Imported Upstream version 0.9.2upstream/0.9.2

1 files changed, 1264 insertions, 0 deletions

diff --git a/src/datastore/plugin_datastore_sqlite.c b/src/datastore/plugin_datastore_sqlite.c
new file mode 100644
index 0000000..cd5ae39
--- /dev/null
+++ b/src/datastore/plugin_datastore_sqlite.c
@@ -0,0 +1,1264 @@
+ /*
+  * This file is part of GNUnet
+  * (C) 2009, 2011 Christian Grothoff (and other contributing authors)
+  *
+  * GNUnet is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published
+  * by the Free Software Foundation; either version 3, or (at your
+  * option) any later version.
+  *
+  * GNUnet is distributed in the hope that it will be useful, but
+  * WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  * General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with GNUnet; see the file COPYING.  If not, write to the
+  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+  * Boston, MA 02111-1307, USA.
+  */
+
+/**
+ * @file datastore/plugin_datastore_sqlite.c
+ * @brief sqlite-based datastore backend
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_datastore_plugin.h"
+#include <sqlite3.h>
+
+/**
+ * Enable or disable logging debug messages.
+ */
+#define DEBUG_SQLITE GNUNET_EXTRA_LOGGING
+
+/**
+ * We allocate items on the stack at times.  To prevent a stack
+ * overflow, we impose a limit on the maximum size for the data per
+ * item.  64k should be enough.
+ */
+#define MAX_ITEM_SIZE 65536
+
+/**
+ * After how many ms "busy" should a DB operation fail for good?
+ * A low value makes sure that we are more responsive to requests
+ * (especially PUTs).  A high value guarantees a higher success
+ * rate (SELECTs in iterate can take several seconds despite LIMIT=1).
+ *
+ * The default value of 250ms should ensure that users do not experience
+ * huge latencies while at the same time allowing operations to succeed
+ * with reasonable probability.
+ */
+#define BUSY_TIMEOUT_MS 250
+
+
+/**
+ * Log an error message at log-level 'level' that indicates
+ * a failure of the command 'cmd' on file 'filename'
+ * with the message given by strerror(errno).
+ */
+#define LOG_SQLITE(db, msg, level, cmd) do { GNUNET_log_from (level, "sqlite", _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, sqlite3_errmsg(db->dbh)); if (msg != NULL) GNUNET_asprintf(msg, _("`%s' failed at %s:%u with error: %s"), cmd, __FILE__, __LINE__, sqlite3_errmsg(db->dbh)); } while(0)
+
+
+
+/**
+ * Context for all functions in this plugin.
+ */
+struct Plugin
+{
+  /**
+   * Our execution environment.
+   */
+  struct GNUNET_DATASTORE_PluginEnvironment *env;
+
+  /**
+   * Database filename.
+   */
+  char *fn;
+
+  /**
+   * Native SQLite database handle.
+   */
+  sqlite3 *dbh;
+
+  /**
+   * Precompiled SQL for deletion.
+   */
+  sqlite3_stmt *delRow;
+
+  /**
+   * Precompiled SQL for update.
+   */
+  sqlite3_stmt *updPrio;
+
+  /**
+   * Get maximum repl value in database.
+   */
+  sqlite3_stmt *maxRepl;
+
+  /**
+   * Precompiled SQL for replication decrement.
+   */
+  sqlite3_stmt *updRepl;
+
+  /**
+   * Precompiled SQL for replication selection.
+   */
+  sqlite3_stmt *selRepl;
+
+  /**
+   * Precompiled SQL for expiration selection.
+   */
+  sqlite3_stmt *selExpi;
+
+  /**
+   * Precompiled SQL for expiration selection.
+   */
+  sqlite3_stmt *selZeroAnon;
+
+  /**
+   * Precompiled SQL for insertion.
+   */
+  sqlite3_stmt *insertContent;
+
+  /**
+   * Should the database be dropped on shutdown?
+   */
+  int drop_on_shutdown;
+
+};
+
+
+/**
+ * @brief Prepare a SQL statement
+ *
+ * @param dbh handle to the database
+ * @param zSql SQL statement, UTF-8 encoded
+ * @param ppStmt set to the prepared statement
+ * @return 0 on success
+ */
+static int
+sq_prepare (sqlite3 * dbh, const char *zSql, sqlite3_stmt ** ppStmt)
+{
+  char *dummy;
+  int result;
+
+  result =
+      sqlite3_prepare_v2 (dbh, zSql, strlen (zSql), ppStmt,
+                          (const char **) &dummy);
+#if DEBUG_SQLITE && 0
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                   "Prepared `%s' / %p: %d\n", zSql, *ppStmt, result);
+#endif
+  return result;
+}
+
+
+/**
+ * Create our database indices.
