common_function/scalars/expression/
is_null.rsuse std::fmt;
use std::fmt::Display;
use std::sync::Arc;
use common_query::error;
use common_query::error::{ArrowComputeSnafu, InvalidFuncArgsSnafu};
use common_query::prelude::{Signature, Volatility};
use datafusion::arrow::array::ArrayRef;
use datafusion::arrow::compute::is_null;
use datatypes::data_type::ConcreteDataType;
use datatypes::prelude::VectorRef;
use datatypes::vectors::Helper;
use snafu::{ensure, ResultExt};
use crate::function::{Function, FunctionContext};
const NAME: &str = "isnull";
#[derive(Clone, Debug, Default)]
pub struct IsNullFunction;
impl Display for IsNullFunction {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", NAME.to_ascii_uppercase())
}
}
impl Function for IsNullFunction {
fn name(&self) -> &str {
NAME
}
fn return_type(&self, _: &[ConcreteDataType]) -> common_query::error::Result<ConcreteDataType> {
Ok(ConcreteDataType::boolean_datatype())
}
fn signature(&self) -> Signature {
Signature::any(1, Volatility::Immutable)
}
fn eval(
&self,
_func_ctx: FunctionContext,
columns: &[VectorRef],
) -> common_query::error::Result<VectorRef> {
ensure!(
columns.len() == 1,
InvalidFuncArgsSnafu {
err_msg: format!(
"The length of the args is not correct, expect exactly one, have: {}",
columns.len()
),
}
);
let values = &columns[0];
let arrow_array = &values.to_arrow_array();
let result = is_null(arrow_array).context(ArrowComputeSnafu)?;
Helper::try_into_vector(Arc::new(result) as ArrayRef).context(error::FromArrowArraySnafu)
}
}
#[cfg(test)]
mod tests {
use std::sync::Arc;
use common_query::prelude::TypeSignature;
use datatypes::scalars::ScalarVector;
use datatypes::vectors::{BooleanVector, Float32Vector};
use super::*;
#[test]
fn test_is_null_function() {
let is_null = IsNullFunction;
assert_eq!("isnull", is_null.name());
assert_eq!(
ConcreteDataType::boolean_datatype(),
is_null.return_type(&[]).unwrap()
);
assert_eq!(
is_null.signature(),
Signature {
type_signature: TypeSignature::Any(1),
volatility: Volatility::Immutable
}
);
let values = vec![None, Some(3.0), None];
let args: Vec<VectorRef> = vec![Arc::new(Float32Vector::from(values))];
let vector = is_null.eval(FunctionContext::default(), &args).unwrap();
let expect: VectorRef = Arc::new(BooleanVector::from_vec(vec![true, false, true]));
assert_eq!(expect, vector);
}
}