Add support for bsdiff of file system metadata blocks

delta_performer_unittest.cc

 // Copyright (c) 2009 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.
 
 #include <sys/mount.h>
 #include <inttypes.h>
 
 #include <algorithm>
 #include <string>
 #include <vector>
@@ skipping 48 matching lines @@
 
   string expected_output = "4096:4096,16384:8192,-1:4096,0:4083";
   string actual_output;
   EXPECT_TRUE(DeltaPerformer::ExtentsToBsdiffPositionsString(extents,
                                                              block_size,
                                                              file_length,
                                                              &actual_output));
   EXPECT_EQ(expected_output, actual_output);
 }
 
-class ScopedLoopMounter {
- public:
-  explicit ScopedLoopMounter(const string& file_path, string* mnt_path,
-                             unsigned long flags) {
-    EXPECT_TRUE(utils::MakeTempDirectory("/tmp/mnt.XXXXXX", mnt_path));
-    dir_remover_.reset(new ScopedDirRemover(*mnt_path));
-
-    string loop_dev = GetUnusedLoopDevice();
-    EXPECT_EQ(0, system(StringPrintf("losetup %s %s", loop_dev.c_str(),
-                                     file_path.c_str()).c_str()));
-    loop_releaser_.reset(new ScopedLoopbackDeviceReleaser(loop_dev));
-
-    EXPECT_TRUE(utils::MountFilesystem(loop_dev, *mnt_path, flags));
-    unmounter_.reset(new ScopedFilesystemUnmounter(*mnt_path));
-  }
- private:
-  scoped_ptr<ScopedDirRemover> dir_remover_;
-  scoped_ptr<ScopedLoopbackDeviceReleaser> loop_releaser_;
-  scoped_ptr<ScopedFilesystemUnmounter> unmounter_;
-};
-
 void CompareFilesByBlock(const string& a_file, const string& b_file) {
   vector<char> a_data, b_data;
   EXPECT_TRUE(utils::ReadFile(a_file, &a_data)) << "file failed: " << a_file;
   EXPECT_TRUE(utils::ReadFile(b_file, &b_data)) << "file failed: " << b_file;
 
   EXPECT_EQ(a_data.size(), b_data.size());
   EXPECT_EQ(0, a_data.size() % kBlockSize);
   for (size_t i = 0; i < a_data.size(); i += kBlockSize) {
     EXPECT_EQ(0, i % kBlockSize);
     vector<char> a_sub(&a_data[i], &a_data[i + kBlockSize]);
@@ skipping 308 matching lines @@
   op.clear_src_extents();
   *(op.add_src_extents()) = ExtentForRange(5, 3);
   EXPECT_TRUE(DeltaPerformer::IsIdempotentOperation(op));
   *(op.add_dst_extents()) = ExtentForRange(20, 6);
   EXPECT_TRUE(DeltaPerformer::IsIdempotentOperation(op));
   *(op.add_src_extents()) = ExtentForRange(19, 2);
   EXPECT_FALSE(DeltaPerformer::IsIdempotentOperation(op));
 }
 
 }  // namespace chromeos_update_engine