Merge lp:~ian-clatworthy/bzr/faster-branch-in-shared-repo into lp:~bzr/bzr/trunk-old

[Ian Clatworthy]

[Ian Clatworthy (ian-clatworthy)]

This small patch speeds up branch in a shared repo for development6-rich-root format. For OOo, the time drops from 265 seconds to 95 seconds.

[Robert Collins (lifeless)]

 review approve
it would be nice, if possible, to test this.

-Rob

review: Approve

=== modified file 'NEWS'
--- NEWS	2009-05-22 01:44:19 +0000
+++ NEWS	2009-05-22 05:35:15 +0000
@@ -18,6 +18,9 @@
 Improvements
 ************
 
+* ``bzr branch`` in a shared repository is now faster for
+  development6-rich-root format. (Ian Clatworthy)
+
 * ``bzr branch --notree`` is now faster. (Ian Clatworthy)
 
 Bug Fixes
 
=== modified file 'bzrlib/workingtree_4.py'
--- bzrlib/workingtree_4.py	2009-05-05 05:39:41 +0000
+++ bzrlib/workingtree_4.py	2009-05-22 05:35:15 +0000
@@ -1434,6 +1434,14 @@
                 if basis_root_id is not None:
                     wt._set_root_id(basis_root_id)
                     wt.flush()
+                # If content filtering is supported, do not use the accelerator
+                # tree - the cost of transforming the content both ways and
+                # checking for changed content can outweight the gains it gives.
+                # Note: do NOT move this logic up higher - using the basis from
+                # the accelerator tree is still desirable because that can save
+                # a minute or more of processing on large trees!
+                if wt.supports_content_filtering():
+                    accelerator_tree = None
                 # delta_from_tree is safe even for DirStateRevisionTrees,
                 # because wt4.apply_inventory_delta does not mutate the input
                 # inventory entries.