The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2007 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | #include "cutils/event_tag_map.h" |
| 17 | #include "cutils/log.h" |
| 18 | |
| 19 | #include <stdlib.h> |
| 20 | #include <string.h> |
| 21 | #include <fcntl.h> |
| 22 | #include <sys/mman.h> |
| 23 | #include <errno.h> |
| 24 | #include <assert.h> |
| 25 | |
| 26 | #define OUT_TAG "EventTagMap" |
| 27 | |
| 28 | /* |
| 29 | * Single entry. |
| 30 | */ |
| 31 | typedef struct EventTag { |
| 32 | unsigned int tagIndex; |
| 33 | const char* tagStr; |
| 34 | } EventTag; |
| 35 | |
| 36 | /* |
| 37 | * Map. |
| 38 | */ |
| 39 | struct EventTagMap { |
| 40 | /* memory-mapped source file; we get strings from here */ |
| 41 | void* mapAddr; |
| 42 | size_t mapLen; |
| 43 | |
| 44 | /* array of event tags, sorted numerically by tag index */ |
| 45 | EventTag* tagArray; |
| 46 | int numTags; |
| 47 | }; |
| 48 | |
| 49 | /* fwd */ |
| 50 | static int processFile(EventTagMap* map); |
| 51 | static int countMapLines(const EventTagMap* map); |
| 52 | static int parseMapLines(EventTagMap* map); |
| 53 | static int scanTagLine(char** pData, EventTag* tag, int lineNum); |
| 54 | static int sortTags(EventTagMap* map); |
| 55 | static void dumpTags(const EventTagMap* map); |
| 56 | |
| 57 | |
| 58 | /* |
| 59 | * Open the map file and allocate a structure to manage it. |
| 60 | * |
| 61 | * We create a private mapping because we want to terminate the log tag |
| 62 | * strings with '\0'. |
| 63 | */ |
| 64 | EventTagMap* android_openEventTagMap(const char* fileName) |
| 65 | { |
| 66 | EventTagMap* newTagMap; |
| 67 | off_t end; |
| 68 | int fd = -1; |
| 69 | |
| 70 | newTagMap = calloc(1, sizeof(EventTagMap)); |
| 71 | if (newTagMap == NULL) |
| 72 | return NULL; |
| 73 | |
| 74 | fd = open(fileName, O_RDONLY); |
| 75 | if (fd < 0) { |
| 76 | fprintf(stderr, "%s: unable to open map '%s': %s\n", |
| 77 | OUT_TAG, fileName, strerror(errno)); |
| 78 | goto fail; |
| 79 | } |
| 80 | |
| 81 | end = lseek(fd, 0L, SEEK_END); |
| 82 | (void) lseek(fd, 0L, SEEK_SET); |
| 83 | if (end < 0) { |
| 84 | fprintf(stderr, "%s: unable to seek map '%s'\n", OUT_TAG, fileName); |
| 85 | goto fail; |
| 86 | } |
| 87 | |
| 88 | newTagMap->mapAddr = mmap(NULL, end, PROT_READ | PROT_WRITE, MAP_PRIVATE, |
| 89 | fd, 0); |
| 90 | if (newTagMap->mapAddr == MAP_FAILED) { |
| 91 | fprintf(stderr, "%s: mmap(%s) failed: %s\n", |
| 92 | OUT_TAG, fileName, strerror(errno)); |
| 93 | goto fail; |
| 94 | } |
| 95 | newTagMap->mapLen = end; |
| 96 | |
| 97 | if (processFile(newTagMap) != 0) |
| 98 | goto fail; |
| 99 | |
| 100 | return newTagMap; |
| 101 | |
| 102 | fail: |
| 103 | android_closeEventTagMap(newTagMap); |
| 104 | if (fd >= 0) |
| 105 | close(fd); |
| 106 | return NULL; |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | * Close the map. |
| 111 | */ |
| 112 | void android_closeEventTagMap(EventTagMap* map) |
| 113 | { |
| 114 | if (map == NULL) |
| 115 | return; |
| 116 | |
| 117 | munmap(map->mapAddr, map->mapLen); |
| 118 | free(map); |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * Look up an entry in the map. |
