source.py: ensure previous track refs are updatedraoul/1010-multiple-track-fix

Updates the refs in the job process (but doesn't write), to ensure
following sources can see consistency of previous sourcse has been
updated. `_save_ref` is renamed `_set_ref` with writing to file now
optional.

This also changes the previous_source_access test to use a remote, so
that it actually tests this cornercase.

Fixes #1010

1 files changed, 15 insertions, 21 deletions

diff --git a/buildstream/source.py b/buildstream/source.py
index 0c07dd41e..b1346eb1b 100644
--- a/buildstream/source.py
+++ b/buildstream/source.py
@@ -742,24 +742,6 @@ class Source(Plugin):
 
         return key
 
-    # Wrapper for set_ref(), also returns whether it changed.
-    #
-    def _set_ref(self, ref, node):
-        current_ref = self.get_ref()  # pylint: disable=assignment-from-no-return
-        changed = False
-
-        # This comparison should work even for tuples and lists,
-        # but we're mostly concerned about simple strings anyway.
-        if current_ref != ref:
-            changed = True
-
-        # Set the ref regardless of whether it changed, the
-        # TrackQueue() will want to update a specific node with
-        # the ref, regardless of whether the original has changed.
-        self.set_ref(ref, node)
-
-        return changed
-
     # _project_refs():
     #
     # Gets the appropriate ProjectRefs object for this source,
@@ -836,7 +818,7 @@ class Source(Plugin):
 
         return redundant_ref
 
-    # _save_ref()
+    # _set_ref()
     #
     # Persists the ref for this source. This will decide where to save the
     # ref, or refuse to persist it, depending on active ref-storage project
@@ -844,6 +826,7 @@ class Source(Plugin):
     #
     # Args:
     #    new_ref (smth): The new reference to save
+    #    save (bool): Whether to write the new reference to file or not
     #
     # Returns:
     #    (bool): Whether the ref has changed
@@ -851,7 +834,7 @@ class Source(Plugin):
     # Raises:
     #    (SourceError): In the case we encounter errors saving a file to disk
     #
-    def _save_ref(self, new_ref):
+    def _set_ref(self, new_ref, *, save):
 
         context = self._get_context()
         project = self._get_project()
@@ -891,7 +874,15 @@ class Source(Plugin):
         #
         clean = _yaml.node_sanitize(node, dict_type=dict)
         to_modify = _yaml.node_sanitize(node, dict_type=dict)
-        if not self._set_ref(new_ref, to_modify):
+
+        current_ref = self.get_ref()  # pylint: disable=assignment-from-no-return
+
+        # Set the ref regardless of whether it changed, the
+        # TrackQueue() will want to update a specific node with
+        # the ref, regardless of whether the original has changed.
+        self.set_ref(new_ref, to_modify)
+
+        if current_ref == new_ref or not save:
             # Note: We do not look for and propagate changes at this point
             # which might result in desync depending if something changes about
             # tracking in the future.  For now, this is quite safe.
@@ -1008,6 +999,9 @@ class Source(Plugin):
         if current_ref != new_ref:
             self.info("Found new revision: {}".format(new_ref))
 
+            # Save ref in local process for subsequent sources
+            self._set_ref(new_ref, save=False)
+
         return new_ref
 
     # _requires_previous_sources()