dbm/apr_dbm_berkeleydb.c

   1 /* Licensed to the Apache Software Foundation (ASF) under one or more
   2  * contributor license agreements.  See the NOTICE file distributed with
   3  * this work for additional information regarding copyright ownership.
   4  * The ASF licenses this file to You under the Apache License, Version 2.0
   5  * (the "License"); you may not use this file except in compliance with
   6  * the License.  You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "apr_strings.h"
  18 #define APR_WANT_MEMFUNC
  19 #include "apr_want.h"
  20
  21 #define APU_WANT_DB
  22 #include "apu_want.h"
  23
  24 #if APR_HAVE_STDLIB_H
  25 #include <stdlib.h> /* for abort() */
  26 #endif
  27
  28 #include "apu.h"
  29
  30 #if APU_HAVE_DB
  31 #include "apr_dbm_private.h"
  32
  33 /*
  34  * We pick up all varieties of Berkeley DB through db.h (included through
  35  * apu_select_dbm.h). This code has been compiled/tested against DB1,
  36  * DB_185, DB2, DB3, and DB4.
  37  */
  38
  39 #if   defined(DB_VERSION_MAJOR) && (DB_VERSION_MAJOR == 4)
  40 /* We will treat anything greater than 4.1 as DB4.
  41  * We can treat 4.0 as DB3.
  42  */
  43 #if   defined(DB_VERSION_MINOR) && (DB_VERSION_MINOR >= 1)
  44 #define DB_VER 4
  45 #else
  46 #define DB_VER 3
  47 #endif
  48 #elif defined(DB_VERSION_MAJOR) && (DB_VERSION_MAJOR == 3)
  49 #define DB_VER 3
  50 #elif defined(DB_VERSION_MAJOR) && (DB_VERSION_MAJOR == 2)
  51 #define DB_VER 2
  52 #else
  53 #define DB_VER 1
  54 #endif
  55
  56 typedef struct {
  57     DB *bdb;
  58 #if DB_VER != 1
  59     DBC *curs;
  60 #endif
  61 } real_file_t;
  62
  63
  64 #if DB_VER == 1
  65 #define TXN_ARG
  66 #else
  67 #define TXN_ARG NULL,
  68 #endif
  69
  70 #define GET_BDB(f)      (((real_file_t *)(f))->bdb)
  71
  72 #define do_fetch(bdb, k, v)     ((*(bdb)->get)(bdb, TXN_ARG &(k), &(v), 0))
  73
  74 #if DB_VER == 1
  75 #include <sys/fcntl.h>
  76 #define APR_DBM_DBMODE_RO       O_RDONLY
  77 #define APR_DBM_DBMODE_RW       O_RDWR
  78 #define APR_DBM_DBMODE_RWCREATE (O_CREAT | O_RDWR)
  79 #define APR_DBM_DBMODE_RWTRUNC  (O_CREAT | O_RDWR | O_TRUNC)
  80 #else
  81 #define APR_DBM_DBMODE_RO       DB_RDONLY
  82 #define APR_DBM_DBMODE_RW       0
  83 #define APR_DBM_DBMODE_RWCREATE DB_CREATE
  84 #define APR_DBM_DBMODE_RWTRUNC  DB_TRUNCATE
  85 #endif /* DBVER == 1 */
  86
  87 /* --------------------------------------------------------------------------
  88 **
  89 ** UTILITY FUNCTIONS
  90 */
  91
  92 /* map a DB error to an apr_status_t */
  93 static apr_status_t db2s(int dberr)
  94 {
  95     if (dberr != 0) {
  96         /* ### need to fix this */
  97         return APR_OS_START_USEERR + dberr;
  98     }
  99
 100     return APR_SUCCESS;
 101 }
 102
 103
 104 static apr_status_t set_error(apr_dbm_t *dbm, apr_status_t dbm_said)
 105 {
 106     apr_status_t rv = APR_SUCCESS;
 107
 108     /* ### ignore whatever the DBM said (dbm_said); ask it explicitly */
 109
 110     if (dbm_said == APR_SUCCESS) {
 111         dbm->errcode = 0;
 112         dbm->errmsg = NULL;
 113     }
 114     else {
 115         /* ### need to fix. dberr was tossed in db2s(). */
 116         /* ### use db_strerror() */
 117         dbm->errcode = dbm_said;
 118 #if DB_VER == 1 || DB_VER == 2
 119         dbm->errmsg = NULL;
 120 #else
 121         dbm->errmsg = db_strerror(dbm_said - APR_OS_START_USEERR);
 122 #endif
 123         rv = dbm_said;
 124     }
 125
 126     return rv;
 127 }
 128
 129 /* --------------------------------------------------------------------------
 130 **
 131 ** DEFINE THE VTABLE FUNCTIONS FOR BERKELEY DB
 132 **
 133 ** ### we may need three sets of these: db1, db2, db3
 134 */
 135
 136 static apr_status_t vt_db_open(apr_dbm_t **pdb, const char *pathname,
 137                                apr_int32_t mode, apr_fileperms_t perm,
 138                                apr_pool_t *pool)
 139 {
 140     real_file_t file;
