chromium/src/third_party/blink/public/mojom/file_system_access/file_system_access_file_writer.mojom

// Copyright 2019 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.

module blink.mojom;

import "third_party/blink/public/mojom/file_system_access/file_system_access_error.mojom";

// Represents an object to modify a file.
interface FileSystemAccessFileWriter {
  // Write data from |stream| to the given |position| in the file being written
  // to. Returns whether the operation succeeded and if so how many bytes were
  // written.
  // TODO(mek): This might need some way of reporting progress events back to
  // the renderer.
  Write(uint64 offset, handle<data_pipe_consumer> stream) =>
      (FileSystemAccessError result, uint64 bytes_written);

  // Changes the length of the file to be |length|. If |length| is larger than
  // the current size of the file, the file will be extended, and the extended
  // part is filled with null bytes.
  Truncate(uint64 length) => (FileSystemAccessError result);

  // Closes the file writer. This will materialize the writes operations on the
  // intended file target in the case of atomic writes.
  // The mojo pipe will be destroyed when Close() completes.
  // Specify the |autoClose| flag to ensure Close() is automatically invoked
  // when the mojo pipe closes.
  // Returns whether the operation succeeded.
  Close() => (FileSystemAccessError result);

  // Aborts the write operation, resulting in the writes not being committed,
  // even if |autoClose| is specified. The mojo pipe will be destroyed when
  // Abort() completes.
  // Returns whether the write operation was aborted successfully.
  Abort() => (FileSystemAccessError result);
};