Add support for bsdiff of file system metadata blocks

delta_diff_generator.h

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H__
 
 #include <string>
 #include <vector>
 #include "base/basictypes.h"
@@ skipping 204 matching lines @@
 
  private:
   // This should never be constructed
   DISALLOW_IMPLICIT_CONSTRUCTORS(DeltaDiffGenerator);
 };
 
 extern const char* const kBsdiffPath;
 extern const char* const kBspatchPath;
 extern const char* const kDeltaMagic;
 
+// Runs the bsdiff tool on two files and returns the resulting delta in
+// 'out'. Returns true on success.
+bool BsdiffFiles(const std::string& old_file,

[adlr, 2010/12/15 03:11:23]

can these be static methods of DeltaDiffGenerator (following convention above)

[thieule, 2010/12/15 19:57:01]

Done.

+                 const std::string& new_file,
+                 std::vector<char>* out);
+
+// The blocks vector contains a reader and writer for each block on the

[petkov, 2010/12/15 18:40:32]

s/blocks/|blocks|/

[thieule, 2010/12/15 19:57:01]

Done.

+// filesystem that's being in-place updated. We populate the reader/writer
+// fields of blocks by calling this function.
+// For each block in 'operation' that is read or written, find that block

[petkov, 2010/12/15 18:40:32]

s/'operation'/|operation|/

same for blocks, graph below.

[thieule, 2010/12/15 19:57:01]

Done.

+// in 'blocks' and set the reader/writer field to the vertex passed.
+// 'graph' is not strictly necessary, but useful for printing out
+// error messages.
+bool AddInstallOpToBlocksVector(
+    const DeltaArchiveManifest_InstallOperation& operation,
+    std::vector<DeltaDiffGenerator::Block>* blocks,

[petkov, 2010/12/15 18:40:32]

it might be good, per style, to move |blocks| to be the last parameter is it's
in/out while all the other parameters are strictly inputs.

[thieule, 2010/12/15 19:57:01]

Done.

+    const Graph& graph,
+    Vertex::Index vertex);
+
 };  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H__