Struct odbc_api::buffers::NullableSliceMut

pub struct NullableSliceMut<'a, T> { /* private fields */ }

Used to fill a column buffer with an iterator. Returned by crate::ColumnarBulkInserter::column_mut as part of an crate::buffers::AnySliceMut.

Implementations

impl<'a, T> NullableSliceMut<'a, T>

pub fn is_empty(&self) -> bool

true if the slice has a length of 0.

pub fn len(&self) -> usize

Number of entries in this slice of the buffer

pub fn set_cell(&mut self, index: usize, cell: Option<T>)

Sets the value at the specified index. Use None to specify a NULL value.

pub fn raw_values(&mut self) -> (&mut [T], &mut [isize])

Write access to the underlying raw value and indicator buffer.

The number of elements in the buffer is equal to len.

This method is useful for writing performant bindings to datastructures with similar binary layout, as it allows for using memcopy rather than iterating over individual values.

Example

use odbc_api::{buffers::NullableSliceMut, sys::NULL_DATA};

// Memcopy the values into the buffer, and set indicators according to mask
// values.
fn copy_values_and_make_mask(
    new_values: &[i32],
    mask: &[bool],
    odbc_slice: &mut NullableSliceMut<i32>)
{
    let (values, indicators) = odbc_slice.raw_values();
    values.copy_from_slice(new_values);
    // Create array of bools indicating null values.
    indicators.iter_mut().zip(mask.iter()).for_each(|(indicator, &mask)| {
        *indicator = if mask {
            0
        } else {
            NULL_DATA
        }
    });
}

impl<'a, T> NullableSliceMut<'a, T>

pub fn write(&mut self, it: impl Iterator<Item = Option<T>>)

Writes the elements returned by the iterator into the buffer, starting at the beginning. Writes elements until the iterator returns None or the buffer can not hold more elements.

Trait Implementations

impl<'a, T: Debug> Debug for NullableSliceMut<'a, T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.