use crate::{
buffer::Buffer,
channels::Channels,
connection_status::ConnectionState,
frames::Frames,
heartbeat::Heartbeat,
internal_rpc::InternalRPCHandle,
protocol::{self, AMQPError, AMQPHardError},
socket_state::{SocketEvent, SocketState},
thread::ThreadHandle,
types::FrameSize,
Configuration, ConnectionStatus, Error, PromiseResolver, Result,
};
use amq_protocol::frame::{gen_frame, parse_frame, AMQPFrame, GenError};
use reactor_trait::AsyncIOHandle;
use std::{
collections::VecDeque,
io,
pin::Pin,
sync::Arc,
task::{Context, Poll, Waker},
thread::Builder as ThreadBuilder,
time::Duration,
};
use tracing::{error, trace};
const FRAMES_STORAGE: usize = 32;
#[derive(Debug, PartialEq)]
enum Status {
Initial,
Connected,
Stop,
}
pub struct IoLoop {
connection_status: ConnectionStatus,
configuration: Configuration,
channels: Channels,
internal_rpc: InternalRPCHandle,
frames: Frames,
heartbeat: Heartbeat,
socket_state: SocketState,
connection_io_loop_handle: ThreadHandle,
stream: Pin<Box<dyn AsyncIOHandle + Send>>,
status: Status,
frame_size: FrameSize,
receive_buffer: Buffer,
send_buffer: Buffer,
serialized_frames: VecDeque<(FrameSize, Option<PromiseResolver<()>>)>,
}
impl IoLoop {
pub(crate) async fn new(
connection_status: ConnectionStatus,
configuration: Configuration,
channels: Channels,
internal_rpc: InternalRPCHandle,
frames: Frames,
socket_state: SocketState,
connection_io_loop_handle: ThreadHandle,
stream: Pin<Box<dyn AsyncIOHandle + Send>>,
heartbeat: Heartbeat,
) -> Result<Self> {
let frame_size = std::cmp::max(
protocol::constants::FRAME_MIN_SIZE,
configuration.frame_max(),
);
Ok(Self {
connection_status,
configuration,
channels,
internal_rpc,
frames,
heartbeat,
socket_state,
connection_io_loop_handle,
stream,
status: Status::Initial,
frame_size,
receive_buffer: Buffer::with_capacity(FRAMES_STORAGE * frame_size as usize),
send_buffer: Buffer::with_capacity(FRAMES_STORAGE * frame_size as usize),
serialized_frames: VecDeque::default(),
})
}
fn readable_waker(&self) -> Waker {
let socket_state_handle = self.socket_state.handle();
waker_fn::waker_fn(move || socket_state_handle.send(SocketEvent::Readable))
}
fn writable_waker(&self) -> Waker {
let socket_state_handle = self.socket_state.handle();
waker_fn::waker_fn(move || socket_state_handle.send(SocketEvent::Writable))
}
fn finish_setup(&mut self) -> Result<bool> {
if self.connection_status.connected() {
let frame_max = self.configuration.frame_max();
self.frame_size = std::cmp::max(self.frame_size, frame_max);
self.receive_buffer
.grow(FRAMES_STORAGE * self.frame_size as usize);
self.send_buffer
.grow(FRAMES_STORAGE * self.frame_size as usize);
let heartbeat = self.configuration.heartbeat();
if heartbeat != 0 {
let heartbeat = Duration::from_millis(u64::from(heartbeat) * 500); self.heartbeat.set_timeout(heartbeat);
self.heartbeat.start();
}
self.status = Status::Connected;
}
Ok(true)
}
fn ensure_setup(&mut self) -> Result<bool> {
match self.status {
Status::Initial => self.finish_setup(),
Status::Connected => Ok(true),
Status::Stop => Ok(false),
}
}
fn has_data(&self) -> bool {
self.frames.has_pending()
|| self.send_buffer.available_data() > 0
|| !self.serialized_frames.is_empty()
}
fn can_write(&mut self) -> bool {
self.socket_state.writable() && self.has_data() && !self.connection_status.blocked()
}
fn can_read(&mut self) -> bool {
self.socket_state.readable() && self.receive_buffer.available_space() > 0
