refactoring: Made Project option private

This required adding two new APIs to make up for it on the Source

  o get_project_directory()

    Added here because elements should not be accessing external
    resources, Sources needed for local files and GPG keys and such

  o translate_url()

    Used by sources to mish-mash the project aliases and create
    real urls.

20 files changed, 105 insertions, 91 deletions

diff --git a/buildstream/__init__.py b/buildstream/__init__.py
index bb7a338a4..b3751a6e3 100644
--- a/buildstream/__init__.py
+++ b/buildstream/__init__.py
@@ -20,7 +20,6 @@
 
 # Core components
 from .context import Context
-from .project import Project
 from .sandbox import Sandbox, SandboxFlags
 
 # Plugin auther facing APIs
diff --git a/buildstream/_artifactcache/ostreecache.py b/buildstream/_artifactcache/ostreecache.py
index 431dd565a..e2e623e78 100644
--- a/buildstream/_artifactcache/ostreecache.py
+++ b/buildstream/_artifactcache/ostreecache.py
@@ -35,7 +35,7 @@ from .pushreceive import PushException
 
 
 def buildref(element, key):
-    project = element.get_project()
+    project = element._get_project()
 
     # Normalize ostree ref unsupported chars
     valid_chars = string.digits + string.ascii_letters + '-._'
@@ -180,7 +180,7 @@ class OSTreeCache(ArtifactCache):
         if not rev:
             raise ArtifactError("Artifact missing for {}".format(ref))
 
-        dest = os.path.join(self.extractdir, element.get_project().name, element.normal_name, rev)
+        dest = os.path.join(self.extractdir, element._get_project().name, element.normal_name, rev)
         if os.path.isdir(dest):
             # artifact has already been extracted
             return dest
diff --git a/buildstream/_artifactcache/tarcache.py b/buildstream/_artifactcache/tarcache.py
index 3d4c925f0..90821874e 100644
--- a/buildstream/_artifactcache/tarcache.py
+++ b/buildstream/_artifactcache/tarcache.py
@@ -32,7 +32,7 @@ from . import ArtifactCache
 
 
 def buildref(element, key):
-    project = element.get_project()
+    project = element._get_project()
 
     # Normalize ostree ref unsupported chars
     element_name = element.normal_name.replace('+', 'X')
@@ -42,7 +42,7 @@ def buildref(element, key):
 
 
 def tarpath(element, key):
-    project = element.get_project()
+    project = element._get_project()
     return os.path.join(project.name, element.normal_name, key + '.tar.bz2')
 
 
@@ -283,7 +283,7 @@ class TarCache(ArtifactCache):
         ref = tarpath(element, element._get_cache_key_for_build())
         weak_ref = tarpath(element, element._get_cache_key(strength=_KeyStrength.WEAK))
 
-        os.makedirs(os.path.join(self.tardir, element.get_project().name, element.normal_name), exist_ok=True)
+        os.makedirs(os.path.join(self.tardir, element._get_project().name, element.normal_name), exist_ok=True)
 
         with utils._tempdir() as temp:
             refdir = os.path.join(temp, element._get_cache_key_for_build())
@@ -330,7 +330,7 @@ class TarCache(ArtifactCache):
         with utils._tempdir(dir=self.extractdir) as tmpdir:
             Tar.extract(os.path.join(self.tardir, path), tmpdir)
 
-            os.makedirs(os.path.join(self.extractdir, element.get_project().name, element.normal_name),
+            os.makedirs(os.path.join(self.extractdir, element._get_project().name, element.normal_name),
                         exist_ok=True)
             try:
                 os.rename(os.path.join(tmpdir, key), dest)
diff --git a/buildstream/_frontend/main.py b/buildstream/_frontend/main.py
index 33e900d5c..3ac6b5222 100644
--- a/buildstream/_frontend/main.py
+++ b/buildstream/_frontend/main.py
@@ -25,9 +25,10 @@ from contextlib import contextmanager
 from blessings import Terminal
 
 # Import buildstream public symbols
-from .. import Context, Project, Scope, Consistency
+from .. import Context, Scope, Consistency
 
 # Import various buildstream internals
+from .._project import Project
 from .._exceptions import BstError, LoadError
 from .._message import MessageType, unconditional_messages
 from .._pipeline import Pipeline, PipelineError
diff --git a/buildstream/project.py b/buildstream/_project.py
index d83159711..46f271f5b 100644
--- a/buildstream/project.py
+++ b/buildstream/_project.py
@@ -18,15 +18,6 @@
 #  Authors:
 #        Tristan Van Berkom <tristan.vanberkom@codethink.co.uk>
 
