diff options
| -rw-r--r-- | src/libstd/sys/wasi/ext/fs.rs | 47 |
1 files changed, 43 insertions, 4 deletions
diff --git a/src/libstd/sys/wasi/ext/fs.rs b/src/libstd/sys/wasi/ext/fs.rs index 10ea4fd34bd..f41c6626ccf 100644 --- a/src/libstd/sys/wasi/ext/fs.rs +++ b/src/libstd/sys/wasi/ext/fs.rs @@ -21,11 +21,29 @@ pub trait FileExt { /// /// The current file cursor is not affected by this function. /// + /// Note that similar to [`File::read`], it is not an error to return with a + /// short read. + /// + /// [`File::read`]: ../../../../std/fs/struct.File.html#method.read + fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> { + let bufs = &mut [IoSliceMut::new(buf)]; + self.read_vectored_at(bufs, offset) + } + + /// Reads a number of bytes starting from a given offset. + /// + /// Returns the number of bytes read. + /// + /// The offset is relative to the start of the file and thus independent + /// from the current cursor. + /// + /// The current file cursor is not affected by this function. + /// /// Note that similar to [`File::read_vectored`], it is not an error to /// return with a short read. /// /// [`File::read`]: ../../../../std/fs/struct.File.html#method.read_vectored - fn read_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize>; + fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize>; /// Reads the exact number of byte required to fill `buf` from the given offset. /// @@ -91,11 +109,32 @@ pub trait FileExt { /// When writing beyond the end of the file, the file is appropriately /// extended and the intermediate bytes are initialized with the value 0. /// + /// Note that similar to [`File::write`], it is not an error to return a + /// short write. + /// + /// [`File::write`]: ../../../../std/fs/struct.File.html#write.v + fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> { + let bufs = &[IoSlice::new(buf)]; + self.write_vectored_at(bufs, offset) + } + + /// Writes a number of bytes starting from a given offset. + /// + /// Returns the number of bytes written. + /// + /// The offset is relative to the start of the file and thus independent + /// from the current cursor. + /// + /// The current file cursor is not affected by this function. + /// + /// When writing beyond the end of the file, the file is appropriately + /// extended and the intermediate bytes are initialized with the value 0. + /// /// Note that similar to [`File::write_vectored`], it is not an error to return a /// short write. /// /// [`File::write`]: ../../../../std/fs/struct.File.html#method.write_vectored - fn write_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize>; + fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize>; /// Attempts to write an entire buffer starting from a given offset. /// @@ -199,11 +238,11 @@ pub trait FileExt { // FIXME: bind random_get maybe? - on crates.io for unix impl FileExt for fs::File { - fn read_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> { + fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> { self.as_inner().fd().pread(bufs, offset) } - fn write_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> { + fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> { self.as_inner().fd().pwrite(bufs, offset) } |