}
fn can_parse(&self) -> bool {
self.receive_buffer.available_data() > 0
}
fn should_continue(&self) -> bool {
(self.status != Status::Connected
|| self.connection_status.connected()
|| self.connection_status.closing())
&& self.status != Status::Stop
&& !self.connection_status.errored()
}
pub fn start(mut self) -> Result<()> {
let waker = self.socket_state.handle();
let handle = self.connection_io_loop_handle.clone();
handle.register(
ThreadBuilder::new()
.name("lapin-io-loop".to_owned())
.spawn(move || {
let readable_waker = self.readable_waker();
let mut readable_context = Context::from_waker(&readable_waker);
let writable_waker = self.writable_waker();
let mut writable_context = Context::from_waker(&writable_waker);
while self.should_continue() {
if let Err(err) = self.run(&mut readable_context, &mut writable_context) {
self.critical_error(err)?;
}
}
self.internal_rpc.stop();
self.heartbeat.cancel();
Ok(())
})?,
);
waker.wake();
Ok(())
}
fn poll_socket_events(&mut self) {
self.socket_state.poll_events();
}
fn check_connection_state(&mut self) {
if self.connection_status.closed() {
self.status = Status::Stop;
}
}
fn run(
&mut self,
readable_context: &mut Context<'_>,
writable_context: &mut Context<'_>,
) -> Result<()> {
trace!("io_loop run");
self.poll_socket_events();
if !self.ensure_setup()? {
return Ok(());
}
self.check_connection_state();
trace!(
can_read=%self.socket_state.readable(),
can_write=%self.socket_state.writable(),
has_data=%self.has_data(),
"io_loop do_run",
);
if !self.can_read() && !self.can_write() && self.should_continue() {
self.socket_state.wait();
}
self.poll_socket_events();
self.attempt_flush(writable_context)?;
self.write(writable_context)?;
self.check_connection_state();
if self.should_continue() {
self.read(readable_context)?;
}
self.handle_frames()?;
self.check_connection_state();
trace!(
can_read=%self.socket_state.readable(),
can_write=%self.socket_state.writable(),
has_data=%self.has_data(),
status=?self.status,
"io_loop do_run done",
);
Ok(())
}
fn critical_error(&mut self, error: Error) -> Result<()> {
if let Some(resolver) = self.connection_status.connection_resolver() {
resolver.swear(Err(error.clone()));
}
self.status = Status::Stop;
self.channels.set_connection_error(error.clone());
for (_, resolver) in std::mem::take(&mut self.serialized_frames) {
if let Some(resolver) = resolver {
resolver.swear(Err(error.clone()));
}
}
Err(error)
}
fn attempt_flush(&mut self, writable_context: &mut Context<'_>) -> Result<()> {
let res = self.flush(writable_context);
self.handle_io_result(res)
}
fn handle_io_result(&mut self, result: Result<()>) -> Result<()> {
if let Err(e) = self.socket_state.handle_io_result(result) {
error!(error=?e, "error doing IO");
self.critical_error(e)?;
}
Ok(())
}
fn flush(&mut self, writable_context: &mut Context<'_>) -> Result<()> {
let res = self.stream.as_mut().poll_flush(writable_context)?;
self.socket_state.handle_write_poll(res);
Ok(())
}
fn write(&mut self, writable_context: &mut Context<'_>) -> Result<()> {
while self.can_write() {
let res = self.write_to_stream(writable_context);
self.handle_io_result(res)?;
}
Ok(())
}
fn read(&mut self, readable_context: &mut Context<'_>) -> Result<()> {
while self.can_read() {
let res = self.read_from_stream(readable_context);
self.handle_io_result(res)?;
}
Ok(())
}
fn write_to_stream(&mut self, writable_context: &mut Context<'_>) -> Result<()> {
