element.py: Remove _get_consistency and introduce explicit methods

This replaces the _get_consistency method by two methods:

`_has_all_sources_resolved` and `_has_all_sources_cached` which allows
a more fine grained control on what information is needed.

5 files changed, 33 insertions, 30 deletions

diff --git a/src/buildstream/_frontend/widget.py b/src/buildstream/_frontend/widget.py
index 44922cac8..fcc951d00 100644
--- a/src/buildstream/_frontend/widget.py
+++ b/src/buildstream/_frontend/widget.py
@@ -27,7 +27,7 @@ from ruamel import yaml
 import click
 
 from .profile import Profile
-from .. import Consistency, Scope
+from .. import Scope
 from .. import __version__ as bst_version
 from .._exceptions import ImplError
 from .._message import MessageType
@@ -346,8 +346,7 @@ class LogLine(Widget):
             line = p.fmt_subst(line, "key", cache_key, fg="yellow", dim=dim_keys)
             line = p.fmt_subst(line, "full-key", full_key, fg="yellow", dim=dim_keys)
 
-            consistency = element._get_consistency()
-            if consistency == Consistency.INCONSISTENT:
+            if not element._has_all_sources_resolved():
                 line = p.fmt_subst(line, "state", "no reference", fg="red")
             else:
                 if element.get_kind() == "junction":
@@ -356,7 +355,7 @@ class LogLine(Widget):
                     line = p.fmt_subst(line, "state", "failed", fg="red")
                 elif element._cached_success():
                     line = p.fmt_subst(line, "state", "cached", fg="magenta")
-                elif consistency == Consistency.RESOLVED and not element._has_all_sources_in_source_cache():
+                elif not element._has_all_sources_in_source_cache() and not element._has_all_sources_cached():
                     line = p.fmt_subst(line, "state", "fetch needed", fg="red")
                 elif element._buildable():
                     line = p.fmt_subst(line, "state", "buildable", fg="green")
diff --git a/src/buildstream/_loader/loader.py b/src/buildstream/_loader/loader.py
index 05c139bb2..531655c09 100644
--- a/src/buildstream/_loader/loader.py
+++ b/src/buildstream/_loader/loader.py
@@ -20,7 +20,6 @@
 import os
 
 from .._exceptions import LoadError, LoadErrorReason
-from .. import Consistency
 from .. import _yaml
 from ..element import Element
 from ..node import Node
@@ -651,16 +650,9 @@ class Loader:
             self._loaders[filename] = loader
             return loader
 
-        # Handle the case where a subproject needs to be fetched
-        #
-        if element._get_consistency() >= Consistency.RESOLVED and not element._has_all_sources_in_source_cache():
-            if ticker:
-                ticker(filename, "Fetching subproject")
-            self._fetch_subprojects([element])
-
         # Handle the case where a subproject has no ref
         #
-        elif element._get_consistency() == Consistency.INCONSISTENT:
+        if not element._has_all_sources_resolved():
             detail = "Try tracking the junction element with `bst source track {}`".format(filename)
             raise LoadError(
                 "{}Subproject has no ref for junction: {}".format(provenance_str, filename),
@@ -668,6 +660,13 @@ class Loader:
                 detail=detail,
             )
 
+        # Handle the case where a subproject needs to be fetched
+        #
+        if not element._has_all_sources_in_source_cache():
+            if ticker:
+                ticker(filename, "Fetching subproject")
+            self._fetch_subprojects([element])
+
         sources = list(element.sources())
         if len(sources) == 1 and sources[0]._get_local_path():
             # Optimization for junctions with a single local source
diff --git a/src/buildstream/_pipeline.py b/src/buildstream/_pipeline.py
index 8d0a3b411..1a98fccf5 100644
--- a/src/buildstream/_pipeline.py
+++ b/src/buildstream/_pipeline.py
@@ -29,7 +29,7 @@ from pyroaring import BitMap  # pylint: disable=no-name-in-module
 from ._exceptions import PipelineError
 from ._message import Message, MessageType
 from ._profile import Topics, PROFILER
-from . import Scope, Consistency
+from . import Scope
 from ._project import ProjectRefStorage
 from .types import _PipelineSelection
 
