text: // Copyright (c) 2011 The Chromium 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 "chrome/installer/util/move_tree_work_item.h"
  
  #include "base/files/file_util.h"
  #include "base/logging.h"
  #include "base/win/shlwapi.h"
  #include "chrome/installer/util/duplicate_tree_detector.h"
  #include "chrome/installer/util/logging_installer.h"
  
  MoveTreeWorkItem::~MoveTreeWorkItem() {}
  
  MoveTreeWorkItem::MoveTreeWorkItem(const base::FilePath& source_path,
                                     const base::FilePath& dest_path,
                                     const base::FilePath& temp_path,
                                     MoveTreeOption duplicate_option)
      : source_path_(source_path),
        dest_path_(dest_path),
        temp_path_(temp_path),
        moved_to_dest_path_(false),
        moved_to_backup_(false),
        source_moved_to_backup_(false),
        duplicate_option_(duplicate_option) {}
  
  bool MoveTreeWorkItem::DoImpl() {
    if (!base::PathExists(source_path_)) {
      LOG(ERROR) << source_path_.value() << " does not exist";
      return false;
    }
  
    // If dest_path_ exists, we can do one of two things:
    // 1) If the contents of src_path_are already fully contained in dest_path_
    //    then do nothing and return success. Fully contained means the full
    //    file structure with identical files is contained in dest_path_. For
    //    Chrome, if dest_path_ exists, this is expected to be the common case.
    // 2) If the contents of src_path_ are NOT fully contained in dest_path_, we
    //    attempt to backup dest_path_ and replace it with src_path_. This will
    //    fail if files in dest_path_ are in use.
    if (base::PathExists(dest_path_)) {
      // Generate a backup path that can keep the original files under dest_path_.
      if (!backup_path_.CreateUniqueTempDirUnderPath(temp_path_)) {
        PLOG(ERROR) << "Failed to get backup path in folder "
                    << temp_path_.value();
        return false;
      }
      base::FilePath backup =
          backup_path_.GetPath().Append(dest_path_.BaseName());
  
      if (duplicate_option_ == CHECK_DUPLICATES) {
        if (installer::IsIdenticalFileHierarchy(source_path_, dest_path_)) {
          // The files we are moving are already present in the destination path.
          // We most likely don't need to do anything. As such, just move the
          // source files to the temp folder as backup.
          if (base::Move(source_path_, backup)) {
            source_moved_to_backup_ = true;
            VLOG(1) << "Moved source " << source_path_.value()
                    << " to backup path " << backup.value();
            return true;
          } else {
            // We failed to move the source tree to the backup path. This is odd
            // but just fall through and attempt the regular behaviour as well.
            PLOG(ERROR) << "Failed to backup source " << source_path_.value()
                        << " to backup path " << backup.value()
                        << " for duplicate trees. Trying regular Move instead.";
          }
        } else {
          VLOG(1) << "Source path " << source_path_.value() << " differs from "
                  << dest_path_.value() << ", updating now.";
        }
      }
  
      if (base::Move(dest_path_, backup)) {
        moved_to_backup_ = true;
        VLOG(1) << "Moved destination " << dest_path_.value()
                << " to backup path " << backup.value();
      } else {
        PLOG(ERROR) << "failed moving " << dest_path_.value() << " to "
                    << backup.value();
        return false;
      }
    }
  
    // Now move source to destination.
    if (base::Move(source_path_, dest_path_)) {
      moved_to_dest_path_ = true;
      VLOG(1) << "Moved source " << source_path_.value() << " to destination "
              << dest_path_.value();
    } else {
      PLOG(ERROR) << "failed move " << source_path_.value() << " to "
                  << dest_path_.value();
      return false;
    }
  
    return true;
  }
  
  void MoveTreeWorkItem::RollbackImpl() {
    if (moved_to_dest_path_ && !base::Move(dest_path_, source_path_)) {
      PLOG(ERROR) << "Can not move " << dest_path_.value() << " to "
                  << source_path_.value();
    }
  
    if (moved_to_backup_ || source_moved_to_backup_) {
      base::FilePath backup =
          backup_path_.GetPath().Append(dest_path_.BaseName());
  
      if (moved_to_backup_ && !base::Move(backup, dest_path_)) {
        PLOG(ERROR) << "failed move " << backup.value() << " to "
                    << dest_path_.value();
      }
  
      if (source_moved_to_backup_ && !base::Move(backup, source_path_)) {
        PLOG(ERROR) << "Can not restore " << backup.value() << " to "
                    << source_path_.value();
      }
    }
  }
  