zircon/system/fidl/fuchsia-io2/memory.fidl

// Copyright 2019 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.io2;

using fuchsia.mem;

/// A file-like node backed by a VMO.
/// No memory-specific methods are provided by this protocol.
/// The client should access it via the the [`MemoryInfo.buffer`] object in
/// [`fuchsia.io2/Representation`].
protocol Memory {
    compose Node;
};

/// Auxiliary data for the memory object representation of a node.
/// The node is a file which is represented as a VMO.
/// The selection of this variant in [`Representation`] implies that the
/// connection speaks the [`fuchsia.io2/Memory`] protocol.
table MemoryInfo {
    /// Although a VMO is returned as a part of this structure, that VMO may
    /// back multiple files. To identify the logical portion of the VMO that
    /// represents the single file, offset and size are also supplied.
    ///
    /// If the range covers the entire VMO (i.e. the offset is zero and the
    /// length matches the size of the VMO), then all clients must receive a
    /// VMO with the same koid. This can be a duplicate of the same underlying
    /// page-aligned VMO.
    ///
    /// The rights on this VMO should correspond to the rights on the
    /// node connection.
    1: fuchsia.mem.Range buffer;
};