public/fidl/fuchsia.mediaplayer/seeking_reader.fidl

// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.mediaplayer;

// Reader with seek semantics.
// TODO(dalesat): Report problems using Problem rather than SeekingReaderResult.
interface SeekingReader {
    // Describes the content. If there’s a problem accessing the content, this
    // is expressed by using result. The size_in_bytes may be reported as
    // UNKNOWN_SIZE if the size of the content is unknown.
    Describe() -> (SeekingReaderResult result, uint64 size, bool can_seek);

    // Reads the content. If there’s a problem performing the read, this is
    // expressed using result. If the read succeeded, the reply must contain a
    // valid socket from which the content can be read.
    ReadAt(uint64 position) -> (SeekingReaderResult SeekingReaderResult,
                                handle<socket>? socket);
};

const uint64 UNKNOWN_SIZE = 0xffffffffffffffff;

enum SeekingReaderResult : int32 {
    OK = 0;
    UNKNOWN_ERROR = -1;

    // Returned by ReadAt if non-zero position is specified and source cannot
    // seek.
    INVALID_ARGUMENT = -2;

    // Returned by either method if the content cannot be found.
    NOT_FOUND = -3;
};