JakeDern commented on code in PR #8001: URL: https://github.com/apache/arrow-rs/pull/8001#discussion_r2264452808
########## arrow-ipc/src/tests/delta_dictionary.rs: ########## @@ -0,0 +1,432 @@ +// 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 crate::{ + reader::IpcMessage, + writer::{DictionaryHandling, IpcWriteOptions, StreamWriter}, +}; +use crate::{ + reader::{FileReader, StreamReader}, + writer::FileWriter, +}; +use arrow_array::{ + builder::StringDictionaryBuilder, types::Int32Type, Array, ArrayRef, DictionaryArray, + RecordBatch, StringArray, +}; +use arrow_schema::{DataType, Field, Schema}; +use std::io::Cursor; +use std::sync::Arc; + +#[test] +fn test_mixed_delta() { + let batches: &[&[&str]] = &[ + &["A"], + &["A", "B"], + &["C"], + &["D", "E"], + &["A", "B", "C", "D", "E"], + ]; + + run_delta_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + MessageType::RecordBatch, + ], + ); + + run_resend_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + MessageType::RecordBatch, + ], + ); +} + +#[test] +fn test_disjoint_delta() { + let batches: &[&[&str]] = &[&["A"], &["B"], &["C", "E"]]; + run_delta_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + ], + ); + + run_resend_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + ], + ); +} + +#[test] +fn test_increasing_delta() { + let batches: &[&[&str]] = &[&["A"], &["A", "B"], &["A", "B", "C"]]; + run_delta_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + ], + ); + + run_resend_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + ], + ); +} + +#[test] +fn test_single_delta() { + let batches: &[&[&str]] = &[&["A", "B", "C"], &["D"]]; + run_delta_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::DeltaDict, + MessageType::RecordBatch, + ], + ); + + run_resend_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::Dict, + MessageType::RecordBatch, + ], + ); +} + +#[test] +fn test_single_same_value_sequence() { + let batches: &[&[&str]] = &[&["A"], &["A"], &["A"], &["A"]]; + run_delta_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::RecordBatch, + MessageType::RecordBatch, + MessageType::RecordBatch, + ], + ); + + run_delta_sequence_test( + batches, + &[ + MessageType::Dict, + MessageType::RecordBatch, + MessageType::RecordBatch, + MessageType::RecordBatch, + MessageType::RecordBatch, + ], + ); +} + +#[test] +fn test_multi_same_value_sequence() { + let batches: &[&[&str]] = &[&["A", "B", "C"], &["A", "B", "C"]]; + run_delta_sequence_test(batches, &[MessageType::Dict, MessageType::RecordBatch]); +} + +#[derive(Debug, PartialEq)] +enum MessageType { + Schema, + Dict, + DeltaDict, + RecordBatch, +} + +impl From<&IpcMessage> for MessageType { + fn from(value: &IpcMessage) -> Self { + match value { + IpcMessage::Schema(_) => MessageType::Schema, + IpcMessage::DictionaryBatch { + id: _, + is_delta, + values: _, + } => match is_delta { + true => MessageType::DeltaDict, + false => MessageType::Dict, + }, + IpcMessage::RecordBatch(_) => MessageType::RecordBatch, + } + } +} + +fn run_resend_sequence_test(batches: &[&[&str]], sequence: &[MessageType]) { + let opts = IpcWriteOptions::default().with_dictionary_handling(DictionaryHandling::Resend); + run_sequence_test(batches, sequence, opts); +} + +fn run_delta_sequence_test(batches: &[&[&str]], sequence: &[MessageType]) { + let opts = IpcWriteOptions::default().with_dictionary_handling(DictionaryHandling::Delta); + run_sequence_test(batches, sequence, opts); +} + +fn run_sequence_test(batches: &[&[&str]], sequence: &[MessageType], options: IpcWriteOptions) { + let stream_buf = write_all_to_stream(options.clone(), batches); + let ipc_stream = get_ipc_message_stream(stream_buf); + for (message, expected_type) in ipc_stream.iter().zip(sequence.iter()) { + let actual_type: MessageType = message.into(); + assert_eq!(actual_type, *expected_type, "Message type mismatch"); + } +} + +fn get_ipc_message_stream(buf: Vec<u8>) -> Vec<IpcMessage> { + let mut reader = StreamReader::try_new(Cursor::new(buf), None).unwrap(); + let mut results = vec![]; + + loop { + match reader.next_ipc_message() { + Ok(Some(message)) => results.push(message), + Ok(None) => break, // End of stream + Err(e) => panic!("Error reading IPC message: {:?