self.flush(writable_context)?;
self.serialize()?;
let res = self
.send_buffer
.poll_write_to(writable_context, Pin::new(&mut self.stream))?;
if let Some(sz) = self.socket_state.handle_write_poll(res) {
if sz > 0 {
self.heartbeat.update_last_write();
trace!("wrote {} bytes", sz);
self.send_buffer.consume(sz);
let mut written = sz as FrameSize;
while written > 0 {
if let Some((to_write, resolver)) = self.serialized_frames.pop_front() {
if written < to_write {
self.serialized_frames
.push_front((to_write - written, resolver));
trace!("{} to write to complete this frame", to_write - written);
written = 0;
} else {
if let Some(resolver) = resolver {
resolver.swear(Ok(()));
}
written -= to_write;
}
} else {
error!(
"We've written {} but didn't expect to write anything",
written
);
break;
}
}
if self.send_buffer.available_data() > 0 {
trace!("Still {} to write", self.send_buffer.available_data());
}
self.flush(writable_context)?;
} else {
error!("Socket was writable but we wrote 0, marking as wouldblock");
self.socket_state.handle_write_poll::<()>(Poll::Pending);
}
}
Ok(())
}
fn read_from_stream(&mut self, readable_context: &mut Context<'_>) -> Result<()> {
match self.connection_status.state() {
ConnectionState::Closed => Ok(()),
ConnectionState::Error => Err(Error::InvalidConnectionState(ConnectionState::Error)),
_ => {
let res = self
.receive_buffer
.poll_read_from(readable_context, Pin::new(&mut self.stream))?;
if let Some(sz) = self.socket_state.handle_read_poll(res) {
if sz > 0 {
trace!("read {} bytes", sz);
self.receive_buffer.fill(sz);
} else {
error!("Socket was readable but we read 0. This usually means that the connection is half closed this mark it as broken");
self.socket_state.handle_io_result(Err(io::Error::from(
io::ErrorKind::ConnectionAborted,
)
.into()))?;
}
}
Ok(())
}
}
}
fn serialize(&mut self) -> Result<()> {
while let Some((next_msg, resolver)) = self.frames.pop(self.channels.flow()) {
trace!(%next_msg, "will write to buffer");
let checkpoint = self.send_buffer.checkpoint();
let res = gen_frame(&next_msg)((&mut self.send_buffer).into());
match res.map(|w| w.into_inner().1) {
Ok(sz) => self
.serialized_frames
.push_back((sz as FrameSize, resolver)),
Err(e) => {
self.send_buffer.rollback(checkpoint);
match e {
GenError::BufferTooSmall(_) => {
self.frames.retry((next_msg, resolver));
break;
}
e => {
error!(error=?e, "error generating frame");
self.critical_error(Error::SerialisationError(Arc::new(e)))?;
}
}
}
}
}
Ok(())
}
fn handle_frames(&mut self) -> Result<()> {
while self.can_parse() {
if let Some(frame) = self.parse()? {
self.channels.handle_frame(frame)?;
} else {
break;
}
}
Ok(())
}
fn parse(&mut self) -> Result<Option<AMQPFrame>> {
match parse_frame(self.receive_buffer.parsing_context()) {
Ok((i, f)) => {
let consumed = self.receive_buffer.offset(i);
let frame_max = self.configuration.frame_max() as usize;
if frame_max > 0 && consumed > frame_max {
error!(bytes = consumed, "received large frame");
let error = AMQPError::new(
AMQPHardError::FRAMEERROR.into(),
format!("frame too large: {} bytes", consumed).into(),
);
self.internal_rpc.close_connection(
error.get_id(),
error.get_message().to_string(),
0,
0,
);
self.critical_error(Error::ProtocolError(error))?;
}
self.receive_buffer.consume(consumed);
Ok(Some(f))
}
Err(e) => {
if !e.is_incomplete() {
error!(error=?e, "parse error");
self.critical_error(Error::ParsingError(e))?;
}
Ok(None)
}
}
}
}