dbm.c

   1 /*      $Id: dbm.c,v 1.4 2016/08/30 22:01:07 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  *
  17  * Map-based version of the mandoc database, for read-only access.
  18  * The interface is defined in "dbm.h".
  19  */
  20 #include "config.h"
  21
  22 #include <assert.h>
  23 #if HAVE_ENDIAN
  24 #include <endian.h>
  25 #elif HAVE_SYS_ENDIAN
  26 #include <sys/endian.h>
  27 #elif HAVE_NTOHL
  28 #include <arpa/inet.h>
  29 #endif
  30 #if HAVE_ERR
  31 #include <err.h>
  32 #endif
  33 #include <errno.h>
  34 #include <regex.h>
  35 #include <stdint.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39
  40 #include "mansearch.h"
  41 #include "dbm_map.h"
  42 #include "dbm.h"
  43
  44 struct macro {
  45         int32_t value;
  46         int32_t pages;
  47 };
  48
  49 struct page {
  50         int32_t name;
  51         int32_t sect;
  52         int32_t arch;
  53         int32_t desc;
  54         int32_t file;
  55 };
  56
  57 enum iter {
  58         ITER_NONE = 0,
  59         ITER_NAME,
  60         ITER_SECT,
  61         ITER_ARCH,
  62         ITER_DESC,
  63         ITER_MACRO
  64 };
  65
  66 static struct macro     *macros[MACRO_MAX];
  67 static int32_t           nvals[MACRO_MAX];
  68 static struct page      *pages;
  69 static int32_t           npages;
  70 static enum iter         iteration;
  71
  72 static struct dbm_res    page_bytitle(enum iter, const struct dbm_match *);
  73 static struct dbm_res    page_byarch(const struct dbm_match *);
  74 static struct dbm_res    page_bymacro(int32_t, const struct dbm_match *);
  75 static char             *macro_bypage(int32_t, int32_t);
  76
  77
  78 /*** top level functions **********************************************/
  79
  80 /*
  81  * Open a disk-based mandoc database for read-only access.
  82  * Map the pages and macros[] arrays.
  83  * Return 0 on success.  Return -1 and set errno on failure.
  84  */
  85 int
  86 dbm_open(const char *fname)
  87 {
  88         const int32_t   *mp, *ep;
  89         int32_t          im;
  90
  91         if (dbm_map(fname) == -1)
  92                 return -1;
  93
  94         if ((npages = be32toh(*dbm_getint(4))) < 0) {
  95                 warnx("dbm_open(%s): Invalid number of pages: %d",
  96                     fname, npages);
  97                 goto fail;
  98         }
  99         pages = (struct page *)dbm_getint(5);
 100
 101         if ((mp = dbm_get(*dbm_getint(2))) == NULL) {
 102                 warnx("dbm_open(%s): Invalid offset of macros array", fname);
 103                 goto fail;
 104         }
 105         if (be32toh(*mp) != MACRO_MAX) {
 106                 warnx("dbm_open(%s): Invalid number of macros: %d",
 107                     fname, be32toh(*mp));
 108                 goto fail;
 109         }
 110         for (im = 0; im < MACRO_MAX; im++) {
 111                 if ((ep = dbm_get(*++mp)) == NULL) {
 112                         warnx("dbm_open(%s): Invalid offset of macro %d",
 113                             fname, im);
 114                         goto fail;
 115                 }
 116                 nvals[im] = be32toh(*ep);
 117                 macros[im] = (struct macro *)++ep;
 118         }
 119         return 0;
 120
 121 fail:
 122         dbm_unmap();
 123         errno = EFTYPE;
 124         return -1;
 125 }
 126
 127 void
 128 dbm_close(void)
 129 {
 130         dbm_unmap();
 131 }
 132
 133
 134 /*** functions for handling pages *************************************/
 135
 136 int32_t
 137 dbm_page_count(void)
 138 {
 139         return npages;
 140 }
 141
 142 /*
 143  * Give the caller pointers to the data for one manual page.
 144  */
 145 struct dbm_page *
 146 dbm_page_get(int32_t ip)
 147 {
 148         static struct dbm_page   res;
 149
 150         assert(ip >= 0);
 151         assert(ip < npages);
 152         res.name = dbm_get(pages[ip].name);
 153         if (res.name == NULL)
 154                 res.name = "(NULL)";
 155         res.sect = dbm_get(pages[ip].sect);
 156         if (res.sect == NULL)
 157                 res.sect = "(NULL)";
 158         res.arch = pages[ip].arch ? dbm_get(pages[ip].arch) : NULL;
 159         res.desc = dbm_get(pages[ip].desc);
 160         if (res.desc == NULL)
 161                 res.desc = "(NULL)";
 162         res.file = dbm_get(pages[ip].file);
 163         if (res.file == NULL)
 164                 res.file = " (NULL)";
 165         res.addr = dbm_addr(pages + ip);
 166         return &res;
 167 }
 168
 169 /*
 170  * Functions to start filtered iterations over manual pages.
