Source:NetHack 3.2.0/dlb.c
(Redirected from NetHack 3.2.0/dlb.c)
Jump to navigation
Jump to search
Below is the full text to dlb.c from the source code of NetHack 3.2.0.
Warning! This is the source code from an old release. For newer releases, see Source code
The NetHack General Public License applies to screenshots, source code and other content from NetHack.
This content was modified from the original NetHack source code distribution (by splitting up NetHack content between wiki pages, and possibly further editing). See the page history for a list of who changed it, and on what dates.
1. /* SCCS Id: @(#)dlb.c 3.2 96/02/14 */ 2. /* Copyright (c) Kenneth Lorber, Bethesda, Maryland, 1993. */ 3. /* NetHack may be freely redistributed. See license for details. */ 4. 5. #include "config.h" 6. #include "dlb.h" 7. 8. #ifdef DLB 9. /* 10. * Data librarian. Present a STDIO-like interface to NetHack while 11. * multiplexing on one or more "data" libraries. If a file is not found 12. * in a given library, look for it outside the libraries. 13. * 14. * When initialized, we open all library files and read in their tables 15. * of contents. The library files stay open all the time. When 16. * a open is requested, the libraries' directories are searched. If 17. * successful, we return a descriptor that contains the library, file 18. * size, and current file mark. This descriptor is used for all 19. * successive calls. 20. * 21. * The ability to open more than one library is supported but used 22. * only in the Amiga port (the second library holds the sound files). 23. * For Unix, the idea would be to split the NetHack library 24. * into text and binary parts, where the text version could be shared. 25. */ 26. 27. 28. #define MAX_LIBS 4 29. static library dlb_libs[MAX_LIBS]; 30. static boolean dlb_initialized = FALSE; 31. 32. static boolean FDECL(readlibdir,(library *lp)); 33. static boolean FDECL(find_file,(const char *name, library **lib, long *startp, 34. long *sizep)); 35. 36. /* not static because shared with dlb_main.c */ 37. boolean FDECL(open_library,(const char *lib_name, library *lp)); 38. void FDECL(close_library,(library *lp)); 39. 40. /* without extern.h via hack.h, these haven't been declared for us */ 41. extern char *FDECL(eos, (char *)); 42. extern FILE *FDECL(fopen_datafile, (const char *,const char *)); 43. 44. /* 45. * Read the directory out of the library. Return 1 if successful, 46. * 0 if it failed. 47. * 48. * NOTE: An improvement of the file structure should be the file 49. * size as part of the directory entry or perhaps in place of the 50. * offset -- the offset can be calculated by a running tally of 51. * the sizes. 52. * 53. * Library file structure: 54. * 55. * HEADER: 56. * %3ld library FORMAT revision (currently rev 1) 57. * %1c space 58. * %8ld # of files in archive (includes 1 for directory) 59. * %1c space 60. * %8ld size of allocation for string space for directory names 61. * %1c space 62. * %8ld library offset - sanity check - lseek target for start of first file 63. * %1c space 64. * %8ld size - sanity check - byte size of complete archive file 65. * 66. * followed by one DIRECTORY entry for each file in the archive, including 67. * the directory itself: 68. * %1c handling information (compression, etc.) Always ' ' in rev 1. 69. * %s file name 70. * %1c space 71. * %8ld offset in archive file of start of this file 72. * %c newline 73. * 74. * followed by the contents of the files 75. */ 76. #define DLB_MIN_VERS 1 /* min library version readable by this code */ 77. #define DLB_MAX_VERS 1 /* max library version readable by this code */ 78. 