Jefffrey commented on code in PR #21331: URL: https://github.com/apache/datafusion/pull/21331#discussion_r3499475395
########## datafusion/spark/src/function/string/encode.rs: ########## @@ -0,0 +1,360 @@ +// 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::borrow::Cow; +use std::sync::Arc; + +use arrow::array::{ + Array, ArrayRef, AsArray, BinaryBuilder, StringArray, StringArrayType, +}; +use arrow::datatypes::{DataType, Field, FieldRef}; +use datafusion_common::utils::take_function_args; +use datafusion_common::{Result, ScalarValue, exec_err, plan_err}; +use datafusion_expr::{ + ColumnarValue, ReturnFieldArgs, ScalarFunctionArgs, ScalarUDFImpl, Signature, + Volatility, +}; + +/// Spark-compatible `encode` expression. +/// Encodes a string or binary value into binary using the specified character encoding. +/// Binary input is interpreted as UTF-8 with lossy conversion (invalid bytes become U+FFFD). +/// +/// # Target Spark version +/// Emulates Spark 3.5 semantics: +/// - Accepts canonical charset names and common aliases (`UTF8`, `LATIN1`, +/// `ISO88591`, `ASCII`, `UTF-32BE`, etc.). +/// - Unmappable characters (non-ASCII in `US-ASCII`, code points above +/// `U+00FF` in `ISO-8859-1`) are silently replaced with `?`. +/// - `UTF-32` is an alias for `UTF-32BE` (no BOM), matching both Spark 3.5 +/// and Spark 4.1. +/// +/// # Spark 4.0 differences (not implemented) +/// Spark 4.0 tightened `encode` in two ways, each gated by a `spark.sql.legacy.*` +/// config that can restore the 3.5 behavior: +/// +/// - Charset whitelist — rejects aliases with `INVALID_PARAMETER_VALUE.CHARSET`. +/// Controlled by `spark.sql.legacy.javaCharsets`. +/// - Unmappable characters — raises `MALFORMED_CHARACTER_CODING`. +/// Controlled by `spark.sql.legacy.codingErrorAction`. +/// +/// TODO: wire both configs so Spark 4.0 behavior can be selected at runtime. +/// See: <https://spark.apache.org/docs/4.0.0/sql-migration-guide.html> +/// +/// <https://spark.apache.org/docs/latest/api/sql/index.html#encode> +#[derive(Debug, PartialEq, Eq, Hash)] +pub struct SparkEncode { + signature: Signature, +} + +impl Default for SparkEncode { + fn default() -> Self { + Self::new() + } +} + +impl SparkEncode { + pub fn new() -> Self { + Self { + signature: Signature::user_defined(Volatility::Immutable), + } + } +} + +/// Encodes a single string value using the specified charset. +/// Unmappable characters are silently replaced with `?` (Spark 3.5 behavior). +fn encode_string(s: &str, charset: &str) -> Result<Vec<u8>> { + match charset { + "UTF-8" | "UTF8" => Ok(s.as_bytes().to_vec()), + "US-ASCII" | "ASCII" => Ok(s + .chars() + .map(|c| if c.is_ascii() { c as u8 } else { b'?' }) + .collect()), + "ISO-8859-1" | "ISO88591" | "LATIN1" => Ok(s + .chars() + .map(|c| { + let cp = c as u32; + if cp <= 255 { cp as u8 } else { b'?' } + }) + .collect()), + "UTF-16BE" | "UTF16BE" => { + let mut bytes = Vec::new(); + for code_unit in s.encode_utf16() { + bytes.extend_from_slice(&code_unit.to_be_bytes()); + } + Ok(bytes) + } + "UTF-16LE" | "UTF16LE" => { + let mut bytes = Vec::new(); + for code_unit in s.encode_utf16() { + bytes.extend_from_slice(&code_unit.to_le_bytes()); + } + Ok(bytes) + } + "UTF-16" | "UTF16" => { + // BOM (big-endian marker) followed by UTF-16BE encoded bytes + let mut bytes = vec![0xFE, 0xFF]; + for code_unit in s.encode_utf16() { + bytes.extend_from_slice(&code_unit.to_be_bytes()); + } + Ok(bytes) + } + // Spark treats UTF-32 as UTF-32BE (no BOM), matching Spark 3.5 and 4.1. + "UTF-32" | "UTF32" | "UTF-32BE" | "UTF32BE" => { + let mut bytes = Vec::with_capacity(s.len() * 4); + for c in s.chars() { + bytes.extend_from_slice(&(c as u32).to_be_bytes()); + } + Ok(bytes) + } + "UTF-32LE" | "UTF32LE" => { + let mut bytes = Vec::with_capacity(s.len() * 4); + for c in s.chars() { + bytes.extend_from_slice(&(c as u32).to_le_bytes()); + } + Ok(bytes) + } + _ => exec_err!