diff options
Diffstat (limited to 'vendor/io-close/src')
-rw-r--r-- | vendor/io-close/src/fs.rs | 24 | ||||
-rw-r--r-- | vendor/io-close/src/lib.rs | 226 |
2 files changed, 250 insertions, 0 deletions
diff --git a/vendor/io-close/src/fs.rs b/vendor/io-close/src/fs.rs new file mode 100644 index 000000000..8b76a80cd --- /dev/null +++ b/vendor/io-close/src/fs.rs @@ -0,0 +1,24 @@ +//! Filesystem manipulation operations. + +use std::fs::File; +use std::io::{Result, Write}; +use std::path::Path; + +use crate::Close; + +/// Write a slice as the entire contents of a file. +/// +/// This function is identical to [`std::fs::write`] but uses [`Close`] +/// to drop the [`File`](std::fs::File) created from path, returning any +/// errors encountered when doing so. +pub fn write<P: AsRef<Path>, C: AsRef<[u8]>>( + path: P, + contents: C, +) -> Result<()> { + fn inner(path: &Path, contents: &[u8]) -> Result<()> { + let mut f = File::create(path)?; + f.write_all(contents)?; + f.close() + } + inner(path.as_ref(), contents.as_ref()) +} diff --git a/vendor/io-close/src/lib.rs b/vendor/io-close/src/lib.rs new file mode 100644 index 000000000..a530c9bb7 --- /dev/null +++ b/vendor/io-close/src/lib.rs @@ -0,0 +1,226 @@ +#![cfg_attr(docsrs, feature(doc_cfg))] + +//! An extension trait for safely dropping [I/O writers](std::io::Write) +//! such as [`File`](std::fs::File) and +//! [`BufWriter`](std::io::BufWriter). Specifically, it is for I/O +//! writers which may contain a resource handle (such as a raw file +//! descriptor), and where the automatic process of closing this handle +//! during drop may generate an unseen I/O error. Using this trait +//! (called [`Close`]) these errors can be seen and dealt with. +//! +//! In the case of Linux [the man page for +//! close(2)](https://linux.die.net/man/2/close) has the following to +//! say: +//! +//! > Not checking the return value of close() is a common but +//! > nevertheless serious programming error. It is quite possible that +//! > errors on a previous write(2) operation are first reported at the +//! > final close(). Not checking the return value when closing the file +//! > may lead to silent loss of data. This can especially be observed +//! > with NFS and with disk quota. +//! +//! Implementations of [`Close`] are provided for most standard library +//! I/O writers and (optionally) for a selection of I/O writers defined +//! in external crates. +//! +//! # BufWriter example +//! +//! ``` +//! use std::io::{BufWriter, Result, Write}; +//! use io_close::Close; +//! +//! fn main() -> Result<()> { +//! let data = b"hello world"; +//! let mut buffer = BufWriter::new(tempfile::tempfile()?); +//! buffer.write_all(data)?; +//! buffer.close()?; // safely drop buffer and its contained File +//! Ok(()) +//! } +//! ``` +//! +//! # Optional implementations +//! +//! Optional implementations of [`Close`] are provided for the following +//! I/O writers defined in external crates, enabled through cargo features: +//! +//! - [`os_pipe::PipeWriter`] (feature: `os_pipe`) + +use std::io::{Error, Result, Write}; + +pub mod fs; + +/// An extension trait for safely dropping I/O writers. +pub trait Close: Write { + /// Drops an I/O writer and closes any resource handle contained + /// inside (such as a raw file descriptor). Ensures that I/O errors + /// resulting from closing a handle are not ignored. The writer is + /// flushed before any handle is closed. If any errors occur during + /// flushing or closing the first such error is returned. + fn close(self) -> Result<()>; +} + +// MACRO DEFINITIONS + +macro_rules! unix_impl_close_raw_fd { + ($ty:ty, "std" $(,$lt:lifetime)* $(,$id:ident)*) => { + unix_impl_close_raw_fd!($ty, "unix" $(,$lt)* $(,$id)*); + }; + ($ty:ty, $ft_fm:literal $(,$lt:lifetime)* $(,$id:ident)*) => { + #[cfg(unix)] + #[cfg(any(feature = $ft_fm, target_family = $ft_fm))] + #[cfg_attr(all(docsrs, feature = $ft_fm), doc(cfg(feature = $ft_fm)))] + impl<$($lt,)* $($id,)*> Close for $ty { + /// Drops an I/O writer containing a raw file descriptor. + fn close(mut self) -> Result<()> { + use std::io::ErrorKind; + use std::os::unix::io::IntoRawFd; + + self.flush()?; + let fd = self.into_raw_fd(); + let rv = unsafe { libc::close(fd) }; + if rv != -1 { + Ok(()) + } else { + match Error::last_os_error() { + e if e.kind() == ErrorKind::Interrupted => Ok(()), + e => Err(e), + } + } + } + } + }; +} + +macro_rules! windows_impl_close_raw_handle { + ($ty:ty, "std" $(,$lt:lifetime)* $(,$id:ident)*) => { + windows_impl_close_raw_handle!