Method occupancy

arrow-array/src/array/dictionary_array.rs:566–583

Computes an occupancy mask for this dictionary's values For each value in [`Self::values`] the corresponding bit will be set in the returned mask if it is referenced by a key in this [`DictionaryArray`]

(&self)

    /// For each value in [`Self::values`] the corresponding bit will be set in the
    /// returned mask if it is referenced by a key in this [`DictionaryArray`]
    pub fn occupancy(&self) -> BooleanBuffer {
        let len = self.values.len();
        let mut builder = BooleanBufferBuilder::new(len);
        builder.resize(len);
        let slice = builder.as_slice_mut();
        match self.keys.nulls().filter(|n| n.null_count() > 0) {
            Some(n) => {
                let v = self.keys.values();
                n.valid_indices()
                    .for_each(|idx| set_bit(slice, v[idx].as_usize()))
            }
            None => {
                let v = self.keys.values();
                v.iter().for_each(|v| set_bit(slice, v.as_usize()))
            }
        }
        builder.finish()
    }
}

/// Constructs a `DictionaryArray` from an `ArrayData`