Trait Source

Source

pub trait Source: Sealed {
    // Required methods
    fn size(&self) -> u64;
    fn slice<'a>(
        &'a mut self,
        offset: u64,
        len: usize,
        scratch: &'a mut Vec<u8>,
    ) -> Result<&'a [u8]>;
    fn read_owned(&mut self, offset: u64, len: usize) -> Result<Vec<u8>>;
}

Expand description

A seekable byte source the reader fetches HDU header and data units from. Sealed — implemented only by this crate’s source types, never externally.

Required Methods§

Source

fn size(&self) -> u64

Total byte length of the source. Fixed for the source’s lifetime and used to reject ranges that run past the end before allocating for them.

Source

fn slice<'a>( &'a mut self, offset: u64, len: usize, scratch: &'a mut Vec<u8>, ) -> Result<&'a [u8]>

The len bytes at offset, borrowed. In-memory sources return a slice of themselves (zero-copy); a streaming source reads into scratch and returns a slice of that. Errors if the range runs past the source.

Source

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

The len bytes at offset in a fresh owned buffer — used where the bytes must outlive the read (the parsed table / ASCII-table backing store). Kept distinct from slice().to_vec() so a streaming source reads straight into the owned buffer (one copy) instead of staging through scratch first (two).