| 123 | * |
| 124 | * The entries are sorted by tag number, so we can do a binary search. |
| 125 | */ |
| 126 | const char* android_lookupEventTag(const EventTagMap* map, int tag) |
| 127 | { |
| 128 | int hi, lo, mid; |
| 129 | |
| 130 | lo = 0; |
| 131 | hi = map->numTags-1; |
| 132 | |
| 133 | while (lo <= hi) { |
| 134 | int cmp; |
| 135 | |
| 136 | mid = (lo+hi)/2; |
| 137 | cmp = map->tagArray[mid].tagIndex - tag; |
| 138 | if (cmp < 0) { |
| 139 | /* tag is bigger */ |
| 140 | lo = mid + 1; |
| 141 | } else if (cmp > 0) { |
| 142 | /* tag is smaller */ |
| 143 | hi = mid - 1; |
| 144 | } else { |
| 145 | /* found */ |
| 146 | return map->tagArray[mid].tagStr; |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | return NULL; |
| 151 | } |
| 152 | |
| 153 | |
| 154 | |
| 155 | /* |
| 156 | * Determine whether "c" is a whitespace char. |
| 157 | */ |
| 158 | static inline int isCharWhitespace(char c) |
| 159 | { |
| 160 | return (c == ' ' || c == '\n' || c == '\r' || c == '\t'); |
| 161 | } |
| 162 | |
| 163 | /* |
| 164 | * Determine whether "c" is a valid tag char. |
| 165 | */ |
| 166 | static inline int isCharValidTag(char c) |
| 167 | { |
| 168 | return ((c >= 'A' && c <= 'Z') || |
| 169 | (c >= 'a' && c <= 'z') || |
| 170 | (c >= '0' && c <= '9') || |
| 171 | (c == '_')); |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * Determine whether "c" is a valid decimal digit. |
| 176 | */ |
| 177 | static inline int isCharDigit(char c) |
| 178 | { |
| 179 | return (c >= '0' && c <= '9'); |
| 180 | } |
| 181 | |
| 182 | |
| 183 | /* |
| 184 | * Crunch through the file, parsing the contents and creating a tag index. |
| 185 | */ |
| 186 | static int processFile(EventTagMap* map) |
| 187 | { |
| 188 | EventTag* tagArray = NULL; |
| 189 | |
| 190 | /* get a tag count */ |
| 191 | map->numTags = countMapLines(map); |
| 192 | if (map->numTags < 0) |
| 193 | return -1; |
| 194 | |
| 195 | //printf("+++ found %d tags\n", map->numTags); |
| 196 | |
| 197 | /* allocate storage for the tag index array */ |
| 198 | map->tagArray = calloc(1, sizeof(EventTag) * map->numTags); |
| 199 | if (map->tagArray == NULL) |
| 200 | return -1; |
| 201 | |
| 202 | /* parse the file, null-terminating tag strings */ |
| 203 | if (parseMapLines(map) != 0) { |
| 204 | fprintf(stderr, "%s: file parse failed\n", OUT_TAG); |
| 205 | return -1; |
| 206 | } |
| 207 | |
| 208 | /* sort the tags and check for duplicates */ |
| 209 | if (sortTags(map) != 0) |
| 210 | return -1; |
| 211 | |
| 212 | return 0; |
| 213 | } |
| 214 | |
| 215 | /* |
| 216 | * Run through all lines in the file, determining whether they're blank, |
| 217 | * comments, or possibly have a tag entry. |
| 218 | * |
| 219 | * This is a very "loose" scan. We don't try to detect syntax errors here. |
| 220 | * The later pass is more careful, but the number of tags found there must |
| 221 | * match the number of tags found here. |
| 222 | * |
| 223 | * Returns the number of potential tag entries found. |
| 224 | */ |
| 225 | static int countMapLines(const EventTagMap* map) |
| 226 | { |
| 227 | int numTags, unknown; |
| 228 | const char* cp; |
