archivist_lib/
component_lifecycle.rs

1// Copyright 2021 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use fidl::endpoints::RequestStream;
6use fidl_fuchsia_process_lifecycle::{LifecycleRequest, LifecycleRequestStream};
7use fuchsia_async as fasync;
8use fuchsia_runtime::{take_startup_handle, HandleInfo, HandleType};
9use futures::{Future, StreamExt};
10use log::{debug, warn};
11
12/// Takes the startup handle for LIFECYCLE and returns a stream listening for Lifecycle FIDL
13/// requests on it.
14pub fn take_lifecycle_request_stream() -> LifecycleRequestStream {
15    let lifecycle_handle_info = HandleInfo::new(HandleType::Lifecycle, 0);
16    let lifecycle_handle = take_startup_handle(lifecycle_handle_info)
17        .expect("must have been provided a lifecycle channel in procargs");
18    let async_chan = fasync::Channel::from_channel(lifecycle_handle.into());
19    LifecycleRequestStream::from_channel(async_chan)
20}
21
22/// Serves the Lifecycle protocol from the component runtime used for controlled shutdown of the
23/// archivist. When Stop is requrested executes the given callback.
24pub async fn on_stop_request<F, Fut>(mut request_stream: LifecycleRequestStream, cb: F)
25where
26    F: FnOnce() -> Fut,
27    Fut: Future<Output = ()>,
28{
29    match request_stream.next().await {
30        None => {
31            warn!("Lifecycle closed");
32        }
33        Some(Err(err)) => {
34            warn!(err:?; "Lifecycle error");
35        }
36        Some(Ok(LifecycleRequest::Stop { .. })) => {
37            debug!("Initiating shutdown.");
38            cb().await
39        }
40    }
41}