Remove send_queue, use out_buffer instead

This commit is contained in:
Alex Butler 2023-05-24 17:12:23 +01:00
parent 483d229707
commit 0203a1849b
4 changed files with 155 additions and 164 deletions

View File

@ -27,14 +27,12 @@ fn main() {
};
let config = Some(WebSocketConfig {
max_send_queue: None,
max_message_size: None,
max_frame_size: None,
// This setting allows to accept client frames which are not masked
// This is not in compliance with RFC 6455 but might be handy in some
// rare cases where it is necessary to integrate with existing/legacy
// clients which are sending unmasked frames
accept_unmasked_frames: true,
..<_>::default()
});
let mut websocket = accept_hdr_with_config(stream.unwrap(), callback, config).unwrap();

View File

@ -53,9 +53,9 @@ pub enum Error {
/// Protocol violation.
#[error("WebSocket protocol error: {0}")]
Protocol(#[from] ProtocolError),
/// Message send queue full.
#[error("Send queue is full")]
SendQueueFull(Message),
/// Message write buffer is full.
#[error("Write buffer is full")]
WriteBufferFull(Message),
/// UTF coding error.
#[error("UTF-8 encoding error")]
Utf8,

View File

@ -6,15 +6,14 @@ pub mod coding;
mod frame;
mod mask;
use std::io::{Error as IoError, ErrorKind as IoErrorKind, Read, Write};
use log::*;
pub use self::frame::{CloseFrame, Frame, FrameHeader};
use crate::{
error::{CapacityError, Error, Result},
ReadBuffer,
Message, ReadBuffer,
};
use log::*;
use std::io::{Error as IoError, ErrorKind as IoErrorKind, Read, Write};
pub use self::frame::{CloseFrame, Frame, FrameHeader};
/// A reader and writer for WebSocket frames.
#[derive(Debug)]
@ -89,6 +88,8 @@ pub(super) struct FrameCodec {
in_buffer: ReadBuffer,
/// Buffer to send packets to the network.
out_buffer: Vec<u8>,
/// Capacity limit for `out_buffer`.
max_out_buffer_len: usize,
/// Header and remaining size of the incoming packet being processed.
header: Option<(FrameHeader, u64)>,
}
@ -96,7 +97,12 @@ pub(super) struct FrameCodec {
impl FrameCodec {
/// Create a new frame codec.
pub(super) fn new() -> Self {
Self { in_buffer: ReadBuffer::new(), out_buffer: Vec::new(), header: None }
Self {
in_buffer: ReadBuffer::new(),
out_buffer: Vec::new(),
max_out_buffer_len: usize::MAX,
header: None,
}
}
/// Create a new frame codec from partially read data.
@ -104,10 +110,22 @@ impl FrameCodec {
Self {
in_buffer: ReadBuffer::from_partially_read(part),
out_buffer: Vec::new(),
max_out_buffer_len: usize::MAX,
header: None,
}
}
/// Sets a maximum size for the out buffer.
pub(super) fn with_max_out_buffer_len(mut self, max: usize) -> Self {
self.max_out_buffer_len = max;
self
}
/// Sets a maximum size for the out buffer.
pub(super) fn set_max_out_buffer_len(&mut self, max: usize) {
self.max_out_buffer_len = max;
}
/// Read a frame from the provided stream.
pub(super) fn read_frame<Stream>(
&mut self,
@ -173,10 +191,25 @@ impl FrameCodec {
where
Stream: Write,
{
if frame.len() + self.out_buffer.len() > self.max_out_buffer_len {
return Err(Error::WriteBufferFull(Message::Frame(frame)));
}
trace!("writing frame {}", frame);
self.out_buffer.reserve(frame.len());
frame.format(&mut self.out_buffer).expect("Bug: can't write to vector");
self.write_out_buffer(stream)
}
/// Write any buffered frames to the provided stream.
///
/// Does **not** flush.
pub(super) fn write_out_buffer<Stream>(&mut self, stream: &mut Stream) -> Result<()>
where
Stream: Write,
{
while !self.out_buffer.is_empty() {
let len = stream.write(&self.out_buffer)?;
if len == 0 {
@ -194,14 +227,6 @@ impl FrameCodec {
}
}
#[cfg(test)]
impl FrameCodec {
/// Returns the size of the output buffer.
pub(super) fn output_buffer_len(&self) -> usize {
self.out_buffer.len()
}
}
#[cfg(test)]
mod tests {

