Spark dayname function implementation

datafusion/spark/src/function/datetime/dayname.rs

@@ -0,0 +1,126 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+use arrow::array::{Array, ArrayRef, AsArray, StringArray};
+use arrow::compute::{CastOptions, DatePart, cast_with_options, date_part};
+use arrow::datatypes::{DataType, Field, FieldRef, Int32Type};
+use datafusion::logical_expr::{
+    Coercion, ColumnarValue, Signature, TypeSignature, TypeSignatureClass, Volatility,
+};
+use datafusion_common::types::{logical_date, logical_string};
+use datafusion_common::utils::take_function_args;
+use datafusion_common::{Result, internal_err};
+use datafusion_expr::{ReturnFieldArgs, ScalarFunctionArgs, ScalarUDFImpl};
+use datafusion_functions::utils::make_scalar_function;
+use std::sync::Arc;
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+pub struct SparkDayName {
+    signature: Signature,
+}
+
+impl Default for SparkDayName {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl SparkDayName {
+    pub fn new() -> Self {
+        Self {
+            signature: Signature::one_of(
+                vec![
+                    TypeSignature::Coercible(vec![Coercion::new_exact(
+                        TypeSignatureClass::Timestamp,
+                    )]),
+                    TypeSignature::Coercible(vec![Coercion::new_exact(
+                        TypeSignatureClass::Native(logical_date()),
+                    )]),
+                    TypeSignature::Coercible(vec![Coercion::new_exact(
+                        TypeSignatureClass::Native(logical_string()),
+                    )]),
+                ],
+                Volatility::Immutable,
+            ),
+        }
+    }
+}
+
+impl ScalarUDFImpl for SparkDayName {
+    fn name(&self) -> &str {
+        "dayname"
+    }
+
+    fn signature(&self) -> &Signature {
+        &self.signature
+    }
+
+    fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> {
+        internal_err!("return_field_from_args should be used instead")
+    }
+
+    fn return_field_from_args(&self, args: ReturnFieldArgs) -> Result<FieldRef> {
+        Ok(Arc::new(Field::new(
+            self.name(),
+            DataType::Utf8,
+            args.arg_fields[0].is_nullable(),
+        )))
+    }
+
+    fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue> {
+        make_scalar_function(spark_day_name, vec![])(&args.args)
+    }
+}
+
+fn spark_day_name(args: &[ArrayRef]) -> Result<ArrayRef> {
+    let [array] = take_function_args("dayname", args)?;
+    match array.data_type() {
+        DataType::Date32 | DataType::Timestamp(_, _) => spark_day_name_inner(array),
+        DataType::Utf8 | DataType::Utf8View | DataType::LargeUtf8 => {
+            let date_array =
+                cast_with_options(array, &DataType::Date32, &CastOptions::default())?;
+            spark_day_name_inner(&date_array)
+        }
+        other => {
+            internal_err!("Unsupported arg {other:?} for Spark function `dayname`")
+        }
+    }
+}
+
+fn spark_day_name_inner(array: &ArrayRef) -> Result<ArrayRef> {
+    let result: StringArray = date_part(array, DatePart::DayOfWeekMonday0)?
+        .as_primitive::<Int32Type>()
+        .iter()
+        .map(|x| x.and_then(get_display_name))
+        .collect();
+    Ok(Arc::new(result))
+}
+
+/// This function supports only the English locale, matching the behavior of Spark's
+/// `dayname` function which return English day names regardless of the system or session locale.
+fn get_display_name(day: i32) -> Option<String> {
+    match day {
+        0 => Some(String::from("Mon")),
+        1 => Some(String::from("Tue")),
+        2 => Some(String::from("Wed")),
+        3 => Some(String::from("Thu")),
+        4 => Some(String::from("Fri")),
+        5 => Some(String::from("Sat")),
+        6 => Some(String::from("Sun")),
+        _ => None,
+    }
+}

datafusion/spark/src/function/datetime/mod.rs

@@ -21,6 +21,7 @@ pub mod date_diff;
 pub mod date_part;
 pub mod date_sub;
 pub mod date_trunc;
+pub mod dayname;
 pub mod extract;
 pub mod from_utc_timestamp;
 pub mod last_day;
@@ -72,6 +73,7 @@ make_udf_function!(
     unix_seconds,
     unix::SparkUnixTimestamp::seconds
 );
+make_udf_function!(dayname::SparkDayName, dayname);
 
 pub mod expr_fn {
     use datafusion_functions::export_functions;
@@ -179,6 +181,11 @@ pub mod expr_fn {
         "Returns the number of seconds since epoch (1970-01-01 00:00:00 UTC) for the given timestamp `ts`.",
         ts
     ));
+    export_functions!((
+        dayname,
+        "Returns the three-letter abbreviated day name from the given date.",
+        arg1
+    ));
 }
 
 pub fn functions() -> Vec<Arc<ScalarUDF>> {
@@ -204,5 +211,6 @@ pub fn functions() -> Vec<Arc<ScalarUDF>> {
         unix_micros(),
         unix_millis(),
         unix_seconds(),
+        dayname(),
     ]
 }

datafusion/sqllogictest/test_files/spark/datetime/dayname.slt

@@ -0,0 +1,81 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+
+#   http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+query T
+SELECT dayname('2008-02-20'::DATE);
+----
+Wed
+
+query T
+SELECT dayname(NULL::DATE);
+----
+NULL
+
+query T
+SELECT dayname('2026-03-09'::DATE);
+----
+Mon
+
+query T
+SELECT dayname('2026-03-08'::DATE);
+----
+Sun
+
+query T
+SELECT dayname('1948-08-10'::DATE);
+----
+Tue
+
+query T
+SELECT dayname('1987-11-13'::DATE);
+----
+Fri
+
+query T
+SELECT dayname('2000-07-27'::DATE);
+----
+Thu
+
+query T
+SELECT dayname('2010-04-24'::DATE);
+----
+Sat
+
+query T
+SELECT dayname('2010-04-24'::STRING);
+----
+Sat
+
+query T
+SELECT dayname(NULL::STRING);
+----
+NULL
+
+query T
+SELECT dayname(''::STRING);
+----
+NULL
+
+query T
+SELECT dayname('2010-04-24'::TIMESTAMP);
+----
+Sat
+
+query T
+SELECT dayname(NULL::TIMESTAMP);
+----
+NULL