lockin: move fifo trait before use

This clarifies what it means to "push" to an array.
This commit is contained in:
Matt Huszagh 2020-11-24 23:30:57 -08:00
parent 8806feb423
commit 3c4e83bf0f
1 changed files with 26 additions and 26 deletions

View File

@ -74,6 +74,32 @@ pub const TIMESTAMP_BUFFER_SIZE: usize = ADC_SAMPLE_BUFFER_SIZE / 2;
/// The number of outputs sent to the DAC for each ADC batch.
pub const DECIMATED_BUFFER_SIZE: usize = 1;
/// Treat the 2-element array as a FIFO. This allows new elements to
/// be pushed into the array, existing elements to shift back in the
/// array, and the last element to fall off the array.
trait Fifo2<T> {
fn push(&mut self, new_element: Option<T>);
}
impl<T: Copy> Fifo2<T> for [Option<T>; 2] {
/// Push a new element into the array. The existing elements move
/// backward in the array by one location, and the current last
/// element is discarded.
///
/// # Arguments
///
/// * `new_element` - New element pushed into the front of the
/// array.
fn push(&mut self, new_element: Option<T>) {
// For array sizes greater than 2 it would be preferable to
// use a rotating index to avoid unnecessary data
// copying. However, this would somewhat complicate the use of
// iterators and for 2 elements, shifting is inexpensive.
self[1] = self[0];
self[0] = new_element;
}
}
/// Performs lock-in amplifier processing of a signal.
pub struct Lockin {
phase_offset: f32,
@ -274,32 +300,6 @@ pub fn magnitude_phase(in_phase: &mut [f32], quadrature: &mut [f32]) {
});
}
/// Treat the 2-element array as a FIFO. This allows new elements to
/// be pushed into the array, existing elements to shift back in the
/// array, and the last element to fall off the array.
trait Fifo2<T> {
fn push(&mut self, new_element: Option<T>);
}
impl<T: Copy> Fifo2<T> for [Option<T>; 2] {
/// Push a new element into the array. The existing elements move
/// backward in the array by one location, and the current last
/// element is discarded.
///
/// # Arguments
///
/// * `new_element` - New element pushed into the front of the
/// array.
fn push(&mut self, new_element: Option<T>) {
// For array sizes greater than 2 it would be preferable to
// use a rotating index to avoid unnecessary data
// copying. However, this would somewhat complicate the use of
// iterators and for 2 elements, shifting is inexpensive.
self[1] = self[0];
self[0] = new_element;
}
}
#[cfg(test)]
mod tests {
use super::*;