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first cut 1brc submission (#216)

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* phd3 initial entry

* Optimize parsing doubles

* Remove redundant check

* Update calculate_average_phd3.sh

---------

Co-authored-by: Gunnar Morling <gunnar.morling@googlemail.com>
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Pratham 2024-01-10 16:40:27 -05:00 committed by GitHub
parent 0f976b8167
commit 473791e188
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calculate_average_phd3.sh Executable file
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#!/bin/sh
#
# Copyright 2023 The original authors
#
# Licensed 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.
#
# -agentpath:/Users/phd3/tools/async-profiler-2.9-macos/build/libasyncProfiler.so=start,event=cpu,file=profile.html
JAVA_OPTS=""
java $JAVA_OPTS -XX:+HeapDumpOnOutOfMemoryError --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_phd3

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src/main/java/dev/morling/onebrc/CalculateAverage_phd3.java Normal file
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/*
* Copyright 2023 The original authors
*
* Licensed 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.
*/
package dev.morling.onebrc;
import static java.nio.charset.StandardCharsets.*;
import static java.util.stream.Collectors.*;
import java.io.File;
import java.io.RandomAccessFile;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.stream.IntStream;
public class CalculateAverage_phd3 {
private static final int NUM_THREADS = Runtime.getRuntime().availableProcessors() * 2;
private static final String FILE = "./measurements.txt";
private static final long FILE_SIZE = new File(FILE).length();
private static final int CHUNK_SIZE = 65536 * 1024;
private static final int PADDING = 512;
private static final double[] POWERS_OF_10 = IntStream.range(0, 6).mapToDouble(x -> Math.pow(10.0, x)).toArray();
private static final Map<String, AggregationInfo> globalMap = new ConcurrentHashMap<>();
private record ResultRow(double min, double mean, double max) {
public String toString() {
return round(min) + "/" + round(mean) + "/" + round(max);
}
private double round(double value) {
return Math.round(value * 10.0) / 10.0;
}
};
public static ResultRow resultRow(AggregationInfo aggregationInfo) {
return new ResultRow(aggregationInfo.min, aggregationInfo.sum / aggregationInfo.count, aggregationInfo.max);
}
public static void main(String[] args) throws Exception {
long fileLength = new File(FILE).length();
int numChunks = (int) Math.ceil(fileLength * 1.0 / CHUNK_SIZE);
ExecutorService executorService = Executors.newFixedThreadPool(NUM_THREADS);
BufferDataProvider provider = new RandomAccessBasedProvider(FILE, FILE_SIZE);
for (int chunkIndex = 0; chunkIndex < numChunks; chunkIndex++) {
executorService.submit(new Aggregator(chunkIndex, provider));
}
executorService.shutdown();
executorService.awaitTermination(10, TimeUnit.MINUTES);
Map<String, ResultRow> measurements = new TreeMap<>(globalMap.entrySet().stream()
.collect(toMap(Map.Entry::getKey, e -> resultRow(e.getValue()))));
System.out.println(measurements);
}
private static class AggregationInfo {
double min = Double.POSITIVE_INFINITY;
double max = Double.NEGATIVE_INFINITY;
double sum;
long count;
public AggregationInfo update(AggregationInfo update) {
this.count += update.count;
this.sum += update.sum;
if (this.max < update.max) {
this.max = update.max;
}
if (this.min > update.min) {
this.min = update.min;
}
return this;
}
public AggregationInfo update(double value) {
this.count++;
this.sum += value;
if (this.max < value) {
this.max = value;
}
if (this.min > value) {
this.min = value;
}
return this;
}
}
private interface BufferDataProvider {
int read(byte[] buffer, long offset) throws Exception;
}
private static class RandomAccessBasedProvider implements BufferDataProvider {
private final String filePath;
private final long fileSize;
RandomAccessBasedProvider(String filePath, long fileSize) {
this.filePath = filePath;
this.fileSize = fileSize;
}
@Override
public int read(byte[] buffer, long offset) throws Exception {
RandomAccessFile file = null;
try {
file = new RandomAccessFile(filePath, "r");
file.seek(offset);
return file.read(buffer);
}
finally {
if (file != null) {
file.close();
}
}
}
}
private static class Aggregator implements Runnable {
private final long startByte;
private final BufferDataProvider dataProvider;
public Aggregator(long chunkIndex, BufferDataProvider dataProvider) {
this.startByte = chunkIndex * CHUNK_SIZE;
this.dataProvider = dataProvider;
}
@Override
public void run() {
try {
// offset for the last byte to be processed (excluded)
long endByte = Math.min(startByte + CHUNK_SIZE, FILE_SIZE);
// read a little more than needed to cover next entry if needed
long bufferSize = endByte - startByte + ((endByte == FILE_SIZE) ? 0 : PADDING);
byte[] buffer = new byte[(int) bufferSize];
int bytes = dataProvider.read(buffer, startByte);
// Partial aggregation to avoid accessing global concurrent map for every entry
Map<String, AggregationInfo> updated = processBuffer(
buffer, startByte == 0, endByte - startByte);
// Full aggregation with global map
updated.entrySet().forEach(entry -> {
globalMap.compute(entry.getKey(), (k, v) -> {
if (v == null) {
return entry.getValue();
}
return v.update(entry.getValue());
});
});
}
catch (Throwable e) {
throw new RuntimeException(e);
}
}
private static Map<String, AggregationInfo> processBuffer(byte[] buffer, boolean isFileStart, long nextChunkStart) {
int start = 0;
// Move to the next entry after '\n'. Don't do this if we're at the start of
// the file to avoid missing first entry.
if (!isFileStart) {
while (buffer[start] != '\n') {
start++;
}
start += 1;
}
// local map for this thread, don't need thread safety
Map<String, AggregationInfo> chunkMap = new HashMap<>();
while (true) {
LineInfo lineInfo = getNextLine(buffer, start);
String key = new String(buffer, start, lineInfo.semicolonIndex - start);
double value = parseDouble(buffer, lineInfo.semicolonIndex + 1, lineInfo.nextStart - 1);
update(chunkMap, key, value);
if ((lineInfo.nextStart > nextChunkStart) || (lineInfo.nextStart >= buffer.length)) {
// we are already at a point where the next line will be processed in the next chunk,
// so the job is done here
break;
}
start = lineInfo.nextStart();
}
return chunkMap;
}
private static double parseDouble(byte[] bytes, int offset, int end) {
boolean negative = (bytes[offset] == '-');
int current = negative ? offset + 1 : offset;
int preFloat = 0;
while (current < end && bytes[current] != '.') {
preFloat = (preFloat * 10) + (bytes[current++] - '0');
}
current++;
int postFloatStart = current;
int postFloat = 0;
while (current < end) {
postFloat = (postFloat * 10) + (bytes[current++] - '0');
}
return (preFloat + ((postFloat) / POWERS_OF_10[end - postFloatStart])) * (negative ? -1 : 1);
}
private static void update(Map<String, AggregationInfo> state, String key, double value) {
AggregationInfo info = state.computeIfAbsent(key, k -> new AggregationInfo());
info.update(value);
}
// identifies indexes of the next ';' and '\n', which will be used to get entry key and value from line
private static LineInfo getNextLine(byte[] buffer, int start) {
// caller guarantees that the access is in bounds, so no index check
while (buffer[start] != ';') {
start++;
}
int semicolonIndex = start;
// caller guarantees that the access is in bