_context.py: Adhere to policy on private symbols

And adjust all surrounding sources for changed symbols.

This is a part of issue #285

15 files changed, 80 insertions, 75 deletions

diff --git a/buildstream/_artifactcache/artifactcache.py b/buildstream/_artifactcache/artifactcache.py
index 8937afb49..b10b6b0b9 100644
--- a/buildstream/_artifactcache/artifactcache.py
+++ b/buildstream/_artifactcache/artifactcache.py
@@ -90,7 +90,7 @@ def artifact_cache_specs_from_config_node(config_node):
 #   A list of ArtifactCacheSpec instances describing the remote artifact caches.
 #
 def configured_remote_artifact_cache_specs(context, project):
-    project_overrides = context._get_overrides(project.name)
+    project_overrides = context.get_overrides(project.name)
     project_extra_specs = artifact_cache_specs_from_config_node(project_overrides)
 
     return list(utils._deduplicate(
diff --git a/buildstream/_artifactcache/ostreecache.py b/buildstream/_artifactcache/ostreecache.py
index 76b4c3507..29f6c0b8c 100644
--- a/buildstream/_artifactcache/ostreecache.py
+++ b/buildstream/_artifactcache/ostreecache.py
@@ -505,7 +505,7 @@ class OSTreeCache(ArtifactCache):
                 remote_results[remote_spec.url] = (push_url, pull_url, remote_refs)
 
         # Prepare push_urls, pull_urls, and remote_refs for each project
-        for project in self.context._get_projects():
+        for project in self.context.get_projects():
             remote_specs = self.global_remote_specs
             if project in self.project_remote_specs:
                 remote_specs = list(utils._deduplicate(remote_specs + self.project_remote_specs[project]))
diff --git a/buildstream/_context.py b/buildstream/_context.py
index 15fadddcc..727be6924 100644
--- a/buildstream/_context.py
+++ b/buildstream/_context.py
@@ -50,9 +50,6 @@ class Context():
         # Filename indicating which configuration file was used, or None for the defaults
         self.config_origin = None
 
-        # Whether elements must be rebuilt when their dependencies have changed
-        self.strict_build_plan = None
-
         # The directory where various sources are stored
         self.sourcedir = None
 
@@ -101,6 +98,9 @@ class Context():
         # What to do when a build fails in non interactive mode
         self.sched_error_action = 'continue'
 
+        # Whether elements must be rebuilt when their dependencies have changed
+        self._strict_build_plan = None
+
         # Make sure the XDG vars are set in the environment before loading anything
         self._init_xdg()
 
@@ -209,27 +209,27 @@ class Context():
                             "{}: on-error should be one of: {}".format(
                                 provenance, ", ".join(valid_actions)))
 
-    # _add_project():
+    # add_project():
     #
     # Add a project to the context.
     #
     # Args:
     #    project (Project): The project to add
     #
-    def _add_project(self, project):
+    def add_project(self, project):
         self._projects.append(project)
 
-    # _get_projects():
+    # get_projects():
     #
     # Return the list of projects in the context.
     #
     # Returns:
     #    (list): The list of projects
     #
-    def _get_projects(self):
+    def get_projects(self):
         return self._projects
 
-    # _get_toplevel_project():
+    # get_toplevel_project():
     #
     # Return the toplevel project, the one which BuildStream was
     # invoked with as opposed to a junctioned subproject.
@@ -237,10 +237,10 @@ class Context():
     # Returns:
     #    (list): The list of projects
     #
-    def _get_toplevel_project(self):
+    def get_toplevel_project(self):
         return self._projects[0]
 
-    # _get_overrides():
+    # get_overrides():
     #
     # Fetch the override dictionary for the active project. This returns
     # a node loaded from YAML and as such, values loaded from the returned
@@ -252,10 +252,10 @@ class Context():
     # Returns:
     #    (Mapping): The overrides dictionary for the specified project
     #
-    def _get_overrides(self, project_name):
+    def get_overrides(self, project_name):
         return _yaml.node_get(self._project_overrides, Mapping, project_name, default_value={})
 
-    # _get_strict():
+    # get_strict():
     #
     # Fetch whether we are strict or not
     #
@@ -265,23 +265,23 @@ class Context():
     # Returns:
     #    (bool): Whether or not to use strict build plan
     #
-    def _get_strict(self, project_name):
+    def get_strict(self, project_name):
 
         # If it was set by the CLI, it overrides any config
-        if self.strict_build_plan is not None:
-            return self.strict_build_plan
+        if self._strict_build_plan is not None:
+            return self._strict_build_plan
 
-        overrides = self._get_overrides(project_name)
+        overrides = self.get_overrides(project_name)
         return _yaml.node_get(overrides, bool, 'strict', default_value=True)
 
-    # _get_cache_key():
+    # get_cache_key():
     #
     # Returns the cache key, calculating it if necessary
     #
     # Returns:
     #    (str): A hex digest cache key for the Context
     #
-    def _get_cache_key(self):
+    def get_cache_key(self):
         if self._cache_key is None:
 
             # Anything that alters the build goes into the unique key
@@ -289,35 +289,28 @@ class Context():
 
         return self._cache_key
 
-    # _set_message_handler()
+    # set_message_handler()
     #
     # Sets the handler for any status messages propagated through
     # the context.
     #
     # The message handler should have the same signature as
-    # the _message() method
-    def _set_message_handler(self, handler):
+    # the message() method
+    def set_message_handler(self, handler):
         self._message_handler = handler
 
-    # _push_message_depth() / _pop_message_depth()
+    # silent_messages():
     #
-    # For status messages, send the depth of timed
-    # activities inside a given task through the message
+    # Returns:
+    #    (bool): Whether messages are currently being silenced
     #
-    def _push_message_depth(self, silent_nested):
-        self._message_depth.appendleft(silent_nested)
-
-    def _pop_message_depth(self):
-        assert self._message_depth
-        self._message_depth.popleft()
-
-    def _silent_messages(self):
+    def silent_messages(self):
         for silent in self._message_depth:
             if silent:
                 return True
         return False
 
-    # _message():
+    # message():
     #
     # Proxies a message back to the caller, this is the central
     # point through which all messages pass.
@@ -325,7 +318,7 @@ class Context():
     # Args:
     #    message: A Message object
     #
-    def _message(self, message):
+    def message(self, message):
 
         # Tag message only once
         if message.depth is None:
@@ -339,7 +332,7 @@ class Context():
         self._message_handler(message, context=self)
         return
 
-    # _silence()
+    # silence()
     #
     # A context manager to silence messages, this behaves in
     # the same way as the `silent_nested` argument of the
@@ -347,14 +340,14 @@ class Context():
     # important messages will not be silenced.
     #
     @contextmanager
-    def _silence(self):
+    def silence(self):
         self._push_message_depth(True)
         try:
             yield
         finally:
             self._pop_message_depth()
 
-    # _timed_activity()
+    # timed_activity()
     #
     # Context manager for performing timed activities and logging those
     #
@@ -365,7 +358,7 @@ class Context():
     #    silent_nested (bool): If specified, nested messages will be silenced
     #
     @contextmanager
-    def _timed_activity(self, activity_name, *, unique_id=None, detail=None, silent_nested=False):
+    def timed_activity(self, activity_name, *, unique_id=None, detail=None, silent_nested=False):
 
         starttime = datetime.datetime.now()
         stopped_time = None
@@ -384,7 +377,7 @@ class Context():
             try:
                 # Push activity depth for status messages
                 message = Message(unique_id, MessageType.START, activity_name, detail=detail)
-                self._message(message)
+                self.message(message)
                 self._push_message_depth(silent_nested)
                 yield
 
@@ -394,13 +387,25 @@ class Context():
                 elapsed = datetime.datetime.now() - starttime
                 message = Message(unique_id, MessageType.FAIL, activity_name, elapsed=elapsed)
                 self._pop_message_depth()
-                self._message(message)
+                self.message(message)
                 raise
 
             elapsed = datetime.datetime.now() - starttime
             message = Message(unique_id, MessageType.SUCCESS, activity_name, elapsed=elapsed)
             self._pop_message_depth()
-            self._message(message)
+            self.message(message)
+
+    # _push_message_depth() / _pop_message_depth()
+    #
+    # For status messages, send the depth of timed
+    # activities inside a given task through the message
+    #
+    def _push_message_depth(self, silent_nested):
+        self._message_depth.appendleft(silent_nested)
+
+    def _pop_message_depth(self):
+        assert self._message_depth
+        self._message_depth.popleft()
 
     # Force the resolved XDG variables into the environment,
     # this is so that they can be used directly to specify
diff --git a/buildstream/_frontend/app.py b/buildstream/_frontend/app.py
index c9c006b7d..ffe12d1db 100644
--- a/buildstream/_frontend/app.py
+++ b/buildstream/_frontend/app.py
@@ -138,7 +138,7 @@ class App():
         # the command line when used, trumps the config files.
         #
         override_map = {
-            'strict': 'strict_build_plan',
+            'strict': '_strict_build_plan',
             'debug': 'log_debug',
             'verbose': 'log_verbose',
             'error_lines': 'log_error_lines',
@@ -178,7 +178,7 @@ class App():
             message_format=self.context.log_message_format)
 
         # Propagate pipeline feedback to the user
-        self.context._set_message_handler(self.message_handler)
+        self.context.set_message_handler(self.message_handler)
 
         try:
             self.project = Project(directory, self.context, cli_options=self.main_options['option'])
@@ -375,8 +375,8 @@ class App():
 
         # Remove workspace directory if prompted
         if remove_dir:
-            with self.context._timed_activity("Removing workspace directory {}"
-                                              .format(workspace.path)):
+            with self.context.timed_activity("Removing workspace directory {}"
+                                             .format(workspace.path)):
                 try:
                     shutil.rmtree(workspace.path)
                 except OSError as e:
@@ -417,7 +417,7 @@ class App():
     #
     def message(self, message_type, message, **kwargs):
         args = dict(kwargs)
-        self.context._message(
+        self.context.message(
             Message(None, message_type, message, **args))
 
     #
@@ -639,7 +639,7 @@ class App():
             self.fail_messages[message.unique_id] = message
 
         # Send to frontend if appropriate
-        if self.context._silent_messages() and (message.message_type not in unconditional_messages):
+        if self.context.silent_messages() and (message.message_type not in unconditional_messages):
             return
 
         if self.status:
diff --git a/buildstream/_frontend/widget.py b/buildstream/_frontend/widget.py
index 90b573636..dd934182c 100644
--- a/buildstream/_frontend/widget.py
+++ b/buildstream/_frontend/widget.py
@@ -520,7 +520,7 @@ class LogLine(Widget):
         values["Source Mirrors"] = context.sourcedir
         values["Build Area"] = context.builddir
         values["Artifact Cache"] = context.artifactdir
-        values["Strict Build Plan"] = "Yes" if context.strict_build_plan else "No"
+        values["Strict Build Plan"] = "Yes" if context.get_strict(project.name) else "No"
         values["Maximum Fetch Tasks"] = context.sched_fetchers
         values["Maximum Build Tasks"] = context.sched_builders
         values["Maximum Push Tasks"] = context.sched_pushers
diff --git a/buildstream/_pipeline.py b/buildstream/_pipeline.py
index 676b068a7..22c3a0b2b 100644
--- a/buildstream/_pipeline.py
+++ b/buildstream/_pipeline.py
@@ -163,7 +163,7 @@ class Pipeline():
             self.artifacts.set_remotes([ArtifactCacheSpec(add_remote_cache, push=True)])
             has_remote_caches = True
         if use_configured_remote_caches:
-            for project in self.context._get_projects():
+            for project in self.context.get_projects():
                 artifact_caches = configured_remote_artifact_cache_specs(self.context, project)
                 if artifact_caches:  # artifact_caches is a list of ArtifactCacheSpec instances
                     self.artifacts.set_remotes(artifact_caches, project=project)
@@ -307,16 +307,16 @@ class Pipeline():
     #
     def message(self, message_type, message, **kwargs):
         args = dict(kwargs)
-        self.context._message(
+        self.context.message(
             Message(None, message_type, message, **args))
 
