xinlifoobar commented on code in PR #12080: URL: https://github.com/apache/datafusion/pull/12080#discussion_r1735604818
########## datafusion/functions/Cargo.toml: ########## @@ -52,7 +52,7 @@ encoding_expressions = ["base64", "hex"] # enable math functions math_expressions = [] # enable regular expressions -regex_expressions = ["regex"] +regex_expressions = ["regex", "string_expressions"] Review Comment: Have to do this for `StringArrayType`. Maybe we should consider relocating it to a common package? ########## datafusion/functions/src/regex/regexpcount.rs: ########## @@ -0,0 +1,766 @@ +// 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, Datum, Int64Array}; +use arrow::datatypes::{DataType, Int64Type}; +use arrow::datatypes::{ + DataType::Int64, DataType::LargeUtf8, DataType::Utf8, DataType::Utf8View, +}; +use arrow::error::ArrowError; +use datafusion_common::{exec_err, internal_err, Result, ScalarValue}; +use datafusion_expr::{ + ColumnarValue, ScalarUDFImpl, Signature, TypeSignature::Exact, + TypeSignature::Uniform, Volatility, +}; +use itertools::izip; +use regex::Regex; +use std::collections::hash_map::Entry; +use std::collections::HashMap; +use std::sync::Arc; + +use crate::string::common::StringArrayType; + +#[derive(Debug)] +pub struct RegexpCountFunc { + signature: Signature, +} + +impl Default for RegexpCountFunc { + fn default() -> Self { + Self::new() + } +} + +impl RegexpCountFunc { + pub fn new() -> Self { + Self { + signature: Signature::one_of( + vec![ + Uniform(2, vec![Utf8, LargeUtf8, Utf8View]), + Exact(vec![Utf8, Utf8, Int64]), + Exact(vec![Utf8, Utf8, Int64, Utf8]), + Exact(vec![LargeUtf8, LargeUtf8, Int64]), + Exact(vec![LargeUtf8, LargeUtf8, Int64, LargeUtf8]), + Exact(vec![Utf8View, Utf8View, Int64]), + Exact(vec![Utf8View, Utf8View, Int64, Utf8View]), + ], + Volatility::Immutable, + ), + } + } +} + +impl ScalarUDFImpl for RegexpCountFunc { + fn as_any(&self) -> &dyn std::any::Any { + self + } + + fn name(&self) -> &str { + "regexp_count" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> { + Ok(Int64) + } + + fn invoke(&self, args: &[datafusion_expr::ColumnarValue]) -> Result<ColumnarValue> { + let len = args + .iter() + .fold(Option::<usize>::None, |acc, arg| match arg { + ColumnarValue::Scalar(_) => acc, + ColumnarValue::Array(a) => Some(a.len()), + }); + + let is_scalar = len.is_none(); + let inferred_length = len.unwrap_or(1); + let args = args + .iter() + .map(|arg| arg.clone().into_array(inferred_length)) + .collect::<Result<Vec<_>>>()?; + + let result = regexp_count_func(&args); + if is_scalar { + // If all inputs are scalar, keeps output as scalar + let result = result.and_then(|arr| ScalarValue::try_from_array(&arr, 0)); + result.map(ColumnarValue::Scalar) + } else { + result.map(ColumnarValue::Array) + } + } +} + +pub fn regexp_count_func(args: &[ArrayRef]) -> Result<ArrayRef> { + let args_len = args.len(); + if !(2..=4).contains(&args_len) { + return exec_err!("regexp_count was called with {args_len} arguments. It requires at least 2 and at most 4."); + } + + let values = &args[0]; + match values.data_type() { + Utf8 | LargeUtf8 | Utf8View => (), + other => { + return internal_err!( + "Unsupported data type {other:?} for function regexp_count" + ); + } + } + + regexp_count( + values, + &args[1], + if args_len > 2 { Some(&args[2]) } else { None }, + if args_len > 3 { Some(&args[3]) } else { None }, + ) + .map_err(|e| e.into()) +} + +/// `arrow-rs` style implementation of `regexp_count` function. +/// This function `regexp_count` is responsible for counting the occurrences of a regular expression pattern +/// within a string array. It supports optional start positions and flags for case insensitivity. +/// +/// The function accepts a variable number of arguments: +/// - `values`: The array of strings to search within. +/// - `regex_array`: The array of regular expression patterns to search for. +/// - `start_array` (optional): The array of start positions for the search. +/// - `flags_array` (optional): The array of flags to modify the search behavior (e.g., case insensitivity). +/// +/// The function handles different combinations of scalar and array inputs for the regex patterns, start positions, +/// and flags. It uses a cache to store compiled regular expressions for efficiency. +/// +/// # Errors +/// Returns an error if the input arrays have mismatched lengths or if the regular expression fails to compile. +pub fn regexp_count( + values: &dyn Array, + regex_array: &dyn Datum, + start_array: Option<&dyn Datum>, + flags_array: Option<&dyn Datum>, +) -> Result<ArrayRef, ArrowError> { + let (regex_array, is_regex_scalar) = regex_array.get(); + let (start_array, is_start_scalar) = start_array.map_or((None, true), |start| { + let (start, is_start_scalar) = start.get(); + (Some(start), is_start_scalar) + }); + let (flags_array, is_flags_scalar) = flags_array.map_or((None, true), |flags| { + let (flags, is_flags_scalar) = flags.get(); + (Some(flags), is_flags_scalar) + }); + + match (values.data_type(), regex_array.data_type(), flags_array) { + (Utf8, Utf8, None) => regexp_count_inner( + values.as_string::<i32>(), + regex_array.as_string::<i32>(), + is_regex_scalar, + start_array.map(|start| start.as_primitive::<Int64Type>()), + is_start_scalar, + None, + is_flags_scalar, + ), + (Utf8, Utf8, Some(flags_array)) if *flags_array.data_type() == Utf8 => regexp_count_inner( + values.as_string::<i32>(), + regex_array.as_string::<i32>(), + is_regex_scalar, + start_array.map(|start| start.as_primitive::<Int64Type>()), + is_start_scalar, + Some(flags_array.as_string::<i32>()), + is_flags_scalar, + ), + (LargeUtf8, LargeUtf8, None) => regexp_count_inner( + values.as_string::<i64>(), + regex_array.as_string::<i64>(), + is_regex_scalar, + start_array.map(|start| start.as_primitive::<Int64Type>()), + is_start_scalar, + None, + is_flags_scalar, + ), + (LargeUtf8, LargeUtf8, Some(flags_array)) if *flags_array.data_type() == LargeUtf8 => regexp_count_inner( + values.as_string::<i64>(), + regex_array.as_string::<i64>(), + is_regex_scalar, + start_array.map(|start| start.as_primitive::<Int64Type>()), + is_start_scalar, + Some(flags_array.as_string::<i64>()), + is_flags_scalar, + ), + (Utf8View, Utf8View, None) => regexp_count_inner( + values.as_string_view(), + regex_array.as_string_view(), + is_regex_scalar, + start_array.map(|start| start.as_primitive::<Int64Type>()), + is_start_scalar, + None, + is_flags_scalar, + ), + (Utf8View, Utf8View, Some(flags_array)) if *flags_array.data_type() == Utf8View => regexp_count_inner( + values.as_string_view(), + regex_array.as_string_view(), + is_regex_scalar, + start_array.map(|start| start.as_primitive::<Int64Type>()), + is_start_scalar, + Some(flags_array.as_string_view()), + is_flags_scalar, + ), + _ => Err(ArrowError::ComputeError( + "regexp_count() expected the input arrays to be of type Utf8, LargeUtf8, or Utf8View and the data types of the values, regex_array, and flags_array to match".to_string(), + )), + } +} + +pub fn regexp_count_inner<'a, S>( + values: S, + regex_array: S, + is_regex_scalar: bool, + start_array: Option<&Int64Array>, + is_start_scalar: bool, + flags_array: Option<S>, + is_flags_scalar: bool, +) -> Result<ArrayRef, ArrowError> +where + S: StringArrayType<'a>, +{ + let (regex_scalar, is_regex_scalar) = if is_regex_scalar || regex_array.len() == 1 { + (Some(regex_array.value(0)), true) + } else { + (None, false) + }; + + let (start_array, start_scalar, is_start_scalar) = + if let Some(start_array) = start_array { + if is_start_scalar || start_array.len() == 1 { + (None, Some(start_array.value(0)), true) + } else { + (Some(start_array), None, false) + } + } else { + (None, Some(1), true) + }; + + let (flags_array, flags_scalar, is_flags_scalar) = + if let Some(flags_array) = flags_array { + if is_flags_scalar || flags_array.len() == 1 { + (None, Some(flags_array.value(0)), true) + } else { + (Some(flags_array), None, false) + } + } else { + (None, None, true) + }; + + match (is_regex_scalar, is_start_scalar, is_flags_scalar) { + (true, true, true) => { + let regex = match regex_scalar { + None | Some("") => { + return Ok(Arc::new(Int64Array::from(vec![0; values.len()]))) + } + Some(regex) => regex, + }; + + let pattern = compile_regex(regex, flags_scalar)?; + + Ok(Arc::new(Int64Array::from_iter_values( + values + .iter() + .map(|value| count_matches(value, &pattern, start_scalar)) + .collect::<Result<Vec<i64>, ArrowError>>()?, + ))) + } + (true, true, false) => { + let regex = match regex_scalar { + None | Some("") => { + return Ok(Arc::new(Int64Array::from(vec![0; values.len()]))) + } + Some(regex) => regex, + }; + + let flags_array = flags_array.unwrap(); + if values.len() != flags_array.len() { + return Err(ArrowError::ComputeError(format!( + "flags_array must be the same length as values array; got {} and {}", + values.len(), + flags_array.len() + ))); + } + + let mut regex_cache = HashMap::new(); + Ok(Arc::new(Int64Array::from_iter_values( + values + .iter() + .zip(flags_array.iter()) + .map(|(value, flags)| { + let pattern = + compile_and_cache_regex(regex, flags, &mut regex_cache)?; + count_matches(value, &pattern, start_scalar) + }) + .collect::<Result<Vec<i64>, ArrowError>>()?, + ))) + } + (true, false, true) => { + let regex = match regex_scalar { + None | Some("") => { + return Ok(Arc::new(Int64Array::from(vec![0; values.len()]))) + } + Some(regex) => regex, + }; + + let pattern = compile_regex(regex, flags_scalar)?; + + let start_array = start_array.unwrap(); + + Ok(Arc::new(Int64Array::from_iter_values( + values + .iter() + .zip(start_array.iter()) + .map(|(value, start)| count_matches(value, &pattern, start)) + .collect::<Result<Vec<i64>, ArrowError>>()?, + ))) + } + (true, false, false) => { + let regex = match regex_scalar { + None | Some("") => { + return Ok(Arc::new(Int64Array::from(vec![0; values.len()]))) + } + Some(regex) => regex, + }; + + let flags_array = flags_array.unwrap(); + if values.len() != flags_array.len() { + return Err(ArrowError::ComputeError(format!( + "flags_array must be the same length as values array; got {} and {}", + values.len(), + flags_array.len() + ))); + } + + let mut regex_cache = HashMap::new(); Review Comment: Do we want a global regex cache? -- This is an automated message from the Apache Git Service. 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