Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 248 insertions, 0 deletions

diff --git a/third_party/rust/nix/src/sys/inotify.rs b/third_party/rust/nix/src/sys/inotify.rs
new file mode 100644
index 0000000000..84356ec70f
--- /dev/null
+++ b/third_party/rust/nix/src/sys/inotify.rs
@@ -0,0 +1,248 @@
+//! Monitoring API for filesystem events.
+//!
+//! Inotify is a Linux-only API to monitor filesystems events.
+//!
+//! For more documentation, please read [inotify(7)](https://man7.org/linux/man-pages/man7/inotify.7.html).
+//!
+//! # Examples
+//!
+//! Monitor all events happening in directory "test":
+//! ```no_run
+//! # use nix::sys::inotify::{AddWatchFlags,InitFlags,Inotify};
+//! #
+//! // We create a new inotify instance.
+//! let instance = Inotify::init(InitFlags::empty()).unwrap();
+//!
+//! // We add a new watch on directory "test" for all events.
+//! let wd = instance.add_watch("test", AddWatchFlags::IN_ALL_EVENTS).unwrap();
+//!
+//! loop {
+//!     // We read from our inotify instance for events.
+//!     let events = instance.read_events().unwrap();
+//!     println!("Events: {:?}", events);
+//! }
+//! ```
+
+use crate::errno::Errno;
+use crate::unistd::read;
+use crate::NixPath;
+use crate::Result;
+use cfg_if::cfg_if;
+use libc::{c_char, c_int};
+use std::ffi::{CStr, OsStr, OsString};
+use std::mem::{size_of, MaybeUninit};
+use std::os::unix::ffi::OsStrExt;
+use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
+use std::ptr;
+
+libc_bitflags! {
+    /// Configuration options for [`inotify_add_watch`](fn.inotify_add_watch.html).
+    pub struct AddWatchFlags: u32 {
+        /// File was accessed.
+        IN_ACCESS;
+        /// File was modified.
+        IN_MODIFY;
+        /// Metadata changed.
+        IN_ATTRIB;
+        /// Writable file was closed.
+        IN_CLOSE_WRITE;
+        /// Nonwritable file was closed.
+        IN_CLOSE_NOWRITE;
+        /// File was opened.
+        IN_OPEN;
+        /// File was moved from X.
+        IN_MOVED_FROM;
+        /// File was moved to Y.
+        IN_MOVED_TO;
+        /// Subfile was created.
+        IN_CREATE;
+        /// Subfile was deleted.
+        IN_DELETE;
+        /// Self was deleted.
+        IN_DELETE_SELF;
+        /// Self was moved.
+        IN_MOVE_SELF;
+
+        /// Backing filesystem was unmounted.
+        IN_UNMOUNT;
+        /// Event queue overflowed.
+        IN_Q_OVERFLOW;
+        /// File was ignored.
+        IN_IGNORED;
+
+        /// Combination of `IN_CLOSE_WRITE` and `IN_CLOSE_NOWRITE`.
+        IN_CLOSE;
+        /// Combination of `IN_MOVED_FROM` and `IN_MOVED_TO`.
+        IN_MOVE;
+
+        /// Only watch the path if it is a directory.
+        IN_ONLYDIR;
+        /// Don't follow symlinks.
+        IN_DONT_FOLLOW;
+
+        /// Event occurred against directory.
+        IN_ISDIR;
+        /// Only send event once.
+        IN_ONESHOT;
+        /// All of the events.
+        IN_ALL_EVENTS;
+    }
+}
+
+libc_bitflags! {
+    /// Configuration options for [`inotify_init1`](fn.inotify_init1.html).
+    pub struct InitFlags: c_int {
+        /// Set the `FD_CLOEXEC` flag on the file descriptor.
+        IN_CLOEXEC;
+        /// Set the `O_NONBLOCK` flag on the open file description referred to by the new file descriptor.
+        IN_NONBLOCK;
+    }
+}
+
+/// An inotify instance. This is also a file descriptor, you can feed it to
+/// other interfaces consuming file descriptors, epoll for example.
+#[derive(Debug, Clone, Copy)]
+pub struct Inotify {
+    fd: RawFd,
+}
+
+/// This object is returned when you create a new watch on an inotify instance.
+/// It is then returned as part of an event once triggered. It allows you to
+/// know which watch triggered which event.
+#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq, Ord, PartialOrd)]
+pub struct WatchDescriptor {
+    wd: i32,
+}
+
+/// A single inotify event.
+///
+/// For more documentation see, [inotify(7)](https://man7.org/linux/man-pages/man7/inotify.7.html).
