Method set_null_bits

arrow-buffer/src/buffer/mutable.rs:248–260

Ensure that `count` bytes from `start` contain zero bits This is used to initialize the bits in a buffer, however, it has no impact on the `len` of the buffer and so can be used to initialize the memory region from `len` to `capacity`. # Panics Panics if the byte range `start..start + count` exceeds the buffer capacity.

(&mut self, start: usize, count: usize)

    ///
    /// Panics if the byte range `start..start + count` exceeds the buffer capacity.
    pub fn set_null_bits(&mut self, start: usize, count: usize) {
        assert!(
            start.saturating_add(count) <= self.layout.size(),
            "range start index {start} and count {count} out of bounds for \
            buffer of length {}",
            self.layout.size(),
        );

        // Safety: `self.data[start..][..count]` is in-bounds and well-aligned for `u8`
        unsafe {
            std::ptr::write_bytes(self.data.as_ptr().add(start), 0, count);
        }
    }

    /// Ensures that this buffer has at least `self.len + additional` bytes. This re-allocates iff
    /// `self.len + additional > capacity`.