2010YOUY01 commented on code in PR #15454: URL: https://github.com/apache/datafusion/pull/15454#discussion_r2016550461
########## datafusion/physical-plan/benches/read_spill.rs: ########## @@ -0,0 +1,157 @@ +// 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::{ + Date32Builder, Decimal128Builder, Int32Builder, RecordBatch, StringBuilder, +}; +use arrow::datatypes::{DataType, Field, Schema}; +use arrow::ipc::reader::StreamReader; +use arrow::ipc::writer::StreamWriter; +use criterion::{criterion_group, criterion_main, BatchSize, BenchmarkId, Criterion}; +use datafusion_common::{exec_datafusion_err, Result}; +use std::fs::File; +use std::path::Path; +use std::sync::mpsc::{channel, Sender}; +use std::sync::Arc; +use std::thread; +use tempfile::NamedTempFile; + +fn create_batch(num_rows: usize, allow_nulls: bool) -> RecordBatch { + let schema = Arc::new(Schema::new(vec![ + Field::new("c0", DataType::Int32, true), + Field::new("c1", DataType::Utf8, true), + Field::new("c2", DataType::Date32, true), + Field::new("c3", DataType::Decimal128(11, 2), true), + ])); + + let mut a = Int32Builder::new(); + let mut b = StringBuilder::new(); + let mut c = Date32Builder::new(); + let mut d = Decimal128Builder::new() + .with_precision_and_scale(11, 2) + .unwrap(); + + for i in 0..num_rows { + a.append_value(i as i32); + c.append_value(i as i32); + d.append_value((i * 1000000) as i128); + if allow_nulls && i % 10 == 0 { + b.append_null(); + } else { + b.append_value(format!("this is string number {i}")); + } + } + + let a = a.finish(); + let b = b.finish(); + let c = c.finish(); + let d = d.finish(); + + RecordBatch::try_new( + schema.clone(), + vec![Arc::new(a), Arc::new(b), Arc::new(c), Arc::new(d)], + ) + .unwrap() +} + +/// Return a temporary file that contains an IPC file with 100 [`RecordBatch`]es +fn ipc_file() -> NamedTempFile { + let mut file = NamedTempFile::new().unwrap(); + let batch = create_batch(8192, true); + let mut writer = + StreamWriter::try_new(file.as_file_mut(), batch.schema().as_ref()).unwrap(); + for _ in 0..100 { + writer.write(&batch).unwrap(); + } + writer.finish().unwrap(); + file +} + +fn bench_spill_read(c: &mut Criterion) { + let file = ipc_file(); + let path = file.path(); + + let mut group = c.benchmark_group("read_spill"); + + let benches = &[ + ( + "StreamReader/read_100/with_validation", + read_spill as fn(_, _) -> _, + ), + ( + "StreamReader/read_100/skip_validation", + read_spill_skip_validation, + ), + ]; + + for &(name, func) in benches { + group.bench_with_input(BenchmarkId::new(name, ""), &path, |b, path| { + b.iter_batched( + // Setup phase: Create fresh state for each benchmark iteration. + // - A channel to send/receive RecordBatch results between threads. + // - A background thread to consume received RecordBatches. + // This ensures each iteration starts with clean resources. + || { + let (sender, receiver) = channel::<Result<RecordBatch>>(); + let join_handle = thread::spawn(move || { + while let Ok(batch) = receiver.recv() { + let _ = batch.unwrap(); + } + }); + (sender, join_handle) + }, + // Benchmark phase: + // - Execute the target function to send batches via the channel + // - Wait for the consumer thread to finish processing + |(sender, join_handle)| { + func(sender, path).unwrap(); + join_handle.join().unwrap(); + }, + BatchSize::LargeInput, + ) + }); + } + + group.finish(); +} +criterion_group!(benches, bench_spill_read); +criterion_main!(benches); + +fn read_spill(sender: Sender<Result<RecordBatch>>, path: &Path) -> Result<()> { Review Comment: I suggest writing the benchmark by timing `SpillManager`'s IO speed for test batches, instead of several thin wrappers on arrow functions, in the future it might get hard to figure out what this micro-bench is for. This way we can also track the IO performance over time, and it's okay not able to compare the validation difference in this PR, we can apply some manual changes to verify the speed-up. ########## datafusion/physical-plan/src/spill/mod.rs: ########## @@ -35,7 +35,10 @@ use datafusion_common::{exec_datafusion_err, HashSet, Result}; fn read_spill(sender: Sender<Result<RecordBatch>>, path: &Path) -> Result<()> { let file = BufReader::new(File::open(path)?); - let reader = StreamReader::try_new(file, None)?; + // SAFETY: DataFusion's spill writer strictly follows Arrow IPC specifications + // with validated schemas and buffers. Skip redundant validation during read + // to speedup read operation. This is a deliberate safety-performance tradeoff. + let reader = unsafe { StreamReader::try_new(file, None)?.with_skip_validation(true) }; Review Comment: 👍🏼 -- This is an automated message from the Apache Git Service. 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