($ty, "windows" $(,$lt)* $(,$id)*); + }; + ($ty:ty, $ft_fm:literal $(,$lt:lifetime)* $(,$id:ident)*) => { + #[cfg(windows)] + #[cfg(any(feature = $ft_fm, target_family = $ft_fm))] + #[cfg_attr(all(docsrs, feature = $ft_fm), doc(cfg(feature = $ft_fm)))] + impl<$($lt,)* $($id,)*> Close for $ty { + /// Drops an I/O writer containing a raw handle. + fn close(mut self) -> Result<()> { + use std::os::windows::io::IntoRawHandle; + use winapi::um::handleapi; + + self.flush()?; + let handle = self.into_raw_handle(); + let rv = unsafe { handleapi::CloseHandle(handle) }; + if rv != 0 { + Ok(()) + } else { + Err(Error::last_os_error()) + } + } + } + }; +} + +macro_rules! windows_impl_close_raw_socket { + ($ty:ty, "std" $(,$lt:lifetime)* $(,$id:ident)*) => { + windows_impl_close_raw_socket!($ty, "windows" $(,$lt)* $(,$id)*); + }; + ($ty:ty, $ft_fm:literal $(,$lt:lifetime)* $(,$id:ident)*) => { + #[cfg(windows)] + #[cfg(any(feature = $ft_fm, target_family = $ft_fm))] + #[cfg_attr(all(docsrs, feature = $ft_fm), doc(cfg(feature = $ft_fm)))] + impl<$($lt,)* $($id,)*> Close for $ty { + /// Drops an I/O writer containing a raw socket. + fn close(mut self) -> Result<()> { + use std::convert::TryInto; + use std::os::windows::io::IntoRawSocket; + use winapi::um::winsock2; + + self.flush()?; + let socket = self.into_raw_socket().try_into().unwrap(); + let rv = unsafe { winsock2::closesocket(socket) }; + if rv == 0 { + Ok(()) + } else { + Err(Error::from_raw_os_error(unsafe { + winsock2::WSAGetLastError() + })) + } + } + } + }; +} + +macro_rules! impl_close_no_error_no_flush { + ($ty:ty, "std" $(,$lt:lifetime)* $(,$id:ident)*) => { + #[cfg(unix)] + impl_close_no_error_no_flush!($ty, "unix" $(,$lt)* $(,$id)*); + #[cfg(windows)] + impl_close_no_error_no_flush!($ty, "windows" $(,$lt)* $(,$id)*); + }; + ($ty:ty, $ft_fm:literal $(,$lt:lifetime)* $(,$id:ident)*) => { + #[cfg(any(unix, windows))] + #[cfg(any(feature = $ft_fm, target_family = $ft_fm))] + #[cfg_attr(all(docsrs, feature = $ft_fm), doc(cfg(feature = $ft_fm)))] + impl<$($lt,)* $($id,)*> Close for $ty { + /// Drops an I/O writer for which `close()` never produces + /// an error, and for which flushing is unnecessary. + #[inline] + fn close(self) -> Result<()> { + Ok(()) + } + } + }; +} + +macro_rules! impl_close_into_inner { + ($ty:ty, "std" $(,$lt:lifetime)* $(,$id:ident)*) => { + #[cfg(unix)] + impl_close_into_inner!($ty, "unix" $(,$lt)* $(,$id)*); + #[cfg(windows)] + impl_close_into_inner!($ty, "windows" $(,$lt)* $(,$id)*); + }; + ($ty:ty, $ft_fm:literal $(,$lt:lifetime)* $(,$id:ident)*) => { + #[cfg(any(unix, windows))] + #[cfg(any(feature = $ft_fm, target_family = $ft_fm))] + #[cfg_attr(all(docsrs, feature = $ft_fm), doc(cfg(feature = $ft_fm)))] + impl<$($lt,)* W: Close, $($id,)*> Close for $ty { + /// Drops an I/O writer which can be unwrapped using + /// `into_inner()` to return an underlying writer. + fn close(self) -> Result<()> { + self.into_inner()?.close() + } + } + }; +} + +// IMPLEMENTATIONS +// +// In the below macro implementations for Close the macro parameters use +// the following system: +// +// 1st paramater: the type that Close is being implemented for +// 2nd parameter: either "std", or a feature name +// 3rd, 4th, etc. parameters: additional generic arguments for type +// +// If the 2nd parameter is a feature name then the implementation will +// be conditionally compiled only when that feature is present. + +unix_impl_close_raw_fd!(std::fs::File, "std"); +unix_impl_close_raw_fd!(std::net::TcpStream, "std"); +unix_impl_close_raw_fd!(std::os::unix::net::UnixStream, "std"); +unix_impl_close_raw_fd!(std::process::ChildStdin, "std"); +unix_impl_close_raw_fd!(os_pipe::PipeWriter, "os_pipe"); + +windows_impl_close_raw_handle!(std::fs::File, "std"); +windows_impl_close_raw_socket!(std::net::TcpStream, "std"); +windows_impl_close_raw_handle!(std::process::ChildStdin, "std"); +windows_impl_close_raw_handle!(os_pipe::PipeWriter, "os_pipe"); + +impl_close_no_error_no_flush!(&mut [u8], "std"); +impl_close_no_error_no_flush!(std::io::Cursor<&mut Vec<u8>>, "std"); +impl_close_no_error_no_flush!(std::io::Cursor<&mut [u8]>, "std"); +impl_close_no_error_no_flush!(std::io::Cursor<Box<[u8]>>, "std"); +impl_close_no_error_no_flush!(std::io::Cursor<Vec<u8>>, "std"); +impl_close_no_error_no_flush!(std::io::Sink, "std"); +impl_close_no_error_no_flush!(Vec<u8>, "std"); + +impl_close_into_inner!(std::io::BufWriter<W>, "std"); +impl_close_into_inner!(std::io::LineWriter<W>, "std"); |