( + "Unsupported charset for encode: '{}'. Supported: US-ASCII, ISO-8859-1, UTF-8, UTF-16, UTF-16BE, UTF-16LE, UTF-32, UTF-32BE, UTF-32LE", + charset + ), + } +} + +/// The charset for each row. `Constant` is a single uppercased charset; `PerRow` +/// uppercases each row on demand, yielding `None` for null entries. +enum Charsets<'a> { + Constant(&'a str), + PerRow(&'a StringArray), +} + +impl Charsets<'_> { + fn get(&self, i: usize) -> Option<Cow<'_, str>> { + match self { + Charsets::Constant(charset) => Some(Cow::Borrowed(charset)), + Charsets::PerRow(array) => { + (!array.is_null(i)).then(|| Cow::Owned(array.value(i).to_uppercase())) + } + } + } +} + +fn null_binary_array(len: usize) -> ArrayRef { + let mut builder = BinaryBuilder::new(); + for _ in 0..len { + builder.append_null(); + } + Arc::new(builder.finish()) +} + +/// Encodes each row to binary. A row is null if its value or charset is null; +/// otherwise it is `encode_string(decode(i), charset)`. `decode` yields the row's +/// value as text — a borrow for string input, or lossy UTF-8 for binary input +/// (invalid bytes become U+FFFD, matching Spark). +fn encode_rows<'a>( + len: usize, + is_null: impl Fn(usize) -> bool, + decode: impl Fn(usize) -> Cow<'a, str>, + charsets: &Charsets, +) -> Result<ArrayRef> { + let mut builder = BinaryBuilder::with_capacity(len, len * 4); + for i in 0..len { + match (is_null(i), charsets.get(i)) { + (false, Some(charset)) => { + builder.append_value(&encode_string(&decode(i), &charset)?) + } + _ => builder.append_null(), + } + } + Ok(Arc::new(builder.finish())) +} + +fn encode_array<'a, S: StringArrayType<'a>>( + array: &S, + charsets: &Charsets, +) -> Result<ArrayRef> { + encode_rows( + array.len(), + |i| array.is_null(i), + |i| Cow::Borrowed(array.value(i)), + charsets, + ) +} + +fn encode_binary_array<'a, B: arrow::array::BinaryArrayType<'a>>( + array: &'a B, + charsets: &Charsets, +) -> Result<ArrayRef> { + encode_rows( + array.len(), + |i| array.is_null(i), + |i| String::from_utf8_lossy(array.value(i)), + charsets, + ) +} + +fn encode_dispatch(arr: &ArrayRef, charsets: &Charsets) -> Result<ArrayRef> { + match arr.data_type() { + DataType::Utf8 => encode_array(&arr.as_string::<i32>(), charsets), + DataType::LargeUtf8 => encode_array(&arr.as_string::<i64>(), charsets), + DataType::Utf8View => encode_array(&arr.as_string_view(), charsets), + DataType::Binary => encode_binary_array(&arr.as_binary::<i32>(), charsets), + DataType::LargeBinary => encode_binary_array(&arr.as_binary::<i64>(), charsets), + DataType::BinaryView => encode_binary_array(&arr.as_binary_view(), charsets), + DataType::Null => Ok(null_binary_array(arr.len())), + dt => exec_err!("encode expects a string or binary argument, got {dt:?}"), + } +} + +/// The uppercased charset from a scalar, or `None` if it is null. +fn scalar_charset(scalar: &ScalarValue) -> Result<Option<String>> { + match scalar { + ScalarValue::Utf8(s) | ScalarValue::LargeUtf8(s) | ScalarValue::Utf8View(s) => { + Ok(s.as_ref().map(|s| s.to_uppercase())) + } + ScalarValue::Null => Ok(None), + other => exec_err!