}", e), + } + } + + results +} + +#[test] +fn test_replace_same_length() { + let batches: &[&[&str]] = &[ + &["A", "B", "C", "D", "E", "F"], + &["A", "G", "H", "I", "J", "K"], + ]; + run_parity_test(batches); +} + +#[test] +fn test_sparse_deltas() { + let batches: &[&[&str]] = &[ + &["A"], + &["C"], + &["E", "F", "D"], + &["FOO"], + &["parquet", "B"], + &["123", "B", "C"], + ]; + run_parity_test(batches); +} + +#[test] +fn test_deltas_with_reset() { + // Dictionary resets at ["C", "D"] + let batches: &[&[&str]] = &[&["A"], &["A", "B"], &["C", "D"], &["A", "B", "C", "D"]]; + run_parity_test(batches); +} + +/// FileWriter can only tolerate very specific patterns of delta dictionaries, +/// because the dictionary cannot be replaced/reset. +#[test] +fn test_deltas_with_file() { + let batches: &[&[&str]] = &[&["A"], &["A", "B"], &["A", "B", "C"], &["A", "B", "C", "D"]]; + run_parity_test(batches); +} + +/// Encode all batches three times and compare all three for the same results +/// on the other end. +/// +/// - Stream encoding with delta +/// - Stream encoding without delta +/// - File encoding with delta (File format does not allow replacement +/// dictionaries) +fn run_parity_test(batches: &[&[&str]]) { + let delta_options = + IpcWriteOptions::default().with_dictionary_handling(DictionaryHandling::Delta); + let delta_stream_buf = write_all_to_stream(delta_options.clone(), batches); + + let resend_options = + IpcWriteOptions::default().with_dictionary_handling(DictionaryHandling::Resend); + let resend_stream_buf = write_all_to_stream(resend_options.clone(), batches); + + let delta_file_buf = write_all_to_file(delta_options, batches); + + let mut streams = vec![ + get_stream_batches(delta_stream_buf), + get_stream_batches(resend_stream_buf), + get_file_batches(delta_file_buf), + ]; + + let (first_stream, other_streams) = streams.split_first_mut().unwrap(); + + let mut idx = 0; + while let Some(batch) = first_stream.next() { + let first_dict = extract_dictionary(batch); + let expected_values = batches[idx]; + assert_eq!(expected_values, &dict_to_vec(first_dict.clone())); + + for stream in other_streams.iter_mut() { + let next_batch = stream + .next() + .expect("All streams should yield same number of elements"); + let next_dict = extract_dictionary(next_batch); + assert_eq!(expected_values, &dict_to_vec(next_dict.clone())); + assert_eq!(first_dict, next_dict); + } + + idx += 1; + } + + for stream in other_streams.iter_mut() { + assert!( + stream.next().is_none(), + "All streams should yield same number of elements" + ); + } +} + +fn dict_to_vec(dict: DictionaryArray<Int32Type>) -> Vec<String> { + let values: Vec<String> = dict + .values() + .as_any() + .downcast_ref::<StringArray>() + .unwrap() + .iter() + .map(|v| v.map(|s| s.to_string()).unwrap_or_default()) + .collect(); + + dict.keys() + .iter() + .map(|i| values[i.unwrap() as usize].clone()) + .collect() +} + +fn get_stream_batches(buf: Vec<u8>) -> Box<dyn Iterator<Item = RecordBatch>> { + let reader = StreamReader::try_new(Cursor::new(buf), None).unwrap(); + Box::new( + reader + .collect::<Vec<Result<_, _>>>() + .into_iter() + .map(|r| r.unwrap()), + ) +} + +fn get_file_batches(buf: Vec<u8>) -> Box<dyn Iterator<Item = RecordBatch>> { + let reader = FileReader::try_new(Cursor::new(buf), None).unwrap(); + Box::new( + reader + .collect::<Vec<Result<_, _>>>() + .into_iter() + .map(|r| r.unwrap()), + ) +} + +fn extract_dictionary(batch: RecordBatch) -> DictionaryArray<arrow_array::types::Int32Type> { + batch + .column(0) + .as_any() + .downcast_ref::<DictionaryArray<arrow_array::types::Int32Type>>() + .unwrap() + .clone() +} + +fn write_all_to_file(options: IpcWriteOptions, vals: &[&[&str]]) -> Vec<u8> { + let batches = build_batches(vals); + let mut buf: Vec<u8> = Vec::new(); + let mut writer = + FileWriter::try_new_with_options(&mut buf, &batches[0].schema(), options).unwrap(); + for batch in batches { + writer.write(&batch).unwrap(); + } + writer.finish().unwrap(); + buf +} + +fn write_all_to_stream(options: IpcWriteOptions, vals: &[&[&str]]) -> Vec<u8> { + let batches = build_batches(vals); + + let mut buf: Vec<u8> = Vec::new(); + let mut writer = + StreamWriter::try_new_with_options(&mut buf, &batches[0].schema(), options).unwrap(); + for batch in batches { + writer.write(&batch).unwrap(); + } + + writer.finish().unwrap(); + + buf +} + +fn build_batches(vals: &[&[&str]]) -> Vec<RecordBatch> { + let mut builder = StringDictionaryBuilder::<arrow_array::types::Int32Type>::new(); + vals.iter().map(|v| build_batch(v, &mut builder)).collect() +} + +fn build_batch( + vals: &[&str], + builder: &mut StringDictionaryBuilder<arrow_array::types::Int32Type>, +) -> RecordBatch { + for &val in vals { + if val.is_empty() { + builder.append_null(); + } else { + builder.append_value(val); + } + } + let array = builder.finish_preserve_values(); Review Comment: Done! -- This is an automated message from the Apache Git Service. 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