lib/libc/citrus/citrus_lookup.c

   1 /*      $NetBSD: citrus_lookup.c,v 1.7 2012/05/04 16:45:05 joerg Exp $  */
   2
   3 /*-
   4  * Copyright (c)2003 Citrus Project,
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 __RCSID("$NetBSD: citrus_lookup.c,v 1.7 2012/05/04 16:45:05 joerg Exp $");
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include "namespace.h"
  35 #include <assert.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <errno.h>
  40 #include <limits.h>
  41 #include <unistd.h>
  42 #include <fcntl.h>
  43 #include <paths.h>
  44 #include <dirent.h>
  45 #include <sys/types.h>
  46
  47 #include "citrus_namespace.h"
  48 #include "citrus_bcs.h"
  49 #include "citrus_region.h"
  50 #include "citrus_memstream.h"
  51 #include "citrus_mmap.h"
  52 #include "citrus_db.h"
  53 #include "citrus_db_hash.h"
  54 #include "citrus_lookup.h"
  55 #include "citrus_lookup_file.h"
  56
  57 struct _citrus_lookup {
  58         union {
  59                 struct {
  60                         struct _citrus_db *db;
  61                         struct _citrus_region file;
  62                         int num, idx;
  63                         struct _db_locator locator;
  64                 } db;
  65                 struct {
  66                         struct _region r;
  67                         struct _memstream ms;
  68                 } plain;
  69         } u;
  70 #define cl_db           u.db.db
  71 #define cl_dbidx        u.db.idx
  72 #define cl_dbfile       u.db.file
  73 #define cl_dbnum        u.db.num
  74 #define cl_dblocator    u.db.locator
  75 #define cl_plainr       u.plain.r
  76 #define cl_plainms      u.plain.ms
  77         int cl_ignore_case;
  78         int cl_rewind;
  79         char *cl_key;
  80         size_t cl_keylen;
  81         int (*cl_next)(struct _citrus_lookup *, struct _region *,
  82                        struct _region *);
  83         int (*cl_lookup)(struct _citrus_lookup *, const char *,
  84                          struct _region *);
  85         int (*cl_num_entries)(struct _citrus_lookup *);
  86         void (*cl_close)(struct _citrus_lookup *);
  87 };
  88
  89 static int
  90 seq_get_num_entries_db(struct _citrus_lookup *cl)
  91 {
  92         return cl->cl_dbnum;
  93 }
  94
  95 static int
  96 seq_next_db(struct _citrus_lookup *cl,
  97             struct _region *key, struct _region *data)
  98 {
  99
 100         if (cl->cl_key) {
 101                 if (key)
 102                         _region_init(key, cl->cl_key, cl->cl_keylen);
 103                 return _db_lookup_by_s(cl->cl_db, cl->cl_key, data,
 104                                        &cl->cl_dblocator);
 105         }
 106
 107         if (cl->cl_rewind) {
 108                 cl->cl_dbidx = 0;
 109         }
 110         cl->cl_rewind = 0;
 111         if (cl->cl_dbidx >= cl->cl_dbnum)
 112                 return ENOENT;
 113
 114         return _db_get_entry(cl->cl_db, cl->cl_dbidx++, key, data);
 115 }
 116
 117 static int
 118 seq_lookup_db(struct _citrus_lookup *cl, const char *key,
 119               struct _region *data)
 120 {
 121         cl->cl_rewind = 0;
 122         free(cl->cl_key);
 123         cl->cl_key = strdup(key);
 124         if (cl->cl_ignore_case)
 125                 _bcs_convert_to_lower(cl->cl_key);
 126         cl->cl_keylen = strlen(cl->cl_key);
 127         _db_locator_init(&cl->cl_dblocator);
 128         return _db_lookup_by_s(cl->cl_db, cl->cl_key, data, &cl->cl_dblocator);
 129 }
 130
 131 static void
 132 seq_close_db(struct _citrus_lookup *cl)
 133 {
 134         _db_close(cl->cl_db);
 135         _unmap_file(&cl->cl_dbfile);
 136 }
 137
 138 static int
 139 seq_open_db(struct _citrus_lookup *cl, const char *name)
 140 {
 141         int ret;
 142         struct _region r;
 143         char path[PATH_MAX];
 144
 145         snprintf(path, sizeof(path), "%s.db", name);
 146         ret = _map_file(&r, path);
 147         if (ret)
 148                 return ret;
 149
 150         ret = _db_open(&cl->cl_db, &r, _CITRUS_LOOKUP_MAGIC,
 151                        _db_hash_std, NULL);
 152         if (ret) {
 153                 _unmap_file(&r);
 154                 return ret;
 155         }
 156
 157         cl->cl_dbfile = r;
 158         cl->cl_dbnum = _db_get_num_entries(cl->cl_db);
 159         cl->cl_dbidx = 0;
 160         cl->cl_rewind = 1;
 161         cl->cl_lookup = &seq_lookup_db;
 162         cl->cl_next = &seq_next_db;
 163         cl->cl_num_entries = &seq_get_num_entries_db;
 164         cl->cl_close = &seq_close_db;
 165
 166         return 0;
 167 }
 168
 169 #define T_COMM '#'
 170 static int
 171 seq_next_plain(struct _citrus_lookup *cl, struct _region *key,
 172                struct _region *data)
 173 {
 174         const char *p, *q;
 175         size_t len;
 176
 177         if (cl->cl_rewind)
 178                 _memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
 179         cl->cl_rewind = 0;
 180
 181 retry:
 182         p = _memstream_getln(&cl->cl_plainms, &len);