View File

@ -6,13 +6,6 @@ mod message;
pub use self::{frame::CloseFrame, message::Message};
use log::*;
use std::{
collections::VecDeque,
io::{ErrorKind as IoErrorKind, Read, Write},
mem::replace,
};
use self::{
frame::{
coding::{CloseCode, Control as OpCtl, Data as OpData, OpCode},
@ -24,6 +17,11 @@ use crate::{
error::{Error, ProtocolError, Result},
util::NonBlockingResult,
};
use log::*;
use std::{
io::{ErrorKind as IoErrorKind, Read, Write},
mem::replace,
};
/// Indicates a Client or Server role of the websocket
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
@ -37,10 +35,12 @@ pub enum Role {
/// The configuration for WebSocket connection.
#[derive(Debug, Clone, Copy)]
pub struct WebSocketConfig {
/// The size of the send queue. You can use it to turn on/off the backpressure features. `None`
/// means here that the size of the queue is unlimited. The default value is the unlimited
/// queue.
/// Does nothing, instead use `max_write_buffer_size`.
#[deprecated]
pub max_send_queue: Option<usize>,
/// The max size of the write buffer in bytes. Setting this can provide backpressure.
/// The default value is unlimited.
pub max_write_buffer_size: usize,
/// The maximum size of a message. `None` means no size limit. The default value is 64 MiB
/// which should be reasonably big for all normal use-cases but small enough to prevent
/// memory eating by a malicious user.
@ -60,8 +60,10 @@ pub struct WebSocketConfig {
impl Default for WebSocketConfig {
fn default() -> Self {
#[allow(deprecated)]
WebSocketConfig {
max_send_queue: None,
max_write_buffer_size: usize::MAX,
max_message_size: Some(64 << 20),
max_frame_size: Some(16 << 20),
accept_unmasked_frames: false,
@ -162,17 +164,24 @@ impl<Stream: Read + Write> WebSocket<Stream> {
self.context.read_message(&mut self.socket)
}
/// Send a message to stream, if possible.
/// Write a message to the provided stream, if possible.
///
/// WebSocket will buffer a configurable number of messages at a time, except to reply to Ping
/// requests. A Pong reply will jump the queue because the
/// A subsequent call should be made to [`Self::write_pending`] to flush writes.
///
/// In the event of stream write failure the message frame will be stored
/// in the write buffer and will try again on the next call to [`Self::write_message`] or [`Self::write_pending`].
///
/// If the write buffer would exceed the configured [`WebSocketConfig::max_write_buffer_size`]
/// `Err(WriteBufferFull(msg_frame))` is returned.
///
/// This call will not flush, except to reply to Ping
/// requests. A Pong reply will flush early because the
/// [websocket RFC](https://tools.ietf.org/html/rfc6455#section-5.5.2) specifies it should be sent
/// as soon as is practical.
///
/// Note that upon receiving a ping message, tungstenite cues a pong reply automatically.
/// When you call either `read_message`, `write_message` or `write_pending` next it will try to send
/// that pong out if the underlying connection can take more data. This means you should not
/// respond to ping frames manually.
/// When you call either `read_message`, `write_message` or `write_pending` next it will try to
/// write & flush the pong reply if possible. This means you should not respond to ping frames manually.
///
/// You can however send pong frames manually in order to indicate a unidirectional heartbeat
/// as described in [RFC 6455](https://tools.ietf.org/html/rfc6455#section-5.5.3). Note that
@ -181,19 +190,19 @@ impl<Stream: Read + Write> WebSocket<Stream> {
/// ping will not be sent, but rather replaced by your custom pong message.
///
/// ## Errors
/// - If the WebSocket's send queue is full, `SendQueueFull` will be returned
/// along with the passed message. Otherwise, the message is queued and Ok(()) is returned.
/// - If the connection is closed and should be dropped, this will return [Error::ConnectionClosed].
/// - If you try again after [Error::ConnectionClosed] was returned either from here or from `read_message`,
