settings/message/
messenger.rs

1// Copyright 2020 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 crate::message::action_fuse::ActionFuseHandle;
6use crate::message::base::{
7    ActionSender, Attribution, Audience, Fingerprint, Message, MessageAction, MessageType,
8    MessengerId, Signature,
9};
10use crate::message::beacon::{Beacon, BeaconBuilder};
11use crate::message::receptor::Receptor;
12
13use zx::MonotonicDuration;
14
15/// MessengerClient is a wrapper around a messenger with a fuse.
16#[derive(Clone, Debug)]
17pub struct MessengerClient {
18    messenger: Messenger,
19    _fuse: ActionFuseHandle, // Handle that maintains scoped messenger cleanup
20}
21
22impl MessengerClient {
23    pub(super) fn new(messenger: Messenger, fuse: ActionFuseHandle) -> MessengerClient {
24        MessengerClient { messenger, _fuse: fuse }
25    }
26
27    /// Creates a MessageBuilder for a new message with the specified payload
28    /// and audience.
29    pub(crate) fn message(&self, payload: crate::Payload, audience: Audience) -> Receptor {
30        self.message_with_timeout(payload, audience, None)
31    }
32
33    /// Creates a MessageBuilder for a new message with the specified payload,
34    /// audience, and timeout.
35    pub(crate) fn message_with_timeout(
36        &self,
37        payload: crate::Payload,
38        audience: Audience,
39        duration: Option<MonotonicDuration>,
40    ) -> Receptor {
41        let (beacon, receptor) =
42            BeaconBuilder::new(self.messenger.clone()).set_timeout(duration).build();
43        self.messenger.transmit(
44            MessageAction::Send(payload, Attribution::Source(MessageType::Origin(audience))),
45            Some(beacon),
46        );
47
48        receptor
49    }
50
51    /// Returns the signature of the client that will handle any sent messages.
52    pub fn get_signature(&self) -> Signature {
53        self.messenger.get_signature()
54    }
55}
56
57/// Messengers provide clients the ability to send messages to other registered
58/// clients. They can only be created through a MessageHub.
59#[derive(Clone, Debug)]
60pub struct Messenger {
61    fingerprint: Fingerprint,
62    action_tx: ActionSender,
63}
64
65impl Messenger {
66    pub(super) fn new(fingerprint: Fingerprint, action_tx: ActionSender) -> Messenger {
67        Messenger { fingerprint, action_tx }
68    }
69
70    /// Returns the identification for this Messenger.
71    pub(super) fn get_id(&self) -> MessengerId {
72        self.fingerprint.id
73    }
74
75    /// Forwards the message to the next Messenger. Note that this method is
76    /// private and only called through the MessageClient.
77    pub(super) fn forward(&self, message: Message, beacon: Option<Beacon>) {
78        self.transmit(MessageAction::Forward(message), beacon);
79    }
80
81    /// Tranmits a given action to the message hub. This is a common utility
82    /// method to be used for immediate actions (forwarding, observing) and
83    /// deferred actions as well (sending, replying).
84    pub(super) fn transmit(&self, action: MessageAction, beacon: Option<Beacon>) {
85        // Do not transmit if the message hub has exited.
86        if self.action_tx.is_closed() {
87            return;
88        }
89
90        // Log info. transmit is called by forward. However, forward might fail if there is no next
91        // Messenger exists.
92        self.action_tx.unbounded_send((self.fingerprint, action, beacon)).unwrap_or_else(|_| {
93            log::warn!("Messenger::transmit, action_tx failed to send message")
94        });
95    }
96
97    pub(super) fn get_signature(&self) -> Signature {
98        self.fingerprint.signature
99    }
100}
settings/message/messenger.rs

settings/message/
messenger.rs
