mojo/services/media/core/interfaces/seeking_reader.mojom

// Copyright 2016 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.

[DartPackage="mojo_services"]
module mojo.media;

import "mojo/services/media/common/interfaces/media_common.mojom";

// Reader with seek semantics.
interface SeekingReader {
  const uint64 kUnknownSize = 0xffffffffffffffff;

  // Gets the content size and whether the reader can seek. The |result|
  // callback parameter is |OK| unless there was a problem accessing the
  // content to be read. Other possible values:
  // |NOT_FOUND|     - The content could not be found.
  // |UNKNOWN_ERROR| - Some other error occurred.
  // A |size| value of |kUnknownSize| if the size of the content isn't known.
  Describe() => (MediaResult result, uint64 size, bool can_seek);

  // Reads into a data pipe starting at a specified position. If the reader
  // can't seek, position must be 0. The |result| callback parameter is |OK|
  // unless there was a problem performing the read. Other possible values:
  // |NOT_FOUND|        - The content could not be found.
  // |INVALID_ARGUMENT| - The reader can't seek and |position| was non-zero.
  // |UNKNOWN_ERROR|    - Some other error occurred.
  ReadAt(uint64 position) =>
      (MediaResult result, handle<data_pipe_consumer>? data_pipe);
};