Omega359 commented on code in PR #12015: URL: https://github.com/apache/datafusion/pull/12015#discussion_r1719199153
########## datafusion/functions/benches/repeat.rs: ########## @@ -0,0 +1,129 @@ +// 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. + +extern crate criterion; + +use arrow::array::{ArrayRef, Int64Array, OffsetSizeTrait}; +use arrow::util::bench_util::{ + create_string_array_with_len, create_string_view_array_with_len, +}; +use criterion::{black_box, criterion_group, criterion_main, Criterion}; +use datafusion_expr::ColumnarValue; +use datafusion_functions::string; +use std::sync::Arc; + +fn create_args<O: OffsetSizeTrait>( + size: usize, + str_len: usize, + repeat_times: i64, + use_string_view: bool, +) -> Vec<ColumnarValue> { + let number_array = Arc::new(Int64Array::from( + (0..size).map(|_| repeat_times).collect::<Vec<_>>(), + )); + + if use_string_view { + let string_array = + Arc::new(create_string_view_array_with_len(size, 0.1, str_len, false)); + vec![ + ColumnarValue::Array(string_array), + ColumnarValue::Array(number_array), + ] + } else { + let string_array = + Arc::new(create_string_array_with_len::<O>(size, 0.1, str_len)); + + vec![ + ColumnarValue::Array(string_array), + ColumnarValue::Array(Arc::clone(&number_array) as ArrayRef), + ] + } +} + +fn criterion_benchmark(c: &mut Criterion) { + let lower = string::lower(); Review Comment: I think this may be a copy/paste error ... shouldn't this be `let repeat = string::repeat();` ? ########## datafusion/functions/src/string/repeat.rs: ########## @@ -79,50 +80,66 @@ impl ScalarUDFImpl for RepeatFunc { } fn invoke(&self, args: &[ColumnarValue]) -> Result<ColumnarValue> { - match args[0].data_type() { - DataType::Utf8View => make_scalar_function(repeat_utf8view, vec![])(args), - DataType::Utf8 => make_scalar_function(repeat::<i32>, vec![])(args), - DataType::LargeUtf8 => make_scalar_function(repeat::<i64>, vec![])(args), - other => exec_err!("Unsupported data type {other:?} for function repeat. Expected Utf8, Utf8View or LargeUtf8"), - } + make_scalar_function(repeat, vec![])(args) } } /// Repeats string the specified number of times. /// repeat('Pg', 4) = 'PgPgPgPg' -fn repeat<T: OffsetSizeTrait>(args: &[ArrayRef]) -> Result<ArrayRef> { - let string_array = as_generic_string_array::<T>(&args[0])?; +fn repeat(args: &[ArrayRef]) -> Result<ArrayRef> { let number_array = as_int64_array(&args[1])?; - - let result = string_array - .iter() - .zip(number_array.iter()) - .map(|(string, number)| repeat_common(string, number)) - .collect::<GenericStringArray<T>>(); - - Ok(Arc::new(result) as ArrayRef) + match args[0].data_type() { + Utf8View => { + let string_view_array = args[0].as_string_view(); + repeat_impl::<i32, &StringViewArray>(string_view_array, number_array) + } + Utf8 => { + let string_array = args[0].as_string::<i32>(); + repeat_impl::<i32, &GenericStringArray<i32>>(string_array, number_array) + } + LargeUtf8 => { + let string_array = args[0].as_string::<i64>(); + repeat_impl::<i64, &GenericStringArray<i64>>(string_array, number_array) + } + other => exec_err!( + "Unsupported data type {other:?} for function repeat. \ + Expected Utf8, Utf8View or LargeUtf8." + ), + } } -fn repeat_utf8view(args: &[ArrayRef]) -> Result<ArrayRef> { - let string_view_array = as_string_view_array(&args[0])?; - let number_array = as_int64_array(&args[1])?; - - let result = string_view_array +fn repeat_impl<'a, T, S>(string_array: S, number_array: &Int64Array) -> Result<ArrayRef> +where + T: OffsetSizeTrait, + S: StringArrayType<'a>, +{ + let mut builder: GenericStringBuilder<T> = GenericStringBuilder::new(); + string_array .iter() .zip(number_array.iter()) - .map(|(string, number)| repeat_common(string, number)) - .collect::<StringArray>(); - - Ok(Arc::new(result) as ArrayRef) + .for_each(|(string, number)| match (string, number) { + (Some(string), Some(number)) if number >= 0 => { + builder.append_value(string.repeat(number as usize)) + } + (Some(_), Some(_)) => builder.append_value(""), + _ => builder.append_null(), + }); + let array = builder.finish(); + + Ok(Arc::new(array) as ArrayRef) } -fn repeat_common(string: Option<&str>, number: Option<i64>) -> Option<String> { - match (string, number) { - (Some(string), Some(number)) if number >= 0 => { - Some(string.repeat(number as usize)) - } - (Some(_), Some(_)) => Some("".to_string()), - _ => None, +trait StringArrayType<'a>: ArrayAccessor<Item = &'a str> + Sized { Review Comment: I think @alamb mentioned this somewhere else but we likely should pull this out to a common util somewhere so that we don't have copies of this in multiple places. -- This is an automated message from the Apache Git Service. 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