lib/libc/citrus/citrus_db.c

   1 /*      $NetBSD: citrus_db.c,v 1.5 2008/02/09 14:56:20 junyoung 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_db.c,v 1.5 2008/02/09 14:56:20 junyoung 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 <sys/types.h>
  42
  43 #include "citrus_namespace.h"
  44 #include "citrus_bcs.h"
  45 #include "citrus_region.h"
  46 #include "citrus_memstream.h"
  47 #include "citrus_mmap.h"
  48 #include "citrus_db.h"
  49 #include "citrus_db_file.h"
  50
  51 struct _citrus_db {
  52         /* private */
  53         struct _region db_region;
  54         uint32_t (*db_hashfunc)(void *, struct _citrus_region *);
  55         void *db_hashfunc_closure;
  56 };
  57
  58 int
  59 _citrus_db_open(struct _citrus_db **rdb, struct _region *r, const char *magic,
  60                 uint32_t (*hashfunc)(void *, struct _citrus_region *),
  61                 void *hashfunc_closure)
  62 {
  63         struct _memstream ms;
  64         struct _citrus_db *db;
  65         struct _citrus_db_header_x *dhx;
  66
  67         _memstream_bind(&ms, r);
  68
  69         /* sanity check */
  70         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
  71         if (dhx == NULL)
  72                 return EFTYPE;
  73         if (strncmp(dhx->dhx_magic, magic, _CITRUS_DB_MAGIC_SIZE) != 0)
  74                 return EFTYPE;
  75         if (_memstream_seek(&ms, be32toh(dhx->dhx_entry_offset), SEEK_SET))
  76                 return EFTYPE;
  77
  78         if (be32toh(dhx->dhx_num_entries)*_CITRUS_DB_ENTRY_SIZE >
  79             _memstream_remainder(&ms))
  80                 return EFTYPE;
  81
  82         db = malloc(sizeof(*db));
  83         if (db==NULL)
  84                 return errno;
  85         db->db_region = *r;
  86         db->db_hashfunc = hashfunc;
  87         db->db_hashfunc_closure = hashfunc_closure;
  88         *rdb = db;
  89
  90         return 0;
  91 }
  92
  93 void
  94 _citrus_db_close(struct _citrus_db *db)
  95 {
  96         free(db);
  97 }
  98
  99 int
 100 _citrus_db_lookup(struct _citrus_db *db, struct _citrus_region *key,
 101                   struct _citrus_region *data, struct _citrus_db_locator *dl)
 102 {
 103         uint32_t hashval, num_entries;
 104         size_t offset;
 105         struct _memstream ms;
 106         struct _citrus_db_header_x *dhx;
 107         struct _citrus_db_entry_x *dex;
 108         struct _citrus_region r;
 109
 110         _memstream_bind(&ms, &db->db_region);
 111
 112         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
 113         _DIAGASSERT(dhx);
 114         num_entries = be32toh(dhx->dhx_num_entries);
 115         if (num_entries == 0)
 116                 return ENOENT;
 117
 118         if (dl != NULL && dl->dl_offset>0) {
 119                 hashval = dl->dl_hashval;
 120                 offset = dl->dl_offset;
 121                 if (offset >= _region_size(&db->db_region))
 122                         return ENOENT;
 123         } else {
 124                 hashval =
 125                     db->db_hashfunc(db->db_hashfunc_closure, key)%num_entries;
 126                 offset =
 127                     be32toh(dhx->dhx_entry_offset) +
 128                     hashval * _CITRUS_DB_ENTRY_SIZE;
 129                 if (dl)
 130                         dl->dl_hashval = hashval;
 131         }
 132         do {
 133                 /* seek to the next entry */
 134                 if (_citrus_memory_stream_seek(&ms, offset, SEEK_SET))
 135                         return EFTYPE;
 136                 /* get the entry record */
 137                 dex = _memstream_getregion(&ms, NULL, _CITRUS_DB_ENTRY_SIZE);
 138                 if (dex == NULL)
 139                         return EFTYPE;
 140
 141                 /* jump to next entry having the same hash value. */
 142                 offset = be32toh(dex->dex_next_offset);
 143
 144                 /* save the current position */
 145                 if (dl) {
 146                         dl->dl_offset = offset;
 147                         if (offset==0)
 148                                 dl->dl_offset = _region_size(&db->db_region);
 149                 }
 150
 151                 /* compare hash value. */
 152                 if (be32toh(dex->dex_hash_value) != hashval)
 153                         /* not found */
 154                         break;
 155                 /* compare key length */
 156                 if (be32toh(dex->dex_key_size) == _region_size(key)) {
 157                         /* seek to the head of the key. */
 158                         if (_memstream_seek(&ms, be32toh(dex->dex_key_offset),
 159                                             SEEK_SET))
 160                                 return EFTYPE;
 161                         /* get the region of the key */
 162                         if (_memstream_getregion(&ms, &r,
 163                                                  _region_size(key)) == NULL)
 164                                 return EFTYPE;
 165                         /* compare key byte stream */
 166                         if (memcmp(_region_head(&r), _region_head(key),
 167                                    _region_size(key)) == 0) {
 168                                 /* match */
 169                                 if (_memstream_seek(
 170                                         &ms, be32toh(dex->dex_data_offset),
 171                                         SEEK_SET))
 172                                         return EFTYPE;
