plugin.py: make _unique_id accessible to the core

_unique_id is set at instantiation and never modified afterwards.

Since the guildelines for the project is to never modify directly
an object's state, accessing _unique_id as an attribute is safe.

Moreover this will save us some cost of calling functions.

5 files changed, 9 insertions, 16 deletions

diff --git a/buildstream/_frontend/app.py b/buildstream/_frontend/app.py
index f89202154..53a342899 100644
--- a/buildstream/_frontend/app.py
+++ b/buildstream/_frontend/app.py
@@ -531,7 +531,7 @@ class App():
                 queue = job.queue
 
                 # Get the last failure message for additional context
-                failure = self._fail_messages.get(element._get_unique_id())
+                failure = self._fail_messages.get(element._unique_id)
 
                 # XXX This is dangerous, sometimes we get the job completed *before*
                 # the failure message reaches us ??
diff --git a/buildstream/_scheduler/jobs/elementjob.py b/buildstream/_scheduler/jobs/elementjob.py
index 8ce5c062f..4d53a9d3d 100644
--- a/buildstream/_scheduler/jobs/elementjob.py
+++ b/buildstream/_scheduler/jobs/elementjob.py
@@ -73,7 +73,7 @@ class ElementJob(Job):
         self._complete_cb = complete_cb        # The complete callable function
 
         # Set the task wide ID for logging purposes
-        self.set_task_id(element._get_unique_id())
+        self.set_task_id(element._unique_id)
 
     @property
     def element(self):
@@ -100,7 +100,7 @@ class ElementJob(Job):
         args = dict(kwargs)
         args['scheduler'] = True
         self._scheduler.context.message(
-            Message(self._element._get_unique_id(),
+            Message(self._element._unique_id,
                     message_type,
                     message,
                     **args))
diff --git a/buildstream/_scheduler/queues/queue.py b/buildstream/_scheduler/queues/queue.py
index af4698350..ec1f1405b 100644
--- a/buildstream/_scheduler/queues/queue.py
+++ b/buildstream/_scheduler/queues/queue.py
@@ -348,7 +348,7 @@ class Queue():
     # a message for the element they are processing
     def _message(self, element, message_type, brief, **kwargs):
         context = element._get_context()
-        message = Message(element._get_unique_id(), message_type, brief, **kwargs)
+        message = Message(element._unique_id, message_type, brief, **kwargs)
         context.message(message)
 
     def _element_log_path(self, element):
diff --git a/buildstream/element.py b/buildstream/element.py
index bc939bc92..dd1169f15 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -1262,7 +1262,7 @@ class Element(Plugin):
         for source in self.__sources:
             old_ref = source.get_ref()
             new_ref = source._track()
-            refs.append((source._get_unique_id(), new_ref))
+            refs.append((source._unique_id, new_ref))
 
             # Complimentary warning that the new ref will be unused.
             if old_ref != new_ref and self._get_workspace():
diff --git a/buildstream/plugin.py b/buildstream/plugin.py
index 001de2355..f6a10384d 100644
--- a/buildstream/plugin.py
+++ b/buildstream/plugin.py
@@ -178,10 +178,10 @@ class Plugin():
         # Unique ID
         #
         # This id allows to uniquely identify a plugin.
-        self.__unique_id = next(self.__id_generator)
+        self._unique_id = next(self.__id_generator)
 
         # register ourself in the table containing all existing plugins
-        self.__TABLE[self.__unique_id] = self
+        self.__TABLE[self._unique_id] = self
 
         self.__context = context        # The Context object
         self.__project = project        # The Project object
@@ -544,7 +544,7 @@ class Plugin():
               self.call(... command which takes time ...)
         """
         with self.__context.timed_activity(activity_name,
-                                           unique_id=self.__unique_id,
+                                           unique_id=self._unique_id,
                                            detail=detail,
                                            silent_nested=silent_nested):
             yield
@@ -667,13 +667,6 @@ class Plugin():
     def _get_project(self):
         return self.__project
 
-    # _get_unique_id():
-    #
-    # Fetch the plugin's unique identifier
-    #
-    def _get_unique_id(self):
-        return self.__unique_id
-
     # _get_provenance():
     #
     # Fetch bst file, line and column of the entity
@@ -758,7 +751,7 @@ class Plugin():
         return (exit_code, output)
 
     def __message(self, message_type, brief, **kwargs):
-        message = Message(self.__unique_id, message_type, brief, **kwargs)
+        message = Message(self._unique_id, message_type, brief, **kwargs)
         self.__context.message(message)
 
     def __note_command(self, output, *popenargs, **kwargs):