advisory_lock/
unix.rs

1use std::fs::File;
2use std::io::Error;
3use std::os::unix::io::{AsRawFd, RawFd};
4
5use crate::{AdvisoryFileLock, FileLockError, FileLockMode};
6
7impl AdvisoryFileLock for File {
8    fn lock(&self, file_lock_mode: FileLockMode) -> Result<(), FileLockError> {
9        self.as_raw_fd().lock(file_lock_mode)
10    }
11
12    fn try_lock(&self, file_lock_mode: FileLockMode) -> Result<(), FileLockError> {
13        self.as_raw_fd().try_lock(file_lock_mode)
14    }
15
16    fn unlock(&self) -> Result<(), FileLockError> {
17        self.as_raw_fd().unlock()
18    }
19}
20
21impl AdvisoryFileLock for RawFd {
22    fn lock(&self, file_lock_mode: FileLockMode) -> Result<(), FileLockError> {
23        lock_file(*self, file_lock_mode, false)
24    }
25
26    fn try_lock(&self, file_lock_mode: FileLockMode) -> Result<(), FileLockError> {
27        lock_file(*self, file_lock_mode, true)
28    }
29
30    fn unlock(&self) -> Result<(), FileLockError> {
31        unlock_file(*self)
32    }
33}
34
35fn lock_file(
36    raw_fd: RawFd,
37    file_lock_mode: FileLockMode,
38    immediate: bool,
39) -> Result<(), FileLockError> {
40    let mut flags = match file_lock_mode {
41        FileLockMode::Shared => libc::LOCK_SH,
42        FileLockMode::Exclusive => libc::LOCK_EX,
43    };
44    if immediate {
45        flags |= libc::LOCK_NB;
46    }
47
48    let result = unsafe { libc::flock(raw_fd, flags) };
49    if result != 0 {
50        let last_os_error = Error::last_os_error();
51        return Err(match last_os_error.raw_os_error() {
52            Some(code) if code == libc::EWOULDBLOCK => FileLockError::AlreadyLocked,
53            _ => FileLockError::Io(last_os_error),
54        });
55    }
56
57    Ok(())
58}
59
60fn unlock_file(raw_fd: RawFd) -> Result<(), FileLockError> {
61    let result = unsafe { libc::flock(raw_fd, libc::LOCK_UN) };
62    if result == 0 {
63        Ok(())
64    } else {
65        Err(FileLockError::Io(Error::last_os_error()))
66    }
67}
advisory_lock/unix.rs

advisory_lock/
unix.rs
