stuff

git-svn-id: https://gnunet.org/svn/gnunet@8602 140774ce-b5e7-0310-ab8b-a85725594a96

7 files changed, 1217 insertions, 41 deletions

diff --git a/RATIONALE b/RATIONALE
index e68dcb883f..dba31fb65f 100644
--- a/RATIONALE
+++ b/RATIONALE
@@ -244,3 +244,25 @@ SOLUTION (draft, not done yet, details missing...):
   => Open question: how to do this without 
      compromising state/scalability?
 
+PROBLEM GROUP 7 (User experience):
+* Searches often do not return a sufficient / significant number of
+  results
+* Sharing a directory with thousands of similar files (image/jpeg)
+  creates thousands of search results for the mime-type keyword
+  (problem with DB performance, network transmission, caching,
+   end-user display, etc.)
+
+SOLUTION (draft, not done yet, details missing...):
+* Canonicalize keywords (see suggestion on mailinglist end of
+  June 2009: keep consonants and sort those alphabetically);
+  while I think we must have an option to disable this feature
+  (for more private sharing), I do think it would make a reasonable
+  default
+* When sharing directories, extract keywords first and then
+  push keywords that are common in all files up to the
+  directory level; when processing an AND-ed query and a directory
+  is found to match the result, do an inspection on the metadata
+  of the files in the directory to possibly produce further results
+  (requires downloading of the directory in the background)
+
+
diff --git a/src/Makefile.am b/src/Makefile.am
index 78e48e110f..c366ce20cb 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -18,7 +18,6 @@ SUBDIRS = \
   resolver \
   statistics \
   template \
-  testing \
   transport \
   core \
   $(HOSTLIST_DIR) \
diff --git a/src/datastore/plugin_datastore.h b/src/datastore/plugin_datastore.h
index 8c42b8b98a..849188ce1f 100644
--- a/src/datastore/plugin_datastore.h
+++ b/src/datastore/plugin_datastore.h
@@ -34,6 +34,14 @@
 #include "gnunet_scheduler_lib.h"
 #include "gnunet_datastore_service.h"
 
+
+/**
+ * How many bytes of overhead will we assume per entry
+ * in the SQlite DB?
+ */
+#define GNUNET_DATASTORE_ENTRY_OVERHEAD 256
+
+
 /**
  * The datastore service will pass a pointer to a struct
  * of this type as the first and only argument to the
diff --git a/src/datastore/plugin_datastore_sqlite.c b/src/datastore/plugin_datastore_sqlite.c
index 6bee1a0c9e..5ae03b9bb2 100644
--- a/src/datastore/plugin_datastore_sqlite.c
+++ b/src/datastore/plugin_datastore_sqlite.c
@@ -25,7 +25,78 @@
  */
 
 #include "platform.h"
+#include "gnunet_statistics_service.h"
 #include "plugin_datastore.h"
+#include <sqlite3.h>
+
+#define DEBUG_SQLITE GNUNET_YES
+
+/**
+ * After how many payload-changing operations
+ * do we sync our statistics?
+ */
+#define MAX_STAT_SYNC_LAG 50
+
+#define QUOTA_STAT_NAME gettext_noop ("file-sharing datastore utilization (in bytes)")
+
+
+/**
+ * Die with an error message that indicates
+ * a failure of the command 'cmd' with the message given
+ * by strerror(errno).
+ */
+#define DIE_SQLITE(db, cmd) do { GNUNET_log_from(GNUNET_ERROR_TYPE_ERROR, "sqlite", _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, sqlite3_errmsg(db->dbh)); abort(); } while(0)
+
+/**
+ * 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 with error: %s\n"), cmd, sqlite3_errmsg(db->dbh)); } while(0)
+
+#define SELECT_IT_LOW_PRIORITY_1 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (prio = ? AND hash > ?) "\
+  "ORDER BY hash ASC LIMIT 1"
+
+#define SELECT_IT_LOW_PRIORITY_2 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (prio > ?) "\
+  "ORDER BY prio ASC, hash ASC LIMIT 1"
+
+#define SELECT_IT_NON_ANONYMOUS_1 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (prio = ? AND hash < ? AND anonLevel = 0) "\
+  " ORDER BY hash DESC LIMIT 1"
+
+#define SELECT_IT_NON_ANONYMOUS_2 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (prio < ? AND anonLevel = 0)"\
+  " ORDER BY prio DESC, hash DESC LIMIT 1"
+
+#define SELECT_IT_EXPIRATION_TIME_1 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (expire = ? AND hash > ?) "\
+  " ORDER BY hash ASC LIMIT 1"
+
+#define SELECT_IT_EXPIRATION_TIME_2 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (expire > ?) "\
+  " ORDER BY expire ASC, hash ASC LIMIT 1"
+
+#define SELECT_IT_MIGRATION_ORDER_1 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (expire = ? AND hash < ?) "\
+  " ORDER BY hash DESC LIMIT 1"
+
+#define SELECT_IT_MIGRATION_ORDER_2 \
+  "SELECT size,type,prio,anonLevel,expire,hash,value,_ROWID_ FROM gn080 WHERE (expire < ?) "\
+  " ORDER BY expire DESC, hash DESC LIMIT 1"
+
+/**
+ * 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
 
