Tasks: only execute the event if the plugin is interested in it

src/lib/Hydra/Event.pm

@@ -38,6 +38,12 @@ sub new_event {
     }, $self;
 }
 
+sub interested {
+    my ($self, $plugin) = @_;
+
+    return $self->{"event"}->interestedIn($plugin);
+}
+
 sub execute {
     my ($self, $db, $plugin) = @_;
     return $self->{"event"}->execute($db, $plugin);

src/lib/Hydra/Event/BuildFinished.pm

@@ -27,6 +27,11 @@ sub new {
     }, $self;
 }
 
+sub interestedIn {
+    my ($self, $plugin) = @_;
+    return int(defined($plugin->can('buildFinished')));
+}
+
 sub load {
     my ($self, $db) = @_;
 

src/lib/Hydra/Event/BuildQueued.pm

@@ -25,6 +25,11 @@ sub new {
     }, $self;
 }
 
+sub interestedIn {
+    my ($self, $plugin) = @_;
+    return int(defined($plugin->can('buildQueued')));
+}
+
 sub load {
     my ($self, $db) = @_;
 

src/lib/Hydra/Event/BuildStarted.pm

@@ -25,6 +25,11 @@ sub new {
     }, $self;
 }
 
+sub interestedIn {
+    my ($self, $plugin) = @_;
+    return int(defined($plugin->can('buildStarted')));
+}
+
 sub load {
     my ($self, $db) = @_;
 

src/lib/Hydra/Event/StepFinished.pm

@@ -34,6 +34,11 @@ sub new :prototype($$$) {
     }, $self;
 }
 
+sub interestedIn {
+    my ($self, $plugin) = @_;
+    return int(defined($plugin->can('stepFinished')));
+}
+
 sub load {
     my ($self, $db) = @_;
 

src/lib/Hydra/Plugin.pm

@@ -25,29 +25,35 @@ sub instantiate {
     return @$plugins;
 }
 
-# Called when build $build has been queued.
-sub buildQueued {
-    my ($self, $build) = @_;
-}
+# To implement behaviors in response to the following events, implement
+# the function in your plugin and it will be executed by hydra-notify.
+#
+# See the tests in t/Event/*.t for arguments, and the documentation for
+# notify events for semantics.
+#
+# # Called when build $build has been queued.
+# sub buildQueued {
+#     my ($self, $build) = @_;
+# }
 
-# Called when build $build has started.
-sub buildStarted {
-    my ($self, $build) = @_;
-}
+# # Called when build $build has started.
+# sub buildStarted {
+#     my ($self, $build) = @_;
+# }
 
-# Called when build $build has finished.  If the build failed, then
-# $dependents is an array ref to a list of builds that have also
-# failed as a result (i.e. because they depend on $build or a failed
-# dependeny of $build).
-sub buildFinished {
-    my ($self, $build, $dependents) = @_;
-}
+# # Called when build $build has finished.  If the build failed, then
+# # $dependents is an array ref to a list of builds that have also
+# # failed as a result (i.e. because they depend on $build or a failed
+# # dependeny of $build).
+# sub buildFinished {
+#     my ($self, $build, $dependents) = @_;
+# }
 
-# Called when step $step has finished. The build log is stored in the
-# file $logPath (bzip2-compressed).
-sub stepFinished {
-    my ($self, $step, $logPath) = @_;
-}
+# # Called when step $step has finished. The build log is stored in the
+# # file $logPath (bzip2-compressed).
+# sub stepFinished {
+#     my ($self, $step, $logPath) = @_;
+# }
 
 # Called to determine the set of supported input types.  The plugin
 # should add these to the $inputTypes hashref, e.g. $inputTypes{'svn'}

src/lib/Hydra/Plugin/GitInput.pm

@@ -14,7 +14,6 @@ use Data::Dumper;
 
 my $CONFIG_SECTION = "git-input";
 
