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wry/src/utils/buffd/formatter.rs
2022-02-09 17:26:50 +01:00

117 lines
3.3 KiB
Rust

use crate::fixed::Fixed;
use crate::object::ObjectId;
use crate::utils::buffd::buf_out::{MsgFds, OutBuffer};
use std::mem;
use std::mem::MaybeUninit;
use std::rc::Rc;
use uapi::OwnedFd;
pub struct MsgFormatter<'a> {
buf: &'a mut OutBuffer,
pos: usize,
fds: &'a mut Vec<Rc<OwnedFd>>,
}
impl<'a> MsgFormatter<'a> {
pub fn new(buf: &'a mut OutBuffer, fds: &'a mut Vec<Rc<OwnedFd>>) -> Self {
Self {
pos: buf.write_pos,
buf,
fds,
}
}
pub fn int(&mut self, int: i32) -> &mut Self {
self.buf.write(uapi::as_maybe_uninit_bytes(&int));
self
}
pub fn uint(&mut self, int: u32) -> &mut Self {
self.buf.write(uapi::as_maybe_uninit_bytes(&int));
self
}
pub fn fixed(&mut self, fixed: Fixed) -> &mut Self {
self.buf.write(uapi::as_maybe_uninit_bytes(&fixed));
self
}
pub fn optstr<S: AsRef<[u8]> + ?Sized>(&mut self, s: Option<&S>) -> &mut Self {
match s {
Some(s) => self.string(s),
_ => self.uint(0),
}
}
pub fn string<S: AsRef<[u8]> + ?Sized>(&mut self, s: &S) -> &mut Self {
let s = s.as_ref();
let len = s.len() + 1;
let cap = (len + 3) & !3;
self.uint(len as u32);
self.buf.write(uapi::as_maybe_uninit_bytes(s));
let none = [MaybeUninit::new(0); 4];
self.buf.write(&none[..cap - len + 1]);
self
}
pub fn fd(&mut self, fd: Rc<OwnedFd>) -> &mut Self {
self.fds.push(fd);
self
}
pub fn object<T: Into<ObjectId>>(&mut self, obj: T) -> &mut Self {
self.uint(obj.into().raw())
}
pub fn header<T: Into<ObjectId>>(&mut self, obj: T, event: u32) -> &mut Self {
self.object(obj).uint(event)
}
#[allow(dead_code)]
pub fn array<F: FnOnce(&mut MsgFormatter<'_>)>(&mut self, f: F) -> &mut Self {
let pos = self.buf.write_pos;
self.uint(0);
let len = {
let mut fmt = MsgFormatter {
buf: self.buf,
pos,
fds: self.fds,
};
f(&mut fmt);
let len = self.buf.write_pos - pos - 4;
let none = [MaybeUninit::new(0); 4];
self.buf
.write(&none[..self.buf.write_pos.wrapping_neg() & 3]);
len as u32
};
unsafe {
(*self.buf.buf)[pos..pos + 4].copy_from_slice(uapi::as_maybe_uninit_bytes(&len));
}
self
}
pub fn binary<T: ?Sized>(&mut self, t: &T) -> &mut Self {
self.uint(mem::size_of_val(t) as u32);
self.buf.write(uapi::as_maybe_uninit_bytes(t));
let none = [MaybeUninit::new(0); 4];
self.buf
.write(&none[..self.buf.write_pos.wrapping_neg() & 3]);
self
}
pub fn write_len(self) {
assert!(self.buf.write_pos - self.pos >= 8);
assert_eq!(self.pos % 4, 0);
unsafe {
let second_ptr = (self.buf.buf as *mut u8).add(self.pos + 4) as *mut u32;
let len = ((self.buf.write_pos - self.pos) as u32) << 16;
*second_ptr |= len;
}
if self.fds.len() > 0 {
self.buf.fds.push_back(MsgFds {
pos: self.pos,
fds: mem::take(self.fds),
})
}
}
}