     # Local timed activities, announces the jobs as well
     #
     @contextmanager
     def timed_activity(self, activity_name, *, detail=None, silent_nested=False):
-        with self.context._timed_activity(activity_name,
-                                          detail=detail,
-                                          silent_nested=silent_nested):
+        with self.context.timed_activity(activity_name,
+                                         detail=detail,
+                                         silent_nested=silent_nested):
             yield
 
     # Internal: Instantiates plugin-provided Element and Source instances
diff --git a/buildstream/_project.py b/buildstream/_project.py
index ce23452f1..b8ee61394 100644
--- a/buildstream/_project.py
+++ b/buildstream/_project.py
@@ -117,7 +117,7 @@ class Project():
         self._load()
         profile_end(Topics.LOAD_PROJECT, self.directory.replace(os.sep, '-'))
 
-        self._context._add_project(self)
+        self._context.add_project(self)
 
     # translate_url():
     #
@@ -204,7 +204,7 @@ class Project():
             self._options.load_yaml_values(self._junction.options, transform=self._junction._subst_string)
 
         # Collect option values specified in the user configuration
-        overrides = self._context._get_overrides(self.name)
+        overrides = self._context.get_overrides(self.name)
         override_options = _yaml.node_get(overrides, Mapping, 'options', default_value={})
         self._options.load_yaml_values(override_options)
         if self._cli_options:
diff --git a/buildstream/_scheduler/job.py b/buildstream/_scheduler/job.py
index 707b78ec0..d4f5238c5 100644
--- a/buildstream/_scheduler/job.py
+++ b/buildstream/_scheduler/job.py
@@ -210,7 +210,7 @@ class Job():
     def message(self, plugin, message_type, message, **kwargs):
         args = dict(kwargs)
         args['scheduler'] = True
-        self.scheduler.context._message(
+        self.scheduler.context.message(
             Message(plugin._get_unique_id(),
                     message_type,
                     message,
@@ -230,7 +230,7 @@ class Job():
         # Set the global message handler in this child
         # process to forward messages to the parent process
         self.queue = queue
-        self.scheduler.context._set_message_handler(self.child_message_handler)
+        self.scheduler.context.set_message_handler(self.child_message_handler)
 
         starttime = datetime.datetime.now()
         stopped_time = None
@@ -378,7 +378,7 @@ class Job():
             message.message_type = MessageType.WARN
 
         # Send to frontend if appropriate
-        if context._silent_messages() and (message.message_type not in unconditional_messages):
+        if context.silent_messages() and (message.message_type not in unconditional_messages):
             return
 
         if message.message_type == MessageType.LOG:
@@ -396,7 +396,7 @@ class Job():
         if envelope.message_type == 'message':
             # Propagate received messages from children
             # back through the context.
-            self.scheduler.context._message(envelope.message)
+            self.scheduler.context.message(envelope.message)
         elif envelope.message_type == 'error':
             # For regression tests only, save the last error domain / reason
             # reported from a child task in the main process, this global state
diff --git a/buildstream/_scheduler/queue.py b/buildstream/_scheduler/queue.py
index f3e0bd7f3..0cea1005f 100644
--- a/buildstream/_scheduler/queue.py
+++ b/buildstream/_scheduler/queue.py
@@ -266,4 +266,4 @@ class Queue():
     def message(self, element, message_type, brief, **kwargs):
         context = element._get_context()
         message = Message(element._get_unique_id(), message_type, brief, **kwargs)
-        context._message(message)
+        context.message(message)
diff --git a/buildstream/element.py b/buildstream/element.py
index 418096c58..b127a0d8e 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -1009,7 +1009,7 @@ class Element(Plugin):
             self.__cache_key_dict = {
                 'artifact-version': "{}.{}".format(_BST_CORE_ARTIFACT_VERSION,
                                                    self.BST_ARTIFACT_VERSION),
-                'context': context._get_cache_key(),
+                'context': context.get_cache_key(),
                 'project': project._get_cache_key(),
                 'element': self.get_unique_key(),
                 'execution-environment': self.__sandbox_config.get_unique_key(),
@@ -1500,7 +1500,7 @@ class Element(Plugin):
             # Fetch the main toplevel project, in case this is a junctioned
             # subproject, we want to use the rules defined by the main one.
             context = self._get_context()
-            project = context._get_toplevel_project()
+            project = context.get_toplevel_project()
 
             if prompt is not None:
                 environment['PS1'] = prompt
@@ -1609,7 +1609,7 @@ class Element(Plugin):
     def _get_strict(self):
         project = self._get_project()
         context = self._get_context()
-        return context._get_strict(project.name)
+        return context.get_strict(project.name)
 
