fn trim_to_tail_bytes(
result: &mut BlockfileReadRangeResult,
first_line: u64,
max_bytes: usize,
)Expand description
tail_bytes: keep the newest lines that fit in max_bytes (the newest
line always stays, however large; a line costs its length plus its
newline), then move the start up to the first turn start among them, if
there is one, so the pane doesn’t open on the tail of a turn. Lines before
first_line were already trimmed (tail_turns): result.offset wins.