_frontend/widget.py: Render core messages more like other messages

In order to test when core activities occur by parsing the stderr
in tests, we should make the messages conform more.

At the same time, this restores alignment of columns in core
messages with the element processing related messages.

Also, _scheduler/scheduler.py is updated to make it's activity names
conform to the (current) 5 character limit for the sake of alignment.

The tests/frontend/logging.py test gets it's regexes updated for
the log lines it checks for in stderr.

buildstream/_frontend/widget.py

@@ -175,29 +175,22 @@ class TypeName(Widget):
 # A widget for displaying the Element name
 class ElementName(Widget):
 
-    def __init__(self, context, content_profile, format_profile):
-        super(ElementName, self).__init__(context, content_profile, format_profile)
-
-        # Pre initialization format string, before we know the length of
-        # element names in the pipeline
-        self._fmt_string = '{: <30}'
-
     def render(self, message):
+        action_name = message.action_name
         element_id = message.task_id or message.unique_id
-        if element_id is None:
-            return ""
-
-        plugin = _plugin_lookup(element_id)
-        name = plugin._get_full_name()
+        if element_id is not None:
+            plugin = _plugin_lookup(element_id)
+            name = plugin._get_full_name()
+            name = '{: <30}'.format(name)
+        else:
+            name = 'core activity'
+            name = '{: <30}'.format(name)
 
-        # Sneak the action name in with the element name
-        action_name = message.action_name
         if not action_name:
             action_name = "Main"
 
         return self.content_profile.fmt("{: >5}".format(action_name.lower())) + \
-            self.format_profile.fmt(':') + \
-            self.content_profile.fmt(self._fmt_string.format(name))
+            self.format_profile.fmt(':') + self.content_profile.fmt(name)
 
 
 # A widget for displaying the primary message text
@@ -219,9 +212,12 @@ class CacheKey(Widget):
     def render(self, message):
 
         element_id = message.task_id or message.unique_id
-        if element_id is None or not self._key_length:
+        if not self._key_length:
             return ""
 
+        if element_id is None:
+            return ' ' * self._key_length
+
         missing = False
         key = ' ' * self._key_length
         plugin = _plugin_lookup(element_id)

buildstream/_scheduler/scheduler.py

@@ -40,8 +40,8 @@ class SchedStatus():
 
 # Some action names for the internal jobs we launch
 #
-_ACTION_NAME_CLEANUP = 'cleanup'
-_ACTION_NAME_CACHE_SIZE = 'cache_size'
+_ACTION_NAME_CLEANUP = 'clean'
+_ACTION_NAME_CACHE_SIZE = 'size'
 
 
 # Scheduler()

tests/frontend/logging.py

@@ -41,7 +41,7 @@ def test_default_logging(cli, tmpdir, datafiles):
     result = cli.run(project=project, args=['source', 'fetch', element_name])
     result.assert_success()
 
-    m = re.search(r"\[\d\d:\d\d:\d\d\]\[\]\[\] SUCCESS Checking sources", result.stderr)
+    m = re.search(r"\[\d\d:\d\d:\d\d\]\[\s*\]\[.*\] SUCCESS Checking sources", result.stderr)
     assert(m is not None)
 
 
@@ -77,7 +77,7 @@ def test_custom_logging(cli, tmpdir, datafiles):
     result = cli.run(project=project, args=['source', 'fetch', element_name])
     result.assert_success()
 
-    m = re.search(r"\d\d:\d\d:\d\d,\d\d:\d\d:\d\d.\d{6},\d\d:\d\d:\d\d,,,SUCCESS,Checking sources", result.stderr)
+    m = re.search(r"\d\d:\d\d:\d\d,\d\d:\d\d:\d\d.\d{6},\d\d:\d\d:\d\d,\s*,.*,SUCCESS,Checking sources", result.stderr)
     assert(m is not None)