/// [Error::AlreadyClosed] will be returned. This indicates a program error on your part.
/// - [Error::Io] is returned if the underlying connection returns an error
/// - If the WebSocket's write buffer is full, [`Error::WriteBufferFull`] will be returned
/// along with the equivalent passed message frame. Otherwise, the message is queued and Ok(()) is returned.
/// - If the connection is closed and should be dropped, this will return [`Error::ConnectionClosed`].
/// - If you try again after [`Error::ConnectionClosed`] was returned either from here or from `read_message`,
/// [`Error::AlreadyClosed`] will be returned. This indicates a program error on your part.
/// - [`Error::Io`] is returned if the underlying connection returns an error
/// (consider these fatal except for WouldBlock).
/// - [Error::Capacity] if your message size is bigger than the configured max message size.
/// - [`Error::Capacity`] if your message size is bigger than the configured max message size.
pub fn write_message(&mut self, message: Message) -> Result<()> {
self.context.write_message(&mut self.socket, message)
}
/// Flush the pending send queue.
/// Flush pending writes.
pub fn write_pending(&mut self) -> Result<()> {
self.context.write_pending(&mut self.socket)
}
@ -235,10 +244,8 @@ pub struct WebSocketContext {
state: WebSocketState,
/// Receive: an incomplete message being processed.
incomplete: Option<IncompleteMessage>,
/// Send: a data send queue.
send_queue: VecDeque<Frame>,
/// Send: an OOB pong message.
pong: Option<Frame>,
/// Send in addition to regular messages E.g. "pong" or "close".
additional_send: Option<Frame>,
/// The configuration for the websocket session.
config: WebSocketConfig,
}
@ -246,28 +253,32 @@ pub struct WebSocketContext {
impl WebSocketContext {
/// Create a WebSocket context that manages a post-handshake stream.
pub fn new(role: Role, config: Option<WebSocketConfig>) -> Self {
let config = config.unwrap_or_default();
WebSocketContext {
role,
frame: FrameCodec::new(),
frame: FrameCodec::new().with_max_out_buffer_len(config.max_write_buffer_size),
state: WebSocketState::Active,
incomplete: None,
send_queue: VecDeque::new(),
pong: None,
config: config.unwrap_or_default(),
additional_send: None,
config,
}
}
/// Create a WebSocket context that manages an post-handshake stream.
pub fn from_partially_read(part: Vec<u8>, role: Role, config: Option<WebSocketConfig>) -> Self {
let config = config.unwrap_or_default();
WebSocketContext {
frame: FrameCodec::from_partially_read(part),
..WebSocketContext::new(role, config)
frame: FrameCodec::from_partially_read(part)
.with_max_out_buffer_len(config.max_write_buffer_size),
..WebSocketContext::new(role, Some(config))
}
}
/// Change the configuration.
pub fn set_config(&mut self, set_func: impl FnOnce(&mut WebSocketConfig)) {
set_func(&mut self.config)
set_func(&mut self.config);
self.frame.set_max_out_buffer_len(self.config.max_write_buffer_size);
}
/// Read the configuration.
@ -299,12 +310,19 @@ impl WebSocketContext {
Stream: Read + Write,
{
// Do not read from already closed connections.
self.state.check_active()?;
self.state.check_not_terminated()?;
loop {
// Since we may get ping or close, we need to reply to the messages even during read.
// Thus we call write_pending() but ignore its blocking.
self.write_pending(stream).no_block()?;
if self.additional_send.is_some() {
// Since we may get ping or close, we need to reply to the messages even during read.
// Thus we call write_pending() but ignore its blocking.
self.write_pending(stream).no_block()?;
} else if self.role == Role::Server && !self.state.can_read() {
self.state = WebSocketState::Terminated;
return Err(Error::ConnectionClosed);
}
// TODO don't flush writes when reading
// If we get here, either write blocks or we have nothing to write.
// Thus if read blocks, just let it return WouldBlock.
if let Some(message) = self.read_message_frame(stream)? {
@ -314,87 +332,84 @@ impl WebSocketContext {
}
}
/// Send a message to the provided stream, if possible.
/// Write a message to the provided stream, if possible.