+#[derive(Debug)]
+pub struct InotifyEvent {
+    /// Watch descriptor. This field corresponds to the watch descriptor you
+    /// were issued when calling add_watch. It allows you to know which watch
+    /// this event comes from.
+    pub wd: WatchDescriptor,
+    /// Event mask. This field is a bitfield describing the exact event that
+    /// occured.
+    pub mask: AddWatchFlags,
+    /// This cookie is a number that allows you to connect related events. For
+    /// now only IN_MOVED_FROM and IN_MOVED_TO can be connected.
+    pub cookie: u32,
+    /// Filename. This field exists only if the event was triggered for a file
+    /// inside the watched directory.
+    pub name: Option<OsString>,
+}
+
+impl Inotify {
+    /// Initialize a new inotify instance.
+    ///
+    /// Returns a Result containing an inotify instance.
+    ///
+    /// For more information see, [inotify_init(2)](https://man7.org/linux/man-pages/man2/inotify_init.2.html).
+    pub fn init(flags: InitFlags) -> Result<Inotify> {
+        let res = Errno::result(unsafe { libc::inotify_init1(flags.bits()) });
+
+        res.map(|fd| Inotify { fd })
+    }
+
+    /// Adds a new watch on the target file or directory.
+    ///
+    /// Returns a watch descriptor. This is not a File Descriptor!
+    ///
+    /// For more information see, [inotify_add_watch(2)](https://man7.org/linux/man-pages/man2/inotify_add_watch.2.html).
+    pub fn add_watch<P: ?Sized + NixPath>(
+        self,
+        path: &P,
+        mask: AddWatchFlags,
+    ) -> Result<WatchDescriptor> {
+        let res = path.with_nix_path(|cstr| unsafe {
+            libc::inotify_add_watch(self.fd, cstr.as_ptr(), mask.bits())
+        })?;
+
+        Errno::result(res).map(|wd| WatchDescriptor { wd })
+    }
+
+    /// Removes an existing watch using the watch descriptor returned by
+    /// inotify_add_watch.
+    ///
+    /// Returns an EINVAL error if the watch descriptor is invalid.
+    ///
+    /// For more information see, [inotify_rm_watch(2)](https://man7.org/linux/man-pages/man2/inotify_rm_watch.2.html).
+    pub fn rm_watch(self, wd: WatchDescriptor) -> Result<()> {
+        cfg_if! {
+            if #[cfg(target_os = "linux")] {
+                let arg = wd.wd;
+            } else if #[cfg(target_os = "android")] {
+                let arg = wd.wd as u32;
+            }
+        }
+        let res = unsafe { libc::inotify_rm_watch(self.fd, arg) };
+
+        Errno::result(res).map(drop)
+    }
+
+    /// Reads a collection of events from the inotify file descriptor. This call
+    /// can either be blocking or non blocking depending on whether IN_NONBLOCK
+    /// was set at initialization.
+    ///
+    /// Returns as many events as available. If the call was non blocking and no
+    /// events could be read then the EAGAIN error is returned.
+    pub fn read_events(self) -> Result<Vec<InotifyEvent>> {
+        let header_size = size_of::<libc::inotify_event>();
+        const BUFSIZ: usize = 4096;
+        let mut buffer = [0u8; BUFSIZ];
+        let mut events = Vec::new();
+        let mut offset = 0;
+
+        let nread = read(self.fd, &mut buffer)?;
+
+        while (nread - offset) >= header_size {
+            let event = unsafe {
+                let mut event = MaybeUninit::<libc::inotify_event>::uninit();
+                ptr::copy_nonoverlapping(
+                    buffer.as_ptr().add(offset),
+                    event.as_mut_ptr() as *mut u8,
+                    (BUFSIZ - offset).min(header_size),
+                );
+                event.assume_init()
+            };
+
+            let name = match event.len {
+                0 => None,
+                _ => {
+                    let ptr = unsafe {
+                        buffer.as_ptr().add(offset + header_size)
+                            as *const c_char
+                    };
+                    let cstr = unsafe { CStr::from_ptr(ptr) };
+
+                    Some(OsStr::from_bytes(cstr.to_bytes()).to_owned())
+                }
+            };
+
+            events.push(InotifyEvent {
+                wd: WatchDescriptor { wd: event.wd },
+                mask: AddWatchFlags::from_bits_truncate(event.mask),
+                cookie: event.cookie,
+                name,
+            });
+
+            offset += header_size + event.len as usize;
+        }
+
+        Ok(events)
+    }
+}
+
+impl AsRawFd for Inotify {
+    fn as_raw_fd(&self) -> RawFd {
+        self.fd
+    }
+}
+
+impl FromRawFd for Inotify {
+    unsafe fn from_raw_fd(fd: RawFd) -> Self {
+        Inotify { fd }
+    }
+}