+ *
+ * @param dbh handle to the database
+ */
+static void
+create_indices (sqlite3 * dbh)
+{
+  /* create indices */
+  if ((SQLITE_OK !=
+       sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS idx_hash ON gn090 (hash)",
+                     NULL, NULL, NULL)) ||
+      (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_hash_vhash ON gn090 (hash,vhash)",
+                     NULL, NULL, NULL)) ||
+      (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_expire_repl ON gn090 (expire ASC,repl DESC)",
+                     NULL, NULL, NULL)) ||
+      (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_comb ON gn090 (anonLevel ASC,expire ASC,prio,type,hash)",
+                     NULL, NULL, NULL)) ||
+      (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_anon_type_hash ON gn090 (anonLevel ASC,type,hash)",
+                     NULL, NULL, NULL)) ||
+      (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_expire ON gn090 (expire ASC)",
+                     NULL, NULL, NULL)) ||
+      (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_repl_rvalue ON gn090 (repl,rvalue)",
+                     NULL, NULL, NULL)) ||
+      (SQLITE_OK !=
+       sqlite3_exec (dbh,
+                     "CREATE INDEX IF NOT EXISTS idx_repl ON gn090 (repl DESC)",
+                     NULL, NULL, NULL)))
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "sqlite",
+                     "Failed to create indices: %s\n", sqlite3_errmsg (dbh));
+}
+
+
+#if 0
+#define CHECK(a) GNUNET_break(a)
+#define ENULL NULL
+#else
+#define ENULL &e
+#define ENULL_DEFINED 1
+#define CHECK(a) if (! a) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "%s\n", e); sqlite3_free(e); }
+#endif
+
+
+/**
+ * Initialize the database connections and associated
+ * data structures (create tables and indices
+ * as needed as well).
+ *
+ * @param cfg our configuration
+ * @param plugin the plugin context (state for this module)
+ * @return GNUNET_OK on success
+ */
+static int
+database_setup (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                struct Plugin *plugin)
+{
+  sqlite3_stmt *stmt;
+  char *afsdir;
+
+#if ENULL_DEFINED
+  char *e;
+#endif
+
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_filename (cfg, "datastore-sqlite",
+                                               "FILENAME", &afsdir))
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "sqlite",
+                     _
+                     ("Option `%s' in section `%s' missing in configuration!\n"),
+                     "FILENAME", "datastore-sqlite");
+    return GNUNET_SYSERR;
+  }
+  if (GNUNET_OK != GNUNET_DISK_file_test (afsdir))
+  {
+    if (GNUNET_OK != GNUNET_DISK_directory_create_for_file (afsdir))
+    {
+      GNUNET_break (0);
+      GNUNET_free (afsdir);
+      return GNUNET_SYSERR;
+    }
+    /* database is new or got deleted, reset payload to zero! */
+    plugin->env->duc (plugin->env->cls, 0);
+  }
+#ifdef ENABLE_NLS
+  plugin->fn =
+      GNUNET_STRINGS_to_utf8 (afsdir, strlen (afsdir), nl_langinfo (CODESET));
+#else
+  plugin->fn = GNUNET_STRINGS_to_utf8 (afsdir, strlen (afsdir), "UTF-8");       /* good luck */
+#endif
+  GNUNET_free (afsdir);
+
+  /* Open database and precompile statements */
+  if (sqlite3_open (plugin->fn, &plugin->dbh) != SQLITE_OK)
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "sqlite",
+                     _("Unable to initialize SQLite: %s.\n"),
+                     sqlite3_errmsg (plugin->dbh));
+    return GNUNET_SYSERR;
+  }
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA temp_store=MEMORY", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA synchronous=OFF", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA legacy_file_format=OFF", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA auto_vacuum=INCREMENTAL", NULL,
+                       NULL, ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA locking_mode=EXCLUSIVE", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA count_changes=OFF", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA page_size=4092", NULL, NULL,
+                       ENULL));
+
+  CHECK (SQLITE_OK == sqlite3_busy_timeout (plugin->dbh, BUSY_TIMEOUT_MS));
+
+
+  /* We have to do it here, because otherwise precompiling SQL might fail */
+  CHECK (SQLITE_OK ==
+         sq_prepare (plugin->dbh,
+                     "SELECT 1 FROM sqlite_master WHERE tbl_name = 'gn090'",
+                     &stmt));
+  if ((sqlite3_step (stmt) == SQLITE_DONE) &&
+      (sqlite3_exec
+       (plugin->dbh,
+        "CREATE TABLE gn090 (" "  repl INT4 NOT NULL DEFAULT 0,"