///
/// WebSocket will buffer a configurable number of messages at a time, except to reply to Ping
/// and Close requests. If the WebSocket's send queue is full, `SendQueueFull` will be returned
/// along with the passed message. Otherwise, the message is queued and Ok(()) is returned.
/// A subsequent call should be made to [`Self::write_pending`] to flush writes.
///
/// Note that only the last pong frame is stored to be sent, and only the
/// In the event of stream write failure the message frame will be stored
/// in the write buffer and will try again on the next call to [`Self::write_message`] or [`Self::write_pending`].
///
/// If the write buffer would exceed the configured [`WebSocketConfig::max_write_buffer_size`]
/// `Err(WriteBufferFull(msg_frame))` is returned.
///
/// Note that only the latest pong frame is stored to be sent, so only the
/// most recent pong frame is sent if multiple pong frames are queued.
pub fn write_message<Stream>(&mut self, stream: &mut Stream, message: Message) -> Result<()>
where
Stream: Read + Write,
{
// When terminated, return AlreadyClosed.
self.state.check_active()?;
self.state.check_not_terminated()?;
// Do not write after sending a close frame.
if !self.state.is_active() {
return Err(Error::Protocol(ProtocolError::SendAfterClosing));
}
if let Some(max_send_queue) = self.config.max_send_queue {
if self.send_queue.len() >= max_send_queue {
// Try to make some room for the new message.
// Do not return here if write would block, ignore WouldBlock silently
// since we must queue the message anyway.
self.write_pending(stream).no_block()?;
}
if self.send_queue.len() >= max_send_queue {
return Err(Error::SendQueueFull(message));
}
}
let frame = match message {
Message::Text(data) => Frame::message(data.into(), OpCode::Data(OpData::Text), true),
Message::Binary(data) => Frame::message(data, OpCode::Data(OpData::Binary), true),
Message::Ping(data) => Frame::ping(data),
Message::Pong(data) => {
self.pong = Some(Frame::pong(data));
return self.write_queue(stream);
self.set_additional(Frame::pong(data));
// Note: user pongs can be user flushed so no need to flush here
return self.write(stream, None).map(|_| ());
}
Message::Close(code) => return self.close(stream, code),
Message::Frame(f) => f,
};
self.send_queue.push_back(frame);
self.write_queue(stream)
let should_flush = self.write(stream, Some(frame))?;
if should_flush {
self.write_pending(stream)?;
}
Ok(())
}
/// Flush the pending send queue.
/// Flush pending writes.
#[inline]
pub fn write_pending<Stream>(&mut self, stream: &mut Stream) -> Result<()>
where
Stream: Read + Write,
{
self.write_queue(stream)?;
_ = self.write(stream, None)?;
Ok(stream.flush()?)
}
/// Write send queue & pongs.
///
/// Does **not** flush.
fn write_queue<Stream>(&mut self, stream: &mut Stream) -> Result<()>
///
/// Returns if the write contents indicate we should flush immediately.
fn write<Stream>(&mut self, stream: &mut Stream, data: Option<Frame>) -> Result<bool>
where
Stream: Read + Write,
{
match data {
Some(data) => self.write_one_frame(stream, data)?,
None => self.frame.write_out_buffer(stream)?,
}
// Upon receipt of a Ping frame, an endpoint MUST send a Pong frame in
// response, unless it already received a Close frame. It SHOULD
// respond with Pong frame as soon as is practical. (RFC 6455)
if let Some(pong) = self.pong.take() {
trace!("Sending pong reply");
self.send_one_frame(stream, pong)?;
}
// If we have any unsent frames, send them.
trace!("Frames still in queue: {}", self.send_queue.len());
while let Some(data) = self.send_queue.pop_front() {
self.send_one_frame(stream, data)?;
}
// If we get to this point, the send queue is empty and the underlying socket is still
// willing to take more data.
let should_flush = if let Some(msg) = self.additional_send.take() {
trace!("Sending pong/close");
self.write_one_frame(stream, msg)?;
true
} else {
false
};
// If we're closing and there is nothing to send anymore, we should close the connection.
