SparkApplicationMaster commented on code in PR #17456: URL: https://github.com/apache/datafusion/pull/17456#discussion_r2346941752
########## datafusion/spark/src/function/map/map_from_arrays.rs: ########## @@ -0,0 +1,208 @@ +// 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::borrow::Cow; +use std::collections::HashSet; +use std::sync::Arc; + +use arrow::array::{Array, ArrayRef, AsArray, BooleanBuilder, MapArray, StructArray}; +use arrow::buffer::OffsetBuffer; +use arrow::compute::filter; +use arrow::datatypes::{DataType, Field, Fields}; +use datafusion_common::utils::take_function_args; +use datafusion_common::{exec_err, internal_err, Result, ScalarValue}; +use datafusion_expr::{ColumnarValue, ScalarUDFImpl, Signature, Volatility}; +use datafusion_functions::utils::make_scalar_function; + +#[derive(Debug, PartialEq, Eq, Hash)] +pub struct MapFromArrays { + signature: Signature, +} + +impl Default for MapFromArrays { + fn default() -> Self { + Self::new() + } +} + +impl MapFromArrays { + pub fn new() -> Self { + Self { + signature: Signature::any(2, Volatility::Immutable), + } + } +} + +impl ScalarUDFImpl for MapFromArrays { + fn as_any(&self) -> &dyn Any { + self + } + + fn name(&self) -> &str { + "map_from_arrays" + } + + fn signature(&self) -> &Signature { + &self.signature + } + + fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> { + let [key_type, value_type] = take_function_args("map_from_arrays", arg_types)?; + Ok(return_type_from_key_value_types( + get_element_type(key_type)?, + get_element_type(value_type)?, + )) + } + + fn invoke_with_args( + &self, + args: datafusion_expr::ScalarFunctionArgs, + ) -> Result<ColumnarValue> { + make_scalar_function(map_from_arrays_inner, vec![])(&args.args) + } +} + +fn get_list_field(data_type: &DataType) -> Result<&Arc<Field>> { + match data_type { + DataType::List(element) + | DataType::LargeList(element) + | DataType::FixedSizeList(element, _) => Ok(element), + _ => exec_err!( + "map_from_arrays expects 2 listarrays for keys and values as arguments, got {data_type:?}" + ), + } +} + +fn get_element_type(data_type: &DataType) -> Result<&DataType> { + get_list_field(data_type).map(|field| field.data_type()) +} + +pub fn return_type_from_key_value_types( + key_type: &DataType, + value_type: &DataType, +) -> DataType { + DataType::Map( + Arc::new(Field::new( + "entries", + DataType::Struct(Fields::from(vec![ + // the key must not be nullable + Field::new("key", key_type.clone(), false), + Field::new("value", value_type.clone(), true), + ])), + false, // the entry is not nullable + )), + false, // the keys are not sorted + ) +} + +fn get_list_values(array: &ArrayRef) -> Result<&ArrayRef> { + match array.data_type() { + DataType::List(_) => Ok(array.as_list::<i32>().values()), + DataType::LargeList(_) => Ok(array.as_list::<i64>().values()), + DataType::FixedSizeList(..) => Ok(array.as_fixed_size_list().values()), + wrong_type => internal_err!( + "get_list_values expects List/LargeList/FixedSizeList as argument, got {wrong_type:?}" + ), + } +} + +fn map_from_arrays_inner(args: &[ArrayRef]) -> Result<ArrayRef> { + let [keys, values] = take_function_args("map_from_arrays", args)?; + + let flat_keys = get_list_values(keys)?; + let flat_values = get_list_values(values)?; + + let offsets: Cow<[i32]> = match keys.data_type() { + DataType::List(_) => Ok(Cow::Borrowed(keys.as_list::<i32>().offsets().as_ref())), + DataType::LargeList(_) => Ok(Cow::Owned( + keys.as_list::<i64>() + .offsets() + .iter() + .map(|i| *i as i32) + .collect::<Vec<_>>(), + )), + DataType::FixedSizeList(_, size) => Ok(Cow::Owned( + (0..=keys.len() as i32).map(|i| size * i).collect() + )), + wrong_type => internal_err!( + "map_from_arrays expects List/LargeList/FixedSizeList as first argument, got {wrong_type:?}" + ), + }?; + + map_from_keys_values_offsets(flat_keys, flat_values, &offsets) +} + +pub fn map_from_keys_values_offsets( + keys: &ArrayRef, + values: &ArrayRef, + offsets: &[i32], +) -> Result<ArrayRef> { + let (keys, values, offsets) = map_deduplicate_keys(keys, values, offsets)?; + + let fields = Fields::from(vec![ + Field::new("key", keys.data_type().clone(), false), + Field::new("value", values.data_type().clone(), true), + ]); + let entries = StructArray::try_new(fields.clone(), vec![keys, values], None)?; + let field = Arc::new(Field::new("entries", DataType::Struct(fields), false)); + Ok(Arc::new(MapArray::try_new( + field, offsets, entries, None, false, Review Comment: finally understood the root cause of the problem: array() is `spark_array` function call spark_array has 'element' field name NULL casted to array type is datafusion core array datafusion core array has 'item' field name so they are really not coercible because of different field name this causes the error (spark and datafusion arrays mixed): ``` query ? select map_from_arrays(a, b) from values (array(1), array('a')), (NULL, NULL), (array(2, 3), array('b', 'c')) as tab(a, b); ---- {1: a} NULL {2: b, 3: c} ``` but this works (only datafusion arrays): ``` query ? select map_from_arrays(a, b) from values (array[1], array['a']), (NULL, NULL), (array[2, 3], array['b', 'c']) as tab(a, b); ---- {1: a} NULL {2: b, 3: c} ``` -- This is an automated message from the Apache Git Service. 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