+        "  type INT4 NOT NULL DEFAULT 0," "  prio INT4 NOT NULL DEFAULT 0,"
+        "  anonLevel INT4 NOT NULL DEFAULT 0,"
+        "  expire INT8 NOT NULL DEFAULT 0," "  rvalue INT8 NOT NULL,"
+        "  hash TEXT NOT NULL DEFAULT ''," "  vhash TEXT NOT NULL DEFAULT '',"
+        "  value BLOB NOT NULL DEFAULT '')", NULL, NULL, NULL) != SQLITE_OK))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_exec");
+    sqlite3_finalize (stmt);
+    return GNUNET_SYSERR;
+  }
+  sqlite3_finalize (stmt);
+  create_indices (plugin->dbh);
+
+  if ((sq_prepare
+       (plugin->dbh,
+        "UPDATE gn090 "
+        "SET prio = prio + ?, expire = MAX(expire,?) WHERE _ROWID_ = ?",
+        &plugin->updPrio) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "UPDATE gn090 " "SET repl = MAX (0, repl - 1) WHERE _ROWID_ = ?",
+        &plugin->updRepl) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ " "FROM gn090 "
+#if SQLITE_VERSION_NUMBER >= 3007000
+        "INDEXED BY idx_repl_rvalue "
+#endif
+        "WHERE repl=?2 AND " " (rvalue>=?1 OR "
+        "  NOT EXISTS (SELECT 1 FROM gn090 "
+#if SQLITE_VERSION_NUMBER >= 3007000
+        "INDEXED BY idx_repl_rvalue "
+#endif
+        "WHERE repl=?2 AND rvalue>=?1 LIMIT 1) ) "
+        "ORDER BY rvalue ASC LIMIT 1", &plugin->selRepl) != SQLITE_OK) ||
+      (sq_prepare (plugin->dbh, "SELECT MAX(repl) FROM gn090"
+#if SQLITE_VERSION_NUMBER >= 3007000
+                   " INDEXED BY idx_repl_rvalue"
+#endif
+                   "", &plugin->maxRepl) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ " "FROM gn090 "
+#if SQLITE_VERSION_NUMBER >= 3007000
+        "INDEXED BY idx_expire "
+#endif
+        "WHERE NOT EXISTS (SELECT 1 FROM gn090 WHERE expire < ?1 LIMIT 1) OR (expire < ?1) "
+        "ORDER BY expire ASC LIMIT 1", &plugin->selExpi) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "SELECT type,prio,anonLevel,expire,hash,value,_ROWID_ " "FROM gn090 "
+#if SQLITE_VERSION_NUMBER >= 3007000
+        "INDEXED BY idx_anon_type_hash "
+#endif
+        "WHERE (anonLevel = 0 AND type=?1) "
+        "ORDER BY hash DESC LIMIT 1 OFFSET ?2",
+        &plugin->selZeroAnon) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "INSERT INTO gn090 (repl, type, prio, anonLevel, expire, rvalue, hash, vhash, value) "
+        "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)",
+        &plugin->insertContent) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh, "DELETE FROM gn090 WHERE _ROWID_ = ?",
+        &plugin->delRow) != SQLITE_OK))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR, "precompiling");
+    return GNUNET_SYSERR;
+  }
+
+  return GNUNET_OK;
+}
+
+
+/**
+ * Shutdown database connection and associate data
+ * structures.
+ * @param plugin the plugin context (state for this module)
+ */
+static void
+database_shutdown (struct Plugin *plugin)
+{
+  int result;
+
+#if SQLITE_VERSION_NUMBER >= 3007000
+  sqlite3_stmt *stmt;
+#endif
+
+  if (plugin->delRow != NULL)
+    sqlite3_finalize (plugin->delRow);
+  if (plugin->updPrio != NULL)
+    sqlite3_finalize (plugin->updPrio);
+  if (plugin->updRepl != NULL)
+    sqlite3_finalize (plugin->updRepl);
+  if (plugin->selRepl != NULL)
+    sqlite3_finalize (plugin->selRepl);
+  if (plugin->maxRepl != NULL)
+    sqlite3_finalize (plugin->maxRepl);
+  if (plugin->selExpi != NULL)
+    sqlite3_finalize (plugin->selExpi);
+  if (plugin->selZeroAnon != NULL)
+    sqlite3_finalize (plugin->selZeroAnon);
+  if (plugin->insertContent != NULL)
+    sqlite3_finalize (plugin->insertContent);
+  result = sqlite3_close (plugin->dbh);
+#if SQLITE_VERSION_NUMBER >= 3007000
+  if (result == SQLITE_BUSY)
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "sqlite",
+                     _
+                     ("Tried to close sqlite without finalizing all prepared statements.\n"));
+    stmt = sqlite3_next_stmt (plugin->dbh, NULL);
+    while (stmt != NULL)
+    {
+#if DEBUG_SQLITE
+      GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                       "Closing statement %p\n", stmt);
+#endif
+      result = sqlite3_finalize (stmt);
+      if (result != SQLITE_OK)
+        GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "sqlite",
+                         "Failed to close statement %p: %d\n", stmt, result);
+      stmt = sqlite3_next_stmt (plugin->dbh, NULL);
+    }
+    result = sqlite3_close (plugin->dbh);
+  }
+#endif
+  if (SQLITE_OK != result)
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite3_close");
+
+  GNUNET_free_non_null (plugin->fn);
+}
+
+
+/**
+ * Delete the database entry with the given
+ * row identifier.
