datafusion_spark/function/datetime/
time_trunc.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use std::any::Any;
19use std::sync::Arc;
20
21use arrow::datatypes::{DataType, Field, FieldRef};
22use datafusion_common::types::logical_string;
23use datafusion_common::{Result, ScalarValue, internal_err, plan_err};
24use datafusion_expr::expr::ScalarFunction;
25use datafusion_expr::simplify::{ExprSimplifyResult, SimplifyContext};
26use datafusion_expr::{
27    Coercion, ColumnarValue, Expr, ReturnFieldArgs, ScalarFunctionArgs, ScalarUDFImpl,
28    Signature, TypeSignatureClass, Volatility,
29};
30
31/// Spark time_trunc function only handles time inputs.
32/// <https://spark.apache.org/docs/latest/api/sql/index.html#time_trunc>
33#[derive(Debug, PartialEq, Eq, Hash)]
34pub struct SparkTimeTrunc {
35    signature: Signature,
36}
37
38impl Default for SparkTimeTrunc {
39    fn default() -> Self {
40        Self::new()
41    }
42}
43
44impl SparkTimeTrunc {
45    pub fn new() -> Self {
46        Self {
47            signature: Signature::coercible(
48                vec![
49                    Coercion::new_exact(TypeSignatureClass::Native(logical_string())),
50                    Coercion::new_exact(TypeSignatureClass::Time),
51                ],
52                Volatility::Immutable,
53            ),
54        }
55    }
56}
57
58impl ScalarUDFImpl for SparkTimeTrunc {
59    fn as_any(&self) -> &dyn Any {
60        self
61    }
62
63    fn name(&self) -> &str {
64        "time_trunc"
65    }
66
67    fn signature(&self) -> &Signature {
68        &self.signature
69    }
70
71    fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> {
72        internal_err!("return_field_from_args should be used instead")
73    }
74
75    fn return_field_from_args(&self, args: ReturnFieldArgs) -> Result<FieldRef> {
76        let nullable = args.arg_fields.iter().any(|f| f.is_nullable());
77
78        Ok(Arc::new(Field::new(
79            self.name(),
80            args.arg_fields[1].data_type().clone(),
81            nullable,
82        )))
83    }
84
85    fn invoke_with_args(&self, _args: ScalarFunctionArgs) -> Result<ColumnarValue> {
86        internal_err!(
87            "spark time_trunc should have been simplified to standard date_trunc"
88        )
89    }
90
91    fn simplify(
92        &self,
93        args: Vec<Expr>,
94        _info: &SimplifyContext,
95    ) -> Result<ExprSimplifyResult> {
96        let fmt_expr = &args[0];
97
98        let fmt = match fmt_expr.as_literal() {
99            Some(ScalarValue::Utf8(Some(v)))
100            | Some(ScalarValue::Utf8View(Some(v)))
101            | Some(ScalarValue::LargeUtf8(Some(v))) => v.to_lowercase(),
102            _ => {
103                return plan_err!(
104                    "First argument of `TIME_TRUNC` must be non-null scalar Utf8"
105                );
106            }
107        };
108
109        if !matches!(
110            fmt.as_str(),
111            "hour" | "minute" | "second" | "millisecond" | "microsecond"
112        ) {
113            return plan_err!(
114                "The format argument of `TIME_TRUNC` must be one of: hour, minute, second, millisecond, microsecond"
115            );
116        }
117
118        Ok(ExprSimplifyResult::Simplified(Expr::ScalarFunction(
119            ScalarFunction::new_udf(datafusion_functions::datetime::date_trunc(), args),
120        )))
121    }
122}
datafusion_spark/function/datetime/time_trunc.rs

datafusion_spark/function/datetime/
time_trunc.rs
