pid: export summary as json

src/main.rs

@@ -96,7 +96,6 @@ fn report_to(channel: usize, channels: &mut Channels, socket: &mut TcpSocket) ->
                     let _ = socket.send_slice(b"\n");
                     // success
                     return true
-                    // TODO: session.mark_report_sent(channel);
                 }
                 Ok(sent) =>
                     warn!("sent only {}/{} bytes of report", sent, buf.len()),
@@ -208,29 +207,30 @@ fn main() -> ! {
                                 }
                                 Command::Show(ShowCommand::Pid) => {
                                     for channel in 0..CHANNELS {
-                                        let state = channels.channel_state(channel);
-                                        let _ = writeln!(socket, "PID settings for channel {}", channel);
-                                        let pid = &state.pid;
-                                        let _ = writeln!(socket, "- target={:.4} °C", pid.target);
-                                        macro_rules! show_pid_parameter {
-                                            ($p: tt) => {
-                                                let _ = writeln!(
-                                                    socket, "- {}={:.4}",
-                                                    stringify!($p), pid.parameters.$p
+                                        let send_free = socket.send_capacity() - socket.send_queue();
+                                        match channels.channel_state(channel).pid.summary(channel).to_json() {
+                                            Ok(buf) if buf.len() > send_free + 1 => {
+                                                // Not enough buffer space, skip report for now
+                                                warn!(
+                                                    "TCP socket has only {}/{} needed {}",
+                                                    send_free + 1, socket.send_capacity(), buf.len(),
                                                 );
-                                            };
                                             }
-                                        show_pid_parameter!(kp);
-                                        show_pid_parameter!(ki);
-                                        show_pid_parameter!(kd);
-                                        show_pid_parameter!(integral_min);
-                                        show_pid_parameter!(integral_max);
-                                        show_pid_parameter!(output_min);
-                                        show_pid_parameter!(output_max);
-                                        if let Some(last_output) = pid.last_output {
-                                            let _ = writeln!(socket, "- last_output={:.3} A", last_output);
+                                            Ok(buf) => {
+                                                match socket.send_slice(&buf) {
+                                                    Ok(sent) if sent == buf.len() => {
+                                                        let _ = socket.send_slice(b"\n");
+                                                        // success
+                                                    }
+                                                    Ok(sent) =>
+                                                        warn!("sent only {}/{} bytes of summary", sent, buf.len()),
+                                                    Err(e) =>
+                                                        error!("error sending summary: {:?}", e),
+                                                }
+                                            }
+                                            Err(e) =>
+                                                error!("unable to serialize pid summary: {:?}", e),
                                         }
-                                        let _ = writeln!(socket, "");
                                     }
                                 }
                                 Command::Show(ShowCommand::Pwm) => {

src/pid.rs

@@ -81,11 +81,35 @@ impl Controller {
         output
     }
 
-    #[allow(dead_code)]
     pub fn reset(&mut self) {
         self.integral = 0.0;
         self.last_input = None;
     }
+
+    pub fn summary(&self, channel: usize) -> Summary {
+        Summary {
+            channel,
+            parameters: self.parameters.clone(),
+            target: self.target,
+            integral: self.integral,
+        }
+    }
+}
+
+type JsonBuffer = heapless::Vec<u8, heapless::consts::U240>;
+
+#[derive(Clone, Serialize, Deserialize)]
+pub struct Summary {
+    channel: usize,
+    parameters: Parameters,
+    target: f64,
+    integral: f64,
+}
+
+impl Summary {
+    pub fn to_json(&self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
+        serde_json_core::to_vec(self)
+    }
 }
 
 #[cfg(test)]
@@ -126,4 +150,13 @@ mod test {
             total_t += 1;
         }
     }
+
+    #[test]
+    fn summary_to_json() {
+        let mut pid = Controller::new(PARAMETERS.clone());
+        pid.target = 30.0 / 1.1;
+        let buf = pid.summary(0).to_json().unwrap();
+        assert_eq!(buf[0], b'{');
+        assert_eq!(buf[buf.len() - 1], b'}');
+    }
 }