Refactor: create a BytesBuf utility crate (will also be usefull in Garage)

1 files changed, 9 insertions, 43 deletions

diff --git a/src/stream.rs b/src/stream.rs
index 5ba2ed4..cc664ce 100644
--- a/src/stream.rs
+++ b/src/stream.rs
@@ -1,4 +1,3 @@
-use std::collections::VecDeque;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
@@ -8,6 +7,8 @@ use futures::Future;
 use futures::{Stream, StreamExt, TryStreamExt};
 use tokio::io::AsyncRead;
 
+use crate::bytes_buf::BytesBuf;
+
 /// A stream of associated data.
 ///
 /// When sent through Netapp, the Vec may be split in smaller chunk in such a way
@@ -23,8 +24,7 @@ pub type Packet = Result<Bytes, u8>;
 
 pub struct ByteStreamReader {
 	stream: ByteStream,
-	buf: VecDeque<Bytes>,
-	buf_len: usize,
+	buf: BytesBuf,
 	eos: bool,
 	err: Option<u8>,
 }
@@ -33,8 +33,7 @@ impl ByteStreamReader {
 	pub fn new(stream: ByteStream) -> Self {
 		ByteStreamReader {
 			stream,
-			buf: VecDeque::with_capacity(8),
-			buf_len: 0,
+			buf: BytesBuf::new(),
 			eos: false,
 			err: None,
 		}
@@ -75,7 +74,7 @@ impl ByteStreamReader {
 	}
 
 	pub fn into_stream(self) -> ByteStream {
-		let buf_stream = futures::stream::iter(self.buf.into_iter().map(Ok));
+		let buf_stream = futures::stream::iter(self.buf.into_slices().into_iter().map(Ok));
 		if let Some(err) = self.err {
 			Box::pin(buf_stream.chain(futures::stream::once(async move { Err(err) })))
 		} else if self.eos {
@@ -86,45 +85,15 @@ impl ByteStreamReader {
 	}
 
 	pub fn take_buffer(&mut self) -> Bytes {
-		let bytes = Bytes::from(self.buf.iter().map(|x| &x[..]).collect::<Vec<_>>().concat());
-		self.buf.clear();
-		self.buf_len = 0;
-		bytes
+		self.buf.take_all()
 	}
 
 	pub fn eos(&self) -> bool {
-		self.buf_len == 0 && self.eos
+		self.buf.is_empty() && self.eos
 	}
 
 	fn try_get(&mut self, read_len: usize) -> Option<Bytes> {
-		if self.buf_len >= read_len {
-			let mut slices = Vec::with_capacity(self.buf.len());
-			let mut taken = 0;
-			while taken < read_len {
-				let front = self.buf.pop_front().unwrap();
-				if taken + front.len() <= read_len {
-					taken += front.len();
-					self.buf_len -= front.len();
-					slices.push(front);
-				} else {
-					let front_take = read_len - taken;
-					slices.push(front.slice(..front_take));
-					self.buf.push_front(front.slice(front_take..));
-					self.buf_len -= front_take;
-					break;
-				}
-			}
-			Some(
-				slices
-					.iter()
-					.map(|x| &x[..])
-					.collect::<Vec<_>>()
-					.concat()
-					.into(),
-			)
-		} else {
-			None
-		}
+		self.buf.take_exact(read_len)
 	}
 }
 
@@ -164,10 +133,7 @@ impl<'a> Future for ByteStreamReadExact<'a> {
 
 			match futures::ready!(this.reader.stream.as_mut().poll_next(cx)) {
 				Some(Ok(slice)) => {
-					if !slice.is_empty() {
-						this.reader.buf_len += slice.len();
-						this.reader.buf.push_back(slice);
-					}
+					this.reader.buf.extend(slice);
 				}
 				Some(Err(e)) => {
 					this.reader.err = Some(e);