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| 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 | + |
| 18 | +use arrow::array::{ |
| 19 | + Array, ArrayRef, AsArray, BinaryArrayType, PrimitiveArray, StringArrayType, |
| 20 | +}; |
| 21 | +use arrow::datatypes::{DataType, Int32Type}; |
| 22 | +use datafusion_common::exec_err; |
| 23 | +use datafusion_expr::{ |
| 24 | + ColumnarValue, ScalarFunctionArgs, ScalarUDFImpl, Signature, Volatility, |
| 25 | +}; |
| 26 | +use datafusion_functions::utils::make_scalar_function; |
| 27 | +use std::sync::Arc; |
| 28 | + |
| 29 | +/// Spark-compatible `length` expression |
| 30 | +/// <https://spark.apache.org/docs/latest/api/sql/index.html#length> |
| 31 | +#[derive(Debug, PartialEq, Eq, Hash)] |
| 32 | +pub struct SparkLengthFunc { |
| 33 | + signature: Signature, |
| 34 | + aliases: Vec<String>, |
| 35 | +} |
| 36 | + |
| 37 | +impl Default for SparkLengthFunc { |
| 38 | + fn default() -> Self { |
| 39 | + Self::new() |
| 40 | + } |
| 41 | +} |
| 42 | + |
| 43 | +impl SparkLengthFunc { |
| 44 | + pub fn new() -> Self { |
| 45 | + Self { |
| 46 | + signature: Signature::uniform( |
| 47 | + 1, |
| 48 | + vec![ |
| 49 | + DataType::Utf8View, |
| 50 | + DataType::Utf8, |
| 51 | + DataType::LargeUtf8, |
| 52 | + DataType::Binary, |
| 53 | + DataType::LargeBinary, |
| 54 | + DataType::BinaryView, |
| 55 | + ], |
| 56 | + Volatility::Immutable, |
| 57 | + ), |
| 58 | + aliases: vec![ |
| 59 | + String::from("character_length"), |
| 60 | + String::from("char_length"), |
| 61 | + String::from("len"), |
| 62 | + ], |
| 63 | + } |
| 64 | + } |
| 65 | +} |
| 66 | + |
| 67 | +impl ScalarUDFImpl for SparkLengthFunc { |
| 68 | + fn as_any(&self) -> &dyn std::any::Any { |
| 69 | + self |
| 70 | + } |
| 71 | + |
| 72 | + fn name(&self) -> &str { |
| 73 | + "length" |
| 74 | + } |
| 75 | + |
| 76 | + fn signature(&self) -> &Signature { |
| 77 | + &self.signature |
| 78 | + } |
| 79 | + |
| 80 | + fn return_type(&self, _args: &[DataType]) -> datafusion_common::Result<DataType> { |
| 81 | + // spark length always returns Int32 |
| 82 | + Ok(DataType::Int32) |
| 83 | + } |
| 84 | + |
| 85 | + fn invoke_with_args( |
| 86 | + &self, |
| 87 | + args: ScalarFunctionArgs, |
| 88 | + ) -> datafusion_common::Result<ColumnarValue> { |
| 89 | + make_scalar_function(spark_length, vec![])(&args.args) |
| 90 | + } |
| 91 | + |
| 92 | + fn aliases(&self) -> &[String] { |
| 93 | + &self.aliases |
| 94 | + } |
| 95 | +} |
| 96 | + |
| 97 | +fn spark_length(args: &[ArrayRef]) -> datafusion_common::Result<ArrayRef> { |
| 98 | + match args[0].data_type() { |
| 99 | + DataType::Utf8 => { |
| 100 | + let string_array = args[0].as_string::<i32>(); |
| 101 | + character_length::<_>(string_array) |
| 102 | + } |
| 103 | + DataType::LargeUtf8 => { |
| 104 | + let string_array = args[0].as_string::<i64>(); |
| 105 | + character_length::<_>(string_array) |
| 106 | + } |
| 107 | + DataType::Utf8View => { |
| 108 | + let string_array = args[0].as_string_view(); |
| 109 | + character_length::<_>(string_array) |
| 110 | + } |
| 111 | + DataType::Binary => { |