 183         if (p == NULL)
 184                 return ENOENT;
 185         /* ignore comment */
 186         q = memchr(p, T_COMM, len);
 187         if (q) {
 188                 len = q-p;
 189         }
 190         /* ignore trailing spaces */
 191         _bcs_trunc_rws_len(p, &len);
 192         p = _bcs_skip_ws_len(p, &len);
 193         q = _bcs_skip_nonws_len(p, &len);
 194         if (p==q)
 195                 goto retry;
 196         if (cl->cl_key && ((size_t)(q-p) != cl->cl_keylen ||
 197                            memcmp(p, cl->cl_key, (size_t)(q-p)) != 0))
 198                 goto retry;
 199
 200         /* found a entry */
 201         if (key)
 202                 _region_init(key, __UNCONST(p), (size_t)(q-p));
 203         p = _bcs_skip_ws_len(q, &len);
 204         if (data)
 205                 _region_init(data, len ? __UNCONST(p) : NULL, len);
 206
 207         return 0;
 208 }
 209
 210 static int
 211 seq_get_num_entries_plain(struct _citrus_lookup *cl)
 212 {
 213         int num;
 214
 215         num = 0;
 216         while (seq_next_plain(cl, NULL, NULL) == 0)
 217                 num++;
 218
 219         return num;
 220 }
 221
 222 static int
 223 seq_lookup_plain(struct _citrus_lookup *cl, const char *key,
 224                  struct _region *data)
 225 {
 226         size_t len;
 227         const char *p;
 228
 229         cl->cl_rewind = 0;
 230         free(cl->cl_key);
 231         cl->cl_key = strdup(key);
 232         if (cl->cl_ignore_case)
 233                 _bcs_convert_to_lower(cl->cl_key);
 234         cl->cl_keylen = strlen(cl->cl_key);
 235         _memstream_bind(&cl->cl_plainms, &cl->cl_plainr);
 236         p = _memstream_matchline(&cl->cl_plainms, cl->cl_key, &len, 0);
 237         if (p == NULL)
 238                 return ENOENT;
 239         if (data)
 240                 _region_init(data, __UNCONST(p), len);
 241
 242         return 0;
 243 }
 244
 245 static void
 246 seq_close_plain(struct _citrus_lookup *cl)
 247 {
 248         _unmap_file(&cl->cl_plainr);
 249 }
 250
 251 static int
 252 seq_open_plain(struct _citrus_lookup *cl, const char *name)
 253 {
 254         int ret;
 255
 256         /* open read stream */
 257         ret = _map_file(&cl->cl_plainr, name);
 258         if (ret)
 259                 return ret;
 260
 261         cl->cl_rewind = 1;
 262         cl->cl_next = &seq_next_plain;
 263         cl->cl_lookup = &seq_lookup_plain;
 264         cl->cl_num_entries = &seq_get_num_entries_plain;
 265         cl->cl_close = &seq_close_plain;
 266
 267         return 0;
 268 }
 269
 270 int
 271 _citrus_lookup_seq_open(struct _citrus_lookup **rcl, const char *name,
 272                         int ignore_case)
 273 {
 274         int ret;
 275         struct _citrus_lookup *cl;
 276
 277         cl = malloc(sizeof(*cl));
 278         if (cl == NULL)
 279                 return ENOMEM;
 280
 281         cl->cl_key = NULL;
 282         cl->cl_keylen = 0;
 283         cl->cl_ignore_case = ignore_case;
 284         ret = seq_open_db(cl, name);
 285         if (ret == ENOENT)
 286                 ret = seq_open_plain(cl, name);
 287         if (!ret)
 288                 *rcl = cl;
 289         else
 290                 free(cl);
 291
 292         return ret;
 293 }
 294
 295 void
 296 _citrus_lookup_seq_rewind(struct _citrus_lookup *cl)
 297 {
 298         cl->cl_rewind = 1;
 299         free(cl->cl_key);
 300         cl->cl_key = NULL;
 301         cl->cl_keylen = 0;
 302 }
 303
 304 int
 305 _citrus_lookup_seq_next(struct _citrus_lookup *cl,
 306                         struct _region *key, struct _region *data)
 307 {
 308         return (*cl->cl_next)(cl, key, data);
 309 }
 310
 311 int
 312 _citrus_lookup_seq_lookup(struct _citrus_lookup *cl, const char *key,
 313                           struct _region *data)
 314 {
 315         return (*cl->cl_lookup)(cl, key, data);
 316 }
 317
 318 int
 319 _citrus_lookup_get_number_of_entries(struct _citrus_lookup *cl)
 320 {
 321         return (*cl->cl_num_entries)(cl);
 322 }
 323
 324 void
 325 _citrus_lookup_seq_close(struct _citrus_lookup *cl)
 326 {
 327         free(cl->cl_key);
 328         (*cl->cl_close)(cl);
 329         free(cl);
 330 }
 331
 332 char *
 333 _citrus_lookup_simple(const char *name, const char *key,
 334                       char *linebuf, size_t linebufsize, int ignore_case)
 335 {
 336         int ret;
 337         struct _citrus_lookup *cl;
 338         struct _region data;
 339
 340         ret = _citrus_lookup_seq_open(&cl, name, ignore_case);
 341         if (ret)
 342                 return NULL;
 343
 344         ret = _citrus_lookup_seq_lookup(cl, key, &data);
 345         if (ret) {
 346                 _citrus_lookup_seq_close(cl);
 347                 return NULL;
 348         }
 349
 350         snprintf(linebuf, linebufsize, "%.*s",
 351                  (int)_region_size(&data), (const char *)_region_head(&data));
 352
 353         _citrus_lookup_seq_close(cl);
 354
 355         return linebuf;
 356 }