 171  */
 172 void
 173 dbm_page_byname(const struct dbm_match *match)
 174 {
 175         assert(match != NULL);
 176         page_bytitle(ITER_NAME, match);
 177 }
 178
 179 void
 180 dbm_page_bysect(const struct dbm_match *match)
 181 {
 182         assert(match != NULL);
 183         page_bytitle(ITER_SECT, match);
 184 }
 185
 186 void
 187 dbm_page_byarch(const struct dbm_match *match)
 188 {
 189         assert(match != NULL);
 190         page_byarch(match);
 191 }
 192
 193 void
 194 dbm_page_bydesc(const struct dbm_match *match)
 195 {
 196         assert(match != NULL);
 197         page_bytitle(ITER_DESC, match);
 198 }
 199
 200 void
 201 dbm_page_bymacro(int32_t im, const struct dbm_match *match)
 202 {
 203         assert(im >= 0);
 204         assert(im < MACRO_MAX);
 205         assert(match != NULL);
 206         page_bymacro(im, match);
 207 }
 208
 209 /*
 210  * Return the number of the next manual page in the current iteration.
 211  */
 212 struct dbm_res
 213 dbm_page_next(void)
 214 {
 215         struct dbm_res                   res = {-1, 0};
 216
 217         switch(iteration) {
 218         case ITER_NONE:
 219                 return res;
 220         case ITER_ARCH:
 221                 return page_byarch(NULL);
 222         case ITER_MACRO:
 223                 return page_bymacro(0, NULL);
 224         default:
 225                 return page_bytitle(iteration, NULL);
 226         }
 227 }
 228
 229 /*
 230  * Functions implementing the iteration over manual pages.
 231  */
 232 static struct dbm_res
 233 page_bytitle(enum iter arg_iter, const struct dbm_match *arg_match)
 234 {
 235         static const struct dbm_match   *match;
 236         static const char               *cp;
 237         static int32_t                   ip;
 238         struct dbm_res                   res = {-1, 0};
 239
 240         assert(arg_iter == ITER_NAME || arg_iter == ITER_DESC ||
 241             arg_iter == ITER_SECT);
 242
 243         /* Initialize for a new iteration. */
 244
 245         if (arg_match != NULL) {
 246                 iteration = arg_iter;
 247                 match = arg_match;
 248                 switch (iteration) {
 249                 case ITER_NAME:
 250                         cp = dbm_get(pages[0].name);
 251                         break;
 252                 case ITER_SECT:
 253                         cp = dbm_get(pages[0].sect);
 254                         break;
 255                 case ITER_DESC:
 256                         cp = dbm_get(pages[0].desc);
 257                         break;
 258                 default:
 259                         abort();
 260                 }
 261                 if (cp == NULL) {
 262                         iteration = ITER_NONE;
 263                         match = NULL;
 264                         cp = NULL;
 265                         ip = npages;
 266                 } else
 267                         ip = 0;
 268                 return res;
 269         }
 270
 271         /* Search for a name. */
 272
 273         while (ip < npages) {
 274                 if (iteration == ITER_NAME)
 275                         cp++;
 276                 if (dbm_match(match, cp))
 277                         break;
 278                 cp = strchr(cp, '\0') + 1;
 279                 if (iteration == ITER_DESC)
 280                         ip++;
 281                 else if (*cp == '\0') {
 282                         cp++;
 283                         ip++;
 284                 }
 285         }
 286
 287         /* Reached the end without a match. */
 288
 289         if (ip == npages) {
 290                 iteration = ITER_NONE;
 291                 match = NULL;
 292                 cp = NULL;
 293                 return res;
 294         }
 295
 296         /* Found a match; save the quality for later retrieval. */
 297
 298         res.page = ip;
 299         res.bits = iteration == ITER_NAME ? cp[-1] : 0;
 300
 301         /* Skip the remaining names of this page. */
 302
 303         if (++ip < npages) {
 304                 do {
 305                         cp++;
 306                 } while (cp[-1] != '\0' ||
 307                     (iteration != ITER_DESC && cp[-2] != '\0'));
 308         }
 309         return res;
 310 }
 311
 312 static struct dbm_res
 313 page_byarch(const struct dbm_match *arg_match)
 314 {
 315         static const struct dbm_match   *match;
 316         struct dbm_res                   res = {-1, 0};
 317         static int32_t                   ip;
 318         const char                      *cp;
 319
 320         /* Initialize for a new iteration. */
