[gnome-builder] meson: make testprovider load tests when build.ninja changes

[Christian Hergert <chergert src gnome org>]

commit f763f8c2959773fc60afd0c0906498da56c51b25
Author: Christian Hergert <chergert redhat com>
Date:   Fri May 10 11:47:46 2019 -0700

    meson: make testprovider load tests when build.ninja changes
    
    This avoids forcing the pipeline to build to load meson tests. To do so,
    we need to watch build.ninja for changes so that we can run "meson
    introspect" as needed.
    
    We also need to always load them after the first pipeline request (which
    is generally to CONFIGURE phase).
    
    The side-benefit to this is that we can avoid advancing to the CONFIGURE
    phase of the build pipeline on startup.

 src/plugins/meson/gbp-meson-test-provider.c | 147 +++++++++++++++++-----------
 1 file changed, 91 insertions(+), 56 deletions(-)
---
diff --git a/src/plugins/meson/gbp-meson-test-provider.c b/src/plugins/meson/gbp-meson-test-provider.c
index c792cedb1..77ffc02be 100644
--- a/src/plugins/meson/gbp-meson-test-provider.c
+++ b/src/plugins/meson/gbp-meson-test-provider.c
@@ -20,6 +20,7 @@
 
 #define G_LOG_DOMAIN "gbp-meson-test-provider"
 
+#include <dazzle.h>
 #include <json-glib/json-glib.h>
 #include <libide-threading.h>
 
@@ -30,8 +31,10 @@
 struct _GbpMesonTestProvider
 {
   IdeTestProvider  parent_instance;
-  GCancellable    *build_cancellable;
+  DzlSignalGroup  *monitor_signals;
+  GFileMonitor    *build_ninja_monitor;
   guint            reload_source;
+  guint            did_initial_load : 1;
 };
 
 typedef struct
@@ -254,33 +257,6 @@ failure:
   IDE_EXIT;
 }
 
-static void
-gbp_meson_test_provider_build_cb (GObject      *object,
-                                  GAsyncResult *result,
-                                  gpointer      user_data)
-{
-  IdePipeline *pipeline = (IdePipeline *)object;
-  g_autoptr(GbpMesonTestProvider) self = user_data;
-  g_autoptr(GError) error = NULL;
-
-  IDE_ENTRY;
-
-  g_assert (IDE_IS_PIPELINE (pipeline));
-  g_assert (G_IS_ASYNC_RESULT (result));
-  g_assert (GBP_IS_MESON_TEST_PROVIDER (self));
-
-  if (!ide_pipeline_build_finish (pipeline, result, &error))
-    {
-      g_message ("%s", error->message);
-      ide_test_provider_set_loading (IDE_TEST_PROVIDER (self), FALSE);
-      IDE_EXIT;
-    }
-
-  gbp_meson_test_provider_do_reload (self, pipeline);
-
-  IDE_EXIT;
-}
-
 static gboolean
 gbp_meson_test_provider_reload (gpointer user_data)
 {
@@ -294,11 +270,7 @@ gbp_meson_test_provider_reload (gpointer user_data)
 
   g_assert (GBP_IS_MESON_TEST_PROVIDER (self));
 
-  self->reload_source = 0;
-
-  /* Cancel any other builds in-flight */
-  g_cancellable_cancel (self->build_cancellable);
-  g_clear_object (&self->build_cancellable);
+  dzl_clear_source (&self->reload_source);
 
   /*
    * Check that we're working with a meson build system.
@@ -318,26 +290,7 @@ gbp_meson_test_provider_reload (gpointer user_data)
     IDE_RETURN (G_SOURCE_REMOVE);
 
   ide_test_provider_set_loading (IDE_TEST_PROVIDER (self), TRUE);
-
-  /*
-   * Make sure that the build pipeline has advanced enough for
-   * us to continue processing the tests.
-   */
-  self->build_cancellable = g_cancellable_new ();
-  /*
-   * TODO: We want to try to avoid the pipeline build like this in
-   * the future because it advances the pipeline when the project
-   * is opened. Instead, we might want a CONFIGURE stage that auto
-   * generates the info, and then watch that GFile.
-   *
-   * But to do that well, we need to coordinate with the panel to
-   * be lazy about fetching unit tests until the panel is displayed.
-   */
-  ide_pipeline_build_async (pipeline,
-                            IDE_PIPELINE_PHASE_CONFIGURE,
-                            self->build_cancellable,
-                            gbp_meson_test_provider_build_cb,
-                            g_object_ref (self));
+  gbp_meson_test_provider_do_reload (self, pipeline);
 
   IDE_RETURN (G_SOURCE_REMOVE);
 }
@@ -357,15 +310,60 @@ gbp_meson_test_provider_queue_reload (IdeTestProvider *provider)
                                                       NULL);
 }
 
