timeline: make log level calculation a lot faster

This is the step where the timeline graph gets colored with the individual log
level colors. It's roughly 4.5 times faster now. Probably can be made even
better, the code also needs a cleanup.

1 files changed, 14 insertions, 2 deletions

diff --git a/GstDebugViewer/Plugins/Timeline.py b/GstDebugViewer/Plugins/Timeline.py
index 5eec14e..65a7aed 100644
--- a/GstDebugViewer/Plugins/Timeline.py
+++ b/GstDebugViewer/Plugins/Timeline.py
@@ -171,13 +171,26 @@ class LevelDistributionSentinel (object):
         if not partitions:
             return
 
+        level_index = 0
+        level_iter = None
+
         finished = False
         while tree_iter:
             y -= 1
             if y == 0:
                 y = YIELD_LIMIT
                 yield True
-            level = model_get (tree_iter, id_level)
+            if level_iter is None:
+                stop_index = level_index + 512
+                levels = self.model.get_value_range (id_level,
+                                                     level_index, stop_index)
+                level_index = stop_index
+                level_iter = iter (levels)
+            try:
+                level = level_iter.next ()
+            except StopIteration:
+                level_iter = None
+                continue
             while i > partitions[partitions_i]:
                 data.append (tuple (counts))
                 counts = [0] * MAX_LEVELS
@@ -189,7 +202,6 @@ class LevelDistributionSentinel (object):
                 break
             counts[level] += 1
             i += 1
-            tree_iter = model_next (tree_iter)
 
         # Now handle the last one:
         data.append (tuple (counts))