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|
use std::io::{Cursor, Read, Result as IoResult};
use bytes::Buf;
use criterion::*;
use input_buffer::InputBuffer;
use tungstenite::buffer::ReadBuffer;
const CHUNK_SIZE: usize = 4096;
/// A FIFO buffer for reading packets from the network.
#[derive(Debug)]
pub struct StackReadBuffer<const CHUNK_SIZE: usize> {
storage: Cursor<Vec<u8>>,
chunk: [u8; CHUNK_SIZE],
}
impl<const CHUNK_SIZE: usize> StackReadBuffer<CHUNK_SIZE> {
/// Create a new empty input buffer.
pub fn new() -> Self {
Self::with_capacity(CHUNK_SIZE)
}
/// Create a new empty input buffer with a given `capacity`.
pub fn with_capacity(capacity: usize) -> Self {
Self::from_partially_read(Vec::with_capacity(capacity))
}
/// Create a input buffer filled with previously read data.
pub fn from_partially_read(part: Vec<u8>) -> Self {
Self { storage: Cursor::new(part), chunk: [0; CHUNK_SIZE] }
}
/// Get a cursor to the data storage.
pub fn as_cursor(&self) -> &Cursor<Vec<u8>> {
&self.storage
}
/// Get a cursor to the mutable data storage.
pub fn as_cursor_mut(&mut self) -> &mut Cursor<Vec<u8>> {
&mut self.storage
}
/// Consume the `ReadBuffer` and get the internal storage.
pub fn into_vec(mut self) -> Vec<u8> {
// Current implementation of `tungstenite-rs` expects that the `into_vec()` drains
// the data from the container that has already been read by the cursor.
self.clean_up();
// Now we can safely return the internal container.
self.storage.into_inner()
}
/// Read next portion of data from the given input stream.
pub fn read_from<S: Read>(&mut self, stream: &mut S) -> IoResult<usize> {
self.clean_up();
let size = stream.read(&mut self.chunk)?;
self.storage.get_mut().extend_from_slice(&self.chunk[..size]);
Ok(size)
}
/// Cleans ups the part of the vector that has been already read by the cursor.
fn clean_up(&mut self) {
let pos = self.storage.position() as usize;
self.storage.get_mut().drain(0..pos).count();
self.storage.set_position(0);
}
}
impl<const CHUNK_SIZE: usize> Buf for StackReadBuffer<CHUNK_SIZE> {
fn remaining(&self) -> usize {
Buf::remaining(self.as_cursor())
}
fn chunk(&self) -> &[u8] {
Buf::chunk(self.as_cursor())
}
fn advance(&mut self, cnt: usize) {
Buf::advance(self.as_cursor_mut(), cnt)
}
}
impl<const CHUNK_SIZE: usize> Default for StackReadBuffer<CHUNK_SIZE> {
fn default() -> Self {
Self::new()
}
}
#[inline]
fn input_buffer(mut stream: impl Read) {
let mut buffer = InputBuffer::with_capacity(CHUNK_SIZE);
while buffer.read_from(&mut stream).unwrap() != 0 {}
}
#[inline]
fn stack_read_buffer(mut stream: impl Read) {
let mut buffer = StackReadBuffer::<CHUNK_SIZE>::new();
while buffer.read_from(&mut stream).unwrap() != 0 {}
}
#[inline]
fn heap_read_buffer(mut stream: impl Read) {
let mut buffer = ReadBuffer::<CHUNK_SIZE>::new();
while buffer.read_from(&mut stream).unwrap() != 0 {}
}
fn benchmark(c: &mut Criterion) {
const STREAM_SIZE: usize = 1024 * 1024 * 4;
let data: Vec<u8> = (0..STREAM_SIZE).map(|_| rand::random()).collect();
let stream = Cursor::new(data);
let mut group = c.benchmark_group("buffers");
group.throughput(Throughput::Bytes(STREAM_SIZE as u64));
group.bench_function("InputBuffer", |b| b.iter(|| input_buffer(black_box(stream.clone()))));
group.bench_function("ReadBuffer (stack)", |b| {
b.iter(|| stack_read_buffer(black_box(stream.clone())))
});
group.bench_function("ReadBuffer (heap)", |b| {
b.iter(|| heap_read_buffer(black_box(stream.clone())))
});
group.finish();
}
criterion_group!(benches, benchmark);
criterion_main!(benches);
|