 
 /**
@@ -37,20 +108,401 @@ struct Plugin
    * Our execution environment.
    */
   struct GNUNET_DATASTORE_PluginEnvironment *env;
+
+  /**
+   * Database filename.
+   */
+  char *fn;
+
+  /**
+   * Native SQLite database handle.
+   */
+  sqlite3 *dbh;
+
+  /**
+   * Precompiled SQL for update.
+   */
+  sqlite3_stmt *updPrio;
+
+  /**
+   * Precompiled SQL for insertion.
+   */
+  sqlite3_stmt *insertContent;
+
+  /**
+   * Handle to the statistics service.
+   */
+  struct GNUNET_STATISTICS_Handle *statistics;
+  
+  /**
+   * How much data are we currently storing
+   * in the database?
+   */
+  unsigned long long payload;
+
+  /**
+   * Number of updates that were made to the
+   * payload value since we last synchronized
+   * it with the statistics service.
+   */
+  unsigned int lastSync;
+
+  /**
+   * Should the database be dropped on shutdown?
+   */
+  int drop_on_shutdown;
 };
 
 
 /**
+ * @brief Prepare a SQL statement
+ *
+ * @param zSql SQL statement, UTF-8 encoded
+ */
+static int
+sq_prepare (sqlite3 * dbh, const char *zSql,
+            sqlite3_stmt ** ppStmt)
+{
+  char *dummy;
+  return sqlite3_prepare (dbh,
+                          zSql,
+                          strlen (zSql), ppStmt, (const char **) &dummy);
+}
+
+
+/**
+ * Create our database indices.
+ */
+static void
+create_indices (sqlite3 * dbh)
+{
+  /* create indices */
+  sqlite3_exec (dbh,
+                "CREATE INDEX idx_hash ON gn080 (hash)", NULL, NULL, NULL);
+  sqlite3_exec (dbh,
+                "CREATE INDEX idx_hash_vhash ON gn080 (hash,vhash)", NULL,
+                NULL, NULL);
+  sqlite3_exec (dbh, "CREATE INDEX idx_prio ON gn080 (prio)", NULL, NULL,
+                NULL);
+  sqlite3_exec (dbh, "CREATE INDEX idx_expire ON gn080 (expire)", NULL, NULL,
+                NULL);
+  sqlite3_exec (dbh, "CREATE INDEX idx_comb3 ON gn080 (prio,anonLevel)", NULL,
+                NULL, NULL);
+  sqlite3_exec (dbh, "CREATE INDEX idx_comb4 ON gn080 (prio,hash,anonLevel)",
+                NULL, NULL, NULL);
+  sqlite3_exec (dbh, "CREATE INDEX idx_comb7 ON gn080 (expire,hash)", NULL,
+                NULL, NULL);
+}
+
+
+
+#if 1
+#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_ERRROR, "%s\n", e); sqlite3_free(e); }
+#endif
+
+
+
+
+/**
+ * Initialize the database connections and associated
+ * data structures (create tables and indices
+ * as needed as well).
+ *
+ * @return GNUNET_OK on success
+ */
+static int
+database_setup (struct GNUNET_CONFIGURATION_Handle *cfg,
+		struct Plugin *plugin)
+{
+  sqlite3_stmt *stmt;
+  char *dir;
+  char *afsdir;
+#if ENULL_DEFINED
+  char *e;
+#endif
+  
+  if (GNUNET_OK != 
+      GNUNET_CONFIGURATION_get_value_filename (cfg,
+					       "FS",
+					       "DIR",
+					       &afsdir))
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+		       "sqlite",
+		       _("Option `%s' in section `%s' missing in configuration!\n"),
+		       "DIR",
+		       "FS");
+      return GNUNET_SYSERR;
+    }
+  GNUNET_asprintf (&dir, "%s/content/gnunet.dat", afsdir);
+  GNUNET_free (afsdir);
+  if (GNUNET_OK != GNUNET_DISK_directory_create_for_file (dir))
+    {
+      GNUNET_break (0);
+      GNUNET_free (dir);
+      return GNUNET_SYSERR;
+    }
+  plugin->fn = GNUNET_STRINGS_to_utf8 (dir, strlen (dir),
+#ifdef ENABLE_NLS
+					      nl_langinfo (CODESET)
+#else
+					      "UTF-8"   /* good luck */
+#endif
+					      );
+  GNUNET_free (dir);
+  
+  /* 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 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 = 'gn080'",
+                     &stmt));
+  if ( (sqlite3_step (stmt) == SQLITE_DONE) &&
+       (sqlite3_exec (plugin->dbh,
+		      "CREATE TABLE gn080 ("
+		      "  size INTEGER NOT NULL DEFAULT 0,"
+		      "  type INTEGER NOT NULL DEFAULT 0,"
+		      "  prio INTEGER NOT NULL DEFAULT 0,"
+		      "  anonLevel INTEGER NOT NULL DEFAULT 0,"
+		      "  expire INTEGER NOT NULL DEFAULT 0,"
+		      "  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);
+
+  CHECK (SQLITE_OK ==
+         sq_prepare (plugin->dbh,
+                     "SELECT 1 FROM sqlite_master WHERE tbl_name = 'gn071'",
+                     &stmt));
+  if ( (sqlite3_step (stmt) == SQLITE_DONE) &&
+       (sqlite3_exec (plugin->dbh,
+		      "CREATE TABLE gn071 ("
+		      "  key TEXT NOT NULL DEFAULT '',"
+		      "  value INTEGER NOT NULL DEFAULT 0)", NULL, NULL,
+		      NULL) != SQLITE_OK) )
+    {
+      LOG_SQLITE (plugin, NULL,
+		  GNUNET_ERROR_TYPE_ERROR, "sqlite3_exec");
+      sqlite3_finalize (stmt);
+      return GNUNET_SYSERR;
+    }
+  sqlite3_finalize (stmt);
+
+  if ((sq_prepare (plugin->dbh,
+                   "UPDATE gn080 SET prio = prio + ?, expire = MAX(expire,?) WHERE "
+                   "_ROWID_ = ?",
+                   &plugin->updPrio) != SQLITE_OK) ||
+      (sq_prepare (plugin->dbh,
+                   "INSERT INTO gn080 (size, type, prio, "
+                   "anonLevel, expire, hash, vhash, value) VALUES "
+                   "(?, ?, ?, ?, ?, ?, ?, ?)",
+                   &plugin->insertContent) != SQLITE_OK))
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR, "precompiling");
+      return GNUNET_SYSERR;
+    }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Synchronize our utilization statistics with the 
+ * statistics service.
+ */
+static void 
+sync_stats (struct Plugin *plugin)
+{
+  GNUNET_STATISTICS_set (plugin->statistics,
+			 QUOTA_STAT_NAME,
+			 plugin->payload,
+			 GNUNET_YES);
+  plugin->lastSync = 0;
+}
+
+
+/**
+ * Shutdown database connection and associate data
+ * structures.
+ */
+static void
+database_shutdown (struct Plugin *plugin)
+{
+  if (plugin->lastSync > 0)
+    sync_stats (plugin);
+  if (plugin->updPrio != NULL)
+    sqlite3_finalize (plugin->updPrio);
+  if (plugin->insertContent != NULL)
+    sqlite3_finalize (plugin->insertContent);
+  sqlite3_close (plugin->dbh);
+  GNUNET_free_non_null (plugin->fn);
+}
+
+
+/**
  * Get an estimate of how much space the database is
  * currently using.
  * @return number of bytes used on disk
  */
 static unsigned long long sqlite_plugin_get_size (void *cls)
 {
-  return 0;
+  struct Plugin *plugin = cls;
+  return plugin->payload;
+}
+
+
+/**
+ * Delete the database entry with the given
+ * row identifier.
+ */
+static int
+delete_by_rowid (struct Plugin* plugin, 
+		 unsigned long long rid)
+{
+  sqlite3_stmt *stmt;
+
+  if (sq_prepare (plugin->dbh,
+                  "DELETE FROM gn080 WHERE _ROWID_ = ?", &stmt) != SQLITE_OK)
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR |
+                  GNUNET_ERROR_TYPE_BULK, "sq_prepare");
+      return GNUNET_SYSERR;
+    }
+  sqlite3_bind_int64 (stmt, 1, rid);
+  if (SQLITE_DONE != sqlite3_step (stmt))
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR |
+                  GNUNET_ERROR_TYPE_BULK, "sqlite3_step");
+      sqlite3_finalize (stmt);
+      return GNUNET_SYSERR;
+    }
+  sqlite3_finalize (stmt);
+  return GNUNET_OK;
 }
 
