diff options
Diffstat (limited to 'library/std/src/fs.rs')
| -rw-r--r-- | library/std/src/fs.rs | 73 |
1 files changed, 51 insertions, 22 deletions
diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs index c550378e7..89dfdfafd 100644 --- a/library/std/src/fs.rs +++ b/library/std/src/fs.rs @@ -15,6 +15,7 @@ use crate::ffi::OsString; use crate::fmt; use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, Read, Seek, SeekFrom, Write}; use crate::path::{Path, PathBuf}; +use crate::sealed::Sealed; use crate::sys::fs as fs_imp; use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner}; use crate::time::SystemTime; @@ -249,9 +250,9 @@ pub struct DirBuilder { pub fn read<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> { fn inner(path: &Path) -> io::Result<Vec<u8>> { let mut file = File::open(path)?; - let size = file.metadata().map(|m| m.len()).unwrap_or(0); - let mut bytes = Vec::with_capacity(size as usize); - io::default_read_to_end(&mut file, &mut bytes)?; + let size = file.metadata().map(|m| m.len() as usize).ok(); + let mut bytes = Vec::with_capacity(size.unwrap_or(0)); + io::default_read_to_end(&mut file, &mut bytes, size)?; Ok(bytes) } inner(path.as_ref()) @@ -289,9 +290,9 @@ pub fn read<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> { pub fn read_to_string<P: AsRef<Path>>(path: P) -> io::Result<String> { fn inner(path: &Path) -> io::Result<String> { let mut file = File::open(path)?; - let size = file.metadata().map(|m| m.len()).unwrap_or(0); - let mut string = String::with_capacity(size as usize); - io::default_read_to_string(&mut file, &mut string)?; + let size = file.metadata().map(|m| m.len() as usize).ok(); + let mut string = String::with_capacity(size.unwrap_or(0)); + io::default_read_to_string(&mut file, &mut string, size)?; Ok(string) } inner(path.as_ref()) @@ -709,6 +710,7 @@ impl File { // `AsRawHandle`/`IntoRawHandle`/`FromRawHandle` on Windows. impl AsInner<fs_imp::File> for File { + #[inline] fn as_inner(&self) -> &fs_imp::File { &self.inner } @@ -732,12 +734,12 @@ impl fmt::Debug for File { } /// Indicates how much extra capacity is needed to read the rest of the file. -fn buffer_capacity_required(mut file: &File) -> usize { - let size = file.metadata().map(|m| m.len()).unwrap_or(0); - let pos = file.stream_position().unwrap_or(0); +fn buffer_capacity_required(mut file: &File) -> Option<usize> { + let size = file.metadata().map(|m| m.len()).ok()?; + let pos = file.stream_position().ok()?; // Don't worry about `usize` overflow because reading will fail regardless // in that case. - size.saturating_sub(pos) as usize + Some(size.saturating_sub(pos) as usize) } #[stable(feature = "rust1", since = "1.0.0")] @@ -761,14 +763,16 @@ impl Read for File { // Reserves space in the buffer based on the file size when available. fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { - buf.reserve(buffer_capacity_required(self)); - io::default_read_to_end(self, buf) + let size = buffer_capacity_required(self); + buf.reserve(size.unwrap_or(0)); + io::default_read_to_end(self, buf, size) } // Reserves space in the buffer based on the file size when available. fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> { - buf.reserve(buffer_capacity_required(self)); - io::default_read_to_string(self, buf) + let size = buffer_capacity_required(self); + buf.reserve(size.unwrap_or(0)); + io::default_read_to_string(self, buf, size) } } #[stable(feature = "rust1", since = "1.0.0")] @@ -817,14 +821,16 @@ impl Read for &File { // Reserves space in the buffer based on the file size when available. fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> { - buf.reserve(buffer_capacity_required(self)); - io::default_read_to_end(self, buf) + let size = buffer_capacity_required(self); + buf.reserve(size.unwrap_or(0)); + io::default_read_to_end(self, buf, size) } // Reserves space in the buffer based on the file size when available. fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> { - buf.reserve(buffer_capacity_required(self)); - io::default_read_to_string(self, buf) + let size = buffer_capacity_required(self); + buf.reserve(size.unwrap_or(0)); + io::default_read_to_string(self, buf, size) } } #[stable(feature = "rust1", since = "1.0.0")] @@ -1083,12 +1089,14 @@ impl OpenOptions { } impl AsInner<fs_imp::OpenOptions> for OpenOptions { + #[inline] fn as_inner(&self) -> &fs_imp::OpenOptions { &self.0 } } impl AsInnerMut<fs_imp::OpenOptions> for OpenOptions { + #[inline] fn as_inner_mut(&mut self) -> &mut fs_imp::OpenOptions { &mut self.0 } @@ -1348,6 +1356,7 @@ impl fmt::Debug for Metadata { } impl AsInner<fs_imp::FileAttr> for Metadata { + #[inline] fn as_inner(&self) -> &fs_imp::FileAttr { &self.0 } @@ -1383,6 +1392,16 @@ impl FileTimes { } } +impl AsInnerMut<fs_imp::FileTimes> for FileTimes { + fn as_inner_mut(&mut self) -> &mut fs_imp::FileTimes { + &mut self.0 + } +} + +// For implementing OS extension traits in `std::os` +#[unstable(feature = "file_set_times", issue = "98245")] +impl Sealed for FileTimes {} + impl Permissions { /// Returns `true` if these permissions describe a readonly (unwritable) file. /// @@ -1600,6 +1619,7 @@ impl FileType { } impl AsInner<fs_imp::FileType> for FileType { + #[inline] fn as_inner(&self) -> &fs_imp::FileType { &self.0 } @@ -1612,6 +1632,7 @@ impl FromInner<fs_imp::FilePermissions> for Permissions { } impl AsInner<fs_imp::FilePermissions> for Permissions { + #[inline] fn as_inner(&self) -> &fs_imp::FilePermissions { &self.0 } @@ -1766,6 +1787,7 @@ impl fmt::Debug for DirEntry { } impl AsInner<fs_imp::DirEntry> for DirEntry { + #[inline] fn as_inner(&self) -> &fs_imp::DirEntry { &self.0 } @@ -1935,7 +1957,7 @@ pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<()> /// On success, the total number of bytes copied is returned and it is equal to /// the length of the `to` file as reported by `metadata`. /// -/// If you’re wanting to copy the contents of one file to another and you’re +/// If you want to copy the contents of one file to another and you’re /// working with [`File`]s, see the [`io::copy()`] function. /// /// # Platform-specific behavior @@ -2280,6 +2302,11 @@ pub fn remove_dir<P: AsRef<Path>>(path: P) -> io::Result<()> { /// /// See [`fs::remove_file`] and [`fs::remove_dir`]. /// +/// `remove_dir_all` will fail if `remove_dir` or `remove_file` fail on any constituent paths, including the root path. +/// As a result, the directory you are deleting must exist, meaning that this function is not idempotent. +/// +/// Consider ignoring the error if validating the removal is not required for your use case. +/// /// [`fs::remove_file`]: remove_file /// [`fs::remove_dir`]: remove_dir /// @@ -2501,6 +2528,7 @@ impl DirBuilder { } impl AsInnerMut<fs_imp::DirBuilder> for DirBuilder { + #[inline] fn as_inner_mut(&mut self) -> &mut fs_imp::DirBuilder { &mut self.inner } @@ -2511,9 +2539,10 @@ impl AsInnerMut<fs_imp::DirBuilder> for DirBuilder { /// This function will traverse symbolic links to query information about the /// destination file. In case of broken symbolic links this will return `Ok(false)`. /// -/// As opposed to the [`Path::exists`] method, this one doesn't silently ignore errors -/// unrelated to the path not existing. (E.g. it will return `Err(_)` in case of permission -/// denied on some of the parent directories.) +/// As opposed to the [`Path::exists`] method, this will only return `Ok(true)` or `Ok(false)` +/// if the path was _verified_ to exist or not exist. If its existence can neither be confirmed +/// nor denied, an `Err(_)` will be propagated instead. This can be the case if e.g. listing +/// permission is denied on one of the parent directories. /// /// Note that while this avoids some pitfalls of the `exists()` method, it still can not /// prevent time-of-check to time-of-use (TOCTOU) bugs. You should only use it in scenarios |