+ *
+ * @param plugin the plugin context (state for this module)
+ * @param rid the ID of the row to delete
+ */
+static int
+delete_by_rowid (struct Plugin *plugin, unsigned long long rid)
+{
+  if (SQLITE_OK != sqlite3_bind_int64 (plugin->delRow, 1, rid))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (plugin->delRow))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return GNUNET_SYSERR;
+  }
+  if (SQLITE_DONE != sqlite3_step (plugin->delRow))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    if (SQLITE_OK != sqlite3_reset (plugin->delRow))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return GNUNET_SYSERR;
+  }
+  if (SQLITE_OK != sqlite3_reset (plugin->delRow))
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  return GNUNET_OK;
+}
+
+
+/**
+ * Store an item in the datastore.
+ *
+ * @param cls closure
+ * @param key key for the item
+ * @param size number of bytes in data
+ * @param data content stored
+ * @param type type of the content
+ * @param priority priority of the content
+ * @param anonymity anonymity-level for the content
+ * @param replication replication-level for the content
+ * @param expiration expiration time for the content
+ * @param msg set to an error message
+ * @return GNUNET_OK on success
+ */
+static int
+sqlite_plugin_put (void *cls, const GNUNET_HashCode * key, uint32_t size,
+                   const void *data, enum GNUNET_BLOCK_Type type,
+                   uint32_t priority, uint32_t anonymity, uint32_t replication,
+                   struct GNUNET_TIME_Absolute expiration, char **msg)
+{
+  struct Plugin *plugin = cls;
+  int n;
+  int ret;
+  sqlite3_stmt *stmt;
+  GNUNET_HashCode vhash;
+  uint64_t rvalue;
+
+  if (size > MAX_ITEM_SIZE)
+    return GNUNET_SYSERR;
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                   "Storing in database block with type %u/key `%s'/priority %u/expiration in %llu ms (%lld).\n",
+                   type, GNUNET_h2s (key), priority,
+                   (unsigned long long)
+                   GNUNET_TIME_absolute_get_remaining (expiration).rel_value,
+                   (long long) expiration.abs_value);
+#endif
+  GNUNET_CRYPTO_hash (data, size, &vhash);
+  stmt = plugin->insertContent;
+  rvalue = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, UINT64_MAX);
+  if ((SQLITE_OK != sqlite3_bind_int (stmt, 1, replication)) ||
+      (SQLITE_OK != sqlite3_bind_int (stmt, 2, type)) ||
+      (SQLITE_OK != sqlite3_bind_int (stmt, 3, priority)) ||
+      (SQLITE_OK != sqlite3_bind_int (stmt, 4, anonymity)) ||
+      (SQLITE_OK != sqlite3_bind_int64 (stmt, 5, expiration.abs_value)) ||
+      (SQLITE_OK != sqlite3_bind_int64 (stmt, 6, rvalue)) ||
+      (SQLITE_OK !=
+       sqlite3_bind_blob (stmt, 7, key, sizeof (GNUNET_HashCode),
+                          SQLITE_TRANSIENT)) ||
+      (SQLITE_OK !=
+       sqlite3_bind_blob (stmt, 8, &vhash, sizeof (GNUNET_HashCode),
+                          SQLITE_TRANSIENT)) ||
+      (SQLITE_OK != sqlite3_bind_blob (stmt, 9, data, size, SQLITE_TRANSIENT)))
+  {
+    LOG_SQLITE (plugin, msg, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return GNUNET_SYSERR;
+  }
+  n = sqlite3_step (stmt);
+  switch (n)
+  {
+  case SQLITE_DONE:
+    plugin->env->duc (plugin->env->cls, size + GNUNET_DATASTORE_ENTRY_OVERHEAD);
+#if DEBUG_SQLITE
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                     "Stored new entry (%u bytes)\n",
+                     size + GNUNET_DATASTORE_ENTRY_OVERHEAD);
+#endif
+    ret = GNUNET_OK;
+    break;
+  case SQLITE_BUSY:
+    GNUNET_break (0);
+    LOG_SQLITE (plugin, msg, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    ret = GNUNET_SYSERR;
+    break;
+  default:
+    LOG_SQLITE (plugin, msg, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    database_shutdown (plugin);
+    database_setup (plugin->env->cfg, plugin);
+    return GNUNET_SYSERR;
+  }
+  if (SQLITE_OK != sqlite3_reset (stmt))
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  return ret;
+}
+
+
+/**
+ * Update the priority for a particular key in the datastore.  If
+ * the expiration time in value is different than the time found in
+ * the datastore, the higher value should be kept.  For the
+ * anonymity level, the lower value is to be used.  The specified
+ * priority should be added to the existing priority, ignoring the
+ * priority in value.
+ *
+ * Note that it is possible for multiple values to match this put.
+ * In that case, all of the respective values are updated.
+ *
+ * @param cls the plugin context (state for this module)
+ * @param uid unique identifier of the datum
+ * @param delta by how much should the priority
+ *     change?  If priority + delta < 0 the
+ *     priority should be set to 0 (never go
+ *     negative).
