[libpeas] Replace plugin loader disabling with enabling

[Garrett Regier <gregier src gnome org>]

commit a3bb19e23029f73628ef560773c8f68c84baf13d
Author: Garrett Regier <alias301 gmail com>
Date:   Thu Feb 10 00:45:58 2011 -0800

    Replace plugin loader disabling with enabling
    
    This way applications are future proof in new
    loaders are enabled that would have been disabled.

 libpeas/peas-engine.c                     |   34 +++++++++-----------
 libpeas/peas-engine.h                     |    2 +-
 peas-demo/peas-demo.c                     |    3 ++
 tests/libpeas/engine.c                    |   25 ++++----------
 tests/libpeas/extension-python.c          |    6 ++-
 tests/libpeas/extension-seed.c            |    6 ++-
 tests/libpeas/testing/testing-extension.h |    6 +++
 tests/libpeas/testing/testing.c           |   49 +++++++++++++++-------------
 tests/libpeas/testing/testing.h           |    2 +
 9 files changed, 68 insertions(+), 65 deletions(-)
---
diff --git a/libpeas/peas-engine.c b/libpeas/peas-engine.c
index af96bf8..55e760f 100644
--- a/libpeas/peas-engine.c
+++ b/libpeas/peas-engine.c
@@ -303,6 +303,8 @@ peas_engine_init (PeasEngine *engine)
                                               PeasEnginePrivate);
 
   engine->priv->in_dispose = FALSE;
+
+  peas_engine_enable_loader (engine, "C");
 }
 
 static void
@@ -671,29 +673,31 @@ get_plugin_loader (PeasEngine     *engine,
                                                     loader_id);
 
   if (loader_info == NULL)
-    loader_info = load_plugin_loader (engine, loader_id);
+    return NULL;
 
   return loader_info->loader;
 }
 
 /**
- * peas_engine_disable_loader:
+ * peas_engine_enable_loader:
  * @engine: A #PeasEngine.
- * @loader_id: The id of the loader to inhibit.
+ * @loader_id: The id of the loader to enable.
  *
- * Disable a loader, avoiding using the plugins written using the
- * related language to be loaded. This method must be called before
- * any plugin relying on the loader @loader_id has been loaded.
+ * Enable a loader, enables a loader for plugins.
+ * The C plugin loader is always enabled.
  *
- * For instance, the following code will prevent any python plugin
+ * For instance, the following code will enable python plugin
  * from being loaded:
  * |[
- * peas_engine_disable_loader (engine, "python");
+ * peas_engine_enable_loader (engine, "python");
  * ]|
+ *
+ * Note: plugin loaders are shared across #PeasEngines so enabeling
+ *       a loader on one #PeasEngine will enable it on all #PeasEngines.
  **/
 void
-peas_engine_disable_loader (PeasEngine  *engine,
-                            const gchar *loader_id)
+peas_engine_enable_loader (PeasEngine  *engine,
+                           const gchar *loader_id)
 {
   LoaderInfo *loader_info;
 
@@ -701,17 +705,9 @@ peas_engine_disable_loader (PeasEngine  *engine,
 
   loader_info = (LoaderInfo *) g_hash_table_lookup (loaders,
                                                     loader_id);
-  if (loader_info != NULL && loader_info->module != NULL)
-    {
-      g_warning ("Loader '%s' cannot be disabled as it is already loaded",
-                 loader_id);
-      return;
-    }
 
-  /* By adding a NULL loader, we simulate a failed load attempt, effectively
-   * disabling the loader for further use. */
   if (loader_info == NULL)
-    add_loader (engine, loader_id, NULL, NULL);
+    load_plugin_loader (engine, loader_id);
 }
 
 /**
diff --git a/libpeas/peas-engine.h b/libpeas/peas-engine.h
index 1a7b45b..e258fd5 100644
--- a/libpeas/peas-engine.h
+++ b/libpeas/peas-engine.h
@@ -77,7 +77,7 @@ void              peas_engine_add_search_path     (PeasEngine      *engine,
                                                    const gchar     *data_dir);
 