 
+/**
+ * Context for the universal iterator.
+ */
+struct NextContext;
+
+/**
+ * Type of a function that will prepare
+ * the next iteration.
+ *
+ * @param cls closure
+ * @param nc the next context; NULL for the last
+ *         call which gives the callback a chance to
+ *         clean up the closure
+ * @return GNUNET_OK on success, GNUNET_NO if there are
+ *        no more values, GNUNET_SYSERR on error
+ */
+typedef int (*PrepareFunction)(void *cls,
+			       struct NextContext *nc);
+
+
+/**
+ * Context we keep for the "next request" callback.
+ */
+struct NextContext
+{
+  /**
+   * Internal state.
+   */ 
+  struct Plugin *plugin;
+
+  /**
+   * Function to call on the next value.
+   */
+  PluginIterator iter;
+
+  /**
+   * Closure for iter.
+   */
+  void *iter_cls;
+
+  /**
+   * Function to call to prepare the next
+   * iteration.
+   */
+  PrepareFunction prep;
+
+  /**
+   * Closure for prep.
+   */
+  void *prep_cls;
+
+  /**
+   * Statement that the iterator will get the data
+   * from (updated or set by prep).
+   */ 
+  sqlite3_stmt *stmt;
+
+  /**
+   * Row ID of the last result.
+   */
+  unsigned long long last_rowid;
+
+  /**
+   * Expiration time of the last value visited.
+   */
+  struct GNUNET_TIME_Absolute lastExpiration;
+
+  /**
+   * Priority of the last value visited.
+   */ 
+  unsigned int lastPriority; 
+
+  /**
+   * Number of results processed so far.
+   */
+  unsigned int count;
+
+  /**
+   * Set to GNUNET_YES if we must stop now.
+   */
+  int end_it;
+};
+
 
