Debug shm reader

src/additional_rfactor.rs

@@ -64,6 +64,24 @@ impl From<&[u8]> for rF2Telemetry {
     }
 }
 
+impl From<&[u8]> for ScoringInfoV01 {
+    fn from(value: &[u8]) -> Self {
+        debug_assert!(value.len() == mem::size_of::<Self>());
+        let fixed_size: [u8; mem::size_of::<Self>()] = value.try_into().unwrap();
+
+        unsafe { mem::transmute(fixed_size) }
+    }
+}
+
+impl From<&[u8]> for VehicleScoringInfoV01 {
+    fn from(value: &[u8]) -> Self {
+        debug_assert!(value.len() == mem::size_of::<Self>());
+        let fixed_size: [u8; mem::size_of::<Self>()] = value.try_into().unwrap();
+
+        unsafe { mem::transmute(fixed_size) }
+    }
+}
+
 #[repr(C, packed(4))]
 #[derive(Debug, Copy, Clone)]
 pub struct rF2Scoring {
@@ -233,5 +251,5 @@ pub struct rF2Wheel {
     pub tire_carcass_temperature: f64,
     pub tire_inner_layer_temperature: [f64; 3],
 
-    expansion: [::std::os::raw::c_uchar; 24],
+    expansion: [u8; 24],
 }

src/lib.rs

@@ -2,7 +2,7 @@ pub mod additional_rfactor;
 #[allow(warnings)]
 mod rfactor_structs;
 
-use std::{cell::Cell, fs::File, marker::PhantomData, path::Path};
+use std::{cell::Cell, fs::File, mem, path::Path};
 
 use additional_rfactor::*;
 pub use additional_rfactor::{rF2Vec3, rF2VehicleTelemetry, rF2Wheel};
@@ -12,19 +12,17 @@ pub use rfactor_structs::{ScoringInfoV01, VehicleScoringInfoV01};
 
 const RFACTOR_SHM_FILE: &str = "/dev/shm";
 
-struct ShMReader<T> {
+struct ShMReader {
     _file: File,
     shm: Mmap,
 
     version: Cell<VersionHeader>,
-
+    last_query: Cell<f32>,
-    data: PhantomData<T>,
+    time_between_writes: f32,
 }
 
-impl<T> ShMReader<T> {
+impl ShMReader {
-    const SIZE: usize = std::mem::size_of::<T>();
+    fn new(mm_file_name: &str, now: f32, time_between_writes: f32) -> Result<Self> {
-
-    fn new(mm_file_name: &str) -> Result<Self> {
         let file = File::open(Path::new(RFACTOR_SHM_FILE).join(mm_file_name))?;
         let mmap = unsafe { Mmap::map(&file)? };
 
@@ -33,67 +31,243 @@ impl<T> ShMReader<T> {
             shm: mmap,
 
             version: Cell::new(VersionHeader::default()),
-
+            last_query: Cell::new(now),
-            data: PhantomData,
+            time_between_writes,
         })
     }
 
     fn check_version_update(&self) -> bool {
+        log("In ShMReader: start check version update");
         let new_version = VersionHeader::from(&self.shm[0..VersionHeader::SIZE]);
 
         let are_different = self.version.get().check_for_update(&new_version);
 
         if are_different {
+            log("In ShMReader: new version found");
             self.version.set(new_version);
         }
 
         are_different
     }
+
+    fn check_time(&self, now: f32) -> bool {
+        log("In ShMReader: start time check");
+
+        if now < self.last_query.get() + self.time_between_writes {
+            log("In ShMReader: time check failed");
+            return false;
         }
 
-impl<'a, T> ShMReader<T>
+        self.last_query.set(now);
-where
+
-    T: From<&'a [u8]>,
+        true
-{
-    fn read(&'a self) -> Option<T> {
-        if self.check_version_update() {
-            Some(T::from(&self.shm[0..Self::SIZE]))
-        } else {
-            None
     }
+
+    fn read(&self, offset: usize, length: usize) -> &[u8] {
+        log(format!(
+            "In ShMReader: read (offset: {}, length: {})",
+            offset, length
+        ));
+        let b = &self.shm[offset..offset + length];
+
+        debug_assert_eq!(b.len(), length);
+        log(format!("In ShMReader: successfully read {} bytes", b.len()));
+
+        b
     }
 }
 
 pub struct TelemetryReader {
-    mm_reader: ShMReader<rF2Telemetry>,
+    mm_reader: ShMReader,
 }
 
 impl TelemetryReader {
-    pub fn new() -> Result<Self> {
+    pub fn new(now: f32) -> Result<Self> {
+        // telemetry gets updated 50 times per second
+        const WAIT_TIME: f32 = 1.0 / 50.0;
+
         Ok(Self {
-            mm_reader: ShMReader::new(MM_TELEMETRY_FILE_NAME)?,
+            mm_reader: ShMReader::new(MM_TELEMETRY_FILE_NAME, now, WAIT_TIME)?,
         })
     }
 