+static void
+pipeline_build_finished_cb (GbpMesonTestProvider *self,
+                            gboolean              failed,
+                            IdePipeline          *pipeline)
+{
+  g_assert (GBP_IS_MESON_TEST_PROVIDER (self));
+  g_assert (IDE_IS_PIPELINE (pipeline));
+
+  if (failed || self->did_initial_load)
+    return;
+
+  self->did_initial_load = TRUE;
+
+  /* We need to do our first load of state, so do that now */
+  gbp_meson_test_provider_reload (self);
+}
+
 static void
 gbp_meson_test_provider_notify_pipeline (GbpMesonTestProvider *self,
                                          GParamSpec           *pspec,
                                          IdeBuildManager      *build_manager)
 {
+  IdePipeline *pipeline;
+
   g_assert (GBP_IS_MESON_TEST_PROVIDER (self));
   g_assert (IDE_IS_BUILD_MANAGER (build_manager));
 
-  gbp_meson_test_provider_queue_reload (IDE_TEST_PROVIDER (self));
+  if (self->build_ninja_monitor != NULL)
+    {
+      g_file_monitor_cancel (self->build_ninja_monitor);
+      g_clear_object (&self->build_ninja_monitor);
+      dzl_signal_group_set_target (self->monitor_signals, NULL);
+    }
+
+  g_assert (self->build_ninja_monitor == NULL);
+
+  if ((pipeline = ide_build_manager_get_pipeline (build_manager)))
+    {
+      g_autofree gchar *build_ninja = NULL;
+      g_autoptr(GFile) file = NULL;
+
+      build_ninja = ide_pipeline_build_builddir_path (pipeline, "build.ninja", NULL);
+      file = g_file_new_for_path (build_ninja);
+      self->build_ninja_monitor = g_file_monitor (file, 0, NULL, NULL);
+      dzl_signal_group_set_target (self->monitor_signals, self->build_ninja_monitor);
+
+      self->did_initial_load = FALSE;
+
+      g_signal_connect_object (pipeline,
+                               "finished",
+                               G_CALLBACK (pipeline_build_finished_cb),
+                               self,
+                               G_CONNECT_SWAPPED);
+    }
 }
 
 static void
@@ -584,18 +582,47 @@ gbp_meson_test_provider_parent_set (IdeObject *object,
   gbp_meson_test_provider_notify_pipeline (self, NULL, build_manager);
 }
 
+static void
+build_ninja_changed_cb (GbpMesonTestProvider *self,
+                        GFile                *file,
+                        GFile                *other_file,
+                        GFileMonitorEvent     event,
+                        GFileMonitor         *monitor)
+{
+  g_assert (GBP_IS_MESON_TEST_PROVIDER (self));
+  g_assert (G_IS_FILE_MONITOR (monitor));
+
+  if (event == G_FILE_MONITOR_EVENT_CHANGED || event == G_FILE_MONITOR_EVENT_CREATED)
+    gbp_meson_test_provider_queue_reload (IDE_TEST_PROVIDER (self));
+}
+
 static void
 gbp_meson_test_provider_dispose (GObject *object)
 {
   GbpMesonTestProvider *self = (GbpMesonTestProvider *)object;
 
   dzl_clear_source (&self->reload_source);
-  g_cancellable_cancel (self->build_cancellable);
-  g_clear_object (&self->build_cancellable);
+  dzl_signal_group_set_target (self->monitor_signals, NULL);
+
+  if (self->build_ninja_monitor)
+    {
+      g_file_monitor_cancel (self->build_ninja_monitor);
+      g_clear_object (&self->build_ninja_monitor);
+    }
 
   G_OBJECT_CLASS (gbp_meson_test_provider_parent_class)->dispose (object);
 }
 
+static void
+gbp_meson_test_provider_finalize (GObject *object)
+{
+  GbpMesonTestProvider *self = (GbpMesonTestProvider *)object;
+
+  g_clear_object (&self->monitor_signals);
+
+  G_OBJECT_CLASS (gbp_meson_test_provider_parent_class)->finalize (object);
+}
+
 static void
 gbp_meson_test_provider_class_init (GbpMesonTestProviderClass *klass)
 {
@@ -604,6 +631,7 @@ gbp_meson_test_provider_class_init (GbpMesonTestProviderClass *klass)
   IdeTestProviderClass *provider_class = IDE_TEST_PROVIDER_CLASS (klass);
 
   object_class->dispose = gbp_meson_test_provider_dispose;
+  object_class->finalize = gbp_meson_test_provider_finalize;
 
   i_object_class->parent_set = gbp_meson_test_provider_parent_set;
 
@@ -615,4 +643,11 @@ gbp_meson_test_provider_class_init (GbpMesonTestProviderClass *klass)
 static void
 gbp_meson_test_provider_init (GbpMesonTestProvider *self)
 {
+  self->monitor_signals = dzl_signal_group_new (G_TYPE_FILE_MONITOR);
+
+  dzl_signal_group_connect_object (self->monitor_signals,
+                                   "changed",
+                                   G_CALLBACK (build_ninja_changed_cb),
+                                   self,
+                                   G_CONNECT_SWAPPED);
 }