Merge CrossFileUtilHelper to FileUtilHelper as Copy() and Move().

webkit/fileapi/file_util_helper.cc

Index: webkit/fileapi/file_util_helper.cc
diff --git a/webkit/fileapi/file_util_helper.cc b/webkit/fileapi/file_util_helper.cc
index 1310f18b559cde1dda87ef071e5ae56c685a088d..b2885de60d8bc61518dd5a5949a2e0e0ca2ef388 100644
--- a/webkit/fileapi/file_util_helper.cc
+++ b/webkit/fileapi/file_util_helper.cc
@@ -12,6 +12,253 @@ using base::PlatformFileError;
 
 namespace fileapi {
 
+namespace {
+
+// A helper class for cross-FileUtil Copy/Move operations.
+class CrossFileUtilHelper {
+ public:
+  enum Operation {
+    OPERATION_COPY,
+    OPERATION_MOVE
+  };
+
+  CrossFileUtilHelper(FileSystemOperationContext* context,
+                      FileSystemFileUtil* src_util,
+                      FileSystemFileUtil* dest_util,
+                      const FileSystemPath& src_path,
+                      const FileSystemPath& dest_path,
+                      Operation operation);
+  ~CrossFileUtilHelper();
+
+  base::PlatformFileError DoWork();
+
+ private:
+  // Performs common pre-operation check and preparation.
+  // This may delete the destination directory if it's empty.
+  base::PlatformFileError PerformErrorCheckAndPreparation();
+
+  // This assumes that the root exists.
+  bool ParentExists(const FileSystemPath& path, FileSystemFileUtil* file_util);
+
+  // Performs recursive copy or move by calling CopyOrMoveFile for individual
+  // files. Operations for recursive traversal are encapsulated in this method.
+  // It assumes src_path and dest_path have passed
+  // PerformErrorCheckAndPreparationForMoveAndCopy().
+  base::PlatformFileError CopyOrMoveDirectory(
+      const FileSystemPath& src_path,
+      const FileSystemPath& dest_path);
+
+  // Determines whether a simple same-filesystem move or copy can be done.  If
+  // so, it delegates to CopyOrMoveFile.  Otherwise it looks up the true
+  // platform path of the source file, delegates to CopyInForeignFile, and [for
+  // move] calls DeleteFile on the source file.
+  base::PlatformFileError CopyOrMoveFile(
+      const FileSystemPath& src_path,
+      const FileSystemPath& dest_path);
+
+  FileSystemOperationContext* context_;
+  FileSystemFileUtil* src_util_;  // Not owned.
+  FileSystemFileUtil* dest_util_;  // Not owned.
+  const FileSystemPath& src_root_path_;
+  const FileSystemPath& dest_root_path_;
+  Operation operation_;
+  bool same_file_system_;
+
+  DISALLOW_COPY_AND_ASSIGN(CrossFileUtilHelper);
+};
+
+CrossFileUtilHelper::CrossFileUtilHelper(
+    FileSystemOperationContext* context,
+    FileSystemFileUtil* src_util,
+    FileSystemFileUtil* dest_util,
+    const FileSystemPath& src_path,
+    const FileSystemPath& dest_path,
+    Operation operation)
+    : context_(context),
+      src_util_(src_util),
+      dest_util_(dest_util),
+      src_root_path_(src_path),
+      dest_root_path_(dest_path),
+      operation_(operation) {
+  same_file_system_ =
+      src_root_path_.origin() == dest_root_path_.origin() &&
+      src_root_path_.type() == dest_root_path_.type();
+}
+
+CrossFileUtilHelper::~CrossFileUtilHelper() {}
+
+base::PlatformFileError CrossFileUtilHelper::DoWork() {
+  base::PlatformFileError error = PerformErrorCheckAndPreparation();
+  if (error != base::PLATFORM_FILE_OK)
+    return error;
+  if (src_util_->DirectoryExists(context_, src_root_path_))
+    return CopyOrMoveDirectory(src_root_path_, dest_root_path_);