-    pub fn query_telemetry(&self) -> Option<Vec<rF2VehicleTelemetry>> {
+    pub fn query_telemetry(&self, now: f32) -> Option<Vec<rF2VehicleTelemetry>> {
-        self.mm_reader.read().map(|v| v.vehicles().to_vec())
+        log("In TelemetryReader: start query telemetry");
+
+        if !self.mm_reader.check_time(now) || !self.mm_reader.check_version_update() {
+            return None;
+        }
+
+        log("In TelemetryReader: read num vehicles");
+
+        // first: query only the amount of vehicles
+        let num_vehicles = i32::from_be_bytes(
+            self.mm_reader
+                .read(VersionHeader::SIZE, mem::size_of::<i32>())
+                .try_into()
+                .unwrap(),
+        );
+
+        log(format!(
+            "In TelemetryReader: vehicle count {}",
+            num_vehicles
+        ));
+
+        debug_assert!(num_vehicles >= 0);
+        debug_assert!(num_vehicles < MAX_MAPPED_VEHICLES as i32);
+
+        log("In TelemetryReader: read vehicles");
+
+        // query only the required amount of memory based on vehicle count
+        let vehicles: &[rF2VehicleTelemetry] = unsafe {
+            mem::transmute(self.mm_reader.read(
+                VersionHeader::SIZE + mem::size_of::<i32>(),
+                mem::size_of::<rF2VehicleTelemetry>() * num_vehicles as usize,
+            ))
+        };
+
+        log(format!(
+            "In TelemetryReader: successfully read vehicles ({})",
+            vehicles.len()
+        ));
+
+        debug_assert_eq!(num_vehicles as usize, vehicles.len());
+
+        Some(vehicles.to_vec())
     }
 }
 
 pub struct ScoringReader {
-    mm_reader: ShMReader<rF2Scoring>,
+    mm_reader: ShMReader,
 }
 
 impl ScoringReader {
-    pub fn new() -> Result<Self> {
+    pub fn new(now: f32) -> Result<Self> {
+        // scoring gets updated 5 times per second
+        const WAIT_TIME: f32 = 1.0 / 5.0;
+
         Ok(Self {
-            mm_reader: ShMReader::new(MM_SCORING_FILE_NAME)?,
+            mm_reader: ShMReader::new(MM_SCORING_FILE_NAME, now, WAIT_TIME)?,
         })
     }
 
-    pub fn vehicle_scoring(&self) -> Option<(ScoringInfoV01, Vec<VehicleScoringInfoV01>)> {
+    pub fn vehicle_scoring(
+        &self,
+        now: f32,
+    ) -> Option<(ScoringInfoV01, Vec<VehicleScoringInfoV01>)> {
+        log("In ScoringReader: start vehicle scoring");
+
+        if !self.mm_reader.check_time(now) || !self.mm_reader.check_version_update() {
+            return None;
+        }
+
+        log("In ScoringReader: read scoring info");
+
+        let scoring_info = ScoringInfoV01::from(
             self.mm_reader
-            .read()
+                .read(VersionHeader::SIZE, mem::size_of::<ScoringInfoV01>()),
-            .map(|s| (s.scoring_info, s.vehicles().to_vec()))
+        );
+
+        log(format!(
+            "In ScoringReader: successfully read scoring info (num vehicles {})",
+            scoring_info.mNumVehicles
+        ));
+
+        let vehicle_info: &[VehicleScoringInfoV01] = unsafe {
+            mem::transmute(self.mm_reader.read(
+                VersionHeader::SIZE + mem::size_of::<ScoringInfoV01>(),
+                mem::size_of::<VehicleScoringInfoV01>() * scoring_info.mNumVehicles as usize,
+            ))
+        };
+
+        debug_assert_eq!(scoring_info.mNumVehicles as usize, vehicle_info.len());
+
+        Some((scoring_info, vehicle_info.to_vec()))
+    }
+}
+
+pub fn log(msg: impl ToString) {
+    let home = std::env::var("HOME").unwrap();
+    let log_file = format!("{}/rf2_vk_hud.log", home);
+
+    if let Ok(mut file) = std::fs::OpenOptions::new()
+        .append(true)
+        .create(true)
+        .open(&log_file)
+    {
+        if let Err(_) =
+            std::io::Write::write_all(&mut file, format!("{}\n", msg.to_string()).as_bytes())
+        {
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{
+        thread::sleep,
+        time::{Duration, Instant},
+    };
+
+    use super::*;
+
+    #[test]
+    fn test_telemetry() {
+        let start = Instant::now();
+        let telemetry_reader = TelemetryReader::new(start.elapsed().as_secs_f32()).unwrap();
+
+        for _ in 0..25 {
+            telemetry_reader.query_telemetry(start.elapsed().as_secs_f32());
+            sleep(Duration::from_secs(2));
+        }
+    }
+
+    #[test]
+    fn test_scoring() {
+        let start = Instant::now();
+        let scoring_reader = ScoringReader::new(start.elapsed().as_secs_f32()).unwrap();
+
+        for _ in 0..25 {
+            scoring_reader.vehicle_scoring(start.elapsed().as_secs_f32());
+            sleep(Duration::from_secs(2));
+        }
+    }
+
+    #[test]
+    fn test_combined() {
+        let start = Instant::now();
+        let scoring_reader = ScoringReader::new(start.elapsed().as_secs_f32()).unwrap();
+        let telemetry_reader = TelemetryReader::new(start.elapsed().as_secs_f32()).unwrap();
+
+        let mut player_id = None;
+
+        for _ in 0..25 {
+            if let Some((score, vehicles)) =
+                scoring_reader.vehicle_scoring(start.elapsed().as_secs_f32())
+            {
+                if score.mNumVehicles == 0 {
+                    player_id = None;
+                } else if player_id.is_none() {
+                    for vehicle in vehicles {
+                        if vehicle.mIsPlayer != 0 {
+                            player_id = Some(vehicle.mID);
+                            break;
+                        }
+                    }
+                }
+            }
+
+            if player_id.is_some() {
+                if let Some(telemetries) =
+                    telemetry_reader.query_telemetry(start.elapsed().as_secs_f32())
+                {
+                    for telemetry in telemetries {
+                        println!("ID: {}", telemetry.id);
+                    }
+                }
+            }
+
+            sleep(Duration::from_secs(2));
+        }
     }
 }