-"""
-Project
-=======
-
-The :class:`.Project` object holds all of the project settings from
-the project configuration file including the project directory it
-was loaded from.
-"""
-
 import os
 import multiprocessing  # for cpu_count()
 from collections import Mapping
@@ -37,42 +28,43 @@ from ._profile import Topics, profile_start, profile_end
 from ._exceptions import LoadError, LoadErrorReason
 from ._options import OptionPool
 
-BST_FORMAT_VERSION = 0
-"""The base BuildStream format version
 
-This version is bumped whenever enhancements are made
-to the ``project.conf`` format or the format in general.
-"""
+# The base BuildStream format version
+#
+# This version is bumped whenever enhancements are made
+# to the ``project.conf`` format or the format in general.
+#
+BST_FORMAT_VERSION = 0
 
+# The base BuildStream artifact version
+#
+# The artifact version changes whenever the cache key
+# calculation algorithm changes in an incompatible way
+# or if buildstream was changed in a way which can cause
+# the same cache key to produce something that is no longer
+# the same.
 BST_ARTIFACT_VERSION = 0
-"""The base BuildStream artifact version
-
-The artifact version changes whenever the cache key
-calculation algorithm changes in an incompatible way
-or if buildstream was changed in a way which can cause
-the same cache key to produce something that is no longer
-the same.
-"""
 
 # The separator we use for user specified aliases
 _ALIAS_SEPARATOR = ':'
 
 
+# Project()
+#
+# The Project Configuration
+#
 class Project():
-    """Project()
 
-    The Project Configuration
-    """
     def __init__(self, directory, context):
 
+        # The project name
         self.name = None
-        """str: The project name"""
 
+        # The project directory
         self.directory = os.path.abspath(directory)
-        """str: The project directory"""
 
+        # Absolute path to where elements are loaded from within the project
         self.element_path = None
-        """str: Absolute path to where elements are loaded from within the project"""
 
         self._context = context  # The invocation Context
         self._variables = {}     # The default variables overridden with project wide overrides
@@ -91,20 +83,21 @@ class Project():
         self._load()
         profile_end(Topics.LOAD_PROJECT, self.directory.replace(os.sep, '-'))
 
+    # translate_url():
+    #
+    # Translates the given url which may be specified with an alias
+    # into a fully qualified url.
+    #
+    # Args:
+    #    url (str): A url, which may be using an alias
+    #
+    # Returns:
+    #    str: The fully qualified url, with aliases resolved
+    #
+    # This method is provided for :class:`.Source` objects to resolve
+    # fully qualified urls based on the shorthand which is allowed
+    # to be specified in the YAML
     def translate_url(self, url):
-        """Translates the given url which may be specified with an alias
-        into a fully qualified url.
-
-        Args:
-           url (str): A url, which may be using an alias
-
-        Returns:
-           str: The fully qualified url, with aliases resolved
-
-        This method is provided for :class:`.Source` objects to resolve
-        fully qualified urls based on the shorthand which is allowed
-        to be specified in the YAML
-        """
         if url and _ALIAS_SEPARATOR in url:
             url_alias, url_body = url.split(_ALIAS_SEPARATOR, 1)
             alias_url = self._aliases.get(url_alias)
diff --git a/buildstream/_scheduler/trackqueue.py b/buildstream/_scheduler/trackqueue.py
index e45fb2db2..3159a3adc 100644
--- a/buildstream/_scheduler/trackqueue.py
+++ b/buildstream/_scheduler/trackqueue.py
@@ -62,7 +62,7 @@ class TrackQueue(Queue):
             if source._set_ref(new_ref, source._Source__origin_node):
 
                 changed = True
-                project = source.get_project()
+                project = source._get_project()
                 toplevel = source._Source__origin_toplevel
                 filename = source._Source__origin_filename
                 fullname = os.path.join(project.element_path, filename)
diff --git a/buildstream/element.py b/buildstream/element.py
index 6c55026ee..86dd2b8dc 100644
--- a/buildstream/element.py
+++ b/buildstream/element.py
@@ -39,7 +39,7 @@ from . import _yaml
 from ._variables import Variables
 from ._exceptions import BstError, LoadError, LoadErrorReason, ImplError
 from . import Plugin, Consistency
-from .project import BST_ARTIFACT_VERSION as BST_CORE_ARTIFACT_VERSION
+from ._project import BST_ARTIFACT_VERSION as BST_CORE_ARTIFACT_VERSION
 from . import SandboxFlags
 from . import utils
 from . import _signals
@@ -856,7 +856,7 @@ class Element(Plugin):
         }
 