if self.role == Role::Server && !self.state.can_read() {
@ -407,7 +422,7 @@ impl WebSocketContext {
self.state = WebSocketState::Terminated;
Err(Error::ConnectionClosed)
} else {
Ok(())
Ok(should_flush)
}
}
@ -423,11 +438,11 @@ impl WebSocketContext {
if let WebSocketState::Active = self.state {
self.state = WebSocketState::ClosedByUs;
let frame = Frame::close(code);
self.send_queue.push_back(frame);
self.write(stream, Some(frame))?;
} else {
// Already closed, nothing to do.
}
self.write_pending(stream)
Ok(stream.flush()?)
}
/// Try to decode one message frame. May return None.
@ -496,7 +511,7 @@ impl WebSocketContext {
let data = frame.into_data();
// No ping processing after we sent a close frame.
if self.state.is_active() {
self.pong = Some(Frame::pong(data.clone()));
self.set_additional(Frame::pong(data.clone()));
}
Ok(Some(Message::Ping(data)))
}
@ -580,7 +595,7 @@ impl WebSocketContext {
let reply = Frame::close(close.clone());
debug!("Replying to close with {:?}", reply);
self.send_queue.push_back(reply);
self.set_additional(reply);
Some(close)
}
@ -597,8 +612,8 @@ impl WebSocketContext {
}
}
/// Send a single pending frame.
fn send_one_frame<Stream>(&mut self, stream: &mut Stream, mut frame: Frame) -> Result<()>
/// Write a single frame into the stream via the write-buffer.
fn write_one_frame<Stream>(&mut self, stream: &mut Stream, mut frame: Frame) -> Result<()>
where
Stream: Read + Write,
{
@ -614,6 +629,17 @@ impl WebSocketContext {
trace!("Sending frame: {:?}", frame);
self.frame.write_frame(stream, frame).check_connection_reset(self.state)
}
/// Replace `additional_send` if it is currently a `Pong` message.
fn set_additional(&mut self, add: Frame) {
let empty_or_pong = self
.additional_send
.as_ref()
.map_or(true, |f| f.header().opcode == OpCode::Control(OpCtl::Pong));
if empty_or_pong {
self.additional_send.replace(add);
}
}
}
/// The current connection state.
@ -645,7 +671,7 @@ impl WebSocketState {
}
/// Check if the state is active, return error if not.
fn check_active(self) -> Result<()> {
fn check_not_terminated(self) -> Result<()> {
match self {
WebSocketState::Terminated => Err(Error::AlreadyClosed),
_ => Ok(()),
@ -697,64 +723,6 @@ mod tests {
}
}
struct WouldBlockStreamMoc;
impl io::Write for WouldBlockStreamMoc {
fn write(&mut self, _: &[u8]) -> io::Result<usize> {
Err(io::Error::new(io::ErrorKind::WouldBlock, "would block"))
}
fn flush(&mut self) -> io::Result<()> {
Err(io::Error::new(io::ErrorKind::WouldBlock, "would block"))
}
}
impl io::Read for WouldBlockStreamMoc {
fn read(&mut self, _: &mut [u8]) -> io::Result<usize> {
Err(io::Error::new(io::ErrorKind::WouldBlock, "would block"))
}
}
#[test]
fn queue_logic() {
// Create a socket with the queue size of 1.
let mut socket = WebSocket::from_raw_socket(
WouldBlockStreamMoc,
Role::Client,
Some(WebSocketConfig { max_send_queue: Some(1), ..Default::default() }),
);
// Test message that we're going to send.
let message = Message::Binary(vec![0xFF; 1024]);
// Helper to check the error.
let assert_would_block = |error| {
if let Error::Io(io_error) = error {
assert_eq!(io_error.kind(), io::ErrorKind::WouldBlock);
} else {
panic!("Expected WouldBlock error");
}
};
// The first attempt of writing must not fail, since the queue is empty at start.
// But since the underlying mock object always returns `WouldBlock`, so is the result.
assert_would_block(dbg!(socket.write_message(message.clone()).unwrap_err()));
// Any subsequent attempts must return an error telling that the queue is full.
for _i in 0..100 {
assert!(matches!(
socket.write_message(message.clone()).unwrap_err(),
Error::SendQueueFull(..)
));
}
// The size of the output buffer must not be bigger than the size of that message
// that we managed to write to the output buffer at first. Since we could not make
// any progress (because of the logic of the moc buffer), the size remains unchanged.
if socket.context.frame.output_buffer_len() > message.len() {
panic!("Too many frames in the queue");
}
}
#[test]
fn receive_messages() {
let incoming = Cursor::new(vec![