1 /* $NetBSD: src/lib/libc/citrus/citrus_db.c,v 1.3 2004/01/02 21:49:35 itojun Exp $ */ 2 /* $DragonFly: src/lib/libc/citrus/citrus_db.c,v 1.2 2005/03/16 06:13:24 joerg 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 } 338