 /* plugin management */
-void              peas_engine_disable_loader      (PeasEngine      *engine,
+void              peas_engine_enable_loader       (PeasEngine      *engine,
                                                    const gchar     *loader_id);
 void              peas_engine_rescan_plugins      (PeasEngine      *engine);
 const GList      *peas_engine_get_plugin_list     (PeasEngine      *engine);
diff --git a/peas-demo/peas-demo.c b/peas-demo/peas-demo.c
index 20640cc..4f762f6 100644
--- a/peas-demo/peas-demo.c
+++ b/peas-demo/peas-demo.c
@@ -125,6 +125,9 @@ main (int    argc,
   peas_engine_add_search_path (engine, plugin_dir, plugin_dir);
   g_free (plugin_dir);
 
+  peas_engine_enable_loader (engine, "python");
+  peas_engine_enable_loader (engine, "seed");
+
   if (run_from_build_dir)
     peas_engine_add_search_path (engine, "./plugins", NULL);
   else
diff --git a/tests/libpeas/engine.c b/tests/libpeas/engine.c
index 9b8e97d..8506636 100644
--- a/tests/libpeas/engine.c
+++ b/tests/libpeas/engine.c
@@ -299,14 +299,13 @@ test_engine_nonexistent_loader (PeasEngine *engine)
 }
 
 static void
-test_engine_disable_loader (PeasEngine *engine)
+test_engine_enable_loader (PeasEngine *engine)
 {
   PeasPluginInfo *info;
 
-  /* We have to use an unused loader because loaders
-   * cannot be disabled after the loader has been loaded.
-   *
-   * The loader is disabled in testing_engine_new()
+  /* The extension tests implicitly test enabling a loader
+   * This is only to test that the engine will fail to load
+   * a plugin if it's loader is not enabled.
    */
 
   info = peas_engine_get_plugin_info (engine, "loader-disabled");
@@ -316,18 +315,8 @@ test_engine_disable_loader (PeasEngine *engine)
   g_assert (!peas_plugin_info_is_available (info, NULL));
 
 
-  info = peas_engine_get_plugin_info (engine, "loadable");
-
-  g_assert (peas_engine_load_plugin (engine, info));
-
-  /* Cannot disable the C loader as it has already been enabled */
-  if (g_test_trap_fork (0, G_TEST_TRAP_SILENCE_STDOUT | G_TEST_TRAP_SILENCE_STDERR))
-    {
-      peas_engine_disable_loader (engine, "C");
-      exit (0);
-    }
-  g_test_trap_assert_failed ();
-  g_test_trap_assert_stderr ("*Loader 'C' cannot be disabled*");
+  /* Make sure loaders can be enabled multiple times */
+  peas_engine_enable_loader (engine, "C");
 }
 
 static void
@@ -403,7 +392,7 @@ main (int    argc,
   TEST ("loaded-plugins", loaded_plugins);
 
   TEST ("nonexistent-loader", nonexistent_loader);
-  TEST ("disable-loader", disable_loader);
+  TEST ("enable-loader", enable_loader);
 
   /* MUST be last */
   TEST ("shutdown", shutdown);
diff --git a/tests/libpeas/extension-python.c b/tests/libpeas/extension-python.c
index 7c4e602..3adef09 100644
--- a/tests/libpeas/extension-python.c
+++ b/tests/libpeas/extension-python.c
@@ -35,6 +35,10 @@ main (int   argc,
 
   g_type_init ();
 
+  testing_init ();
+
+  peas_engine_enable_loader (peas_engine_get_default (), "python");
+
   testing_extension_set_plugin_ ("extension-" "python");
 
   _EXTENSION_TEST ("python", "create-valid", create_valid);
@@ -57,7 +61,5 @@ main (int   argc,
   _EXTENSION_TEST ("python", "properties-readwrite", properties_readwrite);
 #endif
 
-  g_object_unref (peas_engine_get_default ());
-
   return g_test_run ();
 }
diff --git a/tests/libpeas/extension-seed.c b/tests/libpeas/extension-seed.c
index 738978e..42d3bc5 100644
--- a/tests/libpeas/extension-seed.c
+++ b/tests/libpeas/extension-seed.c
@@ -35,6 +35,10 @@ main (int   argc,
 
   g_type_init ();
 
+  testing_init ();
+
+  peas_engine_enable_loader (peas_engine_get_default (), "seed");
+
   testing_extension_set_plugin_ ("extension-" "seed");
 
   _EXTENSION_TEST ("seed", "create-valid", create_valid);
@@ -59,7 +63,5 @@ main (int   argc,
   _EXTENSION_TEST ("seed", "properties-readwrite", properties_readwrite);
 #endif
 
