2 This file is part of GNUnet
3 (C) 2006, 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file datacache/plugin_datacache_sqlite.c
23 * @brief sqlite for an implementation of a database backend for the datacache
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "plugin_datacache.h"
31 #define DEBUG_DATACACHE_SQLITE GNUNET_NO
34 * How much overhead do we assume per entry in the
37 #define OVERHEAD (sizeof(GNUNET_HashCode) + 32)
40 * Context for all functions in this plugin.
45 * Our execution environment.
47 struct GNUNET_DATACACHE_PluginEnvironment *env;
50 * Handle to the sqlite database.
55 * Filename used for the DB.
62 * Log an error message at log-level 'level' that indicates
63 * a failure of the command 'cmd' on file 'filename'
64 * with the message given by strerror(errno).
66 #define LOG_SQLITE(db, level, cmd) do { GNUNET_log(level, _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, sqlite3_errmsg(db)); } while(0)
69 #define SQLITE3_EXEC(db, cmd) do { emsg = NULL; if (SQLITE_OK != sqlite3_exec(db, cmd, NULL, NULL, &emsg)) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, _("`%s' failed at %s:%d with error: %s\n"), "sqlite3_exec", __FILE__, __LINE__, emsg); sqlite3_free(emsg); } } while(0)
73 * @brief Prepare a SQL statement
76 sq_prepare (sqlite3 * dbh, const char *zSql, /* SQL statement, UTF-8 encoded */
77 sqlite3_stmt ** ppStmt)
78 { /* OUT: Statement handle */
80 return sqlite3_prepare (dbh,
82 strlen (zSql), ppStmt, (const char **) &dummy);
87 * Store an item in the datastore.
89 * @param cls closure (our "struct Plugin")
90 * @param key key to store data under
91 * @param size number of bytes in data
92 * @param data data to store
93 * @param type type of the value
94 * @param discard_time when to discard the value in any case
95 * @return 0 on error, number of bytes used otherwise
98 sqlite_plugin_put (void *cls,
99 const GNUNET_HashCode * key,
102 enum GNUNET_BLOCK_Type type,
103 struct GNUNET_TIME_Absolute discard_time)
105 struct Plugin *plugin = cls;
109 #if DEBUG_DATACACHE_SQLITE
110 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
111 "Processing `%s' of %u bytes with key `%4s' and expiration %llums\n",
115 (unsigned long long) GNUNET_TIME_absolute_get_remaining (discard_time).value);
117 dval = (int64_t) discard_time.value;
120 if (sq_prepare (plugin->dbh,
122 "(type, expire, key, value) "
123 "VALUES (?, ?, ?, ?)", &stmt) != SQLITE_OK)
125 GNUNET_log (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
126 _("`%s' failed at %s:%d with error: %s\n"),
127 "sq_prepare", __FILE__, __LINE__,
128 sqlite3_errmsg (plugin->dbh));
131 if ( (SQLITE_OK != sqlite3_bind_int (stmt, 1, type)) ||
132 (SQLITE_OK != sqlite3_bind_int64 (stmt, 2, dval)) ||
133 (SQLITE_OK != sqlite3_bind_blob (stmt, 3, key, sizeof (GNUNET_HashCode),
134 SQLITE_TRANSIENT)) ||
135 (SQLITE_OK != sqlite3_bind_blob (stmt, 4, data, size, SQLITE_TRANSIENT)))
137 LOG_SQLITE (plugin->dbh,
138 GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
140 sqlite3_finalize (stmt);
143 if (SQLITE_DONE != sqlite3_step (stmt))
145 LOG_SQLITE (plugin->dbh,
146 GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
148 sqlite3_finalize (stmt);
151 if (SQLITE_OK != sqlite3_finalize (stmt))
152 LOG_SQLITE (plugin->dbh,
153 GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
155 return size + OVERHEAD;
160 * Iterate over the results for a particular key
163 * @param cls closure (our "struct Plugin")
165 * @param type entries of which type are relevant?
