Merge branch 'feature/mqtt-rework' into feature/telemetry

miniconf.py

@@ -10,6 +10,7 @@ import asyncio
 import json
 import logging
 import sys
+import uuid
 
 from gmqtt import Client as MqttClient
 
@@ -33,28 +34,52 @@ class Miniconf:
             client: A connected MQTT5 client.
             prefix: The MQTT toptic prefix of the device to control.
         """
+        self.uuid = uuid.uuid1(prefix)
+        self.request_id = 0
         self.client = client
         self.prefix = prefix
         self.inflight = {}
         self.client.on_message = self._handle_response
         self.client.subscribe(f'{prefix}/response/#')
 
-    def _handle_response(self, _client, topic, payload, *_args, **_kwargs):
+    def _handle_response(self, _client, _topic, payload, _qos, properties):
         """Callback function for when messages are received over MQTT.
 
         Args:
             _client: The MQTT client.
-            topic: The topic that the message was received on.
+            _topic: The topic that the message was received on.
             payload: The payload of the message.
+            _qos: The quality-of-service level of the received packet
+            properties: A dictionary of properties associated with the message.
         """
-        if topic not in self.inflight:
+        # Extract corrleation data from the properties
-            # TODO use correlation_data to distinguish clients and requests
+        try:
-            logger.warning('Unexpected response on topic: %s', topic)
+            correlation_data = json.loads(properties['correlation_data'])
+        except (json.decoder.JSONDecodeError, KeyError):
+            logger.warning('Ignoring message with invalid correlation data')
             return
 
+        # Validate the correlation data.
+        try:
+            if correlation_data['id'] != self.uuid.hex:
+                logger.info('Ignoring correlation data for different ID')
+                return
+            pid = correlation_data['pid']
+        except KeyError:
+            logger.warning('Ignoring unknown correlation data: %s', correlation_data)
+            return
+
+        if pid not in self.inflight:
+            logger.warning('Unexpected pid: %s', pid)
+            return
+
+        try:
             response = json.loads(payload)
-        self.inflight[topic].set_result((response['code'], response['msg']))
+            self.inflight[pid].set_result((response['code'], response['msg']))
-        del self.inflight[topic]
+            del self.inflight[pid]
+        except json.decoder.JSONDecodeError:
+            logger.warning('Invalid response format: %s', payload)
+
 
     async def command(self, path, value):
         """Write the provided data to the specified path.
@@ -69,21 +94,30 @@ class Miniconf:
         """
         setting_topic = f'{self.prefix}/settings/{path}'
         response_topic = f'{self.prefix}/response/{path}'
-        if response_topic in self.inflight:
+
-            # TODO use correlation_data to distinguish clients and requests
+        # Assign a unique identifier to this update request.
-            raise NotImplementedError(
+        pid = self.request_id
-                    'Only one in-flight message per topic is supported')
+        self.request_id += 1
+        assert pid not in self.inflight, 'Invalid PID encountered'
+
+        correlation_data = json.dumps({
+            'id': self.uuid.hex,
+            'pid': pid,
+        })
 
         value = json.dumps(value)
         logger.info('Sending %s to "%s"', value, setting_topic)
         fut = asyncio.get_running_loop().create_future()
-        self.inflight[response_topic] = fut
+
+        self.inflight[pid] = fut
         self.client.publish(setting_topic, payload=value, qos=0, retain=True,
-                            response_topic=response_topic)
+                            response_topic=response_topic,
+                            correlation_data=correlation_data)
         return await fut
 
 
 def main():
+    """ Main program entry point. """
     parser = argparse.ArgumentParser(
         description='Miniconf command line interface.',
         formatter_class=argparse.RawDescriptionHelpFormatter,
@@ -110,15 +144,13 @@ def main():
 
     async def configure_settings():
         interface = await Miniconf.create(args.prefix, args.broker)
-        failures = 0
+        for key_value in args.settings:
-        for kv in args.settings:
+            path, value = key_value.split("=", 1)
-            path, value = kv.split("=", 1)
             code, response = await interface.command(path, json.loads(value))
-            print(response)
+            print(f'{path}: {response}')
             if code != 0:
-                failures += 1
+                return code
-
+        return 0
-        return failures
 
     sys.exit(loop.run_until_complete(configure_settings()))
 

src/bin/dual-iir.rs

@@ -185,7 +185,7 @@ const APP: () = {
     fn settings_update(mut c: settings_update::Context) {
         // Update the IIR channels.
         let settings = c.resources.mqtt.settings();
-        c.resources.settings.lock(|current| *current = settings);
+        c.resources.settings.lock(|current| *current = *settings);
 
