Trait system_interface::fs::FileIoExt

pub trait FileIoExt: IoExt {
    fn advise(&self, offset: u64, len: u64, advice: Advice) -> Result<()>;
    fn allocate(&self, offset: u64, len: u64) -> Result<()>;
    fn read_at(&self, buf: &mut [u8], offset: u64) -> Result<usize>;
    fn read_exact_at(&self, buf: &mut [u8], offset: u64) -> Result<()>;
    fn read_to_end_at(&self, buf: &mut Vec<u8>, offset: u64) -> Result<usize>;
    fn read_to_string_at(&self, buf: &mut String, offset: u64) -> Result<usize>;
    fn write_at(&self, buf: &[u8], offset: u64) -> Result<usize>;
    fn write_all_at(&self, buf: &[u8], offset: u64) -> Result<()>;
    fn seek(&self, pos: SeekFrom) -> Result<u64>;
    fn stream_position(&self) -> Result<u64>;

    fn read_vectored_at(
        &self,
        bufs: &mut [IoSliceMut<'_>],
        offset: u64
    ) -> Result<usize> { ... }
    fn read_exact_vectored_at(
        &self,
        bufs: &mut [IoSliceMut<'_>],
        offset: u64
    ) -> Result<()> { ... }
    fn is_read_vectored_at(&self) -> bool { ... }
    fn write_vectored_at(
        &self,
        bufs: &[IoSlice<'_>],
        offset: u64
    ) -> Result<usize> { ... }
    fn write_all_vectored_at(
        &self,
        bufs: &mut [IoSlice<'_>],
        offset: u64
    ) -> Result<()> { ... }
    fn is_write_vectored_at(&self) -> bool { ... }
}

Extension trait for std::fs::File and cap_std::fs::File.

Required Methods

fn advise(&self, offset: u64, len: u64, advice: Advice) -> Result<()>

Announce the expected access pattern of the data at the given offset.

fn allocate(&self, offset: u64, len: u64) -> Result<()>

Allocate space in the file, increasing the file size as needed, and ensuring that there are no holes under the given range.

fn read_at(&self, buf: &mut [u8], offset: u64) -> Result<usize>

Reads a number of bytes starting from a given offset.

This is similar to std::os::unix::fs::FileExt::read_at, except it takes self by immutable reference since the entire side effect is I/O, and it’s supported on non-Unix platforms including Windows.

fn read_exact_at(&self, buf: &mut [u8], offset: u64) -> Result<()>

Reads the exact number of byte required to fill buf from the given offset.

This is similar to std::os::unix::fs::FileExt::read_exact_at, except it takes self by immutable reference since the entire side effect is I/O, and it’s supported on non-Unix platforms including Windows.

fn read_to_end_at(&self, buf: &mut Vec<u8>, offset: u64) -> Result<usize>

Read all bytes, starting at offset, until EOF in this source, placing them into buf.

fn read_to_string_at(&self, buf: &mut String, offset: u64) -> Result<usize>

Read all bytes, starting at offset, until EOF in this source, appending them to buf.

fn write_at(&self, buf: &[u8], offset: u64) -> Result<usize>

Writes a number of bytes starting from a given offset.

This is similar to std::os::unix::fs::FileExt::write_at, except it takes self by immutable reference since the entire side effect is I/O, and it’s supported on non-Unix platforms including Windows.

fn write_all_at(&self, buf: &[u8], offset: u64) -> Result<()>

Attempts to write an entire buffer starting from a given offset.

This is similar to std::os::unix::fs::FileExt::write_all_at, except it takes self by immutable reference since the entire side effect is I/O, and it’s supported on non-Unix platforms including Windows.

fn seek(&self, pos: SeekFrom) -> Result<u64>

Seek to an offset, in bytes, in a stream.

This is similar to std::io::Seek::seek, except it takes self by immutable reference since the entire side effect is I/O.

fn stream_position(&self) -> Result<u64>

Returns the current seek position from the start of the stream.

This is similar to std::io::Seek::stream_position, except it’s available on Rust stable.

This may eventually be implemented by rust-lang/rust#62726.

Provided Methods

fn read_vectored_at(
    &self,
    bufs: &mut [IoSliceMut<'_>],
    offset: u64
) -> Result<usize>

Is to read_vectored what read_at is to read.

fn read_exact_vectored_at(
    &self,
    bufs: &mut [IoSliceMut<'_>],
    offset: u64
) -> Result<()>

Is to read_exact_vectored what read_exact_at is to read_exact.

fn is_read_vectored_at(&self) -> bool

Determines if this Reader has an efficient read_vectored_at implementation.

fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> Result<usize>

Is to write_vectored what write_at is to write.

fn write_all_vectored_at(
    &self,
    bufs: &mut [IoSlice<'_>],
    offset: u64
) -> Result<()>

Is to write_all_vectored what write_all_at is to write_all.

fn is_write_vectored_at(&self) -> bool

Determines if this Writer has an efficient write_vectored_at implementation.

Implementors

impl<T: AsFilelike + IoExt> FileIoExt for T

Implement FileIoExt for any type which implements AsRawFd.