bitbake: lib/bb: Fix string concatination potential performance issues

Python scales badly when concatinating strings in loops. Most of these
references aren't problematic but at least one (in data.py) is probably
a performance issue as the issue is compounded as strings become large.

The way to handle this in python is to create lists which don't reconstruct
all the objects when appending to them. We may as well fix all the references
since it stops them being copy/pasted into something problematic in the future.

This patch was based on issues highligthted by a report from AWS Codeguru.

(Bitbake rev: d654139a833127b16274dca0ccbbab7e3bb33ed0)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 8 insertions, 8 deletions

diff --git a/bitbake/lib/bb/ui/buildinfohelper.py b/bitbake/lib/bb/ui/buildinfohelper.py
index 8588849dd4..835e92c299 100644
--- a/bitbake/lib/bb/ui/buildinfohelper.py
+++ b/bitbake/lib/bb/ui/buildinfohelper.py
@@ -571,7 +571,7 @@ class ORMWrapper(object):
         assert isinstance(build_obj, Build)
         assert isinstance(target_obj, Target)
 
-        errormsg = ""
+        errormsg = []
         for p in packagedict:
             # Search name swtiches round the installed name vs package name
             # by default installed name == package name
@@ -636,7 +636,7 @@ class ORMWrapper(object):
                     if packagefile_objects:
                         Package_File.objects.bulk_create(packagefile_objects)
                 except KeyError as e:
-                    errormsg += "  stpi: Key error, package %s key %s \n" % ( p, e )
+                    errormsg.append("  stpi: Key error, package %s key %s \n" % (p, e))
 
             # save disk installed size
             packagedict[p]['object'].installed_size = packagedict[p]['size']
@@ -678,8 +678,8 @@ class ORMWrapper(object):
         else:
             logger.info("No package dependencies created")
 
-        if len(errormsg) > 0:
-            logger.warning("buildinfohelper: target_package_info could not identify recipes: \n%s", errormsg)
+        if errormsg:
+            logger.warning("buildinfohelper: target_package_info could not identify recipes: \n%s", "".join(errormsg))
 
     def save_target_image_file_information(self, target_obj, file_name, file_size):
         Target_Image_File.objects.create(target=target_obj,
@@ -1404,7 +1404,7 @@ class BuildInfoHelper(object):
         assert 'pn' in event._depgraph
         assert 'tdepends' in event._depgraph
 
-        errormsg = ""
+        errormsg = []
 
         # save layer version priorities
         if 'layer-priorities' in event._depgraph.keys():
@@ -1496,7 +1496,7 @@ class BuildInfoHelper(object):
                 elif dep in self.internal_state['recipes']:
                     dependency = self.internal_state['recipes'][dep]
                 else:
-                    errormsg += "  stpd: KeyError saving recipe dependency for %s, %s \n" % (recipe, dep)
+                    errormsg.append("  stpd: KeyError saving recipe dependency for %s, %s \n" % (recipe, dep))
                     continue
                 recipe_dep = Recipe_Dependency(recipe=target,
                                                depends_on=dependency,
@@ -1537,8 +1537,8 @@ class BuildInfoHelper(object):
                 taskdeps_objects.append(Task_Dependency( task = target, depends_on = dep ))
         Task_Dependency.objects.bulk_create(taskdeps_objects)
 
-        if len(errormsg) > 0:
-            logger.warning("buildinfohelper: dependency info not identify recipes: \n%s", errormsg)
+        if errormsg:
+            logger.warning("buildinfohelper: dependency info not identify recipes: \n%s", "".join(errormsg))
 
 
     def store_build_package_information(self, event):