         context = self.get_context()
-        project = self.get_project()
+        project = self._get_project()
         return utils._generate_key({
             'artifact-version': "{}.{}".format(BST_CORE_ARTIFACT_VERSION,
                                                self.BST_ARTIFACT_VERSION),
@@ -1202,7 +1202,7 @@ class Element(Plugin):
     # This matches the order in which things are stored in the artifact cache
     #
     def _logfile(self, action_name, pid=None):
-        project = self.get_project()
+        project = self._get_project()
         context = self.get_context()
         key = self._get_display_key()
         if pid is None:
@@ -1411,7 +1411,7 @@ class Element(Plugin):
     #   (bool): Whether the build plan is strict for this element
     #
     def _get_strict(self):
-        project = self.get_project()
+        project = self._get_project()
         context = self.get_context()
         return context._get_strict(project.name)
 
@@ -1421,7 +1421,7 @@ class Element(Plugin):
     @contextmanager
     def __sandbox(self, directory, stdout=None, stderr=None):
         context = self.get_context()
-        project = self.get_project()
+        project = self._get_project()
         platform = Platform.get_platform()
 
         if directory is not None and os.path.exists(directory):
@@ -1443,7 +1443,7 @@ class Element(Plugin):
             utils._force_rmtree(rootdir)
 
     def __compose_default_splits(self, defaults):
-        project = self.get_project()
+        project = self._get_project()
         project_splits = _yaml.node_chain_copy(project._splits)
 
         element_public = _yaml.node_get(defaults, Mapping, 'public', default_value={})
@@ -1476,7 +1476,7 @@ class Element(Plugin):
 
             # Override the element's defaults with element specific
             # overrides from the project.conf
-            project = self.get_project()
+            project = self._get_project()
             elements = project._elements
             overrides = elements.get(self.get_kind())
             if overrides:
@@ -1490,7 +1490,7 @@ class Element(Plugin):
     # creating sandboxes for this element
     #
     def __extract_environment(self, meta):
-        project = self.get_project()
+        project = self._get_project()
         default_env = _yaml.node_get(self.__defaults, Mapping, 'environment', default_value={})
 
         environment = _yaml.node_chain_copy(project._environment)
@@ -1506,7 +1506,7 @@ class Element(Plugin):
         return final_env
 
     def __extract_env_nocache(self, meta):
-        project = self.get_project()
+        project = self._get_project()
         project_nocache = project._env_nocache
         default_nocache = _yaml.node_get(self.__defaults, list, 'environment-nocache', default_value=[])
         element_nocache = meta.env_nocache
@@ -1522,7 +1522,7 @@ class Element(Plugin):
     # substituting command strings to be run in the sandbox
     #
     def __extract_variables(self, meta):
-        project = self.get_project()
+        project = self._get_project()
         default_vars = _yaml.node_get(self.__defaults, Mapping, 'variables', default_value={})
 
         variables = _yaml.node_chain_copy(project._variables)
diff --git a/buildstream/plugin.py b/buildstream/plugin.py
index abbed7dca..56bee90c1 100644
--- a/buildstream/plugin.py
+++ b/buildstream/plugin.py
@@ -184,14 +184,6 @@ class Plugin():
         """
         return self.__context
 
-    def get_project(self):
-        """Fetches the project
-
-        Returns:
-           (object): The :class:`.Project`
-        """
-        return self.__project
-
     def node_items(self, node):
         """Iterate over a dictionary loaded from YAML
 
@@ -570,6 +562,13 @@ class Plugin():
     #            Private Methods used in BuildStream            #
     #############################################################
 
+    # _get_project()
+    #
+    # Fetches the project object associated with this plugin
+    #
+    def _get_project(self):
+        return self.__project
+
     # _get_unique_id():
     #
     # Fetch the plugin's unique identifier
diff --git a/buildstream/plugins/sources/_downloadablefilesource.py b/buildstream/plugins/sources/_downloadablefilesource.py
index 90d3709c2..a2ed366ad 100644
--- a/buildstream/plugins/sources/_downloadablefilesource.py
+++ b/buildstream/plugins/sources/_downloadablefilesource.py
@@ -13,11 +13,9 @@ class DownloadableFileSource(Source):
     COMMON_CONFIG_KEYS = Source.COMMON_CONFIG_KEYS + ['url', 'ref']
 