79. /* 80. * Read the directory from the library file. This will allocate and 81. * fill in our globals. The file pointer is reset back to position 82. * zero. If any part fails, leave nothing that needs to be deallocated. 83. * 84. * Return TRUE on success, FALSE on failure. 85. */ 86. static boolean 87. readlibdir(lp) 88. library *lp; /* library pointer to fill in */ 89. { 90. int i; 91. char *sp; 92. long liboffset, totalsize; 93. 94. if (fscanf(lp->fdata, "%ld %ld %ld %ld %ld\n", 95. &lp->rev,&lp->nentries,&lp->strsize,&liboffset,&totalsize) != 5) 96. return FALSE; 97. if (lp->rev > DLB_MAX_VERS || lp->rev < DLB_MIN_VERS) return FALSE; 98. 99. lp->dir = (libdir *) alloc(lp->nentries * sizeof(libdir)); 100. lp->sspace = (char *) alloc(lp->strsize); 101. 102. /* read in each directory entry */ 103. for (i = 0, sp = lp->sspace; i < lp->nentries; i++) { 104. lp->dir[i].fname = sp; 105. if (fscanf(lp->fdata, "%c%s %ld\n", 106. &lp->dir[i].handling, sp, &lp->dir[i].foffset) != 3) { 107. free((genericptr_t) lp->dir); 108. free((genericptr_t) lp->sspace); 109. lp->dir = (libdir *) 0; 110. lp->sspace = (char *) 0; 111. return FALSE; 112. } 113. sp = eos(sp) + 1; 114. } 115. 116. /* calculate file sizes using offset information */ 117. for (i = 0; i < lp->nentries; i++) { 118. if (i == lp->nentries - 1) 119. lp->dir[i].fsize = totalsize - lp->dir[i].foffset; 120. else 121. lp->dir[i].fsize = lp->dir[i+1].foffset - lp->dir[i].foffset; 122. } 123. 124. (void) fseek(lp->fdata, 0L, SEEK_SET); /* reset back to zero */ 125. lp->fmark = 0; 126. 127. return TRUE; 128. } 129. 130. /* 131. * Look for the file in our directory structure. Return 1 if successful, 132. * 0 if not found. Fill in the size and starting position. 133. */ 134. static boolean 135. find_file(name, lib, startp, sizep) 136. const char *name; 137. library **lib; 138. long *startp, *sizep; 139. { 140. int i, j; 141. library *lp; 142. 143. for (i = 0; i < MAX_LIBS && dlb_libs[i].fdata; i++) { 144. lp = &dlb_libs[i]; 145. for (j = 0; j < lp->nentries; j++) { 146. if (FILENAME_CMP(name, lp->dir[j].fname) == 0) { 147. *lib = lp; 148. *startp = lp->dir[j].foffset; 149. *sizep = lp->dir[j].fsize; 150. return TRUE; 151. } 152. } 153. } 154. *lib = (library *) 0; 155. *startp = *sizep = 0; 156. return FALSE; 157. } 158. 159. /* 160. * Open the library of the given name and fill in the given library 161. * structure. Return TRUE if successful, FALSE otherwise. 162. */ 163. boolean 164. open_library(lib_name, lp) 165. const char *lib_name; 166. library *lp; 167. { 168. boolean status = FALSE; 169. 170. lp->fdata = fopen_datafile(lib_name, RDBMODE); 171. if (lp->fdata) { 172. if (readlibdir(lp)) { 173. status = TRUE; 174. } else { 175. (void) fclose(lp->fdata); 176. lp->fdata = (FILE *) 0; 177. } 178. } 179. return status; 180. } 181. 182. void 183. close_library(lp) 184. library *lp; 185. { 186. (void) fclose(lp->fdata); 187. free((genericptr_t) lp->dir); 188. free((genericptr_t) lp->sspace); 189. 190. (void) memset((char *)lp, 0, sizeof(library)); 191. } 192. 193. /* 194. * Open the library file once using stdio. Keep it open, but 195. * keep track of the file position. 196. */ 197. boolean 198. dlb_init() 199. { 200. if (dlb_initialized) return TRUE; 201. 202. /* zero out array */ 203. (void) memset((char *)&dlb_libs[0], 0, sizeof(dlb_libs)); 204. 205. /* To open more than one library, add open library calls here. */ 206. if (!open_library(DLBFILE, &dlb_libs[0])) return dlb_initialized; 207. #ifdef DLBFILE2 208. if (!open_library(DLBFILE2, &dlb_libs[1])) return dlb_initialized; 209. #endif 210. 