+ * @param expire new expiration time should be the
+ *     MAX of any existing expiration time and
+ *     this value
+ * @param msg set to an error message
+ * @return GNUNET_OK on success
+ */
+static int
+sqlite_plugin_update (void *cls, uint64_t uid, int delta,
+                      struct GNUNET_TIME_Absolute expire, char **msg)
+{
+  struct Plugin *plugin = cls;
+  int n;
+
+  if ((SQLITE_OK != sqlite3_bind_int (plugin->updPrio, 1, delta)) ||
+      (SQLITE_OK != sqlite3_bind_int64 (plugin->updPrio, 2, expire.abs_value))
+      || (SQLITE_OK != sqlite3_bind_int64 (plugin->updPrio, 3, uid)))
+  {
+    LOG_SQLITE (plugin, msg, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (plugin->updPrio))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return GNUNET_SYSERR;
+
+  }
+  n = sqlite3_step (plugin->updPrio);
+  if (SQLITE_OK != sqlite3_reset (plugin->updPrio))
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  switch (n)
+  {
+  case SQLITE_DONE:
+#if DEBUG_SQLITE
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite", "Block updated\n");
+#endif
+    return GNUNET_OK;
+  case SQLITE_BUSY:
+    LOG_SQLITE (plugin, msg, GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return GNUNET_NO;
+  default:
+    LOG_SQLITE (plugin, msg, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return GNUNET_SYSERR;
+  }
+}
+
+
+/**
+ * Execute statement that gets a row and call the callback
+ * with the result.  Resets the statement afterwards.
+ *
+ * @param plugin the plugin
+ * @param stmt the statement
+ * @param proc processor to call
+ * @param proc_cls closure for 'proc'
+ */
+static void
+execute_get (struct Plugin *plugin, sqlite3_stmt * stmt,
+             PluginDatumProcessor proc, void *proc_cls)
+{
+  int n;
+  struct GNUNET_TIME_Absolute expiration;
+  unsigned long long rowid;
+  unsigned int size;
+  int ret;
+
+  n = sqlite3_step (stmt);
+  switch (n)
+  {
+  case SQLITE_ROW:
+    size = sqlite3_column_bytes (stmt, 5);
+    rowid = sqlite3_column_int64 (stmt, 6);
+    if (sqlite3_column_bytes (stmt, 4) != sizeof (GNUNET_HashCode))
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "sqlite",
+                       _
+                       ("Invalid data in database.  Trying to fix (by deletion).\n"));
+      if (SQLITE_OK != sqlite3_reset (stmt))
+        LOG_SQLITE (plugin, NULL,
+                    GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                    "sqlite3_reset");
+      if (GNUNET_OK == delete_by_rowid (plugin, rowid))
+        plugin->env->duc (plugin->env->cls,
+                          -(size + GNUNET_DATASTORE_ENTRY_OVERHEAD));
+      break;
+    }
+    expiration.abs_value = sqlite3_column_int64 (stmt, 3);
+#if DEBUG_SQLITE
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                     "Found reply in database with expiration %llu\n",
+                     (unsigned long long) expiration.abs_value);
+#endif
+    ret = proc (proc_cls, sqlite3_column_blob (stmt, 4) /* key */ ,
+                size, sqlite3_column_blob (stmt, 5) /* data */ ,
+                sqlite3_column_int (stmt, 0) /* type */ ,
+                sqlite3_column_int (stmt, 1) /* priority */ ,
+                sqlite3_column_int (stmt, 2) /* anonymity */ ,
+                expiration, rowid);
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    if ((GNUNET_NO == ret) && (GNUNET_OK == delete_by_rowid (plugin, rowid)))
+      plugin->env->duc (plugin->env->cls,
+                        -(size + GNUNET_DATASTORE_ENTRY_OVERHEAD));
+    return;
+  case SQLITE_DONE:
+    /* database must be empty */
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    break;
+  case SQLITE_BUSY:
+  case SQLITE_ERROR:
+  case SQLITE_MISUSE:
+  default:
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    GNUNET_break (0);
+    database_shutdown (plugin);
+    database_setup (plugin->env->cfg, plugin);
+    break;
+  }
+  if (SQLITE_OK != sqlite3_reset (stmt))
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+}
+
+
+
+/**
+ * Select a subset of the items in the datastore and call
+ * the given processor for the item.
+ *
+ * @param cls our plugin context
+ * @param offset offset of the result (modulo num-results);
+ *               specific ordering does not matter for the offset
+ * @param type entries of which type should be considered?
+ *        Use 0 for any type.
+ * @param proc function to call on each matching value;
+ *        will be called once with a NULL value at the end
+ * @param proc_cls closure for proc
+ */
+static void
+sqlite_plugin_get_zero_anonymity (void *cls, uint64_t offset,
+                                  enum GNUNET_BLOCK_Type type,
+                                  PluginDatumProcessor proc, void *proc_cls)
+{
+  struct Plugin *plugin = cls;
+  sqlite3_stmt *stmt;
+
+  GNUNET_assert (type != GNUNET_BLOCK_TYPE_ANY);
+  stmt = plugin->selZeroAnon;
+  if ((SQLITE_OK != sqlite3_bind_int (stmt, 1, type)) ||
+      (SQLITE_OK != sqlite3_bind_int64 (stmt, 2, offset)))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  execute_get (plugin, stmt, proc, proc_cls);
+}
+
+
+
+/**
+ * Get results for a particular key in the datastore.
