db: Implement plugin loading and unloading

src/mint/plugin.c

@@ -43,8 +43,35 @@ static char *old_dlsearchpath;
 int
 TALER_MINT_plugin_load (const struct GNUNET_CONFIGURATION_Handle *cfg)
 {
+  char *plugin_name;
+  char *lib_name;
+  struct GNUNET_CONFIGURATION_Handle *cfg_dup;
+
+  if (NULL != plugin)
+    return GNUNET_OK;
+  if (GNUNET_SYSERR ==
+      GNUNET_CONFIGURATION_get_value_string (cfg,
+                                             "mint",
+                                             "db",
+                                             &plugin_name))
+  {
+    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
+                               "mint",
+                               "db");
     return GNUNET_SYSERR;
   }
+  (void) GNUNET_asprintf (&lib_name,
+                          "libtaler_plugin_mintdb_%s",
+                          plugin_name);
+  GNUNET_free (plugin_name);
+  cfg_dup = GNUNET_CONFIGURATION_dup (cfg);
+  plugin = GNUNET_PLUGIN_load (lib_name, cfg_dup);
+  GNUNET_CONFIGURATION_destroy (cfg_dup);
+  GNUNET_free (lib_name);
+  if (NULL == plugin)
+    return GNUNET_SYSERR;
+  return GNUNET_OK;
+}
 
 
 /**
@@ -55,6 +82,8 @@ TALER_MINT_plugin_unload ()
 {
   if (NULL == plugin)
     return;
+  GNUNET_assert (NULL == GNUNET_PLUGIN_unload (plugin->library_name,
+                                               plugin));
 }
 
 

src/mint/plugin_mintdb_postgres.c

@@ -2289,16 +2289,17 @@ libtaler_plugin_mintdb_postgres_init (void *cls)
   /* FIXME: use configuration section with "postgres" in its name... */
   if (GNUNET_OK !=
       GNUNET_CONFIGURATION_get_value_string (cfg,
-                                             "mint", "db",
+                                             "mint", "db_conn_str",
                                              &pg->TALER_MINT_db_connection_cfg_str))
   {
     GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
                                "mint",
-                               "db");
+                               "db_conn_str");
     return NULL;
   }
   plugin = GNUNET_new (struct TALER_MINTDB_Plugin);
   plugin->cls = pg;
+  plugin->library_name = "libtaler_plugin_mintdb_postgres";
   plugin->get_session = &postgres_get_session;
   plugin->drop_temporary = &postgres_drop_temporary;
   plugin->create_tables = &postgres_create_tables;

src/mint/taler_mintdb_plugin.h

@@ -478,6 +478,11 @@ struct TALER_MINTDB_Plugin
    */
   void *cls;
 
+  /**
+   * Name of the library which generated this plugin
+   */
+  const char *library_name;
+
   /**
    * Get the thread-local database-handle.
    * Connect to the db if the connection does not exist yet.

src/mint/test_mint_db.c

@@ -343,6 +343,7 @@ run (void *cls,
   if (NULL != cbc2.sig.rsa_signature)
     GNUNET_CRYPTO_rsa_signature_free (cbc2.sig.rsa_signature);
   dkp = NULL;
+  TALER_MINT_plugin_unload ();
 }