Line data    Source code

       1              : //! A heapless buffer for events of sorts.
       2              : 
       3              : use std::ops;
       4              : 
       5              : use heapless::HistoryBuffer;
       6              : 
       7         3153 : #[derive(Debug, Clone)]
       8              : pub struct HistoryBufferWithDropCounter<T, const L: usize> {
       9              :     buffer: HistoryBuffer<T, L>,
      10              :     drop_count: u64,
      11              : }
      12              : 
      13              : impl<T, const L: usize> HistoryBufferWithDropCounter<T, L> {
      14     33326894 :     pub fn write(&mut self, data: T) {
      15     33326894 :         let len_before = self.buffer.len();
      16     33326894 :         self.buffer.write(data);
      17     33326894 :         let len_after = self.buffer.len();
      18     33326894 :         self.drop_count += u64::from(len_before == len_after);
      19     33326894 :     }
      20           24 :     pub fn drop_count(&self) -> u64 {
      21           24 :         self.drop_count
      22           24 :     }
      23         3157 :     pub fn map<U, F: Fn(&T) -> U>(&self, f: F) -> HistoryBufferWithDropCounter<U, L> {
      24         3157 :         let mut buffer = HistoryBuffer::new();
      25         3157 :         buffer.extend(self.buffer.oldest_ordered().map(f));
      26         3157 :         HistoryBufferWithDropCounter::<U, L> {
      27         3157 :             buffer,
      28         3157 :             drop_count: self.drop_count,
      29         3157 :         }
      30         3157 :     }
      31              : }
      32              : 
      33              : impl<T, const L: usize> Default for HistoryBufferWithDropCounter<T, L> {
      34       302248 :     fn default() -> Self {
      35       302248 :         Self {
      36       302248 :             buffer: HistoryBuffer::default(),
      37       302248 :             drop_count: 0,
      38       302248 :         }
      39       302248 :     }
      40              : }
      41              : 
      42              : impl<T, const L: usize> ops::Deref for HistoryBufferWithDropCounter<T, L> {
      43              :     type Target = HistoryBuffer<T, L>;
      44              : 
      45         6272 :     fn deref(&self) -> &Self::Target {
      46         6272 :         &self.buffer
      47         6272 :     }
      48              : }
      49              : 
      50         6302 : #[derive(serde::Serialize)]
      51              : struct SerdeRepr<T> {
      52              :     buffer: Vec<T>,
      53              :     drop_count: u64,
      54              : }
      55              : 
      56              : impl<'a, T, const L: usize> From<&'a HistoryBufferWithDropCounter<T, L>> for SerdeRepr<T>
      57              : where
      58              :     T: Clone + serde::Serialize,
      59              : {
      60         6302 :     fn from(value: &'a HistoryBufferWithDropCounter<T, L>) -> Self {
      61         6302 :         let HistoryBufferWithDropCounter { buffer, drop_count } = value;
      62         6302 :         SerdeRepr {
      63         6302 :             buffer: buffer.iter().cloned().collect(),
      64         6302 :             drop_count: *drop_count,
      65         6302 :         }
      66         6302 :     }
      67              : }
      68              : 
      69              : impl<T, const L: usize> serde::Serialize for HistoryBufferWithDropCounter<T, L>
      70              : where
      71              :     T: Clone + serde::Serialize,
      72              : {
      73         6302 :     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
      74         6302 :     where
      75         6302 :         S: serde::Serializer,
      76         6302 :     {
      77         6302 :         SerdeRepr::from(self).serialize(serializer)
      78         6302 :     }
      79              : }
      80              : 
      81              : #[cfg(test)]
      82              : mod test {
      83              :     use super::HistoryBufferWithDropCounter;
      84              : 
      85            2 :     #[test]
      86            2 :     fn test_basics() {
      87            2 :         let mut b = HistoryBufferWithDropCounter::<_, 2>::default();
      88            2 :         b.write(1);
      89            2 :         b.write(2);
      90            2 :         b.write(3);
      91            4 :         assert!(b.iter().any(|e| *e == 2));
      92            2 :         assert!(b.iter().any(|e| *e == 3));
      93            4 :         assert!(!b.iter().any(|e| *e == 1));
      94            2 :     }
      95              : 
      96            2 :     #[test]
      97            2 :     fn test_drop_count_works() {
      98            2 :         let mut b = HistoryBufferWithDropCounter::<_, 2>::default();
      99            2 :         b.write(1);
     100            2 :         assert_eq!(b.drop_count(), 0);
     101            2 :         b.write(2);
     102            2 :         assert_eq!(b.drop_count(), 0);
     103            2 :         b.write(3);
     104            2 :         assert_eq!(b.drop_count(), 1);
     105            2 :         b.write(4);
     106            2 :         assert_eq!(b.drop_count(), 2);
     107            2 :     }
     108              : 
     109            2 :     #[test]
     110            2 :     fn test_clone_works() {
     111            2 :         let mut b = HistoryBufferWithDropCounter::<_, 2>::default();
     112            2 :         b.write(1);
     113            2 :         b.write(2);
     114            2 :         b.write(3);
     115            2 :         assert_eq!(b.drop_count(), 1);
     116            2 :         let mut c = b.clone();
     117            2 :         assert_eq!(c.drop_count(), 1);
     118            4 :         assert!(c.iter().any(|e| *e == 2));
     119            2 :         assert!(c.iter().any(|e| *e == 3));
     120            4 :         assert!(!c.iter().any(|e| *e == 1));
     121              : 
     122            2 :         c.write(4);
     123            4 :         assert!(c.iter().any(|e| *e == 4));
     124            4 :         assert!(!b.iter().any(|e| *e == 4));
     125            2 :     }
     126              : 
     127            2 :     #[test]
     128            2 :     fn test_map() {
     129            2 :         let mut b = HistoryBufferWithDropCounter::<_, 2>::default();
     130            2 : 
     131            2 :         b.write(1);
     132            2 :         assert_eq!(b.drop_count(), 0);
     133              :         {
     134            2 :             let c = b.map(|i| i + 10);
     135            2 :             assert_eq!(c.oldest_ordered().cloned().collect::<Vec<_>>(), vec![11]);
     136            2 :             assert_eq!(c.drop_count(), 0);
     137              :         }
     138              : 
     139            2 :         b.write(2);
     140            2 :         assert_eq!(b.drop_count(), 0);
     141              :         {
     142            4 :             let c = b.map(|i| i + 10);
     143            2 :             assert_eq!(
     144            2 :                 c.oldest_ordered().cloned().collect::<Vec<_>>(),
     145            2 :                 vec![11, 12]
     146            2 :             );
     147            2 :             assert_eq!(c.drop_count(), 0);
     148              :         }
     149              : 
     150            2 :         b.write(3);
     151            2 :         assert_eq!(b.drop_count(), 1);
     152              :         {
     153            4 :             let c = b.map(|i| i + 10);
     154            2 :             assert_eq!(
     155            2 :                 c.oldest_ordered().cloned().collect::<Vec<_>>(),
     156            2 :                 vec![12, 13]
     157            2 :             );
     158            2 :             assert_eq!(c.drop_count(), 1);
     159              :         }
     160            2 :     }
     161              : }