+ *
+ * @param cls closure
+ * @param offset offset (mod count).
+ * @param key key to match, never NULL
+ * @param vhash hash of the value, maybe NULL (to
+ *        match all values that have the right key).
+ *        Note that for DBlocks there is no difference
+ *        betwen key and vhash, but for other blocks
+ *        there may be!
+ * @param type entries of which type are relevant?
+ *     Use 0 for any type.
+ * @param proc function to call on each matching value;
+ *        will be called once with a NULL value at the end
+ * @param proc_cls closure for proc
+ */
+static void
+sqlite_plugin_get_key (void *cls, uint64_t offset, const GNUNET_HashCode * key,
+                       const GNUNET_HashCode * vhash,
+                       enum GNUNET_BLOCK_Type type, PluginDatumProcessor proc,
+                       void *proc_cls)
+{
+  struct Plugin *plugin = cls;
+  int ret;
+  int total;
+  int limit_off;
+  unsigned int sqoff;
+  sqlite3_stmt *stmt;
+  char scratch[256];
+
+  GNUNET_assert (proc != NULL);
+  GNUNET_assert (key != NULL);
+  GNUNET_snprintf (scratch, sizeof (scratch),
+                   "SELECT count(*) FROM gn090 WHERE hash=?%s%s",
+                   vhash == NULL ? "" : " AND vhash=?",
+                   type == 0 ? "" : " AND type=?");
+  if (sq_prepare (plugin->dbh, scratch, &stmt) != SQLITE_OK)
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite_prepare");
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  sqoff = 1;
+  ret =
+      sqlite3_bind_blob (stmt, sqoff++, key, sizeof (GNUNET_HashCode),
+                         SQLITE_TRANSIENT);
+  if ((vhash != NULL) && (ret == SQLITE_OK))
+    ret =
+        sqlite3_bind_blob (stmt, sqoff++, vhash, sizeof (GNUNET_HashCode),
+                           SQLITE_TRANSIENT);
+  if ((type != 0) && (ret == SQLITE_OK))
+    ret = sqlite3_bind_int (stmt, sqoff++, type);
+  if (SQLITE_OK != ret)
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite_bind");
+    sqlite3_finalize (stmt);
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  ret = sqlite3_step (stmt);
+  if (ret != SQLITE_ROW)
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite_step");
+    sqlite3_finalize (stmt);
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  total = sqlite3_column_int (stmt, 0);
+  sqlite3_finalize (stmt);
+  if (0 == total)
+  {
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  limit_off = (int) (offset % total);
+  if (limit_off < 0)
+    limit_off += total;
+  GNUNET_snprintf (scratch, sizeof (scratch),
+                   "SELECT type, prio, anonLevel, expire, hash, value, _ROWID_ "
+                   "FROM gn090 WHERE hash=?%s%s "
+                   "ORDER BY _ROWID_ ASC LIMIT 1 OFFSET ?",
+                   vhash == NULL ? "" : " AND vhash=?",
+                   type == 0 ? "" : " AND type=?");
+  if (sq_prepare (plugin->dbh, scratch, &stmt) != SQLITE_OK)
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite_prepare");
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  sqoff = 1;
+  ret =
+      sqlite3_bind_blob (stmt, sqoff++, key, sizeof (GNUNET_HashCode),
+                         SQLITE_TRANSIENT);
+  if ((vhash != NULL) && (ret == SQLITE_OK))
+    ret =
+        sqlite3_bind_blob (stmt, sqoff++, vhash, sizeof (GNUNET_HashCode),
+                           SQLITE_TRANSIENT);
+  if ((type != 0) && (ret == SQLITE_OK))
+    ret = sqlite3_bind_int (stmt, sqoff++, type);
+  if (ret == SQLITE_OK)
+    ret = sqlite3_bind_int64 (stmt, sqoff++, limit_off);
+  if (ret != SQLITE_OK)
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite_bind");
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  execute_get (plugin, stmt, proc, proc_cls);
+  sqlite3_finalize (stmt);
+}
+
+
+
+/**
+ * Context for 'repl_proc' function.
+ */
+struct ReplCtx
+{
+
+  /**
+   * Function to call for the result (or the NULL).
+   */
+  PluginDatumProcessor proc;
+
+  /**
+   * Closure for proc.
+   */
+  void *proc_cls;
+
+  /**
+   * UID to use.
+   */
+  uint64_t uid;
+
+  /**
+   * Yes if UID was set.
+   */
+  int have_uid;
+};
+
+
+/**
+ * Wrapper for the processor for 'sqlite_plugin_replication_get'.
+ * Decrements the replication counter and calls the original
+ * processor.
