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new 991170decb [Variant] Support Timestamp to variant for
`cast_to_variant` kernel (#8113)
991170decb is described below
commit 991170decb10eafd1b2acbb23ba73a439dbb2358
Author: Mark Nash <abacefabmicrobl...@hotmail.com>
AuthorDate: Wed Aug 13 10:45:08 2025 -0700
[Variant] Support Timestamp to variant for `cast_to_variant` kernel (#8113)
# Which issue does this PR close?
We generally require a GitHub issue to be filed for all bug fixes and
enhancements and this helps us generate change logs for our releases.
You can link an issue to this PR using the GitHub syntax.
- Closes #8058 .
# Rationale for this change
Why are you proposing this change? If this is already explained clearly
in the issue then this section is not needed.
Explaining clearly why changes are proposed helps reviewers understand
your changes and offer better suggestions for fixes.
# What changes are included in this PR?
There is no need to duplicate the description in the issue here but it
is sometimes worth providing a summary of the individual changes in this
PR.
# Are these changes tested?
We typically require tests for all PRs in order to:
1. Prevent the code from being accidentally broken by subsequent changes
2. Serve as another way to document the expected behavior of the code
If tests are not included in your PR, please explain why (for example,
are they covered by existing tests)?
I am pretty sure I tested all the code paths
# Are there any user-facing changes?
If there are user-facing changes then we may require documentation to be
updated before approving the PR.
If there are any breaking changes to public APIs, please call them out.
There is some documentation saying that nanoseconds will get truncated
when converted
---------
Co-authored-by: Andrew Lamb <and...@nerdnetworks.org>
---
parquet-variant-compute/Cargo.toml | 1 +
parquet-variant-compute/src/cast_to_variant.rs | 144 ++++++++++++++++++++++++-
2 files changed, 143 insertions(+), 2 deletions(-)
diff --git a/parquet-variant-compute/Cargo.toml
b/parquet-variant-compute/Cargo.toml
index 0aa926ee7f..65ee0b33fc 100644
--- a/parquet-variant-compute/Cargo.toml
+++ b/parquet-variant-compute/Cargo.toml
@@ -36,6 +36,7 @@ arrow-schema = { workspace = true }
half = { version = "2.1", default-features = false }
parquet-variant = { workspace = true }
parquet-variant-json = { workspace = true }
+chrono = {workspace = true}
[lib]
name = "parquet_variant_compute"
diff --git a/parquet-variant-compute/src/cast_to_variant.rs
b/parquet-variant-compute/src/cast_to_variant.rs
index ed40538cab..6c212e3902 100644
--- a/parquet-variant-compute/src/cast_to_variant.rs
+++ b/parquet-variant-compute/src/cast_to_variant.rs
@@ -15,14 +15,24 @@
// specific language governing permissions and limitations
// under the License.
+use std::sync::Arc;
+
use crate::{VariantArray, VariantArrayBuilder};
-use arrow::array::{Array, AsArray};
+use arrow::array::{
+ Array, AsArray, TimestampMicrosecondArray, TimestampMillisecondArray,
TimestampNanosecondArray,
+ TimestampSecondArray,
+};
use arrow::datatypes::{
i256, BinaryType, BinaryViewType, Decimal128Type, Decimal256Type,
Decimal32Type, Decimal64Type,
Float16Type, Float32Type, Float64Type, Int16Type, Int32Type, Int64Type,
Int8Type,
LargeBinaryType, UInt16Type, UInt32Type, UInt64Type, UInt8Type,
};
-use arrow_schema::{ArrowError, DataType};
+use arrow::temporal_conversions::{
+ timestamp_ms_to_datetime, timestamp_ns_to_datetime,
timestamp_s_to_datetime,
+ timestamp_us_to_datetime,
+};
+use arrow_schema::{ArrowError, DataType, TimeUnit};
+use chrono::{DateTime, NaiveDateTime, TimeZone, Utc};
use half::f16;
use parquet_variant::{Variant, VariantDecimal16, VariantDecimal4,
VariantDecimal8};
@@ -75,6 +85,74 @@ macro_rules! non_generic_conversion {
}};
}
+fn convert_timestamp(
+ time_unit: &TimeUnit,
+ time_zone: &Option<Arc<str>>,
+ input: &dyn Array,
+ builder: &mut VariantArrayBuilder,
+) {
+ let native_datetimes: Vec<Option<NaiveDateTime>> = match time_unit {
+ arrow_schema::TimeUnit::Second => {