| 112 | + let binary_array = args[0].as_binary::<i32>(); |
| 113 | + byte_length::<_>(binary_array) |
| 114 | + } |
| 115 | + DataType::LargeBinary => { |
| 116 | + let binary_array = args[0].as_binary::<i64>(); |
| 117 | + byte_length::<_>(binary_array) |
| 118 | + } |
| 119 | + DataType::BinaryView => { |
| 120 | + let binary_array = args[0].as_binary_view(); |
| 121 | + byte_length::<_>(binary_array) |
| 122 | + } |
| 123 | + other => exec_err!("Unsupported data type {other:?} for function `length`"), |
| 124 | + } |
| 125 | +} |
| 126 | + |
| 127 | +fn character_length<'a, V>(array: V) -> datafusion_common::Result<ArrayRef> |
| 128 | +where |
| 129 | + V: StringArrayType<'a>, |
| 130 | +{ |
| 131 | + // String characters are variable length encoded in UTF-8, counting the |
| 132 | + // number of chars requires expensive decoding, however checking if the |
| 133 | + // string is ASCII only is relatively cheap. |
| 134 | + // If strings are ASCII only, count bytes instead. |
| 135 | + let is_array_ascii_only = array.is_ascii(); |
| 136 | + let nulls = array.nulls().cloned(); |
| 137 | + let array = { |
| 138 | + if is_array_ascii_only { |
| 139 | + let values: Vec<_> = (0..array.len()) |
| 140 | + .map(|i| { |
| 141 | + // Safety: we are iterating with array.len() so the index is always valid |
| 142 | + let value = unsafe { array.value_unchecked(i) }; |
| 143 | + value.len() as i32 |
| 144 | + }) |
| 145 | + .collect(); |
| 146 | + PrimitiveArray::<Int32Type>::new(values.into(), nulls) |
| 147 | + } else { |
| 148 | + let values: Vec<_> = (0..array.len()) |
| 149 | + .map(|i| { |
| 150 | + // Safety: we are iterating with array.len() so the index is always valid |
| 151 | + if array.is_null(i) { |
| 152 | + i32::default() |
| 153 | + } else { |
| 154 | + let value = unsafe { array.value_unchecked(i) }; |
| 155 | + if value.is_empty() { |
| 156 | + i32::default() |
| 157 | + } else if value.is_ascii() { |
| 158 | + value.len() as i32 |
| 159 | + } else { |
| 160 | + value.chars().count() as i32 |
| 161 | + } |
| 162 | + } |
| 163 | + }) |
| 164 | + .collect(); |
| 165 | + PrimitiveArray::<Int32Type>::new(values.into(), nulls) |
| 166 | + } |
| 167 | + }; |
| 168 | + |
| 169 | + Ok(Arc::new(array)) |
| 170 | +} |
| 171 | + |
| 172 | +fn byte_length<'a, V>(array: V) -> datafusion_common::Result<ArrayRef> |
| 173 | +where |
| 174 | + V: BinaryArrayType<'a>, |
| 175 | +{ |
| 176 | + let nulls = array.nulls().cloned(); |
| 177 | + let values: Vec<_> = (0..array.len()) |
| 178 | + .map(|i| { |
| 179 | + // Safety: we are iterating with array.len() so the index is always valid |
| 180 | + let value = unsafe { array.value_unchecked(i) }; |
| 181 | + value.len() as i32 |
| 182 | + }) |
| 183 | + .collect(); |
| 184 | + Ok(Arc::new(PrimitiveArray::<Int32Type>::new( |
| 185 | + values.into(), |
| 186 | + nulls, |
| 187 | + ))) |
| 188 | +} |
| 189 | + |
| 190 | +#[cfg(test)] |
| 191 | +mod tests { |
| 192 | + use super::*; |
| 193 | + use crate::function::utils::test::test_scalar_function; |
| 194 | + use arrow::array::{Array, Int32Array}; |
| 195 | + use arrow::datatypes::DataType::Int32; |