 /**
  * Function invoked on behalf of a "PluginIterator"
@@ -68,6 +520,107 @@ static void
 sqlite_next_request (void *next_cls,
 		     int end_it)
 {
+  static struct GNUNET_TIME_Absolute zero;
+  struct NextContext * nc= next_cls;
+  struct Plugin *plugin = nc->plugin;
+  unsigned long long rowid;
+  sqlite3_stmt *stmtd;
+  int ret;
+  unsigned int type;
+  unsigned int size;
+  unsigned int priority;
+  unsigned int anonymity;
+  struct GNUNET_TIME_Absolute expiration;
+  const GNUNET_HashCode *key;
+  const void *data;
+
+  sqlite3_reset (nc->stmt);
+  if ( (GNUNET_YES == end_it) ||
+       (GNUNET_YES == nc->end_it) ||
+       (GNUNET_OK != (nc->prep(nc->prep_cls,
+			       nc))) ||
+       (SQLITE_ROW != sqlite3_step (nc->stmt)) )
+    {
+    END:
+      nc->iter (nc->iter_cls, 
+		NULL, NULL, 0, NULL, 0, 0, 0, 
+		zero, 0);
+      nc->prep (nc->prep_cls, NULL);
+      GNUNET_free (nc);
+      return;
+    }
+
+  rowid = sqlite3_column_int64 (nc->stmt, 7);
+  nc->last_rowid = rowid;
+  type = sqlite3_column_int (nc->stmt, 1);
+  size = sqlite3_column_bytes (nc->stmt, 6);
+  if (sqlite3_column_bytes (nc->stmt, 5) != 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 (nc->stmt))
+        LOG_SQLITE (nc->plugin, NULL,
+                    GNUNET_ERROR_TYPE_ERROR |
+                    GNUNET_ERROR_TYPE_BULK, "sqlite3_reset");
+      if (sq_prepare
+          (nc->plugin->dbh,
+           "DELETE FROM gn080 WHERE NOT LENGTH(hash) = ?",
+           &stmtd) != SQLITE_OK)
+        {
+          LOG_SQLITE (nc->plugin, NULL,
+                      GNUNET_ERROR_TYPE_ERROR |
+                      GNUNET_ERROR_TYPE_BULK, 
+		      "sq_prepare");
+          goto END;
+        }
+
+      if (SQLITE_OK != sqlite3_bind_int (stmtd, 1, sizeof (GNUNET_HashCode)))
+        LOG_SQLITE (nc->plugin, NULL,
+                    GNUNET_ERROR_TYPE_ERROR |
+                    GNUNET_ERROR_TYPE_BULK, "sqlite3_bind_int");
+      if (SQLITE_DONE != sqlite3_step (stmtd))
+        LOG_SQLITE (nc->plugin, NULL,
+                    GNUNET_ERROR_TYPE_ERROR |
+                    GNUNET_ERROR_TYPE_BULK, "sqlite3_step");
+      if (SQLITE_OK != sqlite3_finalize (stmtd))
+        LOG_SQLITE (nc->plugin, NULL,
+                    GNUNET_ERROR_TYPE_ERROR |
+                    GNUNET_ERROR_TYPE_BULK, "sqlite3_finalize");
+      goto END;
+    }
+
+  priority = sqlite3_column_int (nc->stmt, 2);
+  nc->lastPriority = priority;
+  anonymity = sqlite3_column_int (nc->stmt, 3);
+  expiration.value = sqlite3_column_int64 (nc->stmt, 4);
+  nc->lastExpiration = expiration;
+  key = sqlite3_column_blob (nc->stmt, 5);
+  data = sqlite3_column_blob (nc->stmt, 6);
+  nc->count++;
+  ret = nc->iter (nc->iter_cls,
+		  nc,
+		  key,
+		  size,
+		  data, 
+		  type,
+		  priority,
+		  anonymity,
+		  expiration,
+		  rowid);
+  if (ret == GNUNET_SYSERR)
+    {
+      nc->end_it = GNUNET_YES;
+      return;
+    }
+  if ( (ret == GNUNET_NO) &&
+       (GNUNET_OK == delete_by_rowid (plugin, rowid)) )
+    {
+      plugin->payload -= (size + GNUNET_DATASTORE_ENTRY_OVERHEAD);
+      plugin->lastSync++; 
+      if (plugin->lastSync >= MAX_STAT_SYNC_LAG)
+	sync_stats (plugin);
+    }
 }
 
 
@@ -96,37 +649,76 @@ sqlite_plugin_put (void *cls,
 		   struct GNUNET_TIME_Absolute expiration,
 		   char ** msg)
 {
-  *msg = GNUNET_strdup("not implemented");
-  return GNUNET_SYSERR;
-}
+  struct Plugin *plugin = cls;
+  int n;
+  sqlite3_stmt *stmt;
+  GNUNET_HashCode vhash;
 
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+		   "sqlite",
+		   "Storing in database block with type %u/key `%s'/priority %u/expiration %llu.\n",
+		   type, 
+		   GNUNET_h2s(key),
+		   priority,
+		   GNUNET_TIME_absolute_get_remaining (expiration).value);
+#endif
+  GNUNET_CRYPTO_hash (data, size, &vhash);
+  stmt = plugin->insertContent;
+  if ((SQLITE_OK != sqlite3_bind_int (stmt, 1, size)) ||
+      (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.value)) ||
+      (SQLITE_OK !=
+       sqlite3_bind_blob (stmt, 6, key, sizeof (GNUNET_HashCode),
+                          SQLITE_TRANSIENT)) ||
+      (SQLITE_OK !=
+       sqlite3_bind_blob (stmt, 7, &vhash, sizeof (GNUNET_HashCode),
+                          SQLITE_TRANSIENT))
+      || (SQLITE_OK !=
+          sqlite3_bind_blob (stmt, 8, 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;
+    }
 
-/**
- * Iterate over the results for a particular key
- * in the datastore.
- *
- * @param cls closure
- * @param key maybe NULL (to match all entries)
- * @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 iter function to call on each matching value;
- *        will be called once with a NULL value at the end
- * @param iter_cls closure for iter
- */
-static void
-sqlite_plugin_get (void *cls,
-		   const GNUNET_HashCode * key,
-		   const GNUNET_HashCode * vhash,
-		   uint32_t type,
-		   PluginIterator iter, void *iter_cls)
-{
-  static struct GNUNET_TIME_Absolute zero;
-  iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 0);
+  n = sqlite3_step (stmt);
+  if (n != SQLITE_DONE)
+    {
+      if (n == SQLITE_BUSY)
+        {
+	  LOG_SQLITE (plugin, msg,
+		      GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, "sqlite3_step");
+          sqlite3_reset (stmt);
+          GNUNET_break (0);
+          return GNUNET_NO;
+        }
+      LOG_SQLITE (plugin, msg,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, "sqlite3_step");
+      sqlite3_reset (stmt);
+      return GNUNET_SYSERR;
+    }
+  if (SQLITE_OK != sqlite3_reset (stmt))
+    LOG_SQLITE (plugin, NULL,
+                GNUNET_ERROR_TYPE_ERROR |
+                GNUNET_ERROR_TYPE_BULK, "sqlite3_reset");
+  plugin->lastSync++;
+  plugin->payload += size + GNUNET_DATASTORE_ENTRY_OVERHEAD;
+  if (plugin->lastSync >= MAX_STAT_SYNC_LAG)
+    sync_stats (plugin);
+#if DEBUG_SQLITE
+  GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+		   "sqlite",
+		   "done writing content\n");
+#endif
+  return GNUNET_OK;
 }
 
