workspace: move crates under crates

crates/bufio/src/lib.rs

@@ -0,0 +1,183 @@
+use {
+    jay_io_uring::{IoUring, IoUringError},
+    jay_utils::{
+        buf::{Buf, DynamicBuf},
+        queue::AsyncQueue,
+        stack::Stack,
+    },
+    std::{
+        collections::VecDeque,
+        mem::{self},
+        rc::Rc,
+    },
+    thiserror::Error,
+    uapi::{OwnedFd, c},
+};
+
+#[derive(Debug, Error)]
+pub enum BufIoError {
+    #[error("Could not write to the socket")]
+    FlushError(#[source] IoUringError),
+    #[error("Could not read from the socket")]
+    ReadError(#[source] IoUringError),
+    #[error("The socket is closed")]
+    Closed,
+}
+
+pub struct BufIoMessage {
+    pub fds: Vec<Rc<OwnedFd>>,
+    pub buf: Buf,
+}
+
+struct MessageOffset {
+    msg: BufIoMessage,
+    offset: usize,
+}
+
+pub struct BufIo {
+    fd: Rc<OwnedFd>,
+    ring: Rc<IoUring>,
+    bufs: Stack<Buf>,
+    outgoing: AsyncQueue<BufIoMessage>,
+}
+
+pub struct BufIoIncoming {
+    bufio: Rc<BufIo>,
+
+    buf: Buf,
+    buf_start: usize,
+    buf_end: usize,
+    pub fds: VecDeque<Rc<OwnedFd>>,
+}
+
+struct Outgoing {
+    bufio: Rc<BufIo>,
+
+    msgs: VecDeque<MessageOffset>,
+    bufs: Vec<Buf>,
+}
+
+impl BufIo {
+    pub fn new(fd: &Rc<OwnedFd>, ring: &Rc<IoUring>) -> Self {
+        Self {
+            fd: fd.clone(),
+            ring: ring.clone(),
+            bufs: Default::default(),
+            outgoing: Default::default(),
+        }
+    }
+
+    pub fn shutdown(&self) {
+        let _ = uapi::shutdown(self.fd.raw(), c::SHUT_RDWR);
+    }
+
+    pub fn buf(&self) -> DynamicBuf {
+        let buf = self.bufs.pop().unwrap_or_default();
+        DynamicBuf::from_buf(buf)
+    }
+
+    pub fn send(&self, msg: BufIoMessage) {
+        self.outgoing.push(msg);
+    }
+
+    pub async fn outgoing(self: Rc<Self>) -> Result<(), BufIoError> {
+        let mut outgoing = Outgoing {
+            bufio: self,
+            msgs: Default::default(),
+            bufs: vec![],
+        };
+        outgoing.run().await
+    }
+
+    pub fn incoming(self: &Rc<Self>) -> BufIoIncoming {
+        BufIoIncoming {
+            bufio: self.clone(),
+            buf: Buf::new(4096),
+            buf_start: 0,
+            buf_end: 0,
+            fds: Default::default(),
+        }
+    }
+}
+
+impl BufIoIncoming {
+    pub async fn fill_msg_buf(
+        &mut self,
+        mut n: usize,
+        buf: &mut Vec<u8>,
+    ) -> Result<(), BufIoError> {
+        while n > 0 {
+            if self.buf_start == self.buf_end {
+                self.buf_start = 0;
+                self.buf_end = 0;
+                let res = self
+                    .bufio
+                    .ring
+                    .recvmsg(&self.bufio.fd, &mut [self.buf.clone()], &mut self.fds)
+                    .await;
+                match res {
+                    Ok(n) => self.buf_end = n,
+                    Err(e) => return Err(BufIoError::ReadError(e)),
+                }
+                if self.buf_start == self.buf_end {
+                    return Err(BufIoError::Closed);
+                }
+            }
+            let read = n.min(self.buf_end - self.buf_start);
+            let buf_start = self.buf_start;
+            buf.extend_from_slice(&self.buf[buf_start..buf_start + read]);
+            n -= read;
+            self.buf_start += read;
+        }
+        Ok(())
+    }
+}
+
+impl Outgoing {
+    async fn run(&mut self) -> Result<(), BufIoError> {
+        loop {
+            self.bufio.outgoing.non_empty().await;
+            if let Err(e) = self.try_flush().await {
+                return Err(BufIoError::FlushError(e));
+            }
+        }
+    }
+
+    async fn try_flush(&mut self) -> Result<(), IoUringError> {
+        loop {
+            while let Some(msg) = self.bufio.outgoing.try_pop() {
+                self.msgs.push_back(MessageOffset { msg, offset: 0 });
+            }
+            if self.msgs.is_empty() {
+                return Ok(());
+            }
+            let mut fds = Vec::new();
+            for msg in &mut self.msgs {
+                if msg.msg.fds.len() > 0 {
+                    if fds.len() > 0 || self.bufs.len() > 0 {
+                        break;
+                    }
+                    fds = mem::take(&mut msg.msg.fds);
+                }
+                self.bufs.push(msg.msg.buf.slice(msg.offset..));
+            }
+            let res = self
+                .bufio
+                .ring
+                .sendmsg(&self.bufio.fd, &mut self.bufs, fds, None)
+                .await;
+            self.bufs.clear();
+            let mut n = res?;
+            while n > 0 {
+                let len = self.msgs[0].msg.buf.len() - self.msgs[0].offset;
+                if n < len {
+                    self.msgs[0].offset += n;
+                    break;
+                }
+                n -= len;
+                let msg = self.msgs.pop_front().unwrap();
+                self.bufio.bufs.push(msg.msg.buf);
+            }
+        }
+    }
+}