data.py: Split expandKeys into two for loops to benefit from the expand_cache (12% speedup)

2 files changed, 8 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 37f5017ac..a1da18db4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -30,7 +30,7 @@ Changes in Bitbake 1.8.x:
  	  error message.
 	- Rework add_task to be more efficient (6% speedup, 7% number of function calls reduction)
 	- Sort digraph output to make builds more reproducible
-       
+	- Split expandKeys into two for loops to benefit from the expand_cache (12% speedup)
 
 Changes in Bitbake 1.8.6:
 	- Correctly redirect stdin when forking
diff --git a/lib/bb/data.py b/lib/bb/data.py
index 21cdde04a..7ad1acad1 100644
--- a/lib/bb/data.py
+++ b/lib/bb/data.py
@@ -282,6 +282,7 @@ def expandKeys(alterdata, readdata = None):
     if readdata == None:
         readdata = alterdata
 
+    todolist = {}
     for key in keys(alterdata):
         if not '${' in key:
             continue
@@ -289,7 +290,13 @@ def expandKeys(alterdata, readdata = None):
         ekey = expand(key, readdata)
         if key == ekey:
             continue
+        todolist[key] = ekey
 
+    # These two for loops are split for performance to maximise the 
+    # usefulness of the expand cache
+
+    for key in todolist:
+        ekey = todolist[key]
         renameVar(key, ekey, alterdata)
 
 def expandData(alterdata, readdata = None):