Queue: Make queues store counts of the number of skipped/processed elements

We only seen to generate the list so we can get its length, so it is
more efficient to only store a count of skipped/processed elements.

failed_elements needs to remain a list for the moment, as it's used to
retry a failed element job.

3 files changed, 15 insertions, 15 deletions

diff --git a/src/buildstream/_frontend/status.py b/src/buildstream/_frontend/status.py
index 91f47221a..8a3de75f3 100644
--- a/src/buildstream/_frontend/status.py
+++ b/src/buildstream/_frontend/status.py
@@ -429,8 +429,8 @@ class _StatusHeader():
     #                 Private Methods                 #
     ###################################################
     def _render_queue(self, queue):
-        processed = str(len(queue.processed_elements))
-        skipped = str(len(queue.skipped_elements))
+        processed = str(queue.processed_elements_count)
+        skipped = str(queue.skipped_elements_count)
         failed = str(len(queue.failed_elements))
 
         size = 5  # Space for the formatting '[', ':', ' ', ' ' and ']'
diff --git a/src/buildstream/_frontend/widget.py b/src/buildstream/_frontend/widget.py
index dce63e14f..20ea80d0f 100644
--- a/src/buildstream/_frontend/widget.py
+++ b/src/buildstream/_frontend/widget.py
@@ -583,13 +583,13 @@ class LogLine(Widget):
         skipped_maxlen = 1
         failed_maxlen = 1
         for queue in stream.queues:
-            processed_maxlen = max(len(str(len(queue.processed_elements))), processed_maxlen)
-            skipped_maxlen = max(len(str(len(queue.skipped_elements))), skipped_maxlen)
+            processed_maxlen = max(len(str(queue.processed_elements_count)), processed_maxlen)
+            skipped_maxlen = max(len(str(queue.skipped_elements_count)), skipped_maxlen)
             failed_maxlen = max(len(str(len(queue.failed_elements))), failed_maxlen)
 
         for queue in stream.queues:
-            processed = str(len(queue.processed_elements))
-            skipped = str(len(queue.skipped_elements))
+            processed = str(queue.processed_elements_count)
+            skipped = str(queue.skipped_elements_count)
             failed = str(len(queue.failed_elements))
 
             processed_align = ' ' * (processed_maxlen - len(processed))
diff --git a/src/buildstream/_scheduler/queues/queue.py b/src/buildstream/_scheduler/queues/queue.py
index 49a5381c1..adc1cd467 100644
--- a/src/buildstream/_scheduler/queues/queue.py
+++ b/src/buildstream/_scheduler/queues/queue.py
@@ -65,9 +65,9 @@ class Queue():
         #
         # Public members
         #
-        self.failed_elements = []      # List of failed elements, for the frontend
-        self.processed_elements = []   # List of processed elements, for the frontend
-        self.skipped_elements = []     # List of skipped elements, for the frontend
+        self.failed_elements = []           # List of failed elements, for the frontend
+        self.processed_elements_count = 0   # Number of processed elements, for the frontend
+        self.skipped_elements_count = 0     # Number of skipped elements, for the frontend
 
         #
         # Private members
@@ -320,10 +320,10 @@ class Queue():
             self._done_queue.append(element)
 
             # These lists are for bookkeeping purposes for the UI and logging.
-            if status is JobStatus.SKIPPED or job.get_terminated():
-                self.skipped_elements.append(element)
-            elif status is JobStatus.OK:
-                self.processed_elements.append(element)
+            if status == JobStatus.SKIPPED or job.get_terminated():
+                self.skipped_elements_count += 1
+            elif status == JobStatus.OK:
+                self.processed_elements_count += 1
             else:
                 self.failed_elements.append(element)
 
@@ -357,8 +357,8 @@ class Queue():
         status = self.status(element)
         if status == QueueStatus.SKIP:
             # Place skipped elements into the done queue immediately
-            self.skipped_elements.append(element)       # Public record of skipped elements
-            self._done_queue.append(element)            # Elements to proceed to the next queue
+            self.skipped_elements_count += 1   # Public record of skipped elements
+            self._done_queue.append(element)   # Elements to proceed to the next queue
         elif status == QueueStatus.READY:
             # Push elements which are ready to be processed immediately into the queue
             heapq.heappush(self._ready_queue, (element._depth, element))