166 * @param iter maybe NULL (to just count)
167 * @param iter_cls closure for iter
168 * @return the number of results found
171 sqlite_plugin_get (void *cls,
172 const GNUNET_HashCode * key,
173 enum GNUNET_BLOCK_Type type,
174 GNUNET_DATACACHE_Iterator iter,
177 struct Plugin *plugin = cls;
179 struct GNUNET_TIME_Absolute now;
180 struct GNUNET_TIME_Absolute exp;
189 now = GNUNET_TIME_absolute_get ();
190 #if DEBUG_DATACACHE_SQLITE
191 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
192 "Processing `%s' for key `%4s'\n",
196 if (sq_prepare (plugin->dbh,
197 "SELECT count(*) FROM ds090 WHERE key=? AND type=? AND expire >= ?",
200 GNUNET_log (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
201 _("`%s' failed at %s:%d with error: %s\n"),
202 "sq_prepare", __FILE__, __LINE__,
203 sqlite3_errmsg (plugin->dbh));
206 sqlite3_bind_blob (stmt, 1, key, sizeof (GNUNET_HashCode),
208 sqlite3_bind_int (stmt, 2, type);
209 ntime = (int64_t) now.value;
210 GNUNET_assert (ntime >= 0);
211 sqlite3_bind_int64 (stmt, 3, now.value);
212 if (SQLITE_ROW != sqlite3_step (stmt))
214 LOG_SQLITE (plugin->dbh,
215 GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
217 sqlite3_finalize (stmt);
220 total = sqlite3_column_int (stmt, 0);
221 sqlite3_finalize (stmt);
222 if ( (total == 0) || (iter == NULL) )
226 off = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, total);
229 off = (off + 1) % total;
230 GNUNET_snprintf (scratch,
232 "SELECT value,expire FROM ds090 WHERE key=? AND type=? AND expire >= ? LIMIT 1 OFFSET %u",
234 if (sq_prepare (plugin->dbh, scratch, &stmt) != SQLITE_OK)
236 GNUNET_log (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
237 _("`%s' failed at %s:%d with error: %s\n"),
238 "sq_prepare", __FILE__, __LINE__,
239 sqlite3_errmsg (plugin->dbh));
242 sqlite3_bind_blob (stmt, 1, key, sizeof (GNUNET_HashCode),
244 sqlite3_bind_int (stmt, 2, type);
245 sqlite3_bind_int64 (stmt, 3, now.value);
246 if (sqlite3_step (stmt) != SQLITE_ROW)
248 size = sqlite3_column_bytes (stmt, 0);
249 dat = sqlite3_column_blob (stmt, 0);
250 exp.value = sqlite3_column_int64 (stmt, 1);
251 ntime = (int64_t) exp.value;
252 if (ntime == INT64_MAX)
253 exp = GNUNET_TIME_UNIT_FOREVER_ABS;
255 if (GNUNET_OK != iter (iter_cls,
262 sqlite3_finalize (stmt);
265 sqlite3_finalize (stmt);
272 * Delete the entry with the lowest expiration value
273 * from the datacache right now.
