neilconway commented on code in PR #24078: URL: https://github.com/apache/datafusion/pull/24078#discussion_r3713587008
########## datafusion/physical-expr-common/benches/arrow_bytes_map.rs: ########## @@ -0,0 +1,82 @@ +// 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::{ArrayRef, StringArray}; +use criterion::{Criterion, Throughput, criterion_group, criterion_main}; +use datafusion_physical_expr_common::binary_map::{ArrowBytesMap, OutputType}; +use std::hint::black_box; +use std::sync::Arc; + +const NUM_ROWS: usize = 8192; + +fn make_short_strings(cardinality: usize) -> ArrayRef { + let values = (0..NUM_ROWS).map(|index| format!("{:04x}", index % cardinality)); + Arc::new(StringArray::from_iter_values(values)) +} + +fn make_long_strings(cardinality: usize) -> ArrayRef { + let values = (0..NUM_ROWS).map(|index| { + let value = (index % cardinality) as u32; + format!( + "{value:08x}{:08x}{:08x}{:08x}", + value.wrapping_mul(17), + value.wrapping_mul(31), + value.wrapping_mul(127) + ) + }); + Arc::new(StringArray::from_iter_values(values)) +} + +fn bench_arrow_bytes_map(c: &mut Criterion) { + let cases = [ + // Exercises inline entry storage while still growing the output buffer. + ("short_unique", make_short_strings(NUM_ROWS)), + // Exercises repeated buffer growth and out-of-line entry storage. + ("long_unique", make_long_strings(NUM_ROWS)), + // Fits the distinct values in the initial buffer and repeats comparisons. + ("long_low_cardinality", make_long_strings(128)), + ]; + + let mut group = c.benchmark_group("arrow_bytes_map"); + group.throughput(Throughput::Elements(NUM_ROWS as u64)); + + for (name, values) in cases { + group.bench_function(name, |b| { + b.iter(|| { + let mut map = ArrowBytesMap::<i32, usize>::new(OutputType::Utf8); + let mut next_payload = 0; + map.insert_if_new( + &values, + |_| { + let payload = next_payload; + next_payload += 1; + payload + }, + |payload| { + black_box(payload); + }, + ); + black_box(map.into_state()) Review Comment: Not a blocker, but it seems like this will allocate a single map and insert a single 8k batch of values. Is that representative of a realistic workload? I'd expect we would more typically allocate a map once and insert many batches into it. Structuring the benchmark this way might overstate the impact of one-time map allocation work, etc. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