     # _pull_pending()
     #
diff --git a/buildstream/plugin.py b/buildstream/plugin.py
index 28a04600e..c67e177bf 100644
--- a/buildstream/plugin.py
+++ b/buildstream/plugin.py
@@ -439,9 +439,9 @@ class Plugin():
               # This will raise SourceError on its own
               self.call(... command which takes time ...)
         """
-        with self.__context._timed_activity(activity_name,
-                                            detail=detail,
-                                            silent_nested=silent_nested):
+        with self.__context.timed_activity(activity_name,
+                                           detail=detail,
+                                           silent_nested=silent_nested):
             yield
 
     def call(self, *popenargs, fail=None, **kwargs):
@@ -615,7 +615,7 @@ class Plugin():
 
     def __message(self, message_type, brief, **kwargs):
         message = Message(self.__unique_id, message_type, brief, **kwargs)
-        self.__context._message(message)
+        self.__context.message(message)
 
     def __note_command(self, output, *popenargs, **kwargs):
         workdir = os.getcwd()
diff --git a/buildstream/source.py b/buildstream/source.py
index cf362efc2..7de1780fb 100644
--- a/buildstream/source.py
+++ b/buildstream/source.py
@@ -318,7 +318,7 @@ class Source(Plugin):
 
             # Source consistency interrogations are silent.
             context = self._get_context()
-            with context._silence():
+            with context.silence():
                 self.__consistency = self.get_consistency()
 
             if self._has_workspace() and \
@@ -478,7 +478,7 @@ class Source(Plugin):
     def _load_ref(self):
         context = self._get_context()
         project = self._get_project()
-        toplevel = context._get_toplevel_project()
+        toplevel = context.get_toplevel_project()
         redundant_ref = None
 
         element_name = self.__element_name
@@ -536,7 +536,7 @@ class Source(Plugin):
 
         context = self._get_context()
         project = self._get_project()
-        toplevel = context._get_toplevel_project()
+        toplevel = context.get_toplevel_project()
         provenance = self._get_provenance()
 
         element_name = self.__element_name
diff --git a/tests/plugins/pipeline.py b/tests/plugins/pipeline.py
index 805155731..012b48c28 100644
--- a/tests/plugins/pipeline.py
+++ b/tests/plugins/pipeline.py
@@ -21,7 +21,7 @@ def create_pipeline(tmpdir, basedir, target):
     def dummy_handler(message, context):
         pass
 
-    context._set_message_handler(dummy_handler)
+    context.set_message_handler(dummy_handler)
 
     return Pipeline(context, project, [target], [])
 
diff --git a/tests/project/plugins.py b/tests/project/plugins.py
index 8907c7eaf..432983dc5 100644
--- a/tests/project/plugins.py
+++ b/tests/project/plugins.py
@@ -19,7 +19,7 @@ def create_pipeline(tmpdir, basedir, target):
     def dummy_handler(message, context):
         pass
 
-    context._set_message_handler(dummy_handler)
+    context.set_message_handler(dummy_handler)
 
     return Pipeline(context, project, [target], [])
 
diff --git a/tests/variables/variables.py b/tests/variables/variables.py
index 944d19818..233ea5c1f 100644
--- a/tests/variables/variables.py
+++ b/tests/variables/variables.py
@@ -19,7 +19,7 @@ def create_pipeline(tmpdir, basedir, target):
     def dummy_handler(message, context):
         pass
 
-    context._set_message_handler(dummy_handler)
+    context.set_message_handler(dummy_handler)
 
     return Pipeline(context, project, [target], [])