 173                                 if (_memstream_getregion(
 174                                         &ms, data,
 175                                         be32toh(dex->dex_data_size)) == NULL)
 176                                         return EFTYPE;
 177                                 return 0;
 178                         }
 179                 }
 180         } while (offset != 0);
 181
 182         return ENOENT;
 183 }
 184
 185 int
 186 _citrus_db_lookup_by_string(struct _citrus_db *db, const char *key,
 187                             struct _citrus_region *data,
 188                             struct _citrus_db_locator *dl)
 189 {
 190         struct _region r;
 191
 192         _region_init(&r, __UNCONST(key), strlen(key));
 193
 194         return _citrus_db_lookup(db, &r, data, dl);
 195 }
 196
 197 int
 198 _citrus_db_lookup8_by_string(struct _citrus_db *db, const char *key,
 199                              uint8_t *rval, struct _citrus_db_locator *dl)
 200 {
 201         int ret;
 202         struct _region r;
 203
 204         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 205         if (ret)
 206                 return ret;
 207
 208         if (_region_size(&r) != 1)
 209                 return EFTYPE;
 210
 211         if (rval)
 212                 memcpy(rval, _region_head(&r), 1);
 213
 214         return 0;
 215 }
 216
 217 int
 218 _citrus_db_lookup16_by_string(struct _citrus_db *db, const char *key,
 219                               uint16_t *rval, struct _citrus_db_locator *dl)
 220 {
 221         int ret;
 222         struct _region r;
 223         uint16_t val;
 224
 225         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 226         if (ret)
 227                 return ret;
 228
 229         if (_region_size(&r) != 2)
 230                 return EFTYPE;
 231
 232         if (rval) {
 233                 memcpy(&val, _region_head(&r), 2);
 234                 *rval = be16toh(val);
 235         }
 236
 237         return 0;
 238 }
 239
 240 int
 241 _citrus_db_lookup32_by_string(struct _citrus_db *db, const char *key,
 242                               uint32_t *rval, struct _citrus_db_locator *dl)
 243 {
 244         int ret;
 245         struct _region r;
 246         uint32_t val;
 247
 248         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 249         if (ret)
 250                 return ret;
 251
 252         if (_region_size(&r) != 4)
 253                 return EFTYPE;
 254
 255         if (rval) {
 256                 memcpy(&val, _region_head(&r), 4);
 257                 *rval = be32toh(val);
 258         }
 259
 260         return 0;
 261 }
 262
 263 int
 264 _citrus_db_lookup_string_by_string(struct _citrus_db *db, const char *key,
 265                                    const char **rdata,
 266                                    struct _citrus_db_locator *dl)
 267 {
 268         int ret;
 269         struct _region r;
 270
 271         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 272         if (ret)
 273                 return ret;
 274
 275         /* check whether the string is null terminated */
 276         if (_region_size(&r) == 0)
 277                 return EFTYPE;
 278         if (*((const char*)_region_head(&r)+_region_size(&r)-1) != '\0')
 279                 return EFTYPE;
 280
 281         if (rdata)
 282                 *rdata = _region_head(&r);
 283
 284         return 0;
 285 }
 286
 287 int
 288 _citrus_db_get_number_of_entries(struct _citrus_db *db)
 289 {
 290         struct _memstream ms;
 291         struct _citrus_db_header_x *dhx;
 292
 293         _memstream_bind(&ms, &db->db_region);
 294
 295         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
 296         _DIAGASSERT(dhx);
 297         return (int)be32toh(dhx->dhx_num_entries);
 298 }
 299
 300 int
 301 _citrus_db_get_entry(struct _citrus_db *db, int idx,
 302                      struct _region *key, struct _region *data)
 303 {
 304         uint32_t num_entries;
 305         size_t offset;
 306         struct _memstream ms;
 307         struct _citrus_db_header_x *dhx;
 308         struct _citrus_db_entry_x *dex;
 309
 310         _memstream_bind(&ms, &db->db_region);
 311
 312         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
 313         _DIAGASSERT(dhx);
 314         num_entries = be32toh(dhx->dhx_num_entries);
 315         if (idx < 0 || (uint32_t)idx >= num_entries)
 316                 return EINVAL;
 317
 318         /* seek to the next entry */
 319         offset = be32toh(dhx->dhx_entry_offset) + idx * _CITRUS_DB_ENTRY_SIZE;
 320         if (_citrus_memory_stream_seek(&ms, offset, SEEK_SET))
 321                 return EFTYPE;
 322         /* get the entry record */
 323         dex = _memstream_getregion(&ms, NULL, _CITRUS_DB_ENTRY_SIZE);
 324         if (dex == NULL)
 325                 return EFTYPE;
 326         /* seek to the head of the key. */
 327         if (_memstream_seek(&ms, be32toh(dex->dex_key_offset), SEEK_SET))
 328                 return EFTYPE;
 329         /* get the region of the key. */
 330         if (_memstream_getregion(&ms, key, be32toh(dex->dex_key_size))==NULL)
 331                 return EFTYPE;
 332         /* seek to the head of the data. */
 333         if (_memstream_seek(&ms, be32toh(dex->dex_data_offset), SEEK_SET))
 334                 return EFTYPE;
 335         /* get the region of the data. */
 336         if (_memstream_getregion(&ms, data, be32toh(dex->dex_data_size))==NULL)
 337                 return EFTYPE;
 338
 339         return 0;
 340 }