// 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 zx;

protocol DirectoryIterator {
    /// Reads a collection of variably sized directory entries into a buffer.
    ///
    /// The number of entries in a directory may be very large: akin to
    /// calling read multiple times on a file, directories have a seek
    /// offset which is updated on subsequent calls to `Enumerate`.
    /// The caller should always use a receiving buffer size as large as the
    /// maximum channel limit.
    ///
    /// When the end of iteration is reached, the returned `entries` vector
    /// will be empty.
    ///
    /// This method does not require any rights, as the rights are checked
    /// in the [`Directory.Enumerate`] call.
    GetNext() -> (struct {
        entries vector<DirectoryEntry>:MAX_DIRECTORY_BATCH_SIZE;
    }) error zx.status;
};

/// The maximum number of directory entires or watcher events returned
/// in a batch by a hanging-get pattern.
const MAX_DIRECTORY_BATCH_SIZE uint64 = 8192;

/// Options to pass to [`fuchsia.io2/Directory.Enumerate`].
type DirectoryEnumerateOptions = table {};