paycheck: support for in-place BSDIFF operations

When applying BSDIFF operations in payloads, we used to extract the
block sequences from the old partition and serialize it into a temporary
file, and vice versa for the new partition. This worked but did not
allow us to test bspatch as it is actually being used by the update
engine.

This CLs allows paycheck to invoke bspatch so that it reads/writes block
extents directly from/to the partition file, in the same way it's being
used by the update engine. Since performance is the same, this is the
new default behavior; users can opt for the aforementioned old behavior
using a command-line flag (-x or --extract-bsdiff).

BUG=chromium:229705
TEST=bspatch invoked differently depending on the -x flag
TEST=Passes unit/integration tests

Change-Id: I8821754e1163b357617ece6befa42d1c2e575930
Reviewed-on: https://gerrit.chromium.org/gerrit/50486
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Darin Petkov <petkov@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/scripts/update_payload/payload.py b/scripts/update_payload/payload.py
index 34ebaae7..fefc7e4f 100644
--- a/scripts/update_payload/payload.py
+++ b/scripts/update_payload/payload.py
@@ -206,7 +206,7 @@ class Payload(object):
                report_out_file=report_out_file)
 
   def Apply(self, new_kernel_part, new_rootfs_part, old_kernel_part=None,
-            old_rootfs_part=None):
+            old_rootfs_part=None, bsdiff_in_place=True):
     """Applies the update payload.
 
     Args:
@@ -214,6 +214,7 @@ class Payload(object):
       new_rootfs_part: name of dest rootfs partition file
       old_kernel_part: name of source kernel partition file (optional)
       old_rootfs_part: name of source rootfs partition file (optional)
+      bsdiff_in_place: whether to perform BSDIFF operations in-place (optional)
     Raises:
       PayloadError if payload application failed.
 
@@ -221,7 +222,7 @@ class Payload(object):
     self._AssertInit()
 
     # Create a short-lived payload applier object and run it.
-    helper = applier.PayloadApplier(self)
+    helper = applier.PayloadApplier(self, bsdiff_in_place=bsdiff_in_place)
     helper.Run(new_kernel_part, new_rootfs_part,
                old_kernel_part=old_kernel_part,
                old_rootfs_part=old_rootfs_part)