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 } 341