proxmox-backup/pbs-tape/src/tape_read.rs

39 lines
1.2 KiB
Rust

use std::io::Read;
/// Read trait for tape devices
///
/// Normal Read, but allows to query additional status flags.
pub trait TapeRead: Read {
/// Return true if there is an "INCOMPLETE" mark at EOF
///
/// Raises an error if you query this flag before reaching EOF.
fn is_incomplete(&self) -> Result<bool, std::io::Error>;
/// Return true if there is a file end marker before EOF
///
/// Raises an error if you query this flag before reaching EOF.
fn has_end_marker(&self) -> Result<bool, std::io::Error>;
/// Skip data by reading to EOF (position after EOF marker)
///
// Returns the number of bytes skipped. This does not raise an
// error if the stream has no end marker.
fn skip_data(&mut self) -> Result<usize, std::io::Error>;
}
#[derive(thiserror::Error, Debug)]
pub enum BlockReadError {
#[error("{0}")]
Error(#[from] std::io::Error),
#[error("end of file")]
EndOfFile,
#[error("end of data stream")]
EndOfStream,
}
/// Read streams of blocks
pub trait BlockRead {
/// Read the next block (whole buffer)
fn read_block(&mut self, buffer: &mut [u8]) -> Result<usize, BlockReadError>;
}