vortex-array 0.81.0

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright the Vortex contributors

use vortex_error::VortexExpect;
use vortex_error::VortexResult;
use vortex_error::vortex_bail;
use vortex_error::vortex_ensure;
use vortex_error::vortex_ensure_eq;

use crate::dtype::DType;
use crate::dtype::PType;
use crate::scalar::PValue;
use crate::scalar::Scalar;
use crate::scalar::ScalarValue;

impl Scalar {
    /// Validate that the given [`ScalarValue`] is compatible with the given [`DType`].
    pub fn validate(dtype: &DType, value: Option<&ScalarValue>) -> VortexResult<()> {
        let Some(value) = value else {
            vortex_ensure!(
                dtype.is_nullable(),
                "non-nullable dtype {dtype} cannot hold a null value",
            );
            return Ok(());
        };

        // From here onwards, we know that the value is not null.
        match dtype {
            DType::Null => {
                vortex_bail!("null dtype cannot hold a non-null value {value}");
            }
            DType::Bool(_) => {
                vortex_ensure!(
                    matches!(value, ScalarValue::Bool(_)),
                    "bool dtype expected Bool value, got {value}",
                );
            }
            DType::Primitive(ptype, _) => {
                let ScalarValue::Primitive(pvalue) = value else {
                    vortex_bail!("primitive dtype {ptype} expected Primitive value, got {value}",);
                };

                // Note that this is a backwards compatibility check for poor design in the
                // previous implementation. `f16` `ScalarValue`s used to be serialized as
                // `pb::ScalarValue::Uint64Value(v.to_bits() as u64)`, so we need to ensure
                // that we can still represent them as such.
                let f16_backcompat_still_works =
                    matches!(ptype, &PType::F16) && matches!(pvalue, PValue::U64(_));

                vortex_ensure!(
                    f16_backcompat_still_works || pvalue.ptype() == *ptype,
                    "primitive dtype {ptype} is not compatible with value {pvalue}",
                );
            }
            DType::Decimal(dec_dtype, _) => {
                let ScalarValue::Decimal(dvalue) = value else {
                    vortex_bail!("decimal dtype expected Decimal value, got {value}");
                };

                vortex_ensure!(
                    dvalue.fits_in_precision(*dec_dtype),
                    "decimal value {dvalue} does not fit in precision of {dec_dtype}",
                );
            }
            DType::Utf8(_) => {
                vortex_ensure!(
                    matches!(value, ScalarValue::Utf8(_)),
                    "utf8 dtype expected Utf8 value, got {value}",
                );
            }
            DType::Binary(_) => {
                vortex_ensure!(
                    matches!(value, ScalarValue::Binary(_)),
                    "binary dtype expected Binary value, got {value}",
                );
            }
            DType::List(elem_dtype, _) => {
                let ScalarValue::Tuple(elements) = value else {
                    vortex_bail!("list dtype expected Tuple value, got {value}");
                };

                for (i, element) in elements.iter().enumerate() {
                    Self::validate(elem_dtype.as_ref(), element.as_ref())
                        .map_err(|e| vortex_error::vortex_err!("list element at index {i}: {e}"))?;
                }
            }
            DType::FixedSizeList(elem_dtype, size, _) => {
                let ScalarValue::Tuple(elements) = value else {
                    vortex_bail!("fixed-size list dtype expected Tuple value, got {value}",);
                };

                let len = elements.len();
                vortex_ensure_eq!(
                    len,
                    *size as usize,
                    "fixed-size list dtype expected {size} elements, got {len}",
                );

                for (i, element) in elements.iter().enumerate() {
                    Self::validate(elem_dtype.as_ref(), element.as_ref()).map_err(|e| {
                        vortex_error::vortex_err!("fixed-size list element at index {i}: {e}",)
                    })?;
                }
            }
            DType::Struct(fields, _) => {
                let ScalarValue::Tuple(values) = value else {
                    vortex_bail!("struct dtype expected Tuple value, got {value}");
                };

                let nfields = fields.nfields();
                let nvalues = values.len();
                vortex_ensure_eq!(
                    nvalues,
                    nfields,
                    "struct dtype expected {nfields} fields, got {nvalues}",
                );

                for (field, field_value) in fields.fields().zip(values.iter()) {
                    Self::validate(&field, field_value.as_ref())?;
                }
            }
            DType::Union(variants, _) => {
                let ScalarValue::Union(union_value) = value else {
                    vortex_bail!("union dtype expected Union value, got {value}");
                };

                let type_id = union_value.type_id();
                let Some(child_index) = variants.tag_to_child_index(type_id) else {
                    vortex_bail!(
                        "union value has unknown type ID {type_id}; expected one of {:?}",
                        variants.type_ids()
                    );
                };

                let child_dtype = variants
                    .variant_by_index(child_index)
                    .vortex_expect("resolved union child index must be valid");

                Self::validate(&child_dtype, union_value.child_value()).map_err(|error| {
                    vortex_error::vortex_err!(
                        "union value for type ID {type_id} is invalid for dtype {child_dtype}: \
                         {error}"
                    )
                })?;
            }
            DType::Variant(_) => {
                let ScalarValue::Variant(inner) = value else {
                    vortex_bail!("variant dtype expected Variant value, got {value}");
                };

                Self::validate(inner.dtype(), inner.value())?;
                vortex_ensure!(
                    !inner.is_null() || matches!(inner.dtype(), DType::Null),
                    "variant nulls must use a nested null scalar, got {}",
                    inner.dtype(),
                );
            }
            DType::Extension(ext_dtype) => ext_dtype.validate_storage_value(value)?,
        }

        Ok(())
    }
}

#[cfg(test)]
mod tests {
    use vortex_error::VortexResult;

    use crate::dtype::DType;
    use crate::dtype::Nullability;
    use crate::dtype::PType;
    use crate::dtype::UnionVariants;
    use crate::scalar::Scalar;
    use crate::scalar::ScalarValue;
    use crate::scalar::UnionValue;

    #[test]
    fn union_rejects_unknown_tag_and_wrong_value() -> VortexResult<()> {
        let variants = UnionVariants::try_new(
            ["int", "string"].into(),
            vec![
                DType::Primitive(PType::I32, Nullability::Nullable),
                DType::Utf8(Nullability::NonNullable),
            ],
            vec![5, 9],
        )?;
        let dtype = DType::Union(variants, Nullability::NonNullable);

        assert!(
            Scalar::try_new(
                dtype.clone(),
                Some(ScalarValue::Union(UnionValue::new(
                    7,
                    Scalar::primitive(42_i32, Nullability::Nullable).into_value(),
                ))),
            )
            .is_err()
        );

        assert!(
            Scalar::try_new(
                dtype,
                Some(ScalarValue::Union(UnionValue::new(
                    5,
                    Scalar::utf8("wrong", Nullability::NonNullable).into_value(),
                ))),
            )
            .is_err()
        );

        Ok(())
    }
}