275 * @param cls closure (our "struct Plugin")
276 * @return GNUNET_OK on success, GNUNET_SYSERR on error
279 sqlite_plugin_del (void *cls)
281 struct Plugin *plugin = cls;
287 #if DEBUG_DATACACHE_SQLITE
288 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
294 if ((sq_prepare (plugin->dbh,
295 "SELECT type, key, value FROM ds090 ORDER BY expire ASC LIMIT 1",
296 &stmt) != SQLITE_OK) ||
297 (sq_prepare (plugin->dbh,
299 "WHERE key=? AND value=? AND type=?",
300 &dstmt) != SQLITE_OK))
302 GNUNET_log (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
303 _("`%s' failed at %s:%d with error: %s\n"),
304 "sq_prepare", __FILE__, __LINE__, sqlite3_errmsg (plugin->dbh));
306 sqlite3_finalize (dstmt);
308 sqlite3_finalize (stmt);
309 return GNUNET_SYSERR;
311 if (SQLITE_ROW != sqlite3_step (stmt))
313 GNUNET_log (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
314 _("`%s' failed at %s:%d with error: %s\n"),
315 "sqlite3_step", __FILE__, __LINE__,
316 sqlite3_errmsg (plugin->dbh));
317 sqlite3_finalize (dstmt);
318 sqlite3_finalize (stmt);
319 return GNUNET_SYSERR;
321 dtype = sqlite3_column_int (stmt, 0);
322 GNUNET_break (sqlite3_column_bytes (stmt, 1) == sizeof (GNUNET_HashCode));
323 dsize = sqlite3_column_bytes (stmt, 2);
324 sqlite3_bind_blob (dstmt,
325 1, sqlite3_column_blob (stmt, 1),
326 sizeof (GNUNET_HashCode),
328 sqlite3_bind_blob (dstmt,
329 2, sqlite3_column_blob (stmt, 2),
332 sqlite3_bind_int (dstmt, 3, dtype);
333 if (sqlite3_step (dstmt) != SQLITE_DONE)
335 GNUNET_log (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
336 _("`%s' failed at %s:%d with error: %s\n"),
337 "sqlite3_step", __FILE__, __LINE__,
338 sqlite3_errmsg (plugin->dbh));
339 sqlite3_finalize (dstmt);
340 sqlite3_finalize (stmt);
341 return GNUNET_SYSERR;
343 plugin->env->delete_notify (plugin->env->cls,
344 sqlite3_column_blob (stmt, 1),
346 sqlite3_finalize (dstmt);
347 sqlite3_finalize (stmt);
353 * Entry point for the plugin.
355 * @param cls closure (the "struct GNUNET_DATACACHE_PluginEnvironmnet")
356 * @return the plugin's closure (our "struct Plugin")
359 libgnunet_plugin_datacache_sqlite_init (void *cls)
361 struct GNUNET_DATACACHE_PluginEnvironment *env = cls;
362 struct GNUNET_DATACACHE_PluginFunctions *api;
363 struct Plugin *plugin;
369 fn = GNUNET_DISK_mktemp ("gnunet-datacache");
375 fn_utf8 = GNUNET_STRINGS_to_utf8 (fn, strlen (fn),
377 nl_langinfo (CODESET)
379 "UTF-8" /* good luck */
382 if (SQLITE_OK != sqlite3_open (fn_utf8, &dbh))
385 GNUNET_free (fn_utf8);
390 SQLITE3_EXEC (dbh, "PRAGMA temp_store=MEMORY");
391 SQLITE3_EXEC (dbh, "PRAGMA synchronous=OFF");
392 SQLITE3_EXEC (dbh, "PRAGMA count_changes=OFF");
393 SQLITE3_EXEC (dbh, "PRAGMA page_size=4092");
395 "CREATE TABLE ds090 ("
396 " type INTEGER NOT NULL DEFAULT 0,"
397 " expire INTEGER NOT NULL DEFAULT 0,"
398 " key BLOB NOT NULL DEFAULT '',"
399 " value BLOB NOT NULL DEFAULT '')");
400 SQLITE3_EXEC (dbh, "CREATE INDEX idx_hashidx ON ds090 (key,type,expire)");
401 plugin = GNUNET_malloc (sizeof (struct Plugin));
404 plugin->fn = fn_utf8;
405 api = GNUNET_malloc (sizeof (struct GNUNET_DATACACHE_PluginFunctions));
407 api->get = &sqlite_plugin_get;
408 api->put = &sqlite_plugin_put;
409 api->del = &sqlite_plugin_del;
410 GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
411 "sqlite", _("Sqlite datacache running\n"));
417 * Exit point from the plugin.
419 * @param cls closure (our "struct Plugin")
423 libgnunet_plugin_datacache_sqlite_done (void *cls)
425 struct GNUNET_DATACACHE_PluginFunctions *api = cls;
426 struct Plugin *plugin = api->cls;
428 if (0 != UNLINK (plugin->fn))
429 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
432 GNUNET_free (plugin->fn);
433 sqlite3_close (plugin->dbh);
434 GNUNET_free (plugin);
441 /* end of plugin_datacache_sqlite.c */