Fokko commented on code in PR #42: URL: https://github.com/apache/iceberg-rust/pull/42#discussion_r1333384560
########## crates/iceberg/src/transform/truncate.rs: ########## @@ -0,0 +1,217 @@ +// 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::sync::Arc; + +use arrow_array::ArrayRef; +use arrow_schema::DataType; + +use crate::Error; + +use super::TransformFunction; + +pub struct Truncate { + width: u32, +} + +impl Truncate { + pub fn new(width: u32) -> Self { + Self { width } + } + + fn truncate_str_by_char(s: &str, max_chars: usize) -> &str { + match s.char_indices().nth(max_chars) { + None => s, + Some((idx, _)) => &s[..idx], + } + } +} + +impl TransformFunction for Truncate { + fn transform(&self, input: ArrayRef) -> crate::Result<ArrayRef> { + match input.data_type() { + DataType::Int32 => { + let width: i32 = self.width.try_into().map_err(|_| { + Error::new( + crate::ErrorKind::DataInvalid, + "width is failed to convert to i32 when truncate Int32Array", + ) + })?; + let res: arrow_array::Int32Array = input + .as_any() + .downcast_ref::<arrow_array::Int32Array>() + .unwrap() + .unary(|v| v - v.rem_euclid(width)); + Ok(Arc::new(res)) + } + DataType::Int64 => { + let width = self.width as i64; + let res: arrow_array::Int64Array = input + .as_any() + .downcast_ref::<arrow_array::Int64Array>() + .unwrap() + .unary(|v| v - (((v % width) + width) % width)); + Ok(Arc::new(res)) + } + DataType::Decimal128(precision, scale) => { + let width = self.width as i128; + let res: arrow_array::Decimal128Array = input + .as_any() + .downcast_ref::<arrow_array::Decimal128Array>() + .unwrap() + .unary(|v| v - (((v % width) + width) % width)) + .with_precision_and_scale(*precision, *scale) + .map_err(|err| Error::new(crate::ErrorKind::Unexpected, format!("{err}")))?; + Ok(Arc::new(res)) + } + DataType::Utf8 => { + let len = self.width as usize; + let res: arrow_array::StringArray = arrow_array::StringArray::from_iter( + input + .as_any() + .downcast_ref::<arrow_array::StringArray>() + .unwrap() + .iter() + .map(|v| v.map(|v| Self::truncate_str_by_char(v, len))), + ); + Ok(Arc::new(res)) + } + DataType::LargeUtf8 => { + let len = self.width as usize; + let res: arrow_array::LargeStringArray = arrow_array::LargeStringArray::from_iter( + input + .as_any() + .downcast_ref::<arrow_array::LargeStringArray>() + .unwrap() + .iter() + .map(|v| v.map(|v| Self::truncate_str_by_char(v, len))), + ); + Ok(Arc::new(res)) + } + _ => unreachable!("Truncate transform only supports (int,long,decimal,string) types"), + } + } +} + +#[cfg(test)] +mod test { + use std::sync::Arc; + + use arrow_array::{ + builder::PrimitiveBuilder, types::Decimal128Type, Decimal128Array, Int32Array, Int64Array, + }; + + use crate::transform::TransformFunction; + + // Test case ref from: https://iceberg.apache.org/spec/#truncate-transform-details + #[test] + fn test_truncate_simple() { + // test truncate int + let input = Arc::new(Int32Array::from(vec![1, -1])); + let res = super::Truncate::new(10).transform(input).unwrap(); + assert_eq!( + res.as_any().downcast_ref::<Int32Array>().unwrap().value(0), + 0 + ); + assert_eq!( + res.as_any().downcast_ref::<Int32Array>().unwrap().value(1), + -10 + ); + + // test truncate long + let input = Arc::new(Int64Array::from(vec![1, -1])); + let res = super::Truncate::new(10).transform(input).unwrap(); + assert_eq!( + res.as_any().downcast_ref::<Int64Array>().unwrap().value(0), + 0 + ); + assert_eq!( + res.as_any().downcast_ref::<Int64Array>().unwrap().value(1), + -10 + ); + + // test decimal + let mut buidler = PrimitiveBuilder::<Decimal128Type>::new() + .with_precision_and_scale(20, 2) + .unwrap(); + buidler.append_value(1065); + let input = Arc::new(buidler.finish()); + let res = super::Truncate::new(50).transform(input).unwrap(); + assert_eq!( + res.as_any() + .downcast_ref::<Decimal128Array>() + .unwrap() + .value(0), + 1050 + ); + + // test string + let input = Arc::new(arrow_array::StringArray::from(vec!["iceberg"])); + let res = super::Truncate::new(3).transform(input).unwrap(); + assert_eq!( + res.as_any() + .downcast_ref::<arrow_array::StringArray>() + .unwrap() + .value(0), + "ice" + ); + + // test large string + let input = Arc::new(arrow_array::LargeStringArray::from(vec!["iceberg"])); + let res = super::Truncate::new(3).transform(input).unwrap(); + assert_eq!( + res.as_any() + .downcast_ref::<arrow_array::LargeStringArray>() + .unwrap() + .value(0), + "ice" + ); + } + + #[test] + fn test_string_truncate() { + let test1 = "イロハニホヘト"; + let test1_2_expected = "イロ"; + assert_eq!( + super::Truncate::truncate_str_by_char(test1, 2), + test1_2_expected + ); + + let test1_3_expected = "イロハ"; + assert_eq!