     def configure(self, node):
-        project = self.get_project()
-
         self.original_url = self.node_get_member(node, str, 'url')
         self.ref = self.node_get_member(node, str, 'ref', '') or None
-        self.url = project.translate_url(self.original_url)
+        self.url = self.translate_url(self.original_url)
 
     def preflight(self):
         return
diff --git a/buildstream/plugins/sources/bzr.py b/buildstream/plugins/sources/bzr.py
index 82ac711e7..679a3436c 100644
--- a/buildstream/plugins/sources/bzr.py
+++ b/buildstream/plugins/sources/bzr.py
@@ -63,7 +63,7 @@ class BzrSource(Source):
         self.original_url = self.node_get_member(node, str, 'url')
         self.tracking = self.node_get_member(node, str, 'track')
         self.ref = self.node_get_member(node, str, 'ref', '') or None
-        self.url = self.get_project().translate_url(self.original_url)
+        self.url = self.translate_url(self.original_url)
 
     def preflight(self):
         # Check if bzr is installed, get the binary at the same time.
diff --git a/buildstream/plugins/sources/git.py b/buildstream/plugins/sources/git.py
index b3e22494a..afbca252c 100644
--- a/buildstream/plugins/sources/git.py
+++ b/buildstream/plugins/sources/git.py
@@ -78,10 +78,9 @@ class GitMirror():
 
     def __init__(self, source, path, url, ref):
 
-        project = source.get_project()
         self.source = source
         self.path = path
-        self.url = project.translate_url(url)
+        self.url = source.translate_url(url)
         self.ref = ref
         self.mirror = os.path.join(source.get_mirror_directory(), utils.url_directory_name(self.url))
 
diff --git a/buildstream/plugins/sources/local.py b/buildstream/plugins/sources/local.py
index 9f02b0ed4..02486dffb 100644
--- a/buildstream/plugins/sources/local.py
+++ b/buildstream/plugins/sources/local.py
@@ -42,12 +42,10 @@ from buildstream import utils
 class LocalSource(Source):
 
     def configure(self, node):
-        project = self.get_project()
-
         self.node_validate(node, ['path'] + Source.COMMON_CONFIG_KEYS)
 
         self.path = self.node_get_member(node, str, 'path')
-        self.fullpath = os.path.join(project.directory, self.path)
+        self.fullpath = os.path.join(self.get_project_directory(), self.path)
 
     def preflight(self):
         # Check if the configured file or directory really exists
diff --git a/buildstream/plugins/sources/ostree.py b/buildstream/plugins/sources/ostree.py
index 1875384e6..6f2562fc0 100644
--- a/buildstream/plugins/sources/ostree.py
+++ b/buildstream/plugins/sources/ostree.py
@@ -61,12 +61,11 @@ from buildstream._ostree import OSTreeError
 class OSTreeSource(Source):
 
     def configure(self, node):
-        project = self.get_project()
 
         self.node_validate(node, ['url', 'ref', 'track', 'gpg-key'] + Source.COMMON_CONFIG_KEYS)
 
         self.original_url = self.node_get_member(node, str, 'url')
-        self.url = project.translate_url(self.original_url)
+        self.url = self.translate_url(self.original_url)
         self.ref = self.node_get_member(node, str, 'ref', '') or None
         self.tracking = self.node_get_member(node, str, 'track', '') or None
         self.mirror = os.path.join(self.get_mirror_directory(),
@@ -76,7 +75,7 @@ class OSTreeSource(Source):
         self.gpg_key = self.node_get_member(node, str, 'gpg-key', '') or None
         self.gpg_key_path = None
         if self.gpg_key is not None:
-            self.gpg_key_path = os.path.join(project.directory, self.gpg_key)
+            self.gpg_key_path = os.path.join(self.get_project_directory(), self.gpg_key)
 
         # Our OSTree repo handle
         self.repo = None
diff --git a/buildstream/plugins/sources/patch.py b/buildstream/plugins/sources/patch.py
index ab527ec69..9da6ade40 100644
--- a/buildstream/plugins/sources/patch.py
+++ b/buildstream/plugins/sources/patch.py
@@ -46,11 +46,9 @@ from buildstream import utils
 class PatchSource(Source):
 
     def configure(self, node):
-        project = self.get_project()
-
         self.path = self.node_get_member(node, str, "path")
         self.strip_level = self.node_get_member(node, int, "strip-level", 1)
-        self.fullpath = os.path.join(project.directory, self.path)
+        self.fullpath = os.path.join(self.get_project_directory(), self.path)
 
     def preflight(self):
         # Check if the configured file really exists
diff --git a/buildstream/source.py b/buildstream/source.py
index 629d41a6b..ed9ff3aaa 100644
--- a/buildstream/source.py
+++ b/buildstream/source.py
@@ -104,6 +104,31 @@ class Source(Plugin):
         os.makedirs(directory, exist_ok=True)
         return directory
 