+ *
+ * @param cls closure
+ * @param key key for the content
+ * @param size number of bytes in data
+ * @param data content stored
+ * @param type type of the content
+ * @param priority priority of the content
+ * @param anonymity anonymity-level for the content
+ * @param expiration expiration time for the content
+ * @param uid unique identifier for the datum;
+ *        maybe 0 if no unique identifier is available
+ *
+ * @return GNUNET_OK for normal return,
+ *         GNUNET_NO to delete the item
+ */
+static int
+repl_proc (void *cls, const GNUNET_HashCode * key, uint32_t size,
+           const void *data, enum GNUNET_BLOCK_Type type, uint32_t priority,
+           uint32_t anonymity, struct GNUNET_TIME_Absolute expiration,
+           uint64_t uid)
+{
+  struct ReplCtx *rc = cls;
+  int ret;
+
+  ret =
+      rc->proc (rc->proc_cls, key, size, data, type, priority, anonymity,
+                expiration, uid);
+  if (key != NULL)
+  {
+    rc->uid = uid;
+    rc->have_uid = GNUNET_YES;
+  }
+  return ret;
+}
+
+
+/**
+ * Get a random item for replication.  Returns a single random item
+ * from those with the highest replication counters.  The item's
+ * replication counter is decremented by one IF it was positive before.
+ * Call 'proc' with all values ZERO or NULL if the datastore is empty.
+ *
+ * @param cls closure
+ * @param proc function to call the value (once only).
+ * @param proc_cls closure for proc
+ */
+static void
+sqlite_plugin_get_replication (void *cls, PluginDatumProcessor proc,
+                               void *proc_cls)
+{
+  struct Plugin *plugin = cls;
+  struct ReplCtx rc;
+  uint64_t rvalue;
+  uint32_t repl;
+  sqlite3_stmt *stmt;
+
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                   "Getting random block based on replication order.\n");
+#endif
+  rc.have_uid = GNUNET_NO;
+  rc.proc = proc;
+  rc.proc_cls = proc_cls;
+  stmt = plugin->maxRepl;
+  if (SQLITE_ROW != sqlite3_step (stmt))
+  {
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    /* DB empty */
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  repl = sqlite3_column_int (stmt, 0);
+  if (SQLITE_OK != sqlite3_reset (stmt))
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  stmt = plugin->selRepl;
+  rvalue = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, UINT64_MAX);
+  if (SQLITE_OK != sqlite3_bind_int64 (stmt, 1, rvalue))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  if (SQLITE_OK != sqlite3_bind_int (stmt, 2, repl))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  execute_get (plugin, stmt, &repl_proc, &rc);
+  if (GNUNET_YES == rc.have_uid)
+  {
+    if (SQLITE_OK != sqlite3_bind_int64 (plugin->updRepl, 1, rc.uid))
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_bind_XXXX");
+      if (SQLITE_OK != sqlite3_reset (plugin->updRepl))
+        LOG_SQLITE (plugin, NULL,
+                    GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                    "sqlite3_reset");
+      return;
+    }
+    if (SQLITE_DONE != sqlite3_step (plugin->updRepl))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_step");
+    if (SQLITE_OK != sqlite3_reset (plugin->updRepl))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+  }
+}
+
+
+
+/**
+ * Get a random item that has expired or has low priority.
+ * Call 'proc' with all values ZERO or NULL if the datastore is empty.
+ *
+ * @param cls closure
+ * @param proc function to call the value (once only).
+ * @param proc_cls closure for proc
+ */
+static void
+sqlite_plugin_get_expiration (void *cls, PluginDatumProcessor proc,
+                              void *proc_cls)
+{
+  struct Plugin *plugin = cls;
+  sqlite3_stmt *stmt;
+  struct GNUNET_TIME_Absolute now;
+
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                   "Getting random block based on expiration and priority order.\n");
+#endif
+  now = GNUNET_TIME_absolute_get ();
+  stmt = plugin->selExpi;
+  if (SQLITE_OK != sqlite3_bind_int64 (stmt, 1, now.abs_value))
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (stmt))
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    proc (proc_cls, NULL, 0, NULL, 0, 0, 0, GNUNET_TIME_UNIT_ZERO_ABS, 0);
+    return;
+  }
+  execute_get (plugin, stmt, proc, proc_cls);
+}
+
+
+
+/**
+ * Get all of the keys in the datastore.
+ *
+ * @param cls closure
+ * @param proc function to call on each key
+ * @param proc_cls closure for proc
+ */
+static void
+sqlite_plugin_get_keys (void *cls,
+			PluginKeyProcessor proc,
+			void *proc_cls)
+{
+  struct Plugin *plugin = cls;
+  const GNUNET_HashCode *key;
+  sqlite3_stmt *stmt;
+  int ret;
+
+  GNUNET_assert (proc != NULL);
+  if (sq_prepare (plugin->dbh, "SELECT hash FROM gn090", &stmt) != SQLITE_OK)
+  {
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+		"sqlite_prepare");
+    return;
+  }
+  while (SQLITE_ROW == (ret = sqlite3_step (stmt)))
+  {
+    key = sqlite3_column_blob (stmt, 1);
+    if (sizeof (GNUNET_HashCode) == sqlite3_column_bytes (stmt, 1))
+      proc (proc_cls, key, 1);
+  }
+  if (SQLITE_DONE != ret)
+    LOG_SQLITE (plugin, NULL, GNUNET_ERROR_TYPE_ERROR, "sqlite_step");
+  sqlite3_finalize (stmt);
+}
+
+
+/**
+ * Drop database.
