Add support for bsdiff of file system metadata blocks

delta_diff_generator.cc

Index: delta_diff_generator.cc
diff --git a/delta_diff_generator.cc b/delta_diff_generator.cc
index 21a4c03ad84b98decd39afa9c7a94bfd6e4f29d1..4d8ccab0697fa1844d7605d28b10eefc620b95d8 100644
--- a/delta_diff_generator.cc
+++ b/delta_diff_generator.cc
@@ -30,6 +30,7 @@
 #include "update_engine/full_update_generator.h"
 #include "update_engine/graph_types.h"
 #include "update_engine/graph_utils.h"
+#include "update_engine/metadata.h"
 #include "update_engine/omaha_hash_calculator.h"
 #include "update_engine/payload_signer.h"
 #include "update_engine/subprocess.h"
@@ -52,31 +53,6 @@ typedef DeltaDiffGenerator::Block Block;
 typedef map<const DeltaArchiveManifest_InstallOperation*,
             const string*> OperationNameMap;
 
-namespace {
-const size_t kBlockSize = 4096;  // bytes
-
-// TODO(adlr): switch from 1GiB to 2GiB when we no longer care about old
-// clients:
-const size_t kRootFSPartitionSize = 1 * 1024 * 1024 * 1024;  // bytes
-const uint64_t kVersionNumber = 1;
-const uint64_t kFullUpdateChunkSize = 1024 * 1024;  // bytes
-
-static const char* kInstallOperationTypes[] = {
-  "REPLACE",
-  "REPLACE_BZ",
-  "MOVE",
-  "BSDIFF"
-};
-
-// Stores all Extents for a file into 'out'. Returns true on success.
-bool GatherExtents(const string& path,
-                   google::protobuf::RepeatedPtrField<Extent>* out) {
-  vector<Extent> extents;
-  TEST_AND_RETURN_FALSE(extent_mapper::ExtentsForFileFibmap(path, &extents));
-  DeltaDiffGenerator::StoreExtents(extents, out);
-  return true;
-}
-
 // Runs the bsdiff tool on two files and returns the resulting delta in
 // 'out'. Returns true on success.
 bool BsdiffFiles(const string& old_file,
@@ -152,6 +128,31 @@ bool AddInstallOpToBlocksVector(
   return true;
 }
 
+namespace {
+const size_t kBlockSize = 4096;  // bytes
+
+// TODO(adlr): switch from 1GiB to 2GiB when we no longer care about old
+// clients:
+const size_t kRootFSPartitionSize = 1 * 1024 * 1024 * 1024;  // bytes
+const uint64_t kVersionNumber = 1;
+const uint64_t kFullUpdateChunkSize = 1024 * 1024;  // bytes
+
+static const char* kInstallOperationTypes[] = {
+  "REPLACE",
+  "REPLACE_BZ",
+  "MOVE",
+  "BSDIFF"
+};
+
+// Stores all Extents for a file into 'out'. Returns true on success.
+bool GatherExtents(const string& path,
+                   google::protobuf::RepeatedPtrField<Extent>* out) {
+  vector<Extent> extents;
+  TEST_AND_RETURN_FALSE(extent_mapper::ExtentsForFileFibmap(path, &extents));
+  DeltaDiffGenerator::StoreExtents(extents, out);
+  return true;
+}
+
 // For a given regular file which must exist at new_root + path, and
 // may exist at old_root + path, creates a new InstallOperation and
 // adds it to the graph. Also, populates the |blocks| array as
@@ -1390,6 +1391,16 @@ bool DeltaDiffGenerator::GenerateDeltaUpdateFile(
       LOG(INFO) << "done reading normal files";
       CheckGraph(graph);
 
+      LOG(INFO) << "Starting metadata processing";
+      TEST_AND_RETURN_FALSE(DeltaReadMetadata(&graph,
+                                              &blocks,
+                                              old_image,
+                                              new_image,
+                                              fd,
+                                              &data_file_size));
+      LOG(INFO) << "Done metadata processing";
+      CheckGraph(graph);
+
       graph.resize(graph.size() + 1);
       TEST_AND_RETURN_FALSE(ReadUnwrittenBlocks(blocks,
                                                 fd,