+  return CopyOrMoveFile(src_root_path_, dest_root_path_);
+}
+
+PlatformFileError CrossFileUtilHelper::PerformErrorCheckAndPreparation() {
+  // Exits earlier if the source path does not exist.
+  if (!src_util_->PathExists(context_, src_root_path_))
+    return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+
+  // The parent of the |dest_root_path_| does not exist.
+  if (!ParentExists(dest_root_path_, dest_util_))
+    return base::PLATFORM_FILE_ERROR_NOT_FOUND;
+
+  // It is an error to try to copy/move an entry into its child.
+  if (same_file_system_ && src_root_path_.IsParent(dest_root_path_))
+    return base::PLATFORM_FILE_ERROR_INVALID_OPERATION;
+
+  // Now it is ok to return if the |dest_root_path_| does not exist.
+  if (!dest_util_->PathExists(context_, dest_root_path_))
+    return base::PLATFORM_FILE_OK;
+
+  // |src_root_path_| exists and is a directory.
+  // |dest_root_path_| exists and is a file.
+  bool src_is_directory = src_util_->DirectoryExists(context_, src_root_path_);
+  bool dest_is_directory =
+      dest_util_->DirectoryExists(context_, dest_root_path_);
+
+  // Either one of |src_root_path_| or |dest_root_path_| is directory,
+  // while the other is not.
+  if (src_is_directory != dest_is_directory)
+    return base::PLATFORM_FILE_ERROR_INVALID_OPERATION;
+
+  // It is an error to copy/move an entry into the same path.
+  if (same_file_system_ &&
+      src_root_path_.internal_path() == dest_root_path_.internal_path())
+    return base::PLATFORM_FILE_ERROR_EXISTS;
+
+  if (dest_is_directory) {
+    // It is an error to copy/move an entry to a non-empty directory.
+    // Otherwise the copy/move attempt must overwrite the destination, but
+    // the file_util's Copy or Move method doesn't perform overwrite
+    // on all platforms, so we delete the destination directory here.
+    if (base::PLATFORM_FILE_OK !=
+        dest_util_->DeleteSingleDirectory(context_, dest_root_path_)) {
+      if (!dest_util_->IsDirectoryEmpty(context_, dest_root_path_))
+        return base::PLATFORM_FILE_ERROR_NOT_EMPTY;
+      return base::PLATFORM_FILE_ERROR_FAILED;
+    }
+  }
+  return base::PLATFORM_FILE_OK;
+}
+
+bool CrossFileUtilHelper::ParentExists(
+    const FileSystemPath& path, FileSystemFileUtil* file_util) {
+  // If path is in the root, path.DirName() will be ".",
+  // since we use paths with no leading '/'.
+  FilePath parent = path.internal_path().DirName();
+  if (parent == FilePath(FILE_PATH_LITERAL(".")))
+    return true;
+  return file_util->DirectoryExists(
+      context_, path.WithInternalPath(parent));
+}
+
+PlatformFileError CrossFileUtilHelper::CopyOrMoveDirectory(
+    const FileSystemPath& src_path,
+    const FileSystemPath& dest_path) {
+  // At this point we must have gone through
+  // PerformErrorCheckAndPreparationForMoveAndCopy so this must be true.
+  DCHECK(!same_file_system_ ||
+         !src_path.IsParent(dest_path));
+
+  PlatformFileError error = dest_util_->CreateDirectory(
+      context_, dest_path, false, false);
+  if (error != base::PLATFORM_FILE_OK)
+    return error;
+
+  scoped_ptr<FileSystemFileUtil::AbstractFileEnumerator> file_enum(
+      src_util_->CreateFileEnumerator(context_, src_path, true));
+  FilePath src_file_path_each;
+  while (!(src_file_path_each = file_enum->Next()).empty()) {
+    FilePath dest_file_path_each(dest_path.internal_path());
+    src_path.internal_path().AppendRelativePath(
