src/pulsecore/database-gdbm.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2009 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27 #include <gdbm.h>
  28
  29 #include <pulse/xmalloc.h>
  30 #include <pulsecore/core-util.h>
  31 #include <pulsecore/log.h>
  32
  33 #include "database.h"
  34
  35 #define MAKE_GDBM_FILE(x) ((GDBM_FILE) (x))
  36
  37 static inline datum* datum_to_gdbm(datum *to, const pa_datum *from) {
  38     pa_assert(from);
  39     pa_assert(to);
  40
  41     to->dptr = from->data;
  42     to->dsize = from->size;
  43
  44     return to;
  45 }
  46
  47 static inline pa_datum* datum_from_gdbm(pa_datum *to, const datum *from) {
  48     pa_assert(from);
  49     pa_assert(to);
  50
  51     to->data = from->dptr;
  52     to->size = from->dsize;
  53
  54     return to;
  55 }
  56
  57 void pa_datum_free(pa_datum *d) {
  58     pa_assert(d);
  59
  60     free(d->data); /* gdbm uses raw malloc/free hence we should do that here, too */
  61     pa_zero(d);
  62 }
  63
  64 pa_database* pa_database_open(const char *fn, pa_bool_t for_write) {
  65     GDBM_FILE f;
  66     int gdbm_cache_size;
  67     char *path;
  68
  69     pa_assert(fn);
  70
  71     /* We include the host identifier in the file name because gdbm
  72      * files are CPU dependant, and we don't want things to go wrong
  73      * if we are on a multiarch system. */
  74     path = pa_sprintf_malloc("%s."CANONICAL_HOST".gdbm", fn);
  75     errno = 0;
  76
  77     /* We need to set the block size explicitly here, since otherwise
  78      * gdbm takes the native block size of the underlying file system
  79      * which might be incredibly large. */
  80     f = gdbm_open((char*) path, 1024, GDBM_NOLOCK | (for_write ? GDBM_WRCREAT : GDBM_READER), 0644, NULL);
  81
  82     if (f)
  83         pa_log_debug("Opened GDBM database '%s'", path);
  84
  85     pa_xfree(path);
  86
  87     if (!f) {
  88         if (errno == 0)
  89             errno = EIO;
  90         return NULL;
  91     }
  92
  93     /* By default the cache of gdbm is rather large, let's reduce it a bit to save memory */
  94     gdbm_cache_size = 10;
  95     gdbm_setopt(f, GDBM_CACHESIZE, &gdbm_cache_size, sizeof(gdbm_cache_size));
  96
  97     return (pa_database*) f;
  98 }
  99
 100 void pa_database_close(pa_database *db) {
 101     pa_assert(db);
 102
 103     gdbm_close(MAKE_GDBM_FILE(db));
 104 }
 105
 106 pa_datum* pa_database_get(pa_database *db, const pa_datum *key, pa_datum* data) {
 107     datum gdbm_key, gdbm_data;
 108
 109     pa_assert(db);
 110     pa_assert(key);
 111     pa_assert(data);
 112
 113     gdbm_data = gdbm_fetch(MAKE_GDBM_FILE(db), *datum_to_gdbm(&gdbm_key, key));
 114
 115     return gdbm_data.dptr ?
