chrome/installer/util/duplicate_tree_detector.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5
   6 #include "chrome/installer/util/duplicate_tree_detector.h"
   7
   8 #include "base/files/file_enumerator.h"
   9 #include "base/files/file_util.h"
  10 #include "base/logging.h"
  11
  12 namespace installer {
  13
  14 bool IsIdenticalFileHierarchy(const base::FilePath& src_path,
  15                               const base::FilePath& dest_path) {
  16   base::File::Info src_info;
  17   base::File::Info dest_info;
  18
  19   bool is_identical = false;
  20   if (base::GetFileInfo(src_path, &src_info) &&
  21       base::GetFileInfo(dest_path, &dest_info)) {
  22     // Both paths exist, check the types:
  23     if (!src_info.is_directory && !dest_info.is_directory) {
  24       // Two files are "identical" if the file sizes are equivalent.
  25       is_identical = src_info.size == dest_info.size;
  26 #if !defined(OFFICIAL_BUILD)
  27       // For developer builds, also check last modification time (to make sure
  28       // version dir DLLs are replaced on over-install even if the tested change
  29       // doesn't happen to change a given DLL's size).
  30       if (is_identical)
  31         is_identical = (src_info.last_modified == dest_info.last_modified);
  32 #endif
  33     } else if (src_info.is_directory && dest_info.is_directory) {
  34       // Two directories are "identical" if dest_path contains entries that are
  35       // "identical" to all the entries in src_path.
  36       is_identical = true;
  37
  38       base::FileEnumerator path_enum(src_path, false /* not recursive */,
  39           base::FileEnumerator::FILES | base::FileEnumerator::DIRECTORIES);
  40       for (base::FilePath path = path_enum.Next();
  41            is_identical && !path.empty();
  42            path = path_enum.Next()) {
  43         is_identical =
  44             IsIdenticalFileHierarchy(path, dest_path.Append(path.BaseName()));
  45       }
  46     } else {
  47       // The two paths are of different types, so they cannot be identical.
  48       DCHECK(!is_identical);
  49     }
  50   }
  51
  52   return is_identical;
  53 }
  54
  55 }  // namespace installer