| 229 | const char* endp; |
| 230 | |
| 231 | cp = (const char*) map->mapAddr; |
| 232 | endp = cp + map->mapLen; |
| 233 | |
| 234 | numTags = 0; |
| 235 | unknown = 1; |
| 236 | while (cp < endp) { |
| 237 | if (*cp == '\n') { |
| 238 | unknown = 1; |
| 239 | } else if (unknown) { |
| 240 | if (isCharDigit(*cp)) { |
| 241 | /* looks like a tag to me */ |
| 242 | numTags++; |
| 243 | unknown = 0; |
| 244 | } else if (isCharWhitespace(*cp)) { |
| 245 | /* might be leading whitespace before tag num, keep going */ |
| 246 | } else { |
| 247 | /* assume comment; second pass can complain in detail */ |
| 248 | unknown = 0; |
| 249 | } |
| 250 | } else { |
| 251 | /* we've made up our mind; just scan to end of line */ |
| 252 | } |
| 253 | cp++; |
| 254 | } |
| 255 | |
| 256 | return numTags; |
| 257 | } |
| 258 | |
| 259 | /* |
| 260 | * Parse the tags out of the file. |
| 261 | */ |
| 262 | static int parseMapLines(EventTagMap* map) |
| 263 | { |
| 264 | int tagNum, lineStart, lineNum; |
| 265 | char* cp; |
| 266 | char* endp; |
| 267 | |
| 268 | cp = (char*) map->mapAddr; |
| 269 | endp = cp + map->mapLen; |
| 270 | |
| 271 | /* insist on EOL at EOF; simplifies parsing and null-termination */ |
| 272 | if (*(endp-1) != '\n') { |
| 273 | fprintf(stderr, "%s: map file missing EOL on last line\n", OUT_TAG); |
| 274 | return -1; |
| 275 | } |
| 276 | |
| 277 | tagNum = 0; |
| 278 | lineStart = 1; |
| 279 | lineNum = 1; |
| 280 | while (cp < endp) { |
| 281 | //printf("{%02x}", *cp); fflush(stdout); |
| 282 | if (*cp == '\n') { |
| 283 | lineStart = 1; |
| 284 | lineNum++; |
| 285 | } else if (lineStart) { |
| 286 | if (*cp == '#') { |
| 287 | /* comment; just scan to end */ |
| 288 | lineStart = 0; |
| 289 | } else if (isCharDigit(*cp)) { |
| 290 | /* looks like a tag; scan it out */ |
| 291 | if (tagNum >= map->numTags) { |
| 292 | fprintf(stderr, |
| 293 | "%s: more tags than expected (%d)\n", OUT_TAG, tagNum); |
| 294 | return -1; |
| 295 | } |
| 296 | if (scanTagLine(&cp, &map->tagArray[tagNum], lineNum) != 0) |
| 297 | return -1; |
| 298 | tagNum++; |
| 299 | lineNum++; // we eat the '\n' |
| 300 | /* leave lineStart==1 */ |
| 301 | } else if (isCharWhitespace(*cp)) { |
| 302 | /* looks like leading whitespace; keep scanning */ |
| 303 | } else { |
| 304 | fprintf(stderr, |
| 305 | "%s: unexpected chars (0x%02x) in tag number on line %d\n", |
| 306 | OUT_TAG, *cp, lineNum); |
| 307 | return -1; |
| 308 | } |
| 309 | } else { |
| 310 | /* this is a blank or comment line */ |
| 311 | } |
| 312 | cp++; |
| 313 | } |
| 314 | |
| 315 | if (tagNum != map->numTags) { |
| 316 | fprintf(stderr, "%s: parsed %d tags, expected %d\n", |
| 317 | OUT_TAG, tagNum, map->numTags); |
| 318 | return -1; |
| 319 | } |
| 320 | |
| 321 | return 0; |
| 322 | } |
| 323 | |
| 324 | /* |
| 325 | * Scan one tag line. |
| 326 | * |
| 327 | * "*pData" should be pointing to the first digit in the tag number. On |
| 328 | * successful return, it will be pointing to the last character in the |
| 329 | * tag line (i.e. the character before the start of the next line). |
| 330 | * |
| 331 | * Returns 0 on success, nonzero on failure. |