("encode charset argument must be a string, got {other:?}"), + } +} + +impl ScalarUDFImpl for SparkEncode { + fn name(&self) -> &str { + "encode" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn coerce_types(&self, arg_types: &[DataType]) -> Result<Vec<DataType>> { + let [value_type, charset_type] = take_function_args(self.name(), arg_types)?; + + let value_type = match value_type { + DataType::Utf8 + | DataType::LargeUtf8 + | DataType::Utf8View + | DataType::Binary + | DataType::LargeBinary + | DataType::BinaryView + | DataType::Null => value_type.clone(), + other => { + return plan_err!( + "encode expects a string or binary first argument, got {other:?}" + ); + } + }; + + match charset_type { + DataType::Utf8 + | DataType::LargeUtf8 + | DataType::Utf8View + | DataType::Null => {} + other => { + return plan_err!( + "encode expects a string charset second argument, got {other:?}" + ); + } + } + + Ok(vec![value_type, DataType::Utf8]) + } + + fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType> { + datafusion_common::internal_err!( + "return_type should not be called, use return_field_from_args instead" + ) + } + + fn return_field_from_args(&self, args: ReturnFieldArgs) -> Result<FieldRef> { + let nullable = args.arg_fields.iter().any(|f| f.is_nullable()); + Ok(Arc::new(Field::new( + self.name(), + DataType::Binary, + nullable, + ))) + } + + fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue> { + let [value, charset_arg] = take_function_args(self.name(), args.args)?; + + let len = [&value, &charset_arg] + .into_iter() + .find_map(|arg| match arg { + ColumnarValue::Array(a) => Some(a.len()), + _ => None, + }); + let inferred_length = len.unwrap_or(1); + let is_scalar = len.is_none(); + + let value_arr = match value { + ColumnarValue::Scalar(scalar) => scalar.to_array_of_size(inferred_length)?, + ColumnarValue::Array(array) => array, + }; + + // A null charset yields a null result for that row (Spark NullIntolerant). + let result = match &charset_arg { + ColumnarValue::Scalar(scalar) => match scalar_charset(scalar)? { + Some(charset) => { + encode_dispatch(&value_arr, &Charsets::Constant(&charset))? + } + None => null_binary_array(value_arr.len()), Review Comment: ```suggestion None => { return Ok(ColumnarValue::Scalar(ScalarValue::Binary(None))); } ``` ########## datafusion/spark/src/function/string/encode.rs: ########## @@ -0,0 +1,360 @@ +// 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::borrow::Cow; +use std::sync::Arc; + +use arrow::array::{ + Array, ArrayRef, AsArray, BinaryBuilder, StringArray, StringArrayType, +}; +use arrow::datatypes::{DataType, Field, FieldRef}; +use datafusion_common::utils::take_function_args; +use datafusion_common::{Result, ScalarValue, exec_err, plan_err}; +use datafusion_expr::{ + ColumnarValue, ReturnFieldArgs, ScalarFunctionArgs, ScalarUDFImpl, Signature, + Volatility, +}; + +/// Spark-compatible `encode` expression. +/// Encodes a string or binary value into binary using the specified character encoding. +/// Binary input is interpreted as UTF-8 with lossy conversion (invalid bytes become U+FFFD). +/// +/// # Target Spark version +/// Emulates Spark 3.5 semantics: +/// - Accepts canonical charset names and common aliases (`UTF8`, `LATIN1`, +/// `ISO88591`, `ASCII`, `UTF-32BE`, etc.). +/// - Unmappable characters (non-ASCII in `US-ASCII`, code points above +/// `U+00FF` in `ISO-8859-1`) are silently replaced with `?