Method fill

crates/tinywasm/src/store/memory/paged.rs:212–238

(&mut self, addr: usize, len: usize, val: u8)

    #[inline(always)]
    fn fill(&mut self, addr: usize, len: usize, val: u8) -> Option<()> {
        let end = self.checked_end(addr, len)?;
        let mut pos = addr;

        while pos < end {
            let chunk_idx = pos >> self.chunk_shift;
            let chunk_offset = pos & self.chunk_mask;
            let chunk_start = chunk_idx << self.chunk_shift;
            let chunk_full_len = min(self.chunk_size, self.len - chunk_start);
            let chunk_end = min(chunk_start + self.chunk_size, end);
            let fill_len = chunk_end - pos;

            if val == 0 {
                if chunk_offset == 0 && fill_len == chunk_full_len {
                    self.chunks[chunk_idx] = None;
                } else if let Some(Some(chunk)) = self.chunks.get_mut(chunk_idx) {
                    chunk[chunk_offset..chunk_offset + fill_len].fill(0);
                }
            } else {
                self.chunk_mut(chunk_idx).ok()?[chunk_offset..chunk_offset + fill_len].fill(val);
            }

            pos = chunk_end;
        }

        Some(())
    }

    #[inline(always)]
    fn copy_within(&mut self, dst: usize, src: usize, len: usize) -> Option<()> {