Trait system_interface::fs::FileIoExt

source · 
pub trait FileIoExt: IoExt {

Show 16 methods    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 { ... }

}
Expand description

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

Required Methods§

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

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

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.

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.

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

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

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.

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.

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.

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§

Is to read_vectored what read_at is to read.

Examples found in repository?
src/fs/file_io_ext.rs (line 128)
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    fn read_exact_vectored_at(
        &self,
        mut bufs: &mut [IoSliceMut],
        mut offset: u64,
    ) -> io::Result<()> {
        bufs = skip_leading_empties(bufs);
        while !bufs.is_empty() {
            match self.read_vectored_at(bufs, offset) {
                Ok(0) => {
                    return Err(io::Error::new(
                        io::ErrorKind::UnexpectedEof,
                        "failed to fill whole buffer",
                    ))
                }
                Ok(nread) => {
                    offset = offset
                        .checked_add(nread.try_into().unwrap())
                        .ok_or_else(|| io::Error::new(io::ErrorKind::Other, "offset overflow"))?;
                    bufs = advance_mut(bufs, nread);
                }
                Err(ref e) if e.kind() == io::ErrorKind::Interrupted => (),
                Err(e) => return Err(e),
            }
            bufs = skip_leading_empties(bufs);
        }
        Ok(())
    }

Is to read_exact_vectored what read_exact_at is to read_exact.

Determines if this Reader has an efficient read_vectored_at implementation.

Is to write_vectored what write_at is to write.

Examples found in repository?
src/fs/file_io_ext.rs (line 194)
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    fn write_all_vectored_at(&self, mut bufs: &mut [IoSlice], mut offset: u64) -> io::Result<()> {
        while !bufs.is_empty() {
            match self.write_vectored_at(bufs, offset) {
                Ok(nwritten) => {
                    offset = offset
                        .checked_add(nwritten.try_into().unwrap())
                        .ok_or_else(|| io::Error::new(io::ErrorKind::Other, "offset overflow"))?;
                    bufs = advance(bufs, nwritten);
                }
                Err(ref e) if e.kind() == io::ErrorKind::Interrupted => (),
                Err(e) => return Err(e),
            }
        }
        Ok(())
    }

Is to write_all_vectored what write_all_at is to write_all.

Determines if this Writer has an efficient write_vectored_at implementation.

Implementors§

Implement FileIoExt for any type which implements AsRawFd.