 
@@ -158,8 +750,281 @@ sqlite_plugin_update (void *cls,
 		      int delta, struct GNUNET_TIME_Absolute expire,
 		      char **msg)
 {
-  *msg = GNUNET_strdup ("not implemented");
-  return GNUNET_SYSERR;
+  struct Plugin *plugin = cls;
+  int n;
+
+  sqlite3_bind_int (plugin->updPrio, 1, delta);
+  sqlite3_bind_int64 (plugin->updPrio, 2, expire.value);
+  sqlite3_bind_int64 (plugin->updPrio, 3, uid);
+  n = sqlite3_step (plugin->updPrio);
+  if (n != SQLITE_OK)
+    LOG_SQLITE (plugin, msg,
+		GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+		"sqlite3_step");
+#if DEBUG_SQLITE
+  else
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
+		     "sqlite",
+		     "Block updated\n");
+#endif
+  sqlite3_reset (plugin->updPrio);
+
+  if (n == SQLITE_BUSY)
+    return GNUNET_NO;
+  return n == SQLITE_OK ? GNUNET_OK : GNUNET_SYSERR;
+}
+
+
+struct IterContext
+{
+  sqlite3_stmt *stmt_1;
+  sqlite3_stmt *stmt_2;
+  int is_asc;
+  int is_prio;
+  int is_migr;
+  int limit_nonanonymous;
+  uint32_t type;
+  GNUNET_HashCode key;  
+};
+
+
+static int
+iter_next_prepare (void *cls,
+		   struct NextContext *nc)
+{
+  struct IterContext *ic = cls;
+  struct Plugin *plugin = nc->plugin;
+  struct GNUNET_TIME_Absolute now;
+
+  if (nc == NULL)
+    {
+      sqlite3_finalize (ic->stmt_1);
+      sqlite3_finalize (ic->stmt_2);
+      return GNUNET_SYSERR;
+    }
+  now = GNUNET_TIME_absolute_get ();
+  if (ic->is_prio)
+    {
+      sqlite3_bind_int (ic->stmt_1, 1, nc->lastPriority);
+      sqlite3_bind_int (ic->stmt_2, 1, nc->lastPriority);
+    }
+  else
+    {
+      sqlite3_bind_int64 (ic->stmt_1, 1, nc->lastExpiration.value);
+      sqlite3_bind_int64 (ic->stmt_2, 1, nc->lastExpiration.value);
+    }
+  sqlite3_bind_blob (ic->stmt_1, 2, 
+		     &ic->key, 
+		     sizeof (GNUNET_HashCode),
+		     SQLITE_TRANSIENT);
+  datum_1 = NULL;
+  datum_2 = last_datum_2;
+  last_datum_2 = NULL;
+
+  if ( (SQLITE_ROW == (ret = sqlite3_step (stmt_1))) &&
+       ( (GNUNET_NO == ic->is_migr) || 
+	 (sqlite3_column_int64 (stmt_1, 4) >= now.value) ) )
+    {
+      nc->stmt = ic->stmt_1;
+      return GNUNET_OK;
+    }
+  if (ret != SQLITE_DONE)
+    {
+      LOG_SQLITE (plugin, NULL,
+		  GNUNET_ERROR_TYPE_ERROR |
+		  GNUNET_ERROR_TYPE_BULK,
+		  "sqlite3_step");
+      return GNUNET_SYSERR;
+    }
+  if (SQLITE_OK != sqlite3_reset (stmt_1))
+    LOG_SQLITE (handle, NULL,
+		GNUNET_ERROR_TYPE_ERROR | 
+		GNUNET_ERROR_TYPE_BULK, 
+		"sqlite3_reset");
+  
+  if (datum_2 == NULL)
+    {
+      if ( (SQLITE_ROW == (ret = sqlite3_step (ic->stmt_2))) && 
+	   ( (GNUNET_NO == ic->is_migr) ||
+	     sqlite3_column_int64 (stmt_2, 4) >= now.value) )
+	{
+	  nc->stmt = ic->stmt_2;
+	  return GNUNET_OK;
+	}
+      if (ret != SQLITE_DONE)
+	{
+	  LOG_SQLITE (plugin, NULL,
+		      GNUNET_ERROR_TYPE_ERROR |
+		      GNUNET_ERROR_TYPE_BULK,
+		      "sqlite3_step");
+	  return GNUNET_SYSERR;
+	}
+      if (SQLITE_OK != sqlite3_reset (stmt_2))
+	LOG_SQLITE (plugin, NULL,
+		    GNUNET_ERROR_TYPE_ERROR |
+		    GNUNET_ERROR_TYPE_BULK,
+		    "sqlite3_reset");
+    }
+  datum = NULL;
+  if (datum_1 == NULL)
+    {
+      datum = datum_2;
+      rowid = rowid_2;
+      key = key_2;
+    }
+  else if (datum_2 == NULL)
+    {
+      datum = datum_1;
+      rowid = rowid_1;
+      key = key_1;
+    }
+  else
+    {
+      /* have to pick between 1 and 2 */
+      if (is_prio)
+	{
+	  if ((ntohl (datum_1->priority) < ntohl (datum_2->priority)) ==
+	      is_asc)
+	    {
+	      datum = datum_1;
+	      rowid = rowid_1;
+	      key = key_1;