+ *
+ * @param cls our plugin context
+ */
+static void
+sqlite_plugin_drop (void *cls)
+{
+  struct Plugin *plugin = cls;
+
+  plugin->drop_on_shutdown = GNUNET_YES;
+}
+
+
+/**
+ * Get an estimate of how much space the database is
+ * currently using.
+ *
+ * @param cls the 'struct Plugin'
+ * @return the size of the database on disk (estimate)
+ */
+static unsigned long long
+sqlite_plugin_estimate_size (void *cls)
+{
+  struct Plugin *plugin = cls;
+  sqlite3_stmt *stmt;
+  uint64_t pages;
+  uint64_t page_size;
+
+#if ENULL_DEFINED
+  char *e;
+#endif
+
+  if (SQLITE_VERSION_NUMBER < 3006000)
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "datastore-sqlite",
+                     _
+                     ("sqlite version to old to determine size, assuming zero\n"));
+    return 0;
+  }
+  CHECK (SQLITE_OK == sqlite3_exec (plugin->dbh, "VACUUM", NULL, NULL, ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA auto_vacuum=INCREMENTAL", NULL,
+                       NULL, ENULL));
+  CHECK (SQLITE_OK == sq_prepare (plugin->dbh, "PRAGMA page_count", &stmt));
+  if (SQLITE_ROW == sqlite3_step (stmt))
+    pages = sqlite3_column_int64 (stmt, 0);
+  else
+    pages = 0;
+  sqlite3_finalize (stmt);
+  CHECK (SQLITE_OK == sq_prepare (plugin->dbh, "PRAGMA page_size", &stmt));
+  CHECK (SQLITE_ROW == sqlite3_step (stmt));
+  page_size = sqlite3_column_int64 (stmt, 0);
+  sqlite3_finalize (stmt);
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              _
+              ("Using sqlite page utilization to estimate payload (%llu pages of size %llu bytes)\n"),
+              (unsigned long long) pages, (unsigned long long) page_size);
+  return pages * page_size;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls the "struct GNUNET_DATASTORE_PluginEnvironment*"
+ * @return NULL on error, othrewise the plugin context
+ */
+void *
+libgnunet_plugin_datastore_sqlite_init (void *cls)
+{
+  static struct Plugin plugin;
+  struct GNUNET_DATASTORE_PluginEnvironment *env = cls;
+  struct GNUNET_DATASTORE_PluginFunctions *api;
+
+  if (plugin.env != NULL)
+    return NULL;                /* can only initialize once! */
+  memset (&plugin, 0, sizeof (struct Plugin));
+  plugin.env = env;
+  if (GNUNET_OK != database_setup (env->cfg, &plugin))
+  {
+    database_shutdown (&plugin);
+    return NULL;
+  }
+  api = GNUNET_malloc (sizeof (struct GNUNET_DATASTORE_PluginFunctions));
+  api->cls = &plugin;
+  api->estimate_size = &sqlite_plugin_estimate_size;
+  api->put = &sqlite_plugin_put;
+  api->update = &sqlite_plugin_update;
+  api->get_key = &sqlite_plugin_get_key;
+  api->get_replication = &sqlite_plugin_get_replication;
+  api->get_expiration = &sqlite_plugin_get_expiration;
+  api->get_zero_anonymity = &sqlite_plugin_get_zero_anonymity;
+  api->get_keys = &sqlite_plugin_get_keys;
+  api->drop = &sqlite_plugin_drop;
+  GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "sqlite",
+                   _("Sqlite database running\n"));
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ *
+ * @param cls the plugin context (as returned by "init")
+ * @return always NULL
+ */
+void *
+libgnunet_plugin_datastore_sqlite_done (void *cls)
+{
+  char *fn;
+  struct GNUNET_DATASTORE_PluginFunctions *api = cls;
+  struct Plugin *plugin = api->cls;
+
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                   "sqlite plugin is done\n");
+#endif
+
+  fn = NULL;
+  if (plugin->drop_on_shutdown)
+    fn = GNUNET_strdup (plugin->fn);
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                   "Shutting down database\n");
+#endif
+  database_shutdown (plugin);
+  plugin->env = NULL;
+  GNUNET_free (api);
+  if (fn != NULL)
+  {
+    if (0 != UNLINK (fn))
+      GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink", fn);
+    GNUNET_free (fn);
+  }
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                   "sqlite plugin is finished\n");
+#endif
+  return NULL;
+}
+
+/* end of plugin_datastore_sqlite.c */