shehabgamin commented on code in PR #15947: URL: https://github.com/apache/datafusion/pull/15947#discussion_r2074093408
########## datafusion/spark/src/function/math/hex.rs: ########## @@ -0,0 +1,404 @@ +// 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 std::any::Any; +use std::sync::Arc; + +use crate::function::error_utils::{ + invalid_arg_count_exec_err, unsupported_data_type_exec_err, +}; +use arrow::array::{Array, StringArray}; +use arrow::datatypes::DataType; +use arrow::{ + array::{as_dictionary_array, as_largestring_array, as_string_array}, + datatypes::Int32Type, +}; +use datafusion_common::{ + cast::{as_binary_array, as_fixed_size_binary_array, as_int64_array}, + exec_err, DataFusionError, +}; +use datafusion_expr::Signature; +use datafusion_expr::{ColumnarValue, ScalarFunctionArgs, ScalarUDFImpl, Volatility}; +use std::fmt::Write; + +/// <https://spark.apache.org/docs/latest/api/sql/index.html#hex> +#[derive(Debug)] +pub struct SparkHex { + signature: Signature, + aliases: Vec<String>, +} + +impl Default for SparkHex { + fn default() -> Self { + Self::new() + } +} + +impl SparkHex { + pub fn new() -> Self { + Self { + signature: Signature::user_defined(Volatility::Immutable), + aliases: vec![], + } + } +} + +impl ScalarUDFImpl for SparkHex { + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "hex" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type( + &self, + _arg_types: &[DataType], + ) -> datafusion_common::Result<DataType> { + Ok(DataType::Utf8) + } + + fn invoke_with_args( + &self, + args: ScalarFunctionArgs, + ) -> datafusion_common::Result<ColumnarValue> { + spark_hex(&args.args) + } + + fn aliases(&self) -> &[String] { + &self.aliases + } + + fn coerce_types( + &self, + arg_types: &[DataType], + ) -> datafusion_common::Result<Vec<DataType>> { + if arg_types.len() != 1 { + return Err(invalid_arg_count_exec_err("expm1", (1, 1), arg_types.len())); + } + match &arg_types[0] { + DataType::Int64 + | DataType::Utf8 + | DataType::LargeUtf8 + | DataType::Binary + | DataType::LargeBinary => Ok(vec![arg_types[0].clone()]), + DataType::Dictionary(key_type, value_type) => match value_type.as_ref() { Review Comment: @andygrove This seems fine to me. If the logic is unique to `hex`, it probably doesn't make sense to extract it into a reusable function. If the logic is reusable, we could add `SparkSignature` like @alamb suggested. I've found that the existing DataFusion signatures are not always compatible with Spark's behavior. I've also found that a lot of Spark functions have custom and unique coercion behavior. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
