settings/message/
message_client.rs

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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::{ActionFuse, ActionFuseHandle};
6use crate::message::base::{
7    Attribution, Audience, Message, MessageAction, MessageClientId, MessageType, Signature, Status,
8};
9use crate::message::beacon::BeaconBuilder;
10use crate::message::messenger::Messenger;
11use crate::message::receptor::Receptor;
12
13/// MessageClient provides a subset of Messenger functionality around a specific
14/// delivered message. The client may duplicate/move the MessageClient as
15/// desired. Once all MessageClient instances go out of scope, the original
16/// message is forwarded to the next Messenger if no interaction preceded it.
17#[derive(Clone, Debug)]
18pub struct MessageClient {
19    // A unique identifier that identifies this client within the parent message
20    // hub.
21    id: MessageClientId,
22    // The "source" message for the client. Any replies or action are done in the
23    // context of this message.
24    message: Message,
25    // The messenger to receive any actions.
26    messenger: Messenger,
27    // Auto-trigger for automatically forwarding the message to the next
28    // recipient.
29    forwarder: ActionFuseHandle,
30}
31
32impl PartialEq for MessageClient {
33    fn eq(&self, other: &MessageClient) -> bool {
34        other.id == self.id
35    }
36}
37
38impl MessageClient {
39    pub(super) fn new(
40        id: MessageClientId,
41        message: Message,
42        messenger: Messenger,
43    ) -> MessageClient {
44        let fuse_messenger_clone = messenger.clone();
45        let fuse_message_clone = message.clone();
46        MessageClient {
47            id,
48            message,
49            messenger,
50            forwarder: ActionFuse::create(Box::new(move || {
51                fuse_messenger_clone.forward(fuse_message_clone.clone(), None);
52            })),
53        }
54    }
55
56    #[cfg(test)]
57    pub(crate) fn get_modifiers(&self) -> Vec<Signature> {
58        self.message.get_modifiers()
59    }
60
61    /// Returns the Signature of the original author of the associated Message.
62    /// This value can be used to communicate with the author at top-level
63    /// communication.
64    pub(crate) fn get_author(&self) -> Signature {
65        self.message.get_author()
66    }
67
68    /// Returns the audience associated with the underlying [`Message`]. If it
69    /// is a new [`Message`] (origin), it will be the target audience.
70    /// Otherwise it is the author of the reply.
71    pub(crate) fn get_audience(&self) -> Audience {
72        match self.message.get_type() {
73            MessageType::Origin(audience) => audience.clone(),
74            MessageType::Reply(message) => Audience::Messenger(message.get_author()),
75        }
76    }
77
78    /// Creates a dedicated receptor for receiving future communication on this message thread.
79    pub(crate) fn spawn_observer(&mut self) -> Receptor {
80        let (beacon, receptor) = BeaconBuilder::new(self.messenger.clone()).build();
81        self.messenger.forward(self.message.clone(), Some(beacon));
82        ActionFuse::defuse(self.forwarder.clone());
83
84        receptor
85    }
86
87    /// Sends a reply to this message.
88    pub(crate) fn reply(&self, payload: crate::Payload) -> Receptor {
89        self.send(payload, Attribution::Source(MessageType::Reply(Box::new(self.message.clone()))))
90    }
91
92    /// Propagates a derived message on the path of the original message.
93    #[cfg(test)]
94    pub(crate) fn propagate(&self, payload: crate::Payload) -> Receptor {
95        self.send(
96            payload,
97            Attribution::Derived(Box::new(self.message.clone()), self.messenger.get_signature()),
98        )
99    }
100
101    /// Report back to the clients that the message has been acknowledged.
102    pub(crate) async fn acknowledge(&self) {
103        self.message.report_status(Status::Acknowledged).await;
104    }
105
106    /// Tracks the lifetime of the reply listener, firing the fuse when it
107    /// goes out of scope.
108    pub(crate) async fn bind_to_recipient(&mut self, fuse: ActionFuseHandle) {
109        self.message.bind_to_author(fuse).await;
110    }
111
112    fn send(&self, payload: crate::Payload, attribution: Attribution) -> Receptor {
113        let (beacon, receptor) = BeaconBuilder::new(self.messenger.clone()).build();
114        self.messenger.transmit(MessageAction::Send(payload, attribution), Some(beacon));
115
116        ActionFuse::defuse(self.forwarder.clone());
117
118        receptor
119    }
120}
settings/message/message_client.rs

settings/message/
message_client.rs