-  g_object_unref (peas_engine_get_default ());
-
   return g_test_run ();
 }
diff --git a/tests/libpeas/testing/testing-extension.h b/tests/libpeas/testing/testing-extension.h
index cbccec9..34b378b 100644
--- a/tests/libpeas/testing/testing-extension.h
+++ b/tests/libpeas/testing/testing-extension.h
@@ -24,6 +24,8 @@
 
 #include <libpeas/peas-engine.h>
 
+#include "testing.h"
+
 G_BEGIN_DECLS
 
 typedef struct _TestingExtensionFixture_ TestingExtensionFixture_;
@@ -71,6 +73,10 @@ main (int   argc, \
 \
   g_type_init (); \
 \
+  testing_init (); \
+\
+  peas_engine_enable_loader (peas_engine_get_default (), loader); \
+\
   testing_extension_set_plugin_ ("extension-" loader); \
 \
   _EXTENSION_TEST (loader, "create-valid", create_valid); \
diff --git a/tests/libpeas/testing/testing.c b/tests/libpeas/testing/testing.c
index e3da2c4..93a54c1 100644
--- a/tests/libpeas/testing/testing.c
+++ b/tests/libpeas/testing/testing.c
@@ -88,47 +88,50 @@ out:
   abort ();
 }
 
-PeasEngine *
-testing_engine_new (void)
+void
+testing_init (void)
 {
   GError *error = NULL;
   static gboolean initialized = FALSE;
 
-  if (engine != NULL)
-    return engine;
+  if (initialized)
+    return;
 
-  if (!initialized)
-    {
-      /* Don't always abort on warnings */
-      g_log_set_always_fatal (G_LOG_LEVEL_CRITICAL);
+  /* Don't always abort on warnings */
+  g_log_set_always_fatal (G_LOG_LEVEL_CRITICAL);
 
-      default_log_func = g_log_set_default_handler (log_handler, NULL);
+  default_log_func = g_log_set_default_handler (log_handler, NULL);
 
-      g_irepository_prepend_search_path (BUILDDIR "/libpeas");
+  g_irepository_prepend_search_path (BUILDDIR "/libpeas");
 
-      g_setenv ("PEAS_PLUGIN_LOADERS_DIR", BUILDDIR "/loaders", TRUE);
+  g_setenv ("PEAS_PLUGIN_LOADERS_DIR", BUILDDIR "/loaders", TRUE);
 
-      g_irepository_require (g_irepository_get_default (), "Peas", "1.0", 0, &error);
-      g_assert_no_error (error);
+  g_irepository_require (g_irepository_get_default (), "Peas", "1.0", 0, &error);
+  g_assert_no_error (error);
 
-      g_irepository_require_private (g_irepository_get_default (),
-                                     BUILDDIR "/tests/libpeas/introspection",
-                                     "Introspection", "1.0", 0, &error);
-      g_assert_no_error (error);
+  g_irepository_require_private (g_irepository_get_default (),
+                                 BUILDDIR "/tests/libpeas/introspection",
+                                 "Introspection", "1.0", 0, &error);
+  g_assert_no_error (error);
 
-      g_atexit (peas_engine_shutdown);
+  g_atexit (peas_engine_shutdown);
 
-      initialized = TRUE;
-    }
+  initialized = TRUE;
+}
+
+PeasEngine *
+testing_engine_new (void)
+{
+  if (engine != NULL)
+    return engine;
+
+  testing_init ();
 
   /* Must be after requiring typelibs */
   engine = peas_engine_get_default ();
 
   g_object_add_weak_pointer (G_OBJECT (engine), (gpointer *) &engine);
 
-  /* Disabled here incase another tests tries to load it */
-  peas_engine_disable_loader (engine, "disabled");
-
   peas_engine_add_search_path (engine, BUILDDIR "/tests/plugins", NULL);
   peas_engine_add_search_path (engine, BUILDDIR "/tests/libpeas/plugins", NULL);
 
diff --git a/tests/libpeas/testing/testing.h b/tests/libpeas/testing/testing.h
index 31c486c..4c20595 100644
--- a/tests/libpeas/testing/testing.h
+++ b/tests/libpeas/testing/testing.h
@@ -26,6 +26,8 @@
 
 G_BEGIN_DECLS
 
+void        testing_init        (void);
+
 PeasEngine *testing_engine_new  (void);
 void        testing_engine_free (PeasEngine *engine);