Trait ReadSeekExt 

pub trait ReadSeekExt: Read + Seek {
    // Required methods
    fn peek_exact_or_eof(&mut self, buffer: &mut [u8]) -> Result<usize>;
    fn read_exact_or_eof_at(
        &mut self,
        offset: u64,
        buffer: &mut [u8],
    ) -> Result<usize>;
}

Extension methods for values that implement both Read and Seek.

ReadSeekExt provides position-preserving read helpers for common inspection use cases such as file signature checks, MIME detection, and random-offset probing.

Required Methods

fn peek_exact_or_eof(&mut self, buffer: &mut [u8]) -> Result<usize>

Reads from the current position and restores the original position.

This method has the same partial-EOF semantics as crate::ReadExt::read_exact_or_eof, but it leaves the stream positioned where it was before the call when restoration succeeds.

Parameters

• buffer: Destination buffer to fill.

Returns

The number of bytes written into buffer.

Errors

Returns an error when reading the current position, reading bytes, or restoring the original position fails. If both reading and restoration fail, the restoration error is returned because the caller’s stream position contract was not preserved.

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

Reads from offset and restores the original position.

This method seeks to offset, reads until buffer is full or EOF is reached, and then restores the position that was current before the call.

Parameters

• offset: Absolute byte offset from the start of the stream.
• buffer: Destination buffer to fill.

Returns

The number of bytes written into buffer.

Errors

Returns an error when reading the current position, seeking to offset, reading bytes, or restoring the original position fails. If restoration fails, the restoration error is returned.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<T> ReadSeekExt for T

where T: Read + Seek + ?Sized,