Trait odbc_api::buffers::ColumnBuffer

pub unsafe trait ColumnBuffer: for<'a> ColumnProjections<'a> + CDataMut {
    fn view(&self, valid_rows: usize) -> <Self as ColumnProjections<'_>>::View;
    unsafe fn view_mut(
        &mut self, 
        valid_rows: usize
    ) -> <Self as ColumnProjections<'_>>::ViewMut;
    fn fill_default(&mut self, from: usize, to: usize);
    fn capacity(&self) -> usize;
}

A buffer for a single column intended to be used together with ColumnarBuffer.

Safety

Views must not allow access to unintialized / invalid rows.

Required Methods

fn view(&self, valid_rows: usize) -> <Self as ColumnProjections<'_>>::View

Num rows may not exceed the actually amount of valid num_rows filled be the ODBC API. The column buffer does not know how many elements were in the last row group, and therefore can not guarantee the accessed element to be valid and in a defined state. It also can not panic on accessing an undefined element.

unsafe fn view_mut(
    &mut self,
    valid_rows: usize
) -> <Self as ColumnProjections<'_>>::ViewMut

Safety

valid_rows must be valid, otherwise the safe abstraction would provide access to invalid memory.

fn fill_default(&mut self, from: usize, to: usize)

Fills the column with the default representation of values, between from and to index.

fn capacity(&self) -> usize

Current capacity of the column

Implementors

impl ColumnBuffer for AnyColumnBuffer

impl<C: 'static> ColumnBuffer for TextColumn<C> where
    TextColumn<C>: CDataMut + HasDataType, 

impl<T> ColumnBuffer for WithDataType<T> where
    T: ColumnBuffer,