`. +/// - `UTF-32` is an alias for `UTF-32BE` (no BOM), matching both Spark 3.5 +/// and Spark 4.1. +/// +/// # Spark 4.0 differences (not implemented) +/// Spark 4.0 tightened `encode` in two ways, each gated by a `spark.sql.legacy.*` +/// config that can restore the 3.5 behavior: +/// +/// - Charset whitelist — rejects aliases with `INVALID_PARAMETER_VALUE.CHARSET`. +/// Controlled by `spark.sql.legacy.javaCharsets`. +/// - Unmappable characters — raises `MALFORMED_CHARACTER_CODING`. +/// Controlled by `spark.sql.legacy.codingErrorAction`. +/// +/// TODO: wire both configs so Spark 4.0 behavior can be selected at runtime. +/// See: <https://spark.apache.org/docs/4.0.0/sql-migration-guide.html> +/// +/// <https://spark.apache.org/docs/latest/api/sql/index.html#encode> +#[derive(Debug, PartialEq, Eq, Hash)] +pub struct SparkEncode { + signature: Signature, +} + +impl Default for SparkEncode { + fn default() -> Self { + Self::new() + } +} + +impl SparkEncode { + pub fn new() -> Self { + Self { + signature: Signature::user_defined(Volatility::Immutable), + } + } +} + +/// Encodes a single string value using the specified charset. +/// Unmappable characters are silently replaced with `?` (Spark 3.5 behavior). +fn encode_string(s: &str, charset: &str) -> Result<Vec<u8>> { + match charset { + "UTF-8" | "UTF8" => Ok(s.as_bytes().to_vec()), + "US-ASCII" | "ASCII" => Ok(s + .chars() + .map(|c| if c.is_ascii() { c as u8 } else { b'?' }) + .collect()), + "ISO-8859-1" | "ISO88591" | "LATIN1" => Ok(s + .chars() + .map(|c| { + let cp = c as u32; + if cp <= 255 { cp as u8 } else { b'?' } + }) + .collect()), + "UTF-16BE" | "UTF16BE" => { + let mut bytes = Vec::new(); + for code_unit in s.encode_utf16() { + bytes.extend_from_slice(&code_unit.to_be_bytes()); + } + Ok(bytes) + } + "UTF-16LE" | "UTF16LE" => { + let mut bytes = Vec::new(); + for code_unit in s.encode_utf16() { + bytes.extend_from_slice(&code_unit.to_le_bytes()); + } + Ok(bytes) + } + "UTF-16" | "UTF16" => { + // BOM (big-endian marker) followed by UTF-16BE encoded bytes + let mut bytes = vec![0xFE, 0xFF]; + for code_unit in s.encode_utf16() { + bytes.extend_from_slice(&code_unit.to_be_bytes()); + } + Ok(bytes) + } + // Spark treats UTF-32 as UTF-32BE (no BOM), matching Spark 3.5 and 4.1. + "UTF-32" | "UTF32" | "UTF-32BE" | "UTF32BE" => { + let mut bytes = Vec::with_capacity(s.len() * 4); + for c in s.chars() { + bytes.extend_from_slice(&(c as u32).to_be_bytes()); + } + Ok(bytes) + } + "UTF-32LE" | "UTF32LE" => { + let mut bytes = Vec::with_capacity(s.len() * 4); + for c in s.chars() { + bytes.extend_from_slice(&(c as u32).to_le_bytes()); + } + Ok(bytes) + } + _ => exec_err!( + "Unsupported charset for encode: '{}'. Supported: US-ASCII, ISO-8859-1, UTF-8, UTF-16, UTF-16BE, UTF-16LE, UTF-32, UTF-32BE, UTF-32LE", + charset + ), + } +} + +/// The charset for each row. `Constant` is a single uppercased charset; `PerRow` +/// uppercases each row on demand, yielding `None` for null entries. +enum Charsets<'a> { + Constant(&'a str), + PerRow(&'a StringArray), +} + +impl Charsets<'_> { + fn get(&self, i: usize) -> Option<Cow<'_, str>> { + match self { + Charsets::Constant(charset) => Some(Cow::Borrowed(charset)), + Charsets::PerRow(array) => { + (!array.is_null(i)).then(|| Cow::Owned(array.value(i).to_uppercase())) + } + } + } +} + +fn null_binary_array(len: usize) -> ArrayRef { + let mut builder = BinaryBuilder::new(); + for _ in 0..len { + builder.append_null(); + } + Arc::new(builder.finish()) +} + +/// Encodes each row to binary. A row is null if its value or charset is null; +/// otherwise it is `encode_string(decode(i), charset)`. `decode` yields the row's +/// value as text — a borrow for string input, or lossy UTF-8 for binary input +/// (invalid bytes become U+FFFD, matching Spark). +fn encode_rows<'a>( + len: usize, + is_null: impl Fn(usize) -> bool, + decode: impl Fn(usize) -> Cow<'a, str>, + charsets: &Charsets, +) -> Result<ArrayRef> { + let mut builder = BinaryBuilder::with_capacity(len, len * 4); + for i in 0..len { + match (is_null(i), charsets.get(i)) { + (false, Some(charset)) => { + builder.append_value(&encode_string(&decode(i), &charset)?) + } + _ => builder.append_null(), + } + } + Ok(Arc::new(builder.finish())) +} + +fn encode_array<'a, S: StringArrayType<'a>>( + array: &S, + charsets: &Charsets, +) -> Result<ArrayRef> { + encode_rows( + array.len(), + |i| array.is_null(i), + |i| Cow::Borrowed(array.value(i)), + charsets, + ) +} + +fn encode_binary_array<'a, B: arrow::array::BinaryArrayType<'a>>( + array: &'a B, + charsets: &Charsets, +) -> Result<ArrayRef> { + encode_rows( + array.len(), + |i| array.is_null(i), + |i| String::from_utf8_lossy(array.value(i)), + charsets, + ) +} + +fn encode_dispatch(arr: &ArrayRef, charsets: &Charsets) -> Result<ArrayRef> { + match arr.data_type() { + DataType::Utf8 => encode_array(&arr.as_string::<i32>(), charsets), + DataType::LargeUtf8 => encode_array(&arr.as_string::<i64>(), charsets), + DataType::Utf8View => encode_array(&arr.as_string_view(), charsets), + DataType::Binary => encode_binary_array(&arr.as_binary::<i32>(), charsets), + DataType::LargeBinary => encode_binary_array(&arr.as_binary::<i64>(), charsets), + DataType::BinaryView => encode_binary_array(&arr.as_binary_view(), charsets), + DataType::Null => Ok(null_binary_array(arr.len())), + dt => exec_err!("encode expects a string or binary argument, got {dt:?}"), + } +} + +/// The uppercased charset from a scalar, or `None` if it is null. +fn scalar_charset(scalar: &ScalarValue) -> Result<Option<String>> { + match scalar { + ScalarValue::Utf8(s) | ScalarValue::LargeUtf8(s) | ScalarValue::Utf8View(s) => { + Ok(s.as_ref().map(|s| s.to_uppercase())) + } + ScalarValue::Null => Ok(None), + other => exec_err!("encode charset argument must be a string, got {other:?}"), + } +} + +impl ScalarUDFImpl for SparkEncode { + fn name(&self) -> &str { + "encode" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn coerce_types(&self, arg_types: &[DataType]) -> Result<Vec<DataType>> { + let [value_type, charset_type] = take_function_args(self.name(), arg_types)?; + + let value_type = match value_type { + DataType::Utf8 + | DataType::LargeUtf8 + | DataType::Utf8View + | DataType::Binary Review Comment: does Spark also operate on binary types for this function? source code here seems to suggest only strings https://github.com/apache/spark/blob/dd4b74184e36625aff54d3695a134839a9721bd3/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/stringExpressions.scala#L3276-L3280 -- This is an automated message from the Apache Git Service. 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