lib/libc/citrus/citrus_db.c

   1 /* $NetBSD: citrus_db.c,v 1.5 2008/02/09 14:56:20 junyoung Exp $ */
   2 /* $DragonFly: src/lib/libc/citrus/citrus_db.c,v 1.3 2008/04/10 10:21:01 hasso Exp $ */
   3
   4
   5 /*-
   6  * Copyright (c)2003 Citrus Project,
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/types.h>
  32 #include <sys/endian.h>
  33 #include <assert.h>
  34 #include <errno.h>
  35 #include <limits.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39
  40 #include "citrus_namespace.h"
  41 #include "citrus_bcs.h"
  42 #include "citrus_region.h"
  43 #include "citrus_memstream.h"
  44 #include "citrus_mmap.h"
  45 #include "citrus_db.h"
  46 #include "citrus_db_file.h"
  47
  48 struct _citrus_db {
  49         /* private */
  50         struct _region db_region;
  51         uint32_t (*db_hashfunc)(void *, struct _citrus_region *);
  52         void *db_hashfunc_closure;
  53 };
  54
  55 int
  56 _citrus_db_open(struct _citrus_db **rdb, struct _region *r, const char *magic,
  57                 uint32_t (*hashfunc)(void *, struct _citrus_region *),
  58                 void *hashfunc_closure)
  59 {
  60         struct _memstream ms;
  61         struct _citrus_db *db;
  62         struct _citrus_db_header_x *dhx;
  63
  64         _memstream_bind(&ms, r);
  65
  66         /* sanity check */
  67         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
  68         if (dhx == NULL)
  69                 return EFTYPE;
  70         if (strncmp(dhx->dhx_magic, magic, _CITRUS_DB_MAGIC_SIZE) != 0)
  71                 return EFTYPE;
  72         if (_memstream_seek(&ms, be32toh(dhx->dhx_entry_offset), SEEK_SET))
  73                 return EFTYPE;
  74
  75         if (be32toh(dhx->dhx_num_entries)*_CITRUS_DB_ENTRY_SIZE >
  76             _memstream_remainder(&ms))
  77                 return EFTYPE;
  78
  79         db = malloc(sizeof(*db));
  80         if (db==NULL)
  81                 return errno;
  82         db->db_region = *r;
  83         db->db_hashfunc = hashfunc;
  84         db->db_hashfunc_closure = hashfunc_closure;
  85         *rdb = db;
  86
  87         return 0;
  88 }
  89
  90 void
  91 _citrus_db_close(struct _citrus_db *db)
  92 {
  93         free(db);
  94 }
  95
  96 int
  97 _citrus_db_lookup(struct _citrus_db *db, struct _citrus_region *key,
  98                   struct _citrus_region *data, struct _citrus_db_locator *dl)
  99 {
 100         uint32_t hashval, num_entries;
 101         size_t offset;
 102         struct _memstream ms;
 103         struct _citrus_db_header_x *dhx;
 104         struct _citrus_db_entry_x *dex;
 105         struct _citrus_region r;
 106
 107         _memstream_bind(&ms, &db->db_region);
 108
 109         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
 110         _DIAGASSERT(dhx);
 111         num_entries = be32toh(dhx->dhx_num_entries);
 112         if (num_entries == 0)
 113                 return ENOENT;
 114
 115         if (dl != NULL && dl->dl_offset>0) {
 116                 hashval = dl->dl_hashval;
 117                 offset = dl->dl_offset;
 118                 if (offset >= _region_size(&db->db_region))
 119                         return ENOENT;
 120         } else {
 121                 hashval =
 122                     db->db_hashfunc(db->db_hashfunc_closure, key)%num_entries;
 123                 offset =
 124                     be32toh(dhx->dhx_entry_offset) +
 125                     hashval * _CITRUS_DB_ENTRY_SIZE;
 126                 if (dl)
 127                         dl->dl_hashval = hashval;
 128         }
 129         do {
 130                 /* seek to the next entry */
 131                 if (_citrus_memory_stream_seek(&ms, offset, SEEK_SET))
 132                         return EFTYPE;
 133                 /* get the entry record */
 134                 dex = _memstream_getregion(&ms, NULL, _CITRUS_DB_ENTRY_SIZE);
 135                 if (dex == NULL)
 136                         return EFTYPE;
 137
 138                 /* jump to next entry having the same hash value. */
 139                 offset = be32toh(dex->dex_next_offset);
 140
 141                 /* save the current position */
 142                 if (dl) {
 143                         dl->dl_offset = offset;
 144                         if (offset==0)
 145                                 dl->dl_offset = _region_size(&db->db_region);
 146                 }
 147
 148                 /* compare hash value. */
 149                 if (be32toh(dex->dex_hash_value) != hashval)
 150                         /* not found */
 151                         break;
 152                 /* compare key length */
 153                 if (be32toh(dex->dex_key_size) == _region_size(key)) {
 154                         /* seek to the head of the key. */
 155                         if (_memstream_seek(&ms, be32toh(dex->dex_key_offset),
 156                                             SEEK_SET))
 157                                 return EFTYPE;
 158                         /* get the region of the key */
 159                         if (_memstream_getregion(&ms, &r,
 160                                                  _region_size(key)) == NULL)
 161                                 return EFTYPE;
 162                         /* compare key byte stream */
 163                         if (memcmp(_region_head(&r), _region_head(key),
 164                                    _region_size(key)) == 0) {
 165                                 /* match */
 166                                 if (_memstream_seek(
 167                                         &ms, be32toh(dex->dex_data_offset),
 168                                         SEEK_SET))
