// 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.fshost;

using fuchsia.io;
using zx;

/// Manages filesystems which wish to be globally exposed under the filesystem host.
[Discoverable]
protocol Registry {
    /// Registers the output directory of a filesystem. These filesystems are
    /// exported from the fuchsia.fshost.Filesystems service, where they are
    /// be identified by an instance number (of the form "000", "001", etc).
    ///
    /// This directory is automatically de-registered from fuchsia.fshost.Filesystems
    /// if the server end of the connection is closed.
    RegisterFilesystem(fuchsia.io.Directory public_export) -> (zx.status s);
};

/// A collection of all registered filesystems.
[Discoverable]
protocol Filesystems {
    compose fuchsia.io.Directory;
};

/// Manages the block watcher.
[Discoverable]
protocol BlockWatcher {
    /// Pauses the block watcher. This causes the block watcher to drop all
    /// new block device events.
    /// Returns ZX_ERR_UNAVAILABLE if the watcher has been paused too many times.
    Pause() -> (zx.status status);

    /// Resumes the block watcher. The block watcher won't resume until every
    /// Pause() call has had a corresponding Resume().
    /// Returns ZX_ERR_BAD_STATE if the watcher isn't paused.
    Resume() -> (zx.status status);
};

/// Manages fshost lifecycle
[Discoverable]
protocol Admin {
    /// Causes fshost to unmount all filesystems and exit. Fshost has
    /// successfully unmounted all filesystems when this function returns, and
    /// exits immediately after writing the response to this function.
    // TODO(fxbug.dev/43186): replace with the component manager shutdown API once it
    // becomes available.
    Shutdown() -> ();
};