+	      last_datum_2 = datum_2;
+	    }
+	  else
+	    {
+	      datum = datum_2;
+	      rowid = rowid_2;
+	      key = key_2;
+	      GNUNET_free (datum_1);
+	    }
+	}
+      else
+	{
+	  if ((GNUNET_ntohll (datum_1->expiration_time) <
+	       GNUNET_ntohll (datum_2->expiration_time)) == is_asc)
+	    {
+	      datum = datum_1;
+	      rowid = rowid_1;
+	      key = key_1;
+	      last_datum_2 = datum_2;
+	    }
+	  else
+	    {
+	      datum = datum_2;
+	      rowid = rowid_2;
+	      key = key_2;
+	      GNUNET_free (datum_1);
+	    }
+	}
+    }
+  if (datum == NULL)
+    break;
+#if 0
+  printf ("FOUND %4u prio %4u exp %20llu old: %4u, %20llu\n",
+	  (ntohl (datum->size) - sizeof (GNUNET_DatastoreValue)),
+	  ntohl (datum->priority),
+	  GNUNET_ntohll (datum->expiration_time), lastPrio, lastExp);
+#endif
+  if (((GNUNET_NO == limit_nonanonymous) ||
+       (ntohl (datum->anonymity_level) == 0)) &&
+      ((type == GNUNET_ECRS_BLOCKTYPE_ANY) ||
+       (type == ntohl (datum->type))))
+    {
+      count++;
+      if (iter != NULL)
+	{
+	  ret = iter (&key, datum, closure, rowid);
+	  if (ret == GNUNET_SYSERR)
+	    {
+	      GNUNET_free (datum);
+	      break;
+	    }
+	  if (ret == GNUNET_NO)
+	    {
+	      payload -= getContentDatastoreSize (datum);
+	      delete_by_rowid (handle, rowid);
+	    }
+	}
+    }
+}
+
+
+/**
+ * Call a method for each key in the database and
+ * call the callback method on it.
+ *
+ * @param type entries of which type should be considered?
+ * @param iter function to call on each matching value;
+ *        will be called once with a NULL value at the end
+ * @param iter_cls closure for iter
+ * @return the number of results processed,
+ *         GNUNET_SYSERR on error
+ */
+static void
+basic_iter (struct Plugin *plugin,
+	    uint32_t type,
+	    int is_asc,
+	    int is_prio,
+	    int is_migr,
+	    int limit_nonanonymous,
+	    const char *stmt_str_1,
+	    const char *stmt_str_2,
+	    PluginIterator iter,
+	    void *iter_cls)
+{
+  static struct GNUNET_TIME_Absolute zero;
+  struct NextContext *nc;
+  struct IterContext *ic;
+  sqlite3_stmt *stmt_1;
+  sqlite3_stmt *stmt_2;
+
+  if (sq_prepare (plugin->dbh, stmt_str_1, &stmt_1) != SQLITE_OK)
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR |
+                  GNUNET_ERROR_TYPE_BULK, "sqlite3_prepare");
+      iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 0);
+      return;
+    }
+  if (sq_prepare (plugin->dbh, stmt_str_2, &stmt_2) != SQLITE_OK)
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR |
+                  GNUNET_ERROR_TYPE_BULK, "sqlite3_prepare");
+      sqlite3_finalize (stmt_1);
+      iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 0);
+      return;
+    }
+  nc = GNUNET_malloc (sizeof(struct NextContext) + 
+		      sizeof(struct IterContext));
+  nc->plugin = plugin;
+  nc->iter = iter;
+  nc->iter_cls = iter_cls;
+  nc->stmt = NULL;
+  ic = (struct IterContext*) &nc[1];
+  ic->stmt_1 = stmt_1;
+  ic->stmt_2 = stmt_2;
+  ic->type = type;
+  ic->is_asc = is_asc;
+  ic->is_prio = is_prio;
+  ic->is_migr = is_migr;
+  ic->limit_nonanonymous = limit_nonanonymous;
+  nc->prep = &iter_next_prepare;
+  nc->prep_cls = ic;
+  if (is_asc)
+    {
+      nc->lastPriority = 0;
+      nc->lastExpiration.value = 0;
+      memset (&ic->key, 0, sizeof (GNUNET_HashCode));
+    }
+  else
+    {
+      nc->lastPriority = 0x7FFFFFFF;
+      nc->lastExpiration.value = 0x7FFFFFFFFFFFFFFFLL;
+      memset (&ic->key, 255, sizeof (GNUNET_HashCode));
+    }
+  sqlite_next_request (nc, GNUNET_NO);
 }
 