 169                                         return EFTYPE;
 170                                 if (_memstream_getregion(
 171                                         &ms, data,
 172                                         be32toh(dex->dex_data_size)) == NULL)
 173                                         return EFTYPE;
 174                                 return 0;
 175                         }
 176                 }
 177         } while (offset != 0);
 178
 179         return ENOENT;
 180 }
 181
 182 int
 183 _citrus_db_lookup_by_string(struct _citrus_db *db, const char *key,
 184                             struct _citrus_region *data,
 185                             struct _citrus_db_locator *dl)
 186 {
 187         struct _region r;
 188
 189         _region_init(&r, __DECONST(char *, key), strlen(key));
 190
 191         return _citrus_db_lookup(db, &r, data, dl);
 192 }
 193
 194 int
 195 _citrus_db_lookup8_by_string(struct _citrus_db *db, const char *key,
 196                              uint8_t *rval, struct _citrus_db_locator *dl)
 197 {
 198         int ret;
 199         struct _region r;
 200
 201         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 202         if (ret)
 203                 return ret;
 204
 205         if (_region_size(&r) != 1)
 206                 return EFTYPE;
 207
 208         if (rval)
 209                 memcpy(rval, _region_head(&r), 1);
 210
 211         return 0;
 212 }
 213
 214 int
 215 _citrus_db_lookup16_by_string(struct _citrus_db *db, const char *key,
 216                               uint16_t *rval, struct _citrus_db_locator *dl)
 217 {
 218         int ret;
 219         struct _region r;
 220         uint16_t val;
 221
 222         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 223         if (ret)
 224                 return ret;
 225
 226         if (_region_size(&r) != 2)
 227                 return EFTYPE;
 228
 229         if (rval) {
 230                 memcpy(&val, _region_head(&r), 2);
 231                 *rval = be16toh(val);
 232         }
 233
 234         return 0;
 235 }
 236
 237 int
 238 _citrus_db_lookup32_by_string(struct _citrus_db *db, const char *key,
 239                               uint32_t *rval, struct _citrus_db_locator *dl)
 240 {
 241         int ret;
 242         struct _region r;
 243         uint32_t val;
 244
 245         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 246         if (ret)
 247                 return ret;
 248
 249         if (_region_size(&r) != 4)
 250                 return EFTYPE;
 251
 252         if (rval) {
 253                 memcpy(&val, _region_head(&r), 4);
 254                 *rval = be32toh(val);
 255         }
 256
 257         return 0;
 258 }
 259
 260 int
 261 _citrus_db_lookup_string_by_string(struct _citrus_db *db, const char *key,
 262                                    const char **rdata,
 263                                    struct _citrus_db_locator *dl)
 264 {
 265         int ret;
 266         struct _region r;
 267
 268         ret = _citrus_db_lookup_by_string(db, key, &r, dl);
 269         if (ret)
 270                 return ret;
 271
 272         /* check whether the string is null terminated */
 273         if (_region_size(&r) == 0)
 274                 return EFTYPE;
 275         if (*((const char*)_region_head(&r)+_region_size(&r)-1) != '\0')
 276                 return EFTYPE;
 277
 278         if (rdata)
 279                 *rdata = _region_head(&r);
 280
 281         return 0;
 282 }
 283
 284 int
 285 _citrus_db_get_number_of_entries(struct _citrus_db *db)
 286 {
 287         struct _memstream ms;
 288         struct _citrus_db_header_x *dhx;
 289
 290         _memstream_bind(&ms, &db->db_region);
 291
 292         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
 293         _DIAGASSERT(dhx);
 294         return (int)be32toh(dhx->dhx_num_entries);
 295 }
 296
 297 int
 298 _citrus_db_get_entry(struct _citrus_db *db, int idx,
 299                      struct _region *key, struct _region *data)
 300 {
 301         uint32_t num_entries;
 302         size_t offset;
 303         struct _memstream ms;
 304         struct _citrus_db_header_x *dhx;
 305         struct _citrus_db_entry_x *dex;
 306
 307         _memstream_bind(&ms, &db->db_region);
 308
 309         dhx = _memstream_getregion(&ms, NULL, sizeof(*dhx));
 310         _DIAGASSERT(dhx);
 311         num_entries = be32toh(dhx->dhx_num_entries);
 312         if (idx < 0 || (uint32_t)idx >= num_entries)
 313                 return EINVAL;
 314
 315         /* seek to the next entry */
 316         offset = be32toh(dhx->dhx_entry_offset) + idx * _CITRUS_DB_ENTRY_SIZE;
 317         if (_citrus_memory_stream_seek(&ms, offset, SEEK_SET))
 318                 return EFTYPE;
 319         /* get the entry record */
 320         dex = _memstream_getregion(&ms, NULL, _CITRUS_DB_ENTRY_SIZE);
 321         if (dex == NULL)
 322                 return EFTYPE;
 323         /* seek to the head of the key. */
 324         if (_memstream_seek(&ms, be32toh(dex->dex_key_offset), SEEK_SET))
 325                 return EFTYPE;
 326         /* get the region of the key. */
 327         if (_memstream_getregion(&ms, key, be32toh(dex->dex_key_size))==NULL)
 328                 return EFTYPE;
 329         /* seek to the head of the data. */
 330         if (_memstream_seek(&ms, be32toh(dex->dex_data_offset), SEEK_SET))
 331                 return EFTYPE;
 332         /* get the region of the data. */
 333         if (_memstream_getregion(&ms, data, be32toh(dex->dex_data_size))==NULL)
 334                 return EFTYPE;
 335
 336         return 0;
 337 }