         // Update AFEs
         c.resources.afes.0.set_gain(settings.afe[0]);

src/bin/lockin.rs

@@ -231,7 +231,7 @@ const APP: () = {
         c.resources.afes.0.set_gain(settings.afe[0]);
         c.resources.afes.1.set_gain(settings.afe[1]);
 
-        c.resources.settings.lock(|current| *current = settings);
+        c.resources.settings.lock(|current| *current = *settings);
     }
 
     #[task(priority = 1, resources=[mqtt, digital_inputs, settings, telemetry], schedule=[telemetry])]

src/net/messages.rs

@@ -6,10 +6,7 @@ use core::fmt::Write;
 #[derive(Debug, Copy, Clone)]
 pub enum SettingsResponseCode {
     NoError = 0,
-    NoTopic = 1,
+    MiniconfError = 1,
-    InvalidPrefix = 2,
-    UnknownTopic = 3,
-    UpdateFailure = 4,
 }
 
 /// Represents a generic MQTT message.
@@ -70,55 +67,25 @@ impl<'a> MqttMessage<'a> {
     }
 }
 
-impl SettingsResponse {
+impl From<Result<(), miniconf::Error>> for SettingsResponse {
-    /// Construct a settings response upon successful settings update.
+    fn from(result: Result<(), miniconf::Error>) -> Self {
-    ///
+        match result {
-    /// # Args
+            Ok(_) => Self {
-    /// * `path` - The path of the setting that was updated.
+                msg: String::from("OK"),
-    pub fn update_success(path: &str) -> Self {
-        let mut msg: String<consts::U64> = String::new();
-        if write!(&mut msg, "{} updated", path).is_err() {
-            msg = String::from("Latest update succeeded");
-        }
-
-        Self {
-            msg,
                 code: SettingsResponseCode::NoError as u8,
-        }
+            },
-    }
 
-    /// Construct a response when a settings update failed.
+            Err(error) => {
-    ///
+                let mut msg = String::new();
-    /// # Args
+                if write!(&mut msg, "{:?}", error).is_err() {
-    /// * `path` - The settings path that configuration failed for.
+                    msg = String::from("Miniconf Error");
-    /// * `err` - The settings update error that occurred.
-    pub fn update_failure(path: &str, err: miniconf::Error) -> Self {
-        let mut msg: String<consts::U64> = String::new();
-        if write!(&mut msg, "{} update failed: {:?}", path, err).is_err() {
-            if write!(&mut msg, "Latest update failed: {:?}", err).is_err() {
-                msg = String::from("Latest update failed");
-            }
                 }
 
                 Self {
+                    code: SettingsResponseCode::MiniconfError as u8,
                     msg,
-            code: SettingsResponseCode::UpdateFailure as u8,
                 }
             }
-
-    /// Construct a response from a custom response code.
-    ///
-    /// # Args
-    /// * `code` - The response code to provide.
-    pub fn code(code: SettingsResponseCode) -> Self {
-        let mut msg: String<consts::U64> = String::new();
-
-        // Note(unwrap): All code debug names shall fit in the 64 byte string.
-        write!(&mut msg, "{:?}", code).unwrap();
-
-        Self {
-            code: code as u8,
-            msg,
         }
     }
 }

src/net/mod.rs

@@ -11,7 +11,7 @@ use core::fmt::Write;
 
 mod messages;
 mod mqtt_interface;
-use messages::{MqttMessage, SettingsResponse, SettingsResponseCode};
+use messages::{MqttMessage, SettingsResponse};
 pub use mqtt_interface::MqttInterface;
 
 mod telemetry;

src/net/mqtt_interface.rs

@@ -2,27 +2,23 @@ use crate::hardware::{
     design_parameters::MQTT_BROKER, CycleCounter, EthernetPhy, NetworkStack,
 };
 
