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use crate::network::protocol::Protocol;
use alloc::vec::Vec;
use bytes::Bytes;
#[derive(Debug, Clone)]
pub struct MemoryParameters {
pub buffer_size: usize,
pub frame_capacity: usize,
}
impl Default for MemoryParameters {
fn default() -> Self {
Self {
buffer_size: 256,
frame_capacity: 8,
}
}
}
pub(crate) struct ResponseBuffer<P: Protocol> {
decoder: P,
buffer: Vec<u8>,
frames: Vec<Option<P::FrameType>>,
frame_count: usize,
frame_offset: usize,
faulty: bool,
}
impl<P: Protocol> ResponseBuffer<P> {
pub fn new(protocol: P, parameters: MemoryParameters) -> ResponseBuffer<P> {
Self {
decoder: protocol,
buffer: Vec::with_capacity(parameters.buffer_size),
frames: Vec::with_capacity(parameters.frame_capacity),
frame_count: 0,
frame_offset: 0,
faulty: false,
}
}
pub fn append(&mut self, data: &[u8]) {
self.buffer.extend_from_slice(data);
self.parse_frames();
}
pub fn take_frame(&mut self, mut index: usize) -> Option<P::FrameType> {
if index < self.frame_offset {
return None;
}
index -= self.frame_offset;
if self.frames.len() <= index {
return None;
}
let frame = self.frames[index].take();
if frame.is_some() {
self.frame_count -= 1;
}
if self.frame_count == 0 {
self.frame_offset += self.frames.len();
self.frames.clear();
}
frame
}
pub fn take_next_frame(&mut self) -> Option<P::FrameType> {
let index = self.frames.iter().position(|x| x.is_some())?;
self.take_frame(index + self.frame_offset)
}
fn parse_frames(&mut self) {
let mut start = 0;
let mut last_termination = None;
while !self.faulty {
let termination = self.parse_frame(start);
if termination.is_none() {
break;
}
start = termination.unwrap() + 1;
last_termination = termination;
}
if last_termination.is_none() {
return;
}
if (last_termination.unwrap() + 1) == self.buffer.len() {
return self.buffer.clear();
}
self.buffer.drain(..=last_termination.unwrap());
}
fn parse_frame(&mut self, start: usize) -> Option<usize> {
if start >= self.buffer.len() {
return None;
}
let bytes = Bytes::from(self.buffer[start..].to_vec());
let result = self.decoder.decode(&bytes);
if result.is_err() {
self.faulty = true;
return None;
}
if result.as_ref().unwrap().is_none() {
return None;
}
let frame = result.unwrap().unwrap();
self.frames.push(Some(frame.0));
self.frame_count += 1;
Some(frame.1 - 1 + start)
}
pub fn is_complete(&self, mut index: usize) -> bool {
if index < self.frame_offset {
return false;
}
index -= self.frame_offset;
self.frames.len() > index
}
pub fn is_faulty(&self) -> bool {
self.faulty
}
pub fn clear(&mut self) {
self.frames.clear();
self.buffer.clear();
self.frame_offset = 0;
self.frame_count = 0;
self.faulty = false;
}
#[cfg(test)]
pub fn pending_frame_count(&self) -> usize {
self.frame_count
}
#[cfg(test)]
pub fn frame_offset(&self) -> usize {
self.frame_offset
}
}