 116         datum_from_gdbm(data, &gdbm_data) :
 117         NULL;
 118 }
 119
 120 int pa_database_set(pa_database *db, const pa_datum *key, const pa_datum* data, pa_bool_t overwrite) {
 121     datum gdbm_key, gdbm_data;
 122
 123     pa_assert(db);
 124     pa_assert(key);
 125     pa_assert(data);
 126
 127     return gdbm_store(MAKE_GDBM_FILE(db),
 128                       *datum_to_gdbm(&gdbm_key, key),
 129                       *datum_to_gdbm(&gdbm_data, data),
 130                       overwrite ? GDBM_REPLACE : GDBM_INSERT) != 0 ? -1 : 0;
 131 }
 132
 133 int pa_database_unset(pa_database *db, const pa_datum *key) {
 134     datum gdbm_key;
 135
 136     pa_assert(db);
 137     pa_assert(key);
 138
 139     return gdbm_delete(MAKE_GDBM_FILE(db), *datum_to_gdbm(&gdbm_key, key)) != 0 ? -1 : 0;
 140 }
 141
 142 int pa_database_clear(pa_database *db) {
 143     datum gdbm_key;
 144
 145     pa_assert(db);
 146
 147     gdbm_key = gdbm_firstkey(MAKE_GDBM_FILE(db));
 148
 149     while (gdbm_key.dptr) {
 150         datum next;
 151
 152         next = gdbm_nextkey(MAKE_GDBM_FILE(db), gdbm_key);
 153
 154         gdbm_delete(MAKE_GDBM_FILE(db), gdbm_key);
 155
 156         free(gdbm_key.dptr);
 157         gdbm_key = next;
 158     }
 159
 160     return gdbm_reorganize(MAKE_GDBM_FILE(db)) == 0 ? 0 : -1;
 161 }
 162
 163 signed pa_database_size(pa_database *db) {
 164     datum gdbm_key;
 165     unsigned n = 0;
 166
 167     pa_assert(db);
 168
 169     /* This sucks */
 170
 171     gdbm_key = gdbm_firstkey(MAKE_GDBM_FILE(db));
 172
 173     while (gdbm_key.dptr) {
 174         datum next;
 175
 176         n++;
 177
 178         next = gdbm_nextkey(MAKE_GDBM_FILE(db), gdbm_key);
 179         free(gdbm_key.dptr);
 180         gdbm_key = next;
 181     }
 182
 183     return (signed) n;
 184 }
 185
 186 pa_datum* pa_database_first(pa_database *db, pa_datum *key, pa_datum *data) {
 187     datum gdbm_key, gdbm_data;
 188
 189     pa_assert(db);
 190     pa_assert(key);
 191
 192     gdbm_key = gdbm_firstkey(MAKE_GDBM_FILE(db));
 193
 194     if (!gdbm_key.dptr)
 195         return NULL;
 196
 197     if (data) {
 198         gdbm_data = gdbm_fetch(MAKE_GDBM_FILE(db), gdbm_key);
 199
 200         if (!gdbm_data.dptr) {
 201             free(gdbm_key.dptr);
 202             return NULL;
 203         }
 204
 205         datum_from_gdbm(data, &gdbm_data);
 206     }
 207
 208     datum_from_gdbm(key, &gdbm_key);
 209
 210     return key;
 211 }
 212
 213 pa_datum* pa_database_next(pa_database *db, const pa_datum *key, pa_datum *next, pa_datum *data) {
 214     datum gdbm_key, gdbm_data;
 215
 216     pa_assert(db);
 217     pa_assert(key);
 218     pa_assert(next);
 219
 220     if (!key)
 221         return pa_database_first(db, next, data);
 222
 223     gdbm_key = gdbm_nextkey(MAKE_GDBM_FILE(db), *datum_to_gdbm(&gdbm_key, key));
 224
 225     if (!gdbm_key.dptr)
 226         return NULL;
 227
 228     if (data) {
 229         gdbm_data = gdbm_fetch(MAKE_GDBM_FILE(db), gdbm_key);
 230
 231         if (!gdbm_data.dptr) {
 232             free(gdbm_key.dptr);
 233             return NULL;
 234         }
 235
 236         datum_from_gdbm(data, &gdbm_data);
 237     }
 238
 239     datum_from_gdbm(next, &gdbm_key);
 240
 241     return next;
 242 }
 243
 244 int pa_database_sync(pa_database *db) {
 245     pa_assert(db);
 246
 247     gdbm_sync(MAKE_GDBM_FILE(db));
 248     return 0;
 249 }