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#[cfg(target_env = "musl")]
use std::mem;
use std::{
io::{self, Write},
net::SocketAddr,
};
#[cfg(target_os = "linux")]
use std::{
io::{Error, ErrorKind},
os::unix::io::AsRawFd,
};
#[cfg(target_os = "linux")]
use libc::{c_uint, c_void, iovec, msghdr};
use mio::net::UdpSocket;
pub struct MetricSocket {
pub addr: SocketAddr,
pub socket: UdpSocket,
}
impl Write for MetricSocket {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.socket.send_to(buf, self.addr)
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
#[cfg(not(target_os = "linux"))]
pub type MetricsWriter = sozu_command::writer::MultiLineWriter<MetricSocket>;
/// Writes metrics on its UDP socket
#[cfg(target_os = "linux")]
pub struct MetricsWriter {
inner: Option<MetricSocket>,
buf: Vec<u8>,
last_newline: usize,
last_packet_start: usize,
panicked: bool,
packet_indexes: Vec<usize>,
}
#[cfg(target_os = "linux")]
impl MetricsWriter {
pub fn new(inner: MetricSocket) -> MetricsWriter {
MetricsWriter::with_capacity(16384, inner)
}
pub fn with_capacity(capacity: usize, inner: MetricSocket) -> MetricsWriter {
MetricsWriter {
inner: Some(inner),
buf: Vec::with_capacity(capacity),
panicked: false,
last_newline: 0,
last_packet_start: 0,
packet_indexes: vec![],
}
}
pub fn get_ref(&self) -> &MetricSocket {
self.inner.as_ref().unwrap()
}
pub fn get_mut(&mut self) -> &mut MetricSocket {
self.inner.as_mut().unwrap()
}
fn flush_buf(&mut self, flush_entire_buffer: bool) -> io::Result<()> {
let mut written = 0;
let len = if flush_entire_buffer {
self.buf.len()
} else {
self.last_newline + 1
};
let mut ret = Ok(());
while written < len {
self.panicked = true;
let mut last_index = written;
let iovs = self
.packet_indexes
.iter()
.map(|index| {
let iov = iovec {
iov_base: (self.buf.as_ptr() as usize + last_index) as *mut c_void,
iov_len: index - last_index,
};
/*println!("will add the packet ({} bytes): {}",
*index - last_index,
std::str::from_utf8(&self.buf[last_index..*index]).unwrap());
*/
//println!("will add the packet ({} bytes) with iov: {:?}", *index - last_index, iov);
last_index = *index;
vec![iov]
})
.collect::<Vec<_>>();
#[cfg(not(target_env = "musl"))]
let mut messages = iovs
.iter()
.map(|iov| libc::mmsghdr {
msg_hdr: msghdr {
msg_name: std::ptr::null_mut(),
msg_namelen: 0,
msg_iov: iov.as_ptr() as *mut iovec,
msg_iovlen: 1,
msg_control: std::ptr::null_mut(),
msg_controllen: 0,
msg_flags: 0,
},
msg_len: 0,
})
.collect::<Vec<_>>();
#[cfg(target_env = "musl")]
let mut messages = iovs
.iter()
.map(|iov| {
let mhdr = {
// Musl's `msghdr` has private padding fields, so we
// cannot construct it with struct literal syntax.
// `mem::uninitialized` has been UB since Rust 1.39
// (its frozen-bits guarantee was removed in favour of
// `MaybeUninit`). All non-padding fields are explicit
// pointers, lengths, or flags for which zero is the
// valid null / empty representation, so
// `MaybeUninit::zeroed` is both safe and correct.