+    def translate_url(self, url):
+        """Translates the given url which may be specified with an alias
+        into a fully qualified url.
+
+        Args:
+           url (str): A url, which may be using an alias
+
+        Returns:
+           str: The fully qualified url, with aliases resolved
+        """
+        project = self._get_project()
+        return project.translate_url(url)
+
+    def get_project_directory(self):
+        """Fetch the project base directory
+
+        This is useful for sources which need to load resources
+        stored somewhere inside the project.
+
+        Returns:
+           str: The project base directory
+        """
+        project = self._get_project()
+        return project.directory
+
     @contextmanager
     def tempdir(self):
         """Context manager for working in a temporary directory
@@ -220,7 +245,7 @@ class Source(Plugin):
                 # A workspace is considered inconsistent in the case
                 # that it's directory went missing
                 #
-                fullpath = os.path.join(self.get_project().directory, self.__workspace)
+                fullpath = os.path.join(self.get_project_directory(), self.__workspace)
                 if not os.path.exists(fullpath):
                     self.__consistency = Consistency.INCONSISTENT
 
@@ -331,7 +356,7 @@ class Source(Plugin):
     # Stage the workspace
     #
     def _stage_workspace(self, directory):
-        fullpath = os.path.join(self.get_project().directory, self.__workspace)
+        fullpath = os.path.join(self.get_project_directory(), self.__workspace)
 
         with self.timed_activity("Staging local files at {}".format(self.__workspace)):
             if os.path.isdir(fullpath):
@@ -342,7 +367,7 @@ class Source(Plugin):
 
     # Get a unique key for the workspace
     def _get_workspace_key(self):
-        fullpath = os.path.join(self.get_project().directory, self.__workspace)
+        fullpath = os.path.join(self.get_project_directory(), self.__workspace)
 
         # Get a list of tuples of the the project relative paths and fullpaths
         if os.path.isdir(fullpath):
diff --git a/tests/pipeline/load.py b/tests/pipeline/load.py
index 1d5319c45..a0b6d7ae3 100644
--- a/tests/pipeline/load.py
+++ b/tests/pipeline/load.py
@@ -1,7 +1,8 @@
 import os
 import pytest
 
-from buildstream import Context, Project, Scope
+from buildstream import Context, Scope
+from buildstream._project import Project
 from buildstream._pipeline import Pipeline
 from buildstream._platform import Platform
 
diff --git a/tests/plugins/pipeline.py b/tests/plugins/pipeline.py
index f5c9a0c8f..6fac82b89 100644
--- a/tests/plugins/pipeline.py
+++ b/tests/plugins/pipeline.py
@@ -1,7 +1,8 @@
 import os
 import pytest
 
-from buildstream import Context, Project, Scope
+from buildstream import Context, Scope
+from buildstream._project import Project
 from buildstream._exceptions import PluginError
 from buildstream._pipeline import Pipeline
 from buildstream._platform import Platform
diff --git a/tests/project/plugins.py b/tests/project/plugins.py
index 785b42418..424548082 100644
--- a/tests/project/plugins.py
+++ b/tests/project/plugins.py
@@ -1,7 +1,8 @@
 import os
 import pytest
 
-from buildstream import Context, Project, Scope
+from buildstream import Context, Scope
+from buildstream._project import Project
 from buildstream._pipeline import Pipeline
 from buildstream._platform import Platform
 
diff --git a/tests/project/project.py b/tests/project/project.py
index 430e15b11..32a264c6d 100644
--- a/tests/project/project.py
+++ b/tests/project/project.py
@@ -1,7 +1,8 @@
 import os
 import pytest
 
-from buildstream import Project, Context
+from buildstream import Context
+from buildstream._project import Project
 from buildstream._exceptions import LoadError, LoadErrorReason
 
 DATA_DIR = os.path.join(
diff --git a/tests/variables/variables.py b/tests/variables/variables.py
index 8f9fd2750..51af7e27b 100644
--- a/tests/variables/variables.py
+++ b/tests/variables/variables.py
@@ -1,7 +1,8 @@
 import os
 import pytest
 
-from buildstream import Context, Project, BuildElement
+from buildstream import Context, BuildElement
+from buildstream._project import Project
 from buildstream._pipeline import Pipeline
 from buildstream._platform import Platform