+ let ts_array = input
+ .as_any()
+ .downcast_ref::<TimestampSecondArray>()
+ .expect("Array is not TimestampSecondArray");
+
+ ts_array
+ .iter()
+ .map(|x| x.map(|y| timestamp_s_to_datetime(y).unwrap()))
+ .collect()
+ }
+ arrow_schema::TimeUnit::Millisecond => {
+ let ts_array = input
+ .as_any()
+ .downcast_ref::<TimestampMillisecondArray>()
+ .expect("Array is not TimestampMillisecondArray");
+
+ ts_array
+ .iter()
+ .map(|x| x.map(|y| timestamp_ms_to_datetime(y).unwrap()))
+ .collect()
+ }
+ arrow_schema::TimeUnit::Microsecond => {
+ let ts_array = input
+ .as_any()
+ .downcast_ref::<TimestampMicrosecondArray>()
+ .expect("Array is not TimestampMicrosecondArray");
+ ts_array
+ .iter()
+ .map(|x| x.map(|y| timestamp_us_to_datetime(y).unwrap()))
+ .collect()
+ }
+ arrow_schema::TimeUnit::Nanosecond => {
+ let ts_array = input
+ .as_any()
+ .downcast_ref::<TimestampNanosecondArray>()
+ .expect("Array is not TimestampNanosecondArray");
+ ts_array
+ .iter()
+ .map(|x| x.map(|y| timestamp_ns_to_datetime(y).unwrap()))
+ .collect()
+ }
+ };
+
+ for x in native_datetimes {
+ match x {
+ Some(ndt) => {
+ if time_zone.is_none() {
+ builder.append_variant(ndt.into());
+ } else {
+ let utc_dt: DateTime<Utc> = Utc.from_utc_datetime(&ndt);
+ builder.append_variant(utc_dt.into());
+ }
+ }
+ None => {
+ builder.append_null();
+ }
+ }
+ }
+}
+
/// Convert a decimal value to a `VariantDecimal`
macro_rules! decimal_to_variant_decimal {
($v:ident, $scale:expr, $value_type:ty, $variant_type:ty) => {
@@ -123,6 +201,12 @@ macro_rules! decimal_to_variant_decimal {
/// assert!(result.is_null(1)); // note null, not Variant::Null
/// assert_eq!(result.value(2), Variant::Int64(3));
/// ```
+///
+/// For `DataType::Timestamp`s: if the timestamp has any level of precision
+/// greater than a microsecond, it will be truncated. For example
+/// `1970-01-01T00:00:01.234567890Z`
+/// will be truncated to
+/// `1970-01-01T00:00:01.234567Z`
pub fn cast_to_variant(input: &dyn Array) -> Result<VariantArray, ArrowError> {
let mut builder = VariantArrayBuilder::new(input.len());
@@ -234,6 +318,9 @@ pub fn cast_to_variant(input: &dyn Array) ->
Result<VariantArray, ArrowError> {
builder.append_null();
}
}
+ DataType::Timestamp(time_unit, time_zone) => {
+ convert_timestamp(time_unit, time_zone, input, &mut builder);
+ }
dt => {
return Err(ArrowError::CastError(format!(
"Unsupported data type for casting to Variant: {dt:?}",
@@ -274,6 +361,59 @@ mod tests {
};
}
+ #[test]
+ fn test_cast_to_variant_timestamp() {
+ let run_array_tests =
+ |microseconds: i64, array_ntz: Arc<dyn Array>, array_tz: Arc<dyn
Array>| {
+ let timestamp = DateTime::from_timestamp_nanos(microseconds *
1000);
+ run_test(
+ array_tz,
+ vec![Some(Variant::TimestampMicros(timestamp)), None],
+ );
+ run_test(
+ array_ntz,
+ vec![
+
Some(Variant::TimestampNtzMicros(timestamp.naive_utc())),
+ None,
+ ],
+ );
+ };
+
+ let nanosecond = 1234567890;
+ let microsecond = 1234567;
+ let millisecond = 1234;
+ let second = 1;
+
+ let second_array = TimestampSecondArray::from(vec![Some(second),
None]);
+ run_array_tests(
+ second * 1000 * 1000,
+ Arc::new(second_array.clone()),
+ Arc::new(second_array.with_timezone("+01:00".to_string())),
+ );
+
+ let millisecond_array =
TimestampMillisecondArray::from(vec![Some(millisecond), None]);
+ run_array_tests(
+ millisecond * 1000,
+ Arc::new(millisecond_array.clone()),
+ Arc::new(millisecond_array.with_timezone("+01:00".to_string())),
+ );
+
+ let microsecond_array =
TimestampMicrosecondArray::from(vec![Some(microsecond), None]);
+ run_array_tests(
+ microsecond,
+ Arc::new(microsecond_array.clone()),
+ Arc::new(microsecond_array.with_timezone("+01:00".to_string())),
+ );
+
+ // nanoseconds should get truncated to microseconds
+ let nanosecond_array =
TimestampNanosecondArray::from(vec![Some(nanosecond), None]);
+ run_array_tests(
+ microsecond,
+ Arc::new(nanosecond_array.clone()),
+ Arc::new(nanosecond_array.with_timezone("+01:00".to_string())),
+ )
+ }
+
#[test]
fn test_cast_to_variant_fixed_size_binary() {
let v1 = vec![1, 2];