| 332 | */ |
| 333 | static int scanTagLine(char** pData, EventTag* tag, int lineNum) |
| 334 | { |
| 335 | char* cp = *pData; |
| 336 | char* startp; |
| 337 | char* endp; |
| 338 | unsigned long val; |
| 339 | |
| 340 | startp = cp; |
| 341 | while (isCharDigit(*++cp)) |
| 342 | ; |
| 343 | *cp = '\0'; |
| 344 | |
| 345 | val = strtoul(startp, &endp, 10); |
| 346 | assert(endp == cp); |
| 347 | if (endp != cp) |
| 348 | fprintf(stderr, "ARRRRGH\n"); |
| 349 | |
| 350 | tag->tagIndex = val; |
| 351 | |
| 352 | while (*++cp != '\n' && isCharWhitespace(*cp)) |
| 353 | ; |
| 354 | |
| 355 | if (*cp == '\n') { |
| 356 | fprintf(stderr, |
| 357 | "%s: missing tag string on line %d\n", OUT_TAG, lineNum); |
| 358 | return -1; |
| 359 | } |
| 360 | |
| 361 | tag->tagStr = cp; |
| 362 | |
| 363 | while (isCharValidTag(*++cp)) |
| 364 | ; |
| 365 | |
| 366 | if (*cp == '\n') { |
| 367 | /* null terminate and return */ |
| 368 | *cp = '\0'; |
| 369 | } else if (isCharWhitespace(*cp)) { |
| 370 | /* CRLF or trailin spaces; zap this char, then scan for the '\n' */ |
| 371 | *cp = '\0'; |
| 372 | |
| 373 | /* just ignore the rest of the line till \n |
| 374 | TODO: read the tag description that follows the tag name |
| 375 | */ |
| 376 | while (*++cp != '\n') { |
| 377 | } |
| 378 | } else { |
| 379 | fprintf(stderr, |
| 380 | "%s: invalid tag chars on line %d\n", OUT_TAG, lineNum); |
| 381 | return -1; |
| 382 | } |
| 383 | |
| 384 | *pData = cp; |
| 385 | |
| 386 | //printf("+++ Line %d: got %d '%s'\n", lineNum, tag->tagIndex, tag->tagStr); |
| 387 | return 0; |
| 388 | } |
| 389 | |
| 390 | /* |
| 391 | * Compare two EventTags. |
| 392 | */ |
| 393 | static int compareEventTags(const void* v1, const void* v2) |
| 394 | { |
| 395 | const EventTag* tag1 = (const EventTag*) v1; |
| 396 | const EventTag* tag2 = (const EventTag*) v2; |
| 397 | |
| 398 | return tag1->tagIndex - tag2->tagIndex; |
| 399 | } |
| 400 | |
| 401 | /* |
| 402 | * Sort the EventTag array so we can do fast lookups by tag index. After |
| 403 | * the sort we do a quick check for duplicate tag indices. |
| 404 | * |
| 405 | * Returns 0 on success. |
| 406 | */ |
| 407 | static int sortTags(EventTagMap* map) |
| 408 | { |
| 409 | int i; |
| 410 | |
| 411 | qsort(map->tagArray, map->numTags, sizeof(EventTag), compareEventTags); |
| 412 | |
| 413 | for (i = 1; i < map->numTags; i++) { |
| 414 | if (map->tagArray[i].tagIndex == map->tagArray[i-1].tagIndex) { |
| 415 | fprintf(stderr, "%s: duplicate tag entries (%d:%s and %d:%s)\n", |
| 416 | OUT_TAG, |
| 417 | map->tagArray[i].tagIndex, map->tagArray[i].tagStr, |
| 418 | map->tagArray[i-1].tagIndex, map->tagArray[i-1].tagStr); |
| 419 | return -1; |
| 420 | } |
| 421 | } |
| 422 | |
| 423 | return 0; |
| 424 | } |
| 425 | |
| 426 | /* |
| 427 | * Dump the tag array for debugging. |
| 428 | */ |
| 429 | static void dumpTags(const EventTagMap* map) |
| 430 | { |
| 431 | int i; |
| 432 | |
| 433 | for (i = 0; i < map->numTags; i++) { |
| 434 | const EventTag* tag = &map->tagArray[i]; |
| 435 | printf(" %3d: %6d '%s'\n", i, tag->tagIndex, tag->tagStr); |
| 436 | } |
| 437 | } |
| 438 | |