karmaio 0.1.0

A modern, fast, share-nothing asynchronous runtime for Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98

use std::{io, path::Path};

#[cfg(target_os = "linux")]
use crate::driver::backends::iouring::{Submission as UringSubmission, UringOperation};
#[cfg(any(
    target_os = "macos",
    target_os = "freebsd",
    target_os = "netbsd",
    target_os = "openbsd",
    target_os = "dragonfly"
))]
use crate::driver::backends::kqueue::{KqueueAttempt, KqueueOperation};
use crate::{
    driver::{
        helpers::cstr::{OsPath, cstr},
        ops::{Completion, Op},
    },
    fs::Metadata,
    runtime::local::CURRENT_DRIVER,
};

/// Queries metadata for a path, optionally following its final symlink.
pub(crate) struct PathStat {
    path: OsPath,
    follow_symlinks: bool,
    #[cfg(target_os = "linux")]
    statx_buf: Box<libc::statx>,
}

impl Op<PathStat> {
    pub(crate) fn path_stat(path: &Path, follow_symlinks: bool) -> io::Result<Self> {
        let data = PathStat {
            path: cstr(path)?,
            follow_symlinks,
            #[cfg(target_os = "linux")]
            statx_buf: Box::new(unsafe { std::mem::zeroed() }),
        };

        CURRENT_DRIVER.with(|handle| handle.upgrade().expect("Not in a runtime context").submit_op(data))
    }
}

#[cfg(target_os = "linux")]
unsafe impl UringOperation for PathStat {
    type Output = io::Result<Metadata>;

    fn submit(&mut self) -> UringSubmission {
        use io_uring::{opcode, types};

        let statx_buf = self.statx_buf.as_mut() as *mut libc::statx as *mut types::statx;
        let flags = if self.follow_symlinks {
            0
        } else {
            libc::AT_SYMLINK_NOFOLLOW
        };

        opcode::Statx::new(types::Fd(libc::AT_FDCWD), self.path.as_c_str().as_ptr(), statx_buf)
            .flags(flags)
            .mask(libc::STATX_BASIC_STATS | libc::STATX_BTIME)
            .build()
    }

    fn complete(self, completion: Completion) -> Self::Output {
        completion.result?;
        Ok(Metadata::from_statx(*self.statx_buf))
    }
}

#[cfg(any(
    target_os = "macos",
    target_os = "freebsd",
    target_os = "netbsd",
    target_os = "openbsd",
    target_os = "dragonfly"
))]
impl KqueueOperation for PathStat {
    type Output = io::Result<Metadata>;

    fn attempt(&mut self) -> KqueueAttempt {
        let path = self.path.clone();
        let follow_symlinks = self.follow_symlinks;

        kqueue_syscall_blocking!(value {
            let result = if follow_symlinks {
                rustix::fs::stat(path.as_c_str())
            } else {
                rustix::fs::lstat(path.as_c_str())
            };

            result.map_err(io::Error::from)
        })
    }

    fn complete(self, completion: Completion) -> Self::Output {
        let stat = completion.into_blocking_value::<rustix::fs::Stat>()?;
        Ok(Metadata::from_stat(stat))
    }
}