Trait fuse::filesystem::ZeroCopyWriter

source ·

pub trait ZeroCopyWriter {
    // Required method
    fn write_from(
        &mut self,
        f: &mut File,
        count: usize,
        off: u64
    ) -> Result<usize>;

    // Provided methods
    fn write_all_from(
        &mut self,
        f: &mut File,
        count: usize,
        off: u64
    ) -> Result<()> { ... }
    fn copy_to_end(&mut self, f: &mut File, off: u64) -> Result<usize> { ... }
}

Expand description

A trait for directly copying data from a File into the fuse transport without first storing it in an intermediate buffer.

Required Methods§

source

fn write_from(&mut self, f: &mut File, count: usize, off: u64) -> Result<usize>

Copies at most count bytes from f at offset off directly into self without storing it in any intermediate buffers. If the return value is Ok(n) then it must be guaranteed that 0 <= n <= count. If n is 0, then it can indicate one of 3 possibilities:

There is no more data left in f.
There is no more space in self.
count was 0.

§Errors

If any error is returned then the implementation must guarantee that no bytes were copied from f. If the underlying read from f returns 0 then the implementation must return an error of the kind io::ErrorKind::UnexpectedEof.

Provided Methods§

source

fn write_all_from(&mut self, f: &mut File, count: usize, off: u64) -> Result<()>

Copies exactly count bytes of data from f at offset off into self. off + count must be less than u64::MAX.

§Errors

If an error is returned then the number of bytes copied from self is unspecified but it well never be more than count.

source

fn copy_to_end(&mut self, f: &mut File, off: u64) -> Result<usize>

Copies all remaining bytes from f at offset off into self. Equivalent to repeatedly calling write_from until it returns either Ok(0) or a non-ErrorKind::Interrupted error.