Struct DirtyInput 

pub struct DirtyInput {
    pub original_range: Range<u64>,
    pub reader: Pin<Box<dyn AsyncRead + Send>>,
    pub new_length: u64,
}

A single edit applied to the original file: replace original_range with new_length bytes from reader.

All three combinations are supported:

• original_range.len() == new_length → in-place edit (no file size change).
• original_range.len() != new_length → resize edit (file grows or shrinks).
• original_range.start == original_range.end → pure insert at that position.
• new_length == 0 → pure delete of original_range.

Pure append at end of file is { original_range: original_size..original_size, new_length: N, reader: ... }. Pure truncate-to-N is { original_range: N..original_size, new_length: 0, reader: empty }.

Fields

original_range: Range<u64>

reader: Pin<Box<dyn AsyncRead + Send>>

new_length: u64