-use core::{cell::RefCell, fmt::Write};
-
 use heapless::{consts, String};
-use serde::Serialize;
 
-use super::{Action, MqttMessage, SettingsResponse, SettingsResponseCode};
+use super::{Action, MqttMessage, SettingsResponse};
 
 /// MQTT settings interface.
 pub struct MqttInterface<S>
 where
     S: miniconf::Miniconf + Default + Clone,
 {
-    telemetry_topic: String<consts::U128>,
     default_response_topic: String<consts::U128>,
-    mqtt: RefCell<minimq::MqttClient<minimq::consts::U256, NetworkStack>>,
+    mqtt: minimq::MqttClient<minimq::consts::U256, NetworkStack>,
-    settings: RefCell<S>,
+    settings: S,
     clock: CycleCounter,
     phy: EthernetPhy,
     network_was_reset: bool,
     subscribed: bool,
-    id: String<consts::U64>,
+    settings_prefix: String<consts::U64>,
 }
 
 impl<S> MqttInterface<S>
@@ -44,23 +40,22 @@ where
         phy: EthernetPhy,
         clock: CycleCounter,
     ) -> Self {
-        let mqtt_client =
+        let mqtt =
             minimq::MqttClient::new(MQTT_BROKER.into(), client_id, stack)
                 .unwrap();
 
-        let mut telemetry_topic: String<consts::U128> = String::new();
+        let mut response_topic: String<consts::U128> = String::from(prefix);
-        write!(&mut telemetry_topic, "{}/telemetry", prefix).unwrap();
+        response_topic.push_str("/log").unwrap();
 
-        let mut response_topic: String<consts::U128> = String::new();
+        let mut settings_prefix: String<consts::U64> = String::from(prefix);
-        write!(&mut response_topic, "{}/log", prefix).unwrap();
+        settings_prefix.push_str("/settings").unwrap();
 
         Self {
-            mqtt: RefCell::new(mqtt_client),
+            mqtt,
-            settings: RefCell::new(S::default()),
+            settings: S::default(),
-            id: String::from(prefix),
+            settings_prefix,
             clock,
             phy,
-            telemetry_topic,
             default_response_topic: response_topic,
             network_was_reset: false,
             subscribed: false,
@@ -73,11 +68,7 @@ where
     /// An option containing an action that should be completed as a result of network servicing.
     pub fn update(&mut self) -> Option<Action> {
         // First, service the network stack to process any inbound and outbound traffic.
-        let sleep = match self
+        let sleep = match self.mqtt.network_stack.poll(self.clock.current_ms())
-            .mqtt
-            .borrow_mut()
-            .network_stack
-            .poll(self.clock.current_ms())
         {
             Ok(updated) => !updated,
             Err(err) => {
@@ -88,18 +79,19 @@ where
 
         // If the PHY indicates there's no more ethernet link, reset the DHCP server in the network
         // stack.
-        if self.phy.poll_link() == false {
+        match self.phy.poll_link() {
+            true => self.network_was_reset = false,
+
             // Only reset the network stack once per link reconnection. This prevents us from
             // sending an excessive number of DHCP requests.
-            if !self.network_was_reset {
+            false if !self.network_was_reset => {
                 self.network_was_reset = true;
-                self.mqtt.borrow_mut().network_stack.handle_link_reset();
+                self.mqtt.network_stack.handle_link_reset();
-            }
-        } else {
-            self.network_was_reset = false;
             }
+            _ => {},
+        };
 
-        let mqtt_connected = match self.mqtt.borrow_mut().is_connected() {
+        let mqtt_connected = match self.mqtt.is_connected() {
             Ok(connected) => connected,
             Err(minimq::Error::Network(
                 smoltcp_nal::NetworkError::NoIpAddress,
@@ -117,34 +109,61 @@ where
         // If we're no longer subscribed to the settings topic, but we are connected to the broker,
         // resubscribe.
         if !self.subscribed && mqtt_connected {
-            let mut settings_topic: String<consts::U128> = String::new();
+            // Note(unwrap): We construct a string with two more characters than the prefix
-            write!(&mut settings_topic, "{}/settings/#", self.id.as_str())
+            // strucutre, so we are guaranteed to have space for storage.
-                .unwrap();
+            let mut settings_topic: String<consts::U66> =
+                String::from(self.settings_prefix.as_str());
+            settings_topic.push_str("/#").unwrap();
 
