63 | */ |
---|
| 64 | static int32_t range_list_find_previous(const range_list* rl, uint32_t offset) |
---|
| 65 | { |
---|
| 66 | uint32_t h_idx, l_idx, cur_idx; |
---|
| 67 | uint32_t h_val, l_val; |
---|
| 68 | range_list_element* cur_elem; |
---|
| 69 | |
---|
| 70 | if((rl->size == 0) || (offset < rl->elements[0]->offset)) |
---|
| 71 | return -1; |
---|
| 72 | |
---|
| 73 | if(offset >= rl->elements[rl->size-1]->offset) |
---|
| 74 | return rl->size-1; |
---|
| 75 | |
---|
| 76 | h_idx = rl->size-1; |
---|
| 77 | l_idx = 0; |
---|
| 78 | while(h_idx != l_idx) |
---|
| 79 | { |
---|
| 80 | h_val = rl->elements[h_idx]->offset + rl->elements[h_idx]->length; |
---|
| 81 | l_val = rl->elements[l_idx]->offset; |
---|
| 82 | /* Make an educated guess as to the "middle" index based on the |
---|
| 83 | * ratios of the offset and high/low values. |
---|
| 84 | */ |
---|
| 85 | cur_idx = (uint32_t)ceil((((double)offset-l_val)/(h_val-l_val))*(h_idx-l_idx)); |
---|
| 86 | if(cur_idx > h_idx) |
---|
| 87 | cur_idx = h_idx; |
---|
| 88 | if(cur_idx < l_idx) |
---|
| 89 | cur_idx = l_idx; |
---|
| 90 | cur_elem = rl->elements[cur_idx]; |
---|
| 91 | |
---|
| 92 | if((offset >= cur_elem->offset) && (offset < (cur_elem+1)->offset)) |
---|
| 93 | return cur_idx; |
---|
| 94 | |
---|
| 95 | if(offset < cur_elem->offset) |
---|
| 96 | h_idx = cur_idx-1; |
---|
| 97 | else |
---|
| 98 | l_idx = cur_idx+1; |
---|
| 99 | } |
---|
| 100 | |
---|
| 101 | return h_idx; |
---|
| 102 | } |
---|
| 103 | |
---|
| 104 | |
---|
| 105 | /******************/ |
---|
| 106 | /* Public symbols */ |
---|
| 107 | /******************/ |
---|
| 108 | range_list* range_list_new() |
---|
| 109 | { |
---|
| 110 | range_list* rl; |
---|
| 111 | |
---|
| 112 | rl = (range_list*)malloc(sizeof(range_list*)); |
---|
| 113 | if(rl == NULL) |
---|
| 114 | return NULL; |
---|
| 115 | |
---|
| 116 | rl->elements = (range_list_element**)malloc(sizeof(range_list_element*) |
---|
| 117 | * RANGE_LIST_ALLOC_SIZE); |
---|
| 118 | if(rl->elements == NULL) |
---|
| 119 | { |
---|
| 120 | free(rl); |
---|
| 121 | return NULL; |
---|
| 122 | } |
---|
| 123 | |
---|
| 124 | rl->elem_alloced = RANGE_LIST_ALLOC_SIZE; |
---|
| 125 | rl->size = 0; |
---|
| 126 | |
---|
| 127 | return rl; |
---|
| 128 | } |
---|
| 129 | |
---|
| 130 | |
---|
| 131 | void range_list_free(range_list* rl) |
---|
| 132 | { |
---|
| 133 | uint32_t i; |
---|
| 134 | for(i=0; i < rl->size; i++) |
---|
| 135 | free(rl->elements[i]); |
---|
| 136 | |
---|
| 137 | free(rl->elements); |
---|
| 138 | free(rl); |
---|
| 139 | } |
---|
| 140 | |
---|
| 141 | |
---|
| 142 | uint32_t range_list_size(const range_list* rl) |
---|
| 143 | { |
---|
| 144 | return rl->size; |
---|
| 145 | } |
---|
| 146 | |
---|
| 147 | |
---|
| 148 | |
---|
| 149 | bool range_list_add(range_list* rl, uint32_t offset, uint32_t length, void* data) |
---|
| 150 | { |
---|
| 151 | uint32_t insert_index; |
---|
| 152 | range_list_element* elem; |
---|
| 153 | range_list_element* prev_elem; |
---|
| 154 | |
---|
| 155 | /* Sorry, limited to 2**31-1 elements. */ |
---|
| 156 | if(rl->size >= 0x7FFFFFFF) |
---|
| 157 | return false; |
---|
| 158 | |
---|
| 159 | /* 0-length ranges aren't allowed. */ |
---|
| 160 | if(length == 0) |
---|
| 161 | return false; |
---|
| 162 | |
---|
| 163 | /* Check for integer overflows */ |
---|
| 164 | if((uint32_t)(offset+length) < offset || (uint32_t)(offset+length) < length) |
---|
| 165 | return false; |
---|
| 166 | |
---|
| 167 | /* Find insertion point and validate there are no overlaps */ |
---|
| 168 | insert_index = range_list_find_previous(rl, offset)+1; |
---|
| 169 | |
---|
| 170 | /* Does the previous element overlap with this one? */ |
---|
| 171 | if(insert_index > 0) |
---|
| 172 | { |
---|
| 173 | prev_elem = rl->elements[insert_index-1]; |
---|
| 174 | if(offset < prev_elem->length + prev_elem->offset) |
---|
| 175 | return false; |
---|
| 176 | } |
---|
| 177 | |
---|
| 178 | /* Does this new element overlap with the next one? */ |
---|
| 179 | if((insert_index+1 < rl->size) |
---|
