element.py: Remove _get_artifact_size()

There is no justification to hold onto this state here.

Instead, just make `Element._assemble()` return the size of the
artifact it cached, and localize handling of that return value in
the BuildQueue implementation where the value is observed.

2 files changed, 16 insertions, 18 deletions

diff --git a/buildstream/_scheduler/jobs/elementjob.py b/buildstream/_scheduler/jobs/elementjob.py
index 36527794e..b3318302a 100644
--- a/buildstream/_scheduler/jobs/elementjob.py
+++ b/buildstream/_scheduler/jobs/elementjob.py
@@ -109,14 +109,11 @@ class ElementJob(Job):
         data = {}
 
         workspace = self._element._get_workspace()
-        artifact_size = self._element._get_artifact_size()
         artifacts = self._element._get_artifact_cache()
         cache_size = artifacts.compute_cache_size()
 
         if workspace is not None:
             data['workspace'] = workspace.to_dict()
-        if artifact_size is not None:
-            data['artifact_size'] = artifact_size
         data['cache_size'] = cache_size
 
         return data
diff --git a/buildstream/_scheduler/queues/buildqueue.py b/buildstream/_scheduler/queues/buildqueue.py
index 6eb919082..8f593fea7 100644
--- a/buildstream/_scheduler/queues/buildqueue.py
+++ b/buildstream/_scheduler/queues/buildqueue.py
@@ -67,8 +67,7 @@ class BuildQueue(Queue):
         return super().enqueue(to_queue)
 
     def process(self, element):
-        element._assemble()
-        return element._get_unique_id()
+        return element._assemble()
 
     def status(self, element):
         # state of dependencies may have changed, recalculate element state
@@ -87,18 +86,20 @@ class BuildQueue(Queue):
 
         return QueueStatus.READY
 
-    def _check_cache_size(self, job, element):
-        if not job.child_data:
-            return
+    def _check_cache_size(self, job, element, artifact_size):
 
-        artifact_size = job.child_data.get('artifact_size', False)
+        # After completing a build job, add the artifact size
+        # as returned from Element._assemble() to the estimated
+        # artifact cache size
+        #
+        cache = element._get_artifact_cache()
+        cache.add_artifact_size(artifact_size)
 
-        if artifact_size:
-            cache = element._get_artifact_cache()
-            cache.add_artifact_size(artifact_size)
-
-            if cache.get_approximate_cache_size() > cache.cache_quota:
-                self._scheduler.check_cache_size()
+        # If the estimated size outgrows the quota, ask the scheduler
+        # to queue a job to actually check the real cache size.
+        #
+        if cache.get_approximate_cache_size() > cache.cache_quota:
+            self._scheduler.check_cache_size()
 
     def done(self, job, element, result, success):
 
@@ -106,8 +107,8 @@ class BuildQueue(Queue):
             # Inform element in main process that assembly is done
             element._assemble_done()
 
-        # This has to be done after _assemble_done, such that the
-        # element may register its cache key as required
-        self._check_cache_size(job, element)
+            # This has to be done after _assemble_done, such that the
+            # element may register its cache key as required
+            self._check_cache_size(job, element, result)
 
         return True