 141     int dbmode;
 142
 143     *pdb = NULL;
 144
 145     switch (mode) {
 146     case APR_DBM_READONLY:
 147         dbmode = APR_DBM_DBMODE_RO;
 148         break;
 149     case APR_DBM_READWRITE:
 150         dbmode = APR_DBM_DBMODE_RW;
 151         break;
 152     case APR_DBM_RWCREATE:
 153         dbmode = APR_DBM_DBMODE_RWCREATE;
 154         break;
 155     case APR_DBM_RWTRUNC:
 156         dbmode = APR_DBM_DBMODE_RWTRUNC;
 157         break;
 158     default:
 159         return APR_EINVAL;
 160     }
 161
 162     {
 163         int dberr;
 164
 165 #if DB_VER >= 3
 166         if ((dberr = db_create(&file.bdb, NULL, 0)) == 0) {
 167             if ((dberr = (*file.bdb->open)(file.bdb,
 168 #if DB_VER == 4
 169                                            NULL,
 170 #endif
 171                                            pathname, NULL,
 172                                            DB_HASH, dbmode,
 173                                            apr_posix_perms2mode(perm))) != 0) {
 174                 /* close the DB handler */
 175                 (void) (*file.bdb->close)(file.bdb, 0);
 176             }
 177         }
 178         file.curs = NULL;
 179 #elif DB_VER == 2
 180         dberr = db_open(pathname, DB_HASH, dbmode, apr_posix_perms2mode(perm),
 181                         NULL, NULL, &file.bdb);
 182         file.curs = NULL;
 183 #else
 184         file.bdb = dbopen(pathname, dbmode, apr_posix_perms2mode(perm),
 185                           DB_HASH, NULL);
 186         if (file.bdb == NULL)
 187             return APR_EGENERAL;      /* ### need a better error */
 188         dberr = 0;
 189 #endif
 190         if (dberr != 0)
 191             return db2s(dberr);
 192     }
 193
 194     /* we have an open database... return it */
 195     *pdb = apr_pcalloc(pool, sizeof(**pdb));
 196     (*pdb)->pool = pool;
 197     (*pdb)->type = &apr_dbm_type_db;
 198     (*pdb)->file = apr_pmemdup(pool, &file, sizeof(file));
 199
 200     /* ### register a cleanup to close the DBM? */
 201
 202     return APR_SUCCESS;
 203 }
 204
 205 static void vt_db_close(apr_dbm_t *dbm)
 206 {
 207     (*GET_BDB(dbm->file)->close)(GET_BDB(dbm->file)
 208 #if DB_VER != 1
 209                                  , 0
 210 #endif
 211         );
 212 }
 213
 214 static apr_status_t vt_db_fetch(apr_dbm_t *dbm, apr_datum_t key,
 215                                 apr_datum_t * pvalue)
 216 {
 217     DBT ckey = { 0 };
 218     DBT rd = { 0 };
 219     int dberr;
 220
 221     ckey.data = key.dptr;
 222     ckey.size = key.dsize;
 223
 224     dberr = do_fetch(GET_BDB(dbm->file), ckey, rd);
 225
 226     /* "not found" is not an error. return zero'd value. */
 227     if (dberr ==
 228 #if DB_VER == 1
 229         RET_SPECIAL
 230 #else
 231         DB_NOTFOUND
 232 #endif
 233         ) {
 234         memset(&rd, 0, sizeof(rd));
 235         dberr = 0;
 236     }
 237
 238     pvalue->dptr = rd.data;
 239     pvalue->dsize = rd.size;
 240
 241     /* store the error info into DBM, and return a status code. Also, note
 242        that *pvalue should have been cleared on error. */
 243     return set_error(dbm, db2s(dberr));
 244 }
 245
 246 static apr_status_t vt_db_store(apr_dbm_t *dbm, apr_datum_t key,
 247                                 apr_datum_t value)
 248 {
 249     apr_status_t rv;
 250     DBT ckey = { 0 };
 251     DBT cvalue = { 0 };
 252
 253     ckey.data = key.dptr;
 254     ckey.size = key.dsize;
 255
 256     cvalue.data = value.dptr;
 257     cvalue.size = value.dsize;
 258
 259     rv = db2s((*GET_BDB(dbm->file)->put)(GET_BDB(dbm->file),
 260                                          TXN_ARG
 261                                          &ckey,
 262                                          &cvalue,
 263                                          0));
 264
 265     /* store any error info into DBM, and return a status code. */
 266     return set_error(dbm, rv);
 267 }
 268