@@ -340,7 +340,7 @@ class Pipeline:
         inconsistent_workspaced = []
         with self._context.messenger.timed_activity("Checking sources"):
             for element in elements:
-                if element._get_consistency() == Consistency.INCONSISTENT:
+                if not element._has_all_sources_resolved():
                     if element._get_workspace():
                         inconsistent_workspaced.append(element)
                     else:
@@ -375,7 +375,7 @@ class Pipeline:
         uncached = []
         with self._context.messenger.timed_activity("Checking sources"):
             for element in elements:
-                if element._get_consistency() < Consistency.CACHED and not element._has_all_sources_in_source_cache():
+                if not element._has_all_sources_in_source_cache() and not element._has_all_sources_cached():
                     uncached.append(element)
 
         if uncached:
diff --git a/src/buildstream/_scheduler/queues/fetchqueue.py b/src/buildstream/_scheduler/queues/fetchqueue.py
index 77c8b8c9c..8123b7611 100644
--- a/src/buildstream/_scheduler/queues/fetchqueue.py
+++ b/src/buildstream/_scheduler/queues/fetchqueue.py
@@ -18,9 +18,6 @@
 #        Tristan Van Berkom <tristan.vanberkom@codethink.co.uk>
 #        Jürg Billeter <juerg.billeter@codethink.co.uk>
 
-# BuildStream toplevel imports
-from ... import Consistency
-
 # Local imports
 from . import Queue, QueueStatus
 from ..resources import ResourceType
@@ -73,7 +70,7 @@ class FetchQueue(Queue):
 
         # Successful fetch, we must be CACHED or in the sourcecache
         if self._should_fetch_original:
-            assert element._get_consistency() == Consistency.CACHED
+            assert element._has_all_sources_cached()
         else:
             assert element._has_all_sources_in_source_cache()
 
diff --git a/src/buildstream/element.py b/src/buildstream/element.py
index 057b229e8..da62c9bb0 100644
--- a/src/buildstream/element.py
+++ b/src/buildstream/element.py
@@ -1072,13 +1072,6 @@ class Element(Plugin):
         cls.__instantiated_elements = {}
         cls.__redundant_source_refs = []
 
-    # _get_consistency()
-    #
-    # Returns cached consistency state
-    #
-    def _get_consistency(self):
-        return self.__consistency
-
     # _cached():
     #
     # Returns:
@@ -1169,7 +1162,7 @@ class Element(Plugin):
     #    (bool): Whether this element can currently be built
     #
     def _buildable(self):
-        if self._get_consistency() < Consistency.CACHED and not self._has_all_sources_in_source_cache():
+        if not (self._has_all_sources_in_source_cache() or self._has_all_sources_cached()):
             return False
 
         if not self.__assemble_scheduled:
@@ -2178,13 +2171,28 @@ class Element(Plugin):
         self.__has_all_sources_in_source_cache = True
         return True
 
+    # _has_all_sources_resolved()
+    #
+    # Get whether all sources of the element are resolved
+    #
+    def _has_all_sources_resolved(self):
+        return self.__consistency >= Consistency.RESOLVED
+
+    # _has_all_sources_cached()
+    #
+    # Get whether all the sources of the element have their own cached
+    # copy of their sources.
+    #
+    def _has_all_sources_cached(self):
+        return self.__consistency >= Consistency.CACHED
+
     def _should_fetch(self, fetch_original=False):
         """ return bool of if we need to run the fetch stage for this element
 
         Args:
             fetch_original (bool): whether we need to original unstaged source
         """
-        if (self._get_consistency() == Consistency.CACHED and fetch_original) or (
+        if (self._has_all_sources_cached() and fetch_original) or (
             self._has_all_sources_in_source_cache() and not fetch_original
         ):
             return False
@@ -3018,7 +3026,7 @@ class Element(Plugin):
     # dependency has changed.
     #
     def __update_cache_keys(self):
-        if self._get_consistency() == Consistency.INCONSISTENT:
+        if not self._has_all_sources_resolved():
             # Tracking may still be pending
             return