update_engine: Generate PUFFDIFF operation

This patch adds functionality for generating PUFFDIFF operation, but
since the minor verion has not been increase, it actually does not
generate the operation itself. PUFFDIFF is used for patching deflate
based files.

BUG=chromium:767120
TEST=unittest passes; brillo_update_payload {generate|verify} passes;
CQ-DEPEND=CL:726945

Change-Id: I4ffdac8dce3740ef9fc2156cb0dad83a8364c8b5
Reviewed-on: https://chromium-review.googlesource.com/658298
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/payload_generator/filesystem_interface.h b/payload_generator/filesystem_interface.h
index 866c46bb..b1506e44 100644
--- a/payload_generator/filesystem_interface.h
+++ b/payload_generator/filesystem_interface.h
@@ -33,6 +33,7 @@
 
 #include <base/macros.h>
 #include <brillo/key_value_store.h>
+#include <puffin/utils.h>
 
 #include "update_engine/update_metadata.pb.h"
 
@@ -62,6 +63,10 @@ class FilesystemInterface {
     // between 0 and GetBlockCount() - 1. The blocks are encoded in extents,
     // indicating the starting block, and the number of consecutive blocks.
     std::vector<Extent> extents;
+
+    // All the deflate locations in the file. These locations are not relative
+    // to the extents. They are relative to the file system itself.
+    std::vector<puffin::BitExtent> deflates;
   };
 
   virtual ~FilesystemInterface() = default;