+        src_file_path_each, &dest_file_path_each);
+
+    if (file_enum->IsDirectory()) {
+      PlatformFileError error = dest_util_->CreateDirectory(
+          context_,
+          dest_path.WithInternalPath(dest_file_path_each),
+          true /* exclusive */, false /* recursive */);
+      if (error != base::PLATFORM_FILE_OK)
+        return error;
+    } else {
+      PlatformFileError error = CopyOrMoveFile(
+          src_path.WithInternalPath(src_file_path_each),
+          dest_path.WithInternalPath(dest_file_path_each));
+      if (error != base::PLATFORM_FILE_OK)
+        return error;
+    }
+  }
+
+  if (operation_ == OPERATION_MOVE) {
+    PlatformFileError error =
+        FileUtilHelper::Delete(context_, src_util_,
+                               src_path, true /* recursive */);
+    if (error != base::PLATFORM_FILE_OK)
+      return error;
+  }
+
+  return base::PLATFORM_FILE_OK;
+}
+
+PlatformFileError CrossFileUtilHelper::CopyOrMoveFile(
+    const FileSystemPath& src_path,
+    const FileSystemPath& dest_path) {
+  if (same_file_system_) {
+    DCHECK(src_util_ == dest_util_);
+    // Source and destination are in the same FileSystemFileUtil; now we can
+    // safely call FileSystemFileUtil method on src_util_ (== dest_util_).
+    return src_util_->CopyOrMoveFile(context_, src_path, dest_path,
+                                     operation_ == OPERATION_COPY);
+  }
+
+  // Resolve the src_path's underlying file path.
+  base::PlatformFileInfo file_info;
+  FilePath platform_file_path;
+  PlatformFileError error = src_util_->GetFileInfo(
+      context_, src_path, &file_info, &platform_file_path);
+  if (error != base::PLATFORM_FILE_OK)
+    return error;
+
+  // Call CopyInForeignFile() on the dest_util_ with the resolved source path
+  // to perform limited cross-FileSystemFileUtil copy/move.
+  error = dest_util_->CopyInForeignFile(
+      context_, src_path.WithInternalPath(platform_file_path), dest_path);
+
+  if (operation_ == OPERATION_COPY || error != base::PLATFORM_FILE_OK)
+    return error;
+  return src_util_->DeleteFile(context_, src_path);
+}
+
+}  // anonymous namespace
+
+// static
+base::PlatformFileError FileUtilHelper::Copy(
+    FileSystemOperationContext* context,
+    FileSystemFileUtil* src_file_util,
+    FileSystemFileUtil* dest_file_util,
+    const FileSystemPath& src_root_path,
+    const FileSystemPath& dest_root_path) {
+  return CrossFileUtilHelper(context, src_file_util, dest_file_util,
+                             src_root_path, dest_root_path,
+                             CrossFileUtilHelper::OPERATION_COPY).DoWork();
+}
+
+// static
+base::PlatformFileError FileUtilHelper::Move(
+    FileSystemOperationContext* context,
+    FileSystemFileUtil* src_file_util,
+    FileSystemFileUtil* dest_file_util,
+    const FileSystemPath& src_root_path,
+    const FileSystemPath& dest_root_path) {
+  return CrossFileUtilHelper(context, src_file_util, dest_file_util,
+                             src_root_path, dest_root_path,
+                             CrossFileUtilHelper::OPERATION_MOVE).DoWork();
+}
+
+// static
 base::PlatformFileError FileUtilHelper::Delete(
     FileSystemOperationContext* context,
     FileSystemFileUtil* file_util,
@@ -27,6 +274,7 @@ base::PlatformFileError FileUtilHelper::Delete(
   }
 }
 
+// static
 base::PlatformFileError FileUtilHelper::DeleteDirectoryRecursive(
     FileSystemOperationContext* context,
     FileSystemFileUtil* file_util,