-
 sub supportedInputTypes {
     my ($self, $inputTypes) = @_;
     $inputTypes->{'git'} = 'Git checkout';

src/lib/Hydra/TaskDispatcher.pm

@@ -117,6 +117,11 @@ sub new {
         type => "counter",
         help => "Number of tasks that have not been processed because the plugin does not exist."
     );
+    $prometheus->declare(
+        "notify_plugin_not_interested",
+        type => "counter",
+        help => "Number of tasks that have not been processed because the plugin was not interested in the event."
+    );
 
     my %plugins_by_name = map { ref $_ => $_ } @{$plugins};
 
@@ -190,6 +195,11 @@ sub dispatch_task {
         return 0;
     }
 
+    if (!$task->{"event"}->interested($plugin)) {
+        $self->{"prometheus"}->inc("notify_plugin_not_interested", $event_labels);
+        return 0;
+    }
+
     $self->{"prometheus"}->inc("notify_plugin_executions", $event_labels);
     eval {
         my $start_time = [gettimeofday()];

t/Event/BuildFinished.t

@@ -54,6 +54,28 @@ my $jobset = createBaseJobset("basic", "basic.nix", $ctx{jobsdir});
 ok(evalSucceeds($jobset),               "Evaluating jobs/basic.nix should exit with return code 0");
 is(nrQueuedBuildsForJobset($jobset), 3, "Evaluating jobs/basic.nix should result in 3 builds");
 
+subtest "interested" => sub {
+    my $event = Hydra::Event::BuildFinished->new(123, []);
+
+    subtest "A plugin which does not implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => ();
+
+        is($event->interestedIn($plugin), 0, "The plugin is not interesting.");
+    };
+
+    subtest "A plugin which does implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => (
+            add => [
+                "buildFinished" => sub {}
+            ]
+        );
+
+        is($event->interestedIn($plugin), 1, "The plugin is interesting.");
+    };
+};
+
 subtest "load" => sub {
     my ($build, $dependent_a, $dependent_b) = $db->resultset('Builds')->search(
       { },

t/Event/BuildQueued.t

@@ -39,6 +39,28 @@ subtest "Parsing build_queued" => sub {
     );
 };
 
+subtest "interested" => sub {
+    my $event = Hydra::Event::BuildQueued->new(123, []);
+
+    subtest "A plugin which does not implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => ();
+
+        is($event->interestedIn($plugin), 0, "The plugin is not interesting.");
+    };
+
+    subtest "A plugin which does implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => (
+            add => [
+                "buildQueued" => sub {}
+            ]
+        );
+
+        is($event->interestedIn($plugin), 1, "The plugin is interesting.");
+    };
+};
+
 subtest "load" => sub {
     my $build = $builds->{"empty_dir"};
 

t/Event/BuildStarted.t

@@ -45,6 +45,28 @@ subtest "Parsing build_started" => sub {
     );
 };
 
+subtest "interested" => sub {
+    my $event = Hydra::Event::BuildStarted->new(123, []);
+
+    subtest "A plugin which does not implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => ();
+
+        is($event->interestedIn($plugin), 0, "The plugin is not interesting.");
+    };
+
+    subtest "A plugin which does implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => (
+            add => [
+                "buildStarted" => sub {}
+            ]
+        );
+
+        is($event->interestedIn($plugin), 1, "The plugin is interesting.");
+    };
+};
+
 subtest "load" => sub {
     my $build = $db->resultset('Builds')->search(
       { },

t/Event/StepFinished.t

@@ -64,6 +64,28 @@ subtest "Parsing step_finished" => sub {
     );
 };
 
+subtest "interested" => sub {
+    my $event = Hydra::Event::StepFinished->new(123, []);
+
+    subtest "A plugin which does not implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => ();
+
+        is($event->interestedIn($plugin), 0, "The plugin is not interesting.");
+    };
+
+    subtest "A plugin which does implement the API" => sub {
+        my $plugin = {};
+        my $mock = mock_obj $plugin => (
+            add => [
+                "stepFinished" => sub {}
+            ]
+        );
+
+        is($event->interestedIn($plugin), 1, "The plugin is interesting.");
+    };
+};
+
 subtest "load" => sub {
 
     my $step = $db->resultset('BuildSteps')->search(