 321
 322         if (arg_match != NULL) {
 323                 iteration = ITER_ARCH;
 324                 match = arg_match;
 325                 ip = 0;
 326                 return res;
 327         }
 328
 329         /* Search for an architecture. */
 330
 331         for ( ; ip < npages; ip++)
 332                 if (pages[ip].arch)
 333                         for (cp = dbm_get(pages[ip].arch);
 334                             *cp != '\0';
 335                             cp = strchr(cp, '\0') + 1)
 336                                 if (dbm_match(match, cp)) {
 337                                         res.page = ip++;
 338                                         return res;
 339                                 }
 340
 341         /* Reached the end without a match. */
 342
 343         iteration = ITER_NONE;
 344         match = NULL;
 345         return res;
 346 }
 347
 348 static struct dbm_res
 349 page_bymacro(int32_t im, const struct dbm_match *match)
 350 {
 351         static const int32_t    *pp;
 352         struct dbm_res           res = {-1, 0};
 353         const char              *cp;
 354         int32_t                  iv;
 355
 356         assert(im >= 0);
 357         assert(im < MACRO_MAX);
 358
 359         /* Initialize for a new iteration. */
 360
 361         if (match != NULL) {
 362                 iteration = ITER_MACRO;
 363                 cp = nvals[im] ? dbm_get(macros[im]->value) : NULL;
 364                 for (iv = 0; iv < nvals[im]; iv++) {
 365                         if (dbm_match(match, cp))
 366                                 break;
 367                         cp = strchr(cp, '\0') + 1;
 368                 }
 369                 pp = iv == nvals[im] ? NULL : dbm_get(macros[im][iv].pages);
 370                 return res;
 371         }
 372         if (iteration != ITER_MACRO)
 373                 return res;
 374
 375         /* No more matches. */
 376
 377         if (pp == NULL || *pp == 0) {
 378                 iteration = ITER_NONE;
 379                 pp = NULL;
 380                 return res;
 381         }
 382
 383         /* Found a match. */
 384
 385         res.page = (struct page *)dbm_get(*pp++) - pages;
 386         return res;
 387 }
 388
 389
 390 /*** functions for handling macros ************************************/
 391
 392 int32_t
 393 dbm_macro_count(int32_t im)
 394 {
 395         assert(im >= 0);
 396         assert(im < MACRO_MAX);
 397         return nvals[im];
 398 }
 399
 400 struct dbm_macro *
 401 dbm_macro_get(int32_t im, int32_t iv)
 402 {
 403         static struct dbm_macro macro;
 404
 405         assert(im >= 0);
 406         assert(im < MACRO_MAX);
 407         assert(iv >= 0);
 408         assert(iv < nvals[im]);
 409         macro.value = dbm_get(macros[im][iv].value);
 410         macro.pp = dbm_get(macros[im][iv].pages);
 411         return &macro;
 412 }
 413
 414 /*
 415  * Filtered iteration over macro entries.
 416  */
 417 void
 418 dbm_macro_bypage(int32_t im, int32_t ip)
 419 {
 420         assert(im >= 0);
 421         assert(im < MACRO_MAX);
 422         assert(ip != 0);
 423         macro_bypage(im, ip);
 424 }
 425
 426 char *
 427 dbm_macro_next(void)
 428 {
 429         return macro_bypage(MACRO_MAX, 0);
 430 }
 431
 432 static char *
 433 macro_bypage(int32_t arg_im, int32_t arg_ip)
 434 {
 435         static const int32_t    *pp;
 436         static int32_t           im, ip, iv;
 437
 438         /* Initialize for a new iteration. */
 439
 440         if (arg_im < MACRO_MAX && arg_ip != 0) {
 441                 im = arg_im;
 442                 ip = arg_ip;
 443                 pp = dbm_get(macros[im]->pages);
 444                 iv = 0;
 445                 return NULL;
 446         }
 447         if (im >= MACRO_MAX)
 448                 return NULL;
 449
 450         /* Search for the next value. */
 451
 452         while (iv < nvals[im]) {
 453                 if (*pp == ip)
 454                         break;
 455                 if (*pp == 0)
 456                         iv++;
 457                 pp++;
 458         }
 459
 460         /* Reached the end without a match. */
 461
 462         if (iv == nvals[im]) {
 463                 im = MACRO_MAX;
 464                 ip = 0;
 465                 pp = NULL;
 466                 return NULL;
 467         }
 468
 469         /* Found a match; skip the remaining pages of this entry. */
 470
 471         if (++iv < nvals[im])
 472                 while (*pp++ != 0)
 473                         continue;
 474
 475         return dbm_get(macros[im][iv - 1].value);
 476 }