 269 static apr_status_t vt_db_del(apr_dbm_t *dbm, apr_datum_t key)
 270 {
 271     apr_status_t rv;
 272     DBT ckey = { 0 };
 273
 274     ckey.data = key.dptr;
 275     ckey.size = key.dsize;
 276
 277     rv = db2s((*GET_BDB(dbm->file)->del)(GET_BDB(dbm->file),
 278                                          TXN_ARG
 279                                          &ckey,
 280                                          0));
 281
 282     /* store any error info into DBM, and return a status code. */
 283     return set_error(dbm, rv);
 284 }
 285
 286 static int vt_db_exists(apr_dbm_t *dbm, apr_datum_t key)
 287 {
 288     DBT ckey = { 0 };   /* converted key */
 289     DBT data = { 0 };
 290     int dberr;
 291
 292     ckey.data = key.dptr;
 293     ckey.size = key.dsize;
 294
 295     dberr = do_fetch(GET_BDB(dbm->file), ckey, data);
 296
 297     /* note: the result data is "loaned" to us; we don't need to free it */
 298
 299     /* DB returns DB_NOTFOUND if it doesn't exist. but we want to say
 300        that *any* error means it doesn't exist. */
 301     return dberr == 0;
 302 }
 303
 304 static apr_status_t vt_db_firstkey(apr_dbm_t *dbm, apr_datum_t * pkey)
 305 {
 306     real_file_t *f = dbm->file;
 307     DBT first = { 0 };
 308     DBT data = { 0 };
 309     int dberr;
 310
 311 #if DB_VER == 1
 312     dberr = (*f->bdb->seq)(f->bdb, &first, &data, R_FIRST);
 313 #else
 314     if ((dberr = (*f->bdb->cursor)(f->bdb, NULL, &f->curs
 315 #if DB_VER >= 3 || ((DB_VERSION_MAJOR == 2) && (DB_VERSION_MINOR > 5))
 316                                    , 0
 317 #endif
 318              )) == 0) {
 319         dberr = (*f->curs->c_get)(f->curs, &first, &data, DB_FIRST);
 320         if (dberr == DB_NOTFOUND) {
 321             memset(&first, 0, sizeof(first));
 322             (*f->curs->c_close)(f->curs);
 323             f->curs = NULL;
 324             dberr = 0;
 325         }
 326     }
 327 #endif
 328
 329     pkey->dptr = first.data;
 330     pkey->dsize = first.size;
 331
 332     /* store any error info into DBM, and return a status code. */
 333     return set_error(dbm, db2s(dberr));
 334 }
 335
 336 static apr_status_t vt_db_nextkey(apr_dbm_t *dbm, apr_datum_t * pkey)
 337 {
 338     real_file_t *f = dbm->file;
 339     DBT ckey = { 0 };
 340     DBT data = { 0 };
 341     int dberr;
 342
 343     ckey.data = pkey->dptr;
 344     ckey.size = pkey->dsize;
 345
 346 #if DB_VER == 1
 347     dberr = (*f->bdb->seq)(f->bdb, &ckey, &data, R_NEXT);
 348     if (dberr == RET_SPECIAL) {
 349         dberr = 0;
 350         ckey.data = NULL;
 351         ckey.size = 0;
 352     }
 353 #else
 354     if (f->curs == NULL)
 355         return APR_EINVAL;
 356
 357     dberr = (*f->curs->c_get)(f->curs, &ckey, &data, DB_NEXT);
 358     if (dberr == DB_NOTFOUND) {
 359         (*f->curs->c_close)(f->curs);
 360         f->curs = NULL;
 361         dberr = 0;
 362         ckey.data = NULL;
 363         ckey.size = 0;
 364     }
 365 #endif
 366
 367     pkey->dptr = ckey.data;
 368     pkey->dsize = ckey.size;
 369
 370     /* store any error info into DBM, and return a status code. */
 371     /* ### or use db2s(dberr) instead of APR_SUCCESS? */
 372     return set_error(dbm, APR_SUCCESS);
 373 }
 374
 375 static void vt_db_freedatum(apr_dbm_t *dbm, apr_datum_t data)
 376 {
 377     /* nothing to do */
 378 }
 379
 380 static void vt_db_usednames(apr_pool_t *pool, const char *pathname,
 381                             const char **used1, const char **used2)
 382 {
 383     *used1 = apr_pstrdup(pool, pathname);
 384     *used2 = NULL;
 385 }
 386
 387
 388 APU_DECLARE_DATA const apr_dbm_type_t apr_dbm_type_db = {
 389     "db",
 390
 391     vt_db_open,
 392     vt_db_close,
 393     vt_db_fetch,
 394     vt_db_store,
 395     vt_db_del,
 396     vt_db_exists,
 397     vt_db_firstkey,
 398     vt_db_nextkey,
 399     vt_db_freedatum,
 400     vt_db_usednames
 401 };
 402
 403 #endif /* APU_HAVE_DB */