 
@@ -179,8 +1044,13 @@ sqlite_plugin_iter_low_priority (void *cls,
 				 PluginIterator iter,
 				 void *iter_cls)
 {
-  static struct GNUNET_TIME_Absolute zero;
-  iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 0);
+  basic_iter (cls,
+	      type, 
+	      GNUNET_YES, GNUNET_YES, 
+	      GNUNET_NO, GNUNET_NO,
+	      SELECT_IT_LOW_PRIORITY_1,
+	      SELECT_IT_LOW_PRIORITY_2, 
+	      iter, iter_cls);
 }
 
 
@@ -271,29 +1141,262 @@ sqlite_plugin_iter_all_now (void *cls,
 }
 
 
+struct GetNextContext
+{
+  int total;
+  int off;
+  int have_vhash;
+  unsigned int type;
+  sqlite3_stmt *stmt;
+  GNUNET_HashCode key;
+  GNUNET_HashCode vhash;
+};
+
+
+static int
+get_next_prepare (void *cls,
+		  struct NextContext *nc)
+{
+  struct GetNextContext *gnc = cls;
+  int sqoff;
+  int ret;
+  int limit_off;
+
+  if (nc == NULL)
+    {
+      sqlite3_finalize (gnc->stmt);
+      return GNUNET_SYSERR;
+    }
+  if (nc->count == gnc->total)
+    return GNUNET_NO;
+  if (nc->count + gnc->off == gnc->total)
+    nc->last_rowid = 0;
+  if (nc->count == 0)
+    limit_off = gnc->off;
+  else
+    limit_off = 0;
+  sqoff = 1;
+  ret = sqlite3_bind_blob (nc->stmt,
+			   sqoff++,
+			   &gnc->key, 
+			   sizeof (GNUNET_HashCode),
+			   SQLITE_TRANSIENT);
+  if ((gnc->have_vhash) && (ret == SQLITE_OK))
+    ret = sqlite3_bind_blob (nc->stmt,
+			     sqoff++,
+			     &gnc->vhash,
+			     sizeof (GNUNET_HashCode), SQLITE_TRANSIENT);
+  if ((gnc->type != 0) && (ret == SQLITE_OK))
+    ret = sqlite3_bind_int (nc->stmt, sqoff++, gnc->type);
+  if (ret == SQLITE_OK)
+    ret = sqlite3_bind_int64 (nc->stmt, sqoff++, nc->last_rowid + 1);
+  if (ret == SQLITE_OK)
+    ret = sqlite3_bind_int (nc->stmt, sqoff++, limit_off);
+  if (ret != SQLITE_OK)
+    return GNUNET_SYSERR;
+  if (SQLITE_ROW != sqlite3_step (nc->stmt))
+    return GNUNET_NO;
+  return GNUNET_OK;
+}
+
+
+/**
+ * Iterate over the results for a particular key
+ * in the datastore.
+ *
+ * @param cls closure
+ * @param key maybe NULL (to match all entries)
+ * @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 iter function to call on each matching value;
+ *        will be called once with a NULL value at the end
+ * @param iter_cls closure for iter
+ */
+static void
+sqlite_plugin_get (void *cls,
+		   const GNUNET_HashCode * key,
+		   const GNUNET_HashCode * vhash,
+		   uint32_t type,
+		   PluginIterator iter, void *iter_cls)
+{
+  static struct GNUNET_TIME_Absolute zero;
+  struct Plugin *plugin = cls;
+  struct GetNextContext *gpc;
+  struct NextContext *nc;
+  int ret;
+  int total;
+  sqlite3_stmt *stmt;
+  char scratch[256];
+  int sqoff;
+
+  GNUNET_assert (iter != NULL);
+  if (key == NULL)
+    {
+      sqlite_plugin_iter_low_priority (cls, type, iter, iter_cls);
+      return;
+    }
+  GNUNET_snprintf (scratch, 256,
+                   "SELECT count(*) FROM gn080 WHERE hash=:1%s%s",
+                   vhash == NULL ? "" : " AND vhash=:2",
+                   type == 0 ? "" : (vhash ==
+                                     NULL) ? " AND type=:2" : " AND type=:3");
+  if (sq_prepare (plugin->dbh, scratch, &stmt) != SQLITE_OK)
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, "sqlite_prepare");
+      iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 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_reset (stmt);
+      sqlite3_finalize (stmt);
+      iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 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_reset (stmt);
+      sqlite3_finalize (stmt);
+      iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 0);
+      return;
+    }
+  total = sqlite3_column_int (stmt, 0);
+  sqlite3_reset (stmt);
+  sqlite3_finalize (stmt);
+  if (0 == total)
+    {
+      iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 0);
+      return;
+    }
+
+  GNUNET_snprintf (scratch, 256,
+                   "SELECT size, type, prio, anonLevel, expire, hash, value, _ROWID_ "
+                   "FROM gn080 WHERE hash=:1%s%s AND _ROWID_ >= :%d "
+                   "ORDER BY _ROWID_ ASC LIMIT 1 OFFSET :d",
+                   vhash == NULL ? "" : " AND vhash=:2",
+                   type == 0 ? "" : (vhash ==
+                                     NULL) ? " AND type=:2" : " AND type=:3",
+                   sqoff, sqoff + 1);
+  if (sq_prepare (plugin->dbh, scratch, &stmt) != SQLITE_OK)
+    {
+      LOG_SQLITE (plugin, NULL,
+                  GNUNET_ERROR_TYPE_ERROR |
+                  GNUNET_ERROR_TYPE_BULK, "sqlite_prepare");
+      iter (iter_cls, NULL, NULL, 0, NULL, 0, 0, 0, zero, 0);
+      return;
+    }
+  nc = GNUNET_malloc (sizeof(struct NextContext) + 
+		      sizeof(struct GetNextContext));
+  nc->plugin = plugin;
+  nc->iter = iter;
+  nc->iter_cls = iter_cls;
+  nc->stmt = stmt;
+  gpc = (struct GetNextContext*) &nc[1];
+  gpc->total = total;
+  gpc->type = type;
+  gpc->key = *key;
+  gpc->stmt = stmt; /* alias used for freeing at the end! */
+  if (NULL != vhash)
+    {
+      gpc->have_vhash = GNUNET_YES;
+      gpc->vhash = *vhash;
+    }
+  gpc->off = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, total);
+  nc->prep = &get_next_prepare;
+  nc->prep_cls = gpc;
+  sqlite_next_request (nc, GNUNET_NO);
+}
+
+
 /**
  * Drop database.
  */
 static void 
 sqlite_plugin_drop (void *cls)
 {
+  struct Plugin *plugin = cls;
+  plugin->drop_on_shutdown = GNUNET_YES;
 }
 