// SAFETY: `msghdr` is a C POD — every byte pattern
// is a legal representation, so zero-init satisfies
// `assume_init`'s invariant.
let mut mhdr: msghdr = unsafe { mem::MaybeUninit::zeroed().assume_init() };
mhdr.msg_name = std::ptr::null_mut();
mhdr.msg_namelen = 0;
mhdr.msg_iov = iov.as_ptr() as *mut _;
mhdr.msg_iovlen = 1;
mhdr.msg_control = std::ptr::null_mut();
mhdr.msg_controllen = 0;
mhdr.msg_flags = 0;
mhdr
};
libc::mmsghdr {
msg_hdr: mhdr,
msg_len: 0,
}
})
.collect::<Vec<_>>();
//println!("created {} packets", messages.len());
if messages.is_empty() {
break;
}
// SAFETY: `messages` is a non-empty owned `Vec` (the
// `is_empty` check above ensures `messages[0]` is valid). Each
// `mmsghdr` contains an `msg_hdr` whose `msg_iov` points into
// the surrounding `iov` array, kept alive for the duration of
// the call. `messages.len()` matches the pointer's allocation
// length. libc writes per-message `msg_len` results in place
// and returns the number sent (or -1 on error, which we check).
unsafe {
let r = libc::sendmmsg(
self.inner.as_ref().unwrap().socket.as_raw_fd(),
&mut messages[0] as *mut libc::mmsghdr,
messages.len() as c_uint,
0,
);
self.panicked = false;
match r {
-1 => {
//println!("last error: {:?}", io::Error::last_os_error());
let e = io::Error::last_os_error();
if e.kind() != io::ErrorKind::Interrupted {
ret = Err(e);
break;
}
}
sent => {
//println!("sent: {:?}", sent);
/*for i in 0..messages.len() {
println!("message {} wrote {} bytes from {:?}",
i, messages[i].msg_len,
*messages[i].msg_hdr.msg_iov);
}*/
let mut currently_written = 0;
for message in messages.iter().take(sent as usize) {
currently_written += message.msg_len as usize;
}
written += currently_written;
//println!("written (packet indexes: {:?}): {}, total {}", self.packet_indexes,
// currently_written, written);
//println!("written {}, total {}", currently_written, written);
if currently_written == 0 {
ret = Err(Error::new(
ErrorKind::WriteZero,
"failed to write the buffered data",
));
break;
}
if sent as usize == self.packet_indexes.len() {
self.packet_indexes.clear();
break;
} else {
for _i in 0..(sent as usize) {
let _ = self.packet_indexes.remove(0);
}
}
}
}
};
}
//println!("buf len {} last newline {}, written {}", self.buf.len(), self.last_newline, written);
if written > 0 {
//println!("FLUSHED: {}", ::std::str::from_utf8(&self.buf[..written]).unwrap());
self.buf.drain(..written);
}
if flush_entire_buffer || written > self.last_newline {
self.last_newline = 0;
self.last_packet_start = 0;
} else {
self.last_newline -= written;
self.last_packet_start = 0;
}
ret
}
}
#[cfg(target_os = "linux")]
impl Write for MetricsWriter {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
if self.buf.len() + buf.len() > self.buf.capacity() {
self.flush_buf(false)?;
}
if buf.len() >= self.buf.capacity() {
self.panicked = true;
let r = self.get_mut().write(buf);
self.panicked = false;
r
} else {
if let Some(i) = memchr::memrchr(b'\n', buf) {
let newline_index = self.buf.len() + i;
// we limit UDP payload size to 502 bytes
if newline_index - self.last_packet_start > 502 {
self.last_packet_start = self.last_newline;
self.packet_indexes.push(self.last_newline);
}
self.last_newline = newline_index;
};
self.buf.write(buf)
}
}
fn flush(&mut self) -> io::Result<()> {
self.flush_buf(true).and_then(|()| self.get_mut().flush())
}
}
#[cfg(target_os = "linux")]
impl Drop for MetricsWriter {
fn drop(&mut self) {
if self.inner.is_some() && !self.panicked {
// dtors should not panic, so we ignore a failed flush
let _r = self.flush_buf(true);
}
}
}