| 196 | + use datafusion_common::{Result, ScalarValue}; |
| 197 | + use datafusion_expr::{ColumnarValue, ScalarUDFImpl}; |
| 198 | + |
| 199 | + macro_rules! test_spark_length_string { |
| 200 | + ($INPUT:expr, $EXPECTED:expr) => { |
| 201 | + test_scalar_function!( |
| 202 | + SparkLengthFunc::new(), |
| 203 | + vec![ColumnarValue::Scalar(ScalarValue::Utf8($INPUT))], |
| 204 | + $EXPECTED, |
| 205 | + i32, |
| 206 | + Int32, |
| 207 | + Int32Array |
| 208 | + ); |
| 209 | + |
| 210 | + test_scalar_function!( |
| 211 | + SparkLengthFunc::new(), |
| 212 | + vec![ColumnarValue::Scalar(ScalarValue::LargeUtf8($INPUT))], |
| 213 | + $EXPECTED, |
| 214 | + i32, |
| 215 | + Int32, |
| 216 | + Int32Array |
| 217 | + ); |
| 218 | + |
| 219 | + test_scalar_function!( |
| 220 | + SparkLengthFunc::new(), |
| 221 | + vec![ColumnarValue::Scalar(ScalarValue::Utf8View($INPUT))], |
| 222 | + $EXPECTED, |
| 223 | + i32, |
| 224 | + Int32, |
| 225 | + Int32Array |
| 226 | + ); |
| 227 | + }; |
| 228 | + } |
| 229 | + |
| 230 | + macro_rules! test_spark_length_binary { |
| 231 | + ($INPUT:expr, $EXPECTED:expr) => { |
| 232 | + test_scalar_function!( |
| 233 | + SparkLengthFunc::new(), |
| 234 | + vec![ColumnarValue::Scalar(ScalarValue::Binary($INPUT))], |
| 235 | + $EXPECTED, |
| 236 | + i32, |
| 237 | + Int32, |
| 238 | + Int32Array |
| 239 | + ); |
| 240 | + |
| 241 | + test_scalar_function!( |
| 242 | + SparkLengthFunc::new(), |
| 243 | + vec![ColumnarValue::Scalar(ScalarValue::LargeBinary($INPUT))], |
| 244 | + $EXPECTED, |
| 245 | + i32, |
| 246 | + Int32, |
| 247 | + Int32Array |
| 248 | + ); |
| 249 | + |
| 250 | + test_scalar_function!( |
| 251 | + SparkLengthFunc::new(), |
| 252 | + vec![ColumnarValue::Scalar(ScalarValue::BinaryView($INPUT))], |
| 253 | + $EXPECTED, |
| 254 | + i32, |
| 255 | + Int32, |
| 256 | + Int32Array |
| 257 | + ); |
| 258 | + }; |
| 259 | + } |
| 260 | + |
| 261 | + #[test] |
| 262 | + fn test_functions() -> Result<()> { |
| 263 | + test_spark_length_string!(Some(String::from("chars")), Ok(Some(5))); |
| 264 | + test_spark_length_string!(Some(String::from("josé")), Ok(Some(4))); |
| 265 | + // test long strings (more than 12 bytes for StringView) |
| 266 | + test_spark_length_string!(Some(String::from("joséjoséjoséjosé")), Ok(Some(16))); |
| 267 | + test_spark_length_string!(Some(String::from("")), Ok(Some(0))); |
| 268 | + test_spark_length_string!(None, Ok(None)); |
| 269 | + |
| 270 | + test_spark_length_binary!(Some(String::from("chars").into_bytes()), Ok(Some(5))); |
| 271 | + test_spark_length_binary!(Some(String::from("josé").into_bytes()), Ok(Some(5))); |
| 272 | + // test long strings (more than 12 bytes for BinaryView) |
| 273 | + test_spark_length_binary!( |
| 274 | + Some(String::from("joséjoséjoséjosé").into_bytes()), |
| 275 | + Ok(Some(20)) |
| 276 | + ); |
| 277 | + test_spark_length_binary!(Some(String::from("").into_bytes()), Ok(Some(0))); |
| 278 | + test_spark_length_binary!(None, Ok(None)); |
| 279 | + |
| 280 | + Ok(()) |
| 281 | + } |
| 282 | +} |
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