( + super::Truncate::truncate_str_by_char(test1, 3), + test1_3_expected + ); + + let test2 = "щщаεはчωいにπάほхεろへσκζ"; Review Comment: 👍 ########## crates/iceberg/src/transform/truncate.rs: ########## @@ -0,0 +1,217 @@ +// 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::sync::Arc; + +use arrow_array::ArrayRef; +use arrow_schema::DataType; + +use crate::Error; + +use super::TransformFunction; + +pub struct Truncate { + width: u32, +} + +impl Truncate { + pub fn new(width: u32) -> Self { + Self { width } + } + + fn truncate_str_by_char(s: &str, max_chars: usize) -> &str { + match s.char_indices().nth(max_chars) { + None => s, + Some((idx, _)) => &s[..idx], + } + } +} + +impl TransformFunction for Truncate { + fn transform(&self, input: ArrayRef) -> crate::Result<ArrayRef> { + match input.data_type() { + DataType::Int32 => { + let width: i32 = self.width.try_into().map_err(|_| { + Error::new( + crate::ErrorKind::DataInvalid, + "width is failed to convert to i32 when truncate Int32Array", + ) + })?; + let res: arrow_array::Int32Array = input + .as_any() + .downcast_ref::<arrow_array::Int32Array>() + .unwrap() + .unary(|v| v - v.rem_euclid(width)); + Ok(Arc::new(res)) + } + DataType::Int64 => { + let width = self.width as i64; + let res: arrow_array::Int64Array = input + .as_any() + .downcast_ref::<arrow_array::Int64Array>() + .unwrap() + .unary(|v| v - (((v % width) + width) % width)); + Ok(Arc::new(res)) + } + DataType::Decimal128(precision, scale) => { + let width = self.width as i128; + let res: arrow_array::Decimal128Array = input + .as_any() + .downcast_ref::<arrow_array::Decimal128Array>() + .unwrap() + .unary(|v| v - (((v % width) + width) % width)) + .with_precision_and_scale(*precision, *scale) + .map_err(|err| Error::new(crate::ErrorKind::Unexpected, format!("{err}")))?; + Ok(Arc::new(res)) + } + DataType::Utf8 => { + let len = self.width as usize; + let res: arrow_array::StringArray = arrow_array::StringArray::from_iter( + input + .as_any() + .downcast_ref::<arrow_array::StringArray>() + .unwrap() + .iter() + .map(|v| v.map(|v| Self::truncate_str_by_char(v, len))), + ); + Ok(Arc::new(res)) + } + DataType::LargeUtf8 => { + let len = self.width as usize; + let res: arrow_array::LargeStringArray = arrow_array::LargeStringArray::from_iter( + input + .as_any() + .downcast_ref::<arrow_array::LargeStringArray>() + .unwrap() + .iter() + .map(|v| v.map(|v| Self::truncate_str_by_char(v, len))), + ); + Ok(Arc::new(res)) + } + _ => unreachable!("Truncate transform only supports (int,long,decimal,string) types"), + } + } +} + +#[cfg(test)] +mod test { + use std::sync::Arc; + + use arrow_array::{ + builder::PrimitiveBuilder, types::Decimal128Type, Decimal128Array, Int32Array, Int64Array, + }; + + use crate::transform::TransformFunction; + + // Test case ref from: https://iceberg.apache.org/spec/#truncate-transform-details + #[test] + fn test_truncate_simple() { + // test truncate int + let input = Arc::new(Int32Array::from(vec![1, -1])); + let res = super::Truncate::new(10).transform(input).unwrap(); + assert_eq!( + res.as_any().downcast_ref::<Int32Array>().unwrap().value(0), + 0 + ); + assert_eq!( + res.as_any().downcast_ref::<Int32Array>().unwrap().value(1), + -10 + ); + + // test truncate long + let input = Arc::new(Int64Array::from(vec![1, -1])); + let res = super::Truncate::new(10).transform(input).unwrap(); + assert_eq!( + res.as_any().downcast_ref::<Int64Array>().unwrap().value(0), + 0 + ); + assert_eq!( + res.as_any().downcast_ref::<Int64Array>().unwrap().value(1), + -10 + ); + + // test decimal + let mut buidler = PrimitiveBuilder::<Decimal128Type>::new() + .with_precision_and_scale(20, 2) + .unwrap(); + buidler.append_value(1065); + let input = Arc::new(buidler.finish()); + let res = super::Truncate::new(50).transform(input).unwrap(); + assert_eq!( + res.as_any() + .downcast_ref::<Decimal128Array>() + .unwrap() + .value(0), + 1050 + ); + + // test string + let input = Arc::new(arrow_array::StringArray::from(vec!["iceberg"])); + let res = super::Truncate::new(3).transform(input).unwrap(); + assert_eq!( + res.as_any() + .downcast_ref::<arrow_array::StringArray>() + .unwrap() + .value(0), + "ice" + ); + + // test large string + let input = Arc::new(arrow_array::LargeStringArray::from(vec!["iceberg"])); + let res = super::Truncate::new(3).transform(input).unwrap(); + assert_eq!( + res.as_any() + .downcast_ref::<arrow_array::LargeStringArray>() + .unwrap() + .value(0), + "ice" + ); + } + + #[test] + fn test_string_truncate() { + let test1 = "イロハニホヘト"; + let test1_2_expected = "イロ"; + assert_eq!( + super::Truncate::truncate_str_by_char(test1, 2), + test1_2_expected + ); + + let test1_3_expected = "イロハ"; + assert_eq!( + super::Truncate::truncate_str_by_char(test1, 3), + test1_3_expected + ); + + let test2 = "щщаεはчωいにπάほхεろへσκζ"; Review Comment: 👍 -- This is an automated message from the Apache Git Service. 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