 
 /**
+ * Callback function to process statistic values.
+ *
+ * @param cls closure
+ * @param subsystem name of subsystem that created the statistic
+ * @param name the name of the datum
+ * @param value the current value
+ * @param is_persistent GNUNET_YES if the value is persistent, GNUNET_NO if not
+ * @return GNUNET_OK to continue, GNUNET_SYSERR to abort iteration
+ */
+static int
+process_stat_in (void *cls,
+		 const char *subsystem,
+		 const char *name,
+		 unsigned long long value,
+		 int is_persistent)
+{
+  struct Plugin *plugin = cls;
+  plugin->payload += value;
+  return GNUNET_OK;
+}
+			 		 
+
+/**
  * Entry point for the plugin.
  */
 void *
 libgnunet_plugin_datastore_sqlite_init (void *cls)
 {
+  static struct Plugin plugin;
   struct GNUNET_DATASTORE_PluginEnvironment *env = cls;
   struct GNUNET_DATASTORE_PluginFunctions *api;
-  struct Plugin *plugin;
 
-  plugin = GNUNET_malloc (sizeof (struct Plugin));
-  plugin->env = env;
+  if (plugin.env != NULL)
+    return NULL; /* can only initialize once! */
+  memset (&plugin, 0, sizeof(struct Plugin));
+  plugin.env = env;
+  plugin.statistics = GNUNET_STATISTICS_create (env->sched,
+						"sqlite",
+						env->cfg);
+  GNUNET_STATISTICS_get (plugin.statistics,
+			 "sqlite",
+			 QUOTA_STAT_NAME,
+			 GNUNET_TIME_UNIT_MINUTES,
+			 NULL,
+			 &process_stat_in,
+			 &plugin);
+  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->cls = &plugin;
   api->get_size = &sqlite_plugin_get_size;
   api->put = &sqlite_plugin_put;
   api->next_request = &sqlite_next_request;
@@ -317,11 +1420,25 @@ libgnunet_plugin_datastore_sqlite_init (void *cls)
 void *
 libgnunet_plugin_datastore_sqlite_done (void *cls)
 {
+  char *fn;
   struct GNUNET_DATASTORE_PluginFunctions *api = cls;
   struct Plugin *plugin = api->cls;
 
-  GNUNET_free (plugin);
+  fn = NULL;
+  if (plugin->drop_on_shutdown)
+    fn = GNUNET_strdup (plugin->fn);
+  database_shutdown (plugin);
+  plugin->env = NULL; 
+  plugin->payload = 0;
   GNUNET_free (api);
+  if (fn != NULL)
+    {
+      if (0 != UNLINK(fn))
+	GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
+				  "unlink",
+				  fn);
+      GNUNET_free (fn);
+    }
   return NULL;
 }
 
diff --git a/src/include/gnunet_common.h b/src/include/gnunet_common.h
index 18358c0297..aacf6328a8 100644
--- a/src/include/gnunet_common.h
+++ b/src/include/gnunet_common.h
@@ -207,6 +207,17 @@ void GNUNET_logger_remove (GNUNET_Logger logger, void *logger_cls);
 
 
 /**
+ * Convert a hash value to a string (for printing debug messages).
+ * This is one of the very few calls in the entire API that is
+ * NOT reentrant!
+ *
+ * @param hc the hash code
+ * @return string 
+ */
+const char *GNUNET_h2s (const GNUNET_HashCode *hc);
+
+
+/**
  * Convert a peer identity to a string (for printing debug messages).
  * This is one of the very few calls in the entire API that is
  * NOT reentrant!
diff --git a/src/statistics/statistics_api.c b/src/statistics/statistics_api.c
index be78d260a2..13a091955f 100644
--- a/src/statistics/statistics_api.c
+++ b/src/statistics/statistics_api.c
@@ -587,7 +587,8 @@ GNUNET_STATISTICS_get (struct GNUNET_STATISTICS_Handle *handle,
                   "Failed to connect to statistics service, can not get value `%s:%s'.\n",
                   strlen (subsystem) ? subsystem : "*",
                   strlen (name) ? name : "*");
-      cont (cls, GNUNET_SYSERR);
+      if (cont != NULL)
+	cont (cls, GNUNET_SYSERR);
       return;
     }
   if (subsystem == NULL)
diff --git a/src/util/common_logging.c b/src/util/common_logging.c
index c77464eb54..a1a60b800b 100644
--- a/src/util/common_logging.c
+++ b/src/util/common_logging.c
@@ -381,6 +381,24 @@ GNUNET_error_type_to_string (enum GNUNET_ErrorType kind)
 
 
 /**
+ * Convert a hash to a string (for printing debug messages).
+ * This is one of the very few calls in the entire API that is
+ * NOT reentrant!
+ *
+ * @param pid the peer identity
+ * @return string form; will be overwritten by next call to GNUNET_h2s.
+ */
+const char *
+GNUNET_h2s (const GNUNET_HashCode *pid)
+{
+  static struct GNUNET_CRYPTO_HashAsciiEncoded ret;
+  GNUNET_CRYPTO_hash_to_enc (pid, &ret);
+  ret.encoding[8] = '\0';
+  return (const char *) ret.encoding;
+}
+
+
+/**
  * Convert a peer identity to a string (for printing debug messages).
  * This is one of the very few calls in the entire API that is
  * NOT reentrant!