211. dlb_initialized = TRUE; 212. 213. return dlb_initialized; 214. } 215. 216. void 217. dlb_cleanup() 218. { 219. int i; 220. 221. if (dlb_initialized) { 222. /* close the data file(s) */ 223. for (i = 0; i < MAX_LIBS && dlb_libs[i].fdata; i++) 224. close_library(&dlb_libs[i]); 225. 226. dlb_initialized = FALSE; 227. } 228. } 229. 230. dlb * 231. dlb_fopen(name, mode) 232. const char *name, *mode; 233. { 234. long start, size; 235. library *lp; 236. FILE *fp; 237. dlb *dp = (dlb *) 0; 238. 239. if (!dlb_initialized) return (dlb *) 0; 240. 241. /* look up file in directory */ 242. if (find_file(name, &lp, &start, &size)) { 243. dp = (dlb *) alloc(sizeof(dlb)); 244. dp->fp = (FILE *) 0; 245. dp->lib = lp; 246. dp->start = start; 247. dp->size = size; 248. dp->mark = 0; 249. } else if ((fp = fopen_datafile(name, mode)) != 0) { 250. /* use an external file */ 251. dp = (dlb *) alloc(sizeof(dlb)); 252. dp->fp = fp; 253. dp->lib = (library *) 0; 254. dp->start = 0; 255. dp->size = 0; 256. dp->mark = 0; 257. } 258. return dp; 259. } 260. 261. int 262. dlb_fclose(dp) 263. dlb *dp; 264. { 265. if (dlb_initialized) { 266. if (dp->fp) (void) fclose(dp->fp); 267. free((genericptr_t) dp); 268. } 269. return 0; 270. } 271. 272. int 273. dlb_fread(buf, size, quan, dp) 274. char *buf; 275. int size, quan; 276. dlb *dp; 277. { 278. long pos, nread, nbytes; 279. 280. if (!dlb_initialized || size <= 0 || quan <= 0) return 0; 281. if (dp->fp) return 282. #ifdef __SASC_60 283. (int) 284. #endif 285. fread(buf, size, quan, dp->fp); 286. 287. /* make sure we don't read into the next file */ 288. if ((dp->size - dp->mark) < (size * quan)) 289. quan = (dp->size - dp->mark) / size; 290. if (quan == 0) return 0; 291. 292. pos = dp->start + dp->mark; 293. if (dp->lib->fmark != pos) 294. fseek(dp->lib->fdata, pos, SEEK_SET); /* check for error??? */ 295. 296. nread = fread(buf, size, quan, dp->lib->fdata); 297. nbytes = nread * size; 298. dp->mark += nbytes; 299. dp->lib->fmark += nbytes; 300. 301. return nread; 302. } 303. 304. int 305. dlb_fseek(dp, pos, whence) 306. dlb *dp; 307. long pos; 308. int whence; 309. { 310. long curpos; 311. 312. if (!dlb_initialized) return EOF; 313. if (dp->fp) return fseek(dp->fp, pos, whence); 314. 315. switch (whence) { 316. case SEEK_CUR: curpos = dp->mark + pos; break; 317. case SEEK_END: curpos = dp->size - pos; break; 318. default: /* set */ curpos = pos; break; 319. } 320. if (curpos < 0) curpos = 0; 321. if (curpos > dp->size) curpos = dp->size; 322. 323. dp->mark = curpos; 324. return 0; 325. } 326. 327. char * 328. dlb_fgets(buf, len, dp) 329. char *buf; 330. int len; 331. dlb *dp; 332. { 333. int i; 334. char *bp, c = 0; 335. 336. if (!dlb_initialized) return (char *) 0; 337. if (dp->fp) return fgets(buf, len, dp->fp); 338. 339. if (len <= 0) return buf; /* sanity check */ 340. 341. /* return NULL on EOF */ 342. if (dp->mark >= dp->size) return (char *) 0; 343. 344. len--; /* save room for null */ 345. for (i = 0, bp = buf; 346. i < len && dp->mark < dp->size && c != '\n'; i++, bp++) { 347. if (dlb_fread(bp, 1, 1, dp) <= 0) break; /* EOF or error */ 348. c = *bp; 349. } 350. *bp = '\0'; 351. 352. return buf; 353. } 354. 355. int 356. dlb_fgetc(dp) 357. dlb *dp; 358. { 359. char c; 360. 361. if (!dlb_initialized) return EOF; 362. if (dp->fp) return fgetc(dp->fp); 363. 364. if (dlb_fread(&c, 1, 1, dp) != 1) return EOF; 365. return (int) c; 366. } 367. 368. long 369. dlb_ftell(dp) 370. dlb *dp; 371. { 372. if (!dlb_initialized) return 0; 373. if (dp->fp) return ftell(dp->fp); 374. return dp->mark; 375. } 376. 377. #endif /* DLB */ 378. 379. /*dlb.c*/