-            self.mqtt
+            self.mqtt.subscribe(&settings_topic, &[]).unwrap();
-                .borrow_mut()
-                .subscribe(&settings_topic, &[])
-                .unwrap();
             self.subscribed = true;
         }
 
         // Handle any MQTT traffic.
+        let settings = &mut self.settings;
+        let mqtt = &mut self.mqtt;
+        let prefix = self.settings_prefix.as_str();
+        let default_response_topic = self.default_response_topic.as_str();
+
         let mut update = false;
-        match self.mqtt.borrow_mut().poll(
+        match mqtt.poll(|client, topic, message, properties| {
-            |client, topic, message, properties| {
+            let path = match topic.strip_prefix(prefix) {
-                let (response, settings_update) =
+                // For paths, we do not want to include the leading slash.
-                    self.route_message(topic, message, properties);
+                Some(path) => {
+                    if path.len() > 0 {
+                        &path[1..]
+                    } else {
+                        path
+                    }
+                }
+                None => {
+                    info!("Unexpected MQTT topic: {}", topic);
+                    return;
+                }
+            };
+
+            let message: SettingsResponse = settings
+                .string_set(path.split('/').peekable(), message)
+                .and_then(|_| {
+                    update = true;
+                    Ok(())
+                })
+                .into();
+
+            let response =
+                MqttMessage::new(properties, default_response_topic, &message);
+
             client
                 .publish(
                     response.topic,
                     &response.message,
+                    // TODO: When Minimq supports more QoS levels, this should be increased to
+                    // ensure that the client has received it at least once.
                     minimq::QoS::AtMostOnce,
                     &response.properties,
                 )
                 .ok();
-                update = settings_update;
+        }) {
-            },
-        ) {
             // If settings updated,
             Ok(_) => {
                 if update {
@@ -170,75 +189,7 @@ where
         }
     }
 
-    fn route_message<'a, 'me: 'a>(
+    pub fn settings(&self) -> &S {
-        &'me self,
+        &self.settings
-        topic: &str,
-        message: &[u8],
-        properties: &[minimq::Property<'a>],
-    ) -> (MqttMessage<'a>, bool) {
-        let mut update = false;
-        let response_msg =
-            if let Some(path) = topic.strip_prefix(self.id.as_str()) {
-                let mut parts = path[1..].split('/');
-                match parts.next() {
-                    Some("settings") => {
-                        match self
-                            .settings
-                            .borrow_mut()
-                            .string_set(parts.peekable(), message)
-                        {
-                            Ok(_) => {
-                                update = true;
-                                SettingsResponse::update_success(path)
-                            }
-                            Err(error) => {
-                                SettingsResponse::update_failure(path, error)
-                            }
-                        }
-                    }
-                    Some(_) => SettingsResponse::code(
-                        SettingsResponseCode::UnknownTopic,
-                    ),
-                    _ => SettingsResponse::code(SettingsResponseCode::NoTopic),
-                }
-            } else {
-                SettingsResponse::code(SettingsResponseCode::InvalidPrefix)
-            };
-
-        let response = MqttMessage::new(
-            properties,
-            &self.default_response_topic,
-            &response_msg,
-        );
-
-        (response, update)
-    }
-
-    /// Publish telemetry to the default telemetry topic.
-    ///
-    /// # Note
-    /// Telemetry is transmitted in a "best-effort" manner. There is no guarantee it will be
-    /// transmitted.
-    ///
-    /// # Args
-    /// * `telemetry` - The telemetry message to transmit.
-    pub fn publish_telemetry(&mut self, telemetry: &impl Serialize) {
-        let telemetry =
-            miniconf::serde_json_core::to_string::<consts::U256, _>(telemetry)
-                .unwrap();
-        self.mqtt
-            .borrow_mut()
-            .publish(
-                &self.telemetry_topic,
-                telemetry.as_bytes(),
-                minimq::QoS::AtMostOnce,
-                &[],
-            )
-            .ok();
-    }
-
-    /// Get a copy of the current settings.
-    pub fn settings(&self) -> S {
-        self.settings.borrow().clone()
     }
 }