| 180 | && (offset+length > rl->elements[insert_index+1]->offset)) |
---|
| 181 | return false; |
---|
| 182 | |
---|
| 183 | elem = (range_list_element*)malloc(sizeof(range_list_element)); |
---|
| 184 | if(elem == NULL) |
---|
| 185 | return false; |
---|
| 186 | elem->offset = offset; |
---|
| 187 | elem->length = length; |
---|
| 188 | elem->data = data; |
---|
| 189 | |
---|
| 190 | if(!range_list_insert(rl, elem, insert_index)) |
---|
| 191 | { |
---|
| 192 | free(elem); |
---|
| 193 | return false; |
---|
| 194 | } |
---|
| 195 | |
---|
| 196 | return true; |
---|
| 197 | } |
---|
| 198 | |
---|
| 199 | |
---|
| 200 | bool range_list_remove(range_list* rl, uint32_t index) |
---|
| 201 | { |
---|
| 202 | uint32_t i; |
---|
| 203 | range_list_element** tmp; |
---|
| 204 | |
---|
| 205 | if(index >= rl->size) |
---|
| 206 | return false; |
---|
| 207 | |
---|
| 208 | free(rl->elements[index]); |
---|
| 209 | |
---|
| 210 | /* Do the shuffle to the left. */ |
---|
| 211 | for(i=index; i < (rl->size-1); i++) |
---|
| 212 | rl->elements[i] = rl->elements[i+1]; |
---|
| 213 | rl->elements[rl->size-1] = NULL; |
---|
| 214 | rl->size--; |
---|
| 215 | |
---|
| 216 | /* Try to keep memory usage down */ |
---|
| 217 | if(rl->size < (rl->elem_alloced - 2*RANGE_LIST_ALLOC_SIZE)) |
---|
| 218 | { |
---|
| 219 | tmp = (range_list_element**)realloc(rl->elements, |
---|
| 220 | rl->elem_alloced - 2*RANGE_LIST_ALLOC_SIZE); |
---|
| 221 | if(tmp != NULL) |
---|
| 222 | { |
---|
| 223 | rl->elements = tmp; |
---|
| 224 | rl->elem_alloced -= 2*RANGE_LIST_ALLOC_SIZE; |
---|
| 225 | } |
---|
| 226 | } |
---|
| 227 | |
---|
| 228 | return true; |
---|
| 229 | } |
---|
| 230 | |
---|
| 231 | |
---|
| 232 | const range_list_element* range_list_get(const range_list* rl, uint32_t index) |
---|
| 233 | { |
---|
| 234 | if(index >= rl->size) |
---|
| 235 | return NULL; |
---|
| 236 | |
---|
| 237 | return rl->elements[index]; |
---|
| 238 | } |
---|
| 239 | |
---|
| 240 | |
---|
| 241 | int32_t range_list_find(const range_list* rl, uint32_t offset) |
---|
| 242 | { |
---|
| 243 | uint32_t prev_idx; |
---|
| 244 | range_list_element* elem; |
---|
| 245 | |
---|
| 246 | if((offset < rl->elements[0]->offset) |
---|
| 247 | || (offset > rl->elements[rl->size-1]->offset |
---|
| 248 | + rl->elements[rl->size-1]->length)) |
---|
| 249 | return -1; |
---|
| 250 | |
---|
| 251 | prev_idx = range_list_find_previous(rl, offset); |
---|
| 252 | elem = rl->elements[prev_idx]; |
---|
| 253 | if(offset < elem->offset+elem->length) |
---|
| 254 | return prev_idx; |
---|
| 255 | |
---|
| 256 | return -2; |
---|
| 257 | } |
---|
| 258 | |
---|
| 259 | |
---|
| 260 | void* range_list_find_data(const range_list* rl, uint32_t offset) |
---|
| 261 | { |
---|
| 262 | int32_t index = range_list_find(rl, offset); |
---|
| 263 | if(index < 0) |
---|
| 264 | return NULL; |
---|
| 265 | |
---|
| 266 | return rl->elements[index]->data; |
---|
| 267 | } |
---|
| 268 | |
---|
| 269 | |
---|
| 270 | bool range_list_split_element(range_list* rl, uint32_t index, uint32_t offset) |
---|
| 271 | { |
---|
| 272 | range_list_element* cur_elem; |
---|
| 273 | range_list_element* new_elem; |
---|
| 274 | |
---|
| 275 | if(index >= rl->size) |
---|
| 276 | return false; |
---|
| 277 | |
---|
| 278 | cur_elem = rl->elements[index]; |
---|
| 279 | if((offset <= cur_elem->offset) |
---|
| 280 | || (offset >= cur_elem->offset+cur_elem->length)) |
---|
| 281 | return false; |
---|
| 282 | |
---|
| 283 | new_elem = (range_list_element*)malloc(sizeof(range_list_element)); |
---|
| 284 | if(new_elem == NULL) |
---|
| 285 | return false; |
---|
| 286 | |
---|
| 287 | new_elem->offset = offset; |
---|
| 288 | new_elem->length = cur_elem->offset + cur_elem->length - offset; |
---|
| 289 | new_elem->data = cur_elem->data; |
---|
| 290 | |
---|
| 291 | if(!range_list_insert(rl, new_elem, index+1)) |
---|
| 292 | { |
---|
| 293 | free(new_elem); |
---|
| 294 | return false; |
---|
| 295 | } |
---|
| 296 | |
---|
| 297 | cur_elem->length = new_elem->offset - cur_elem->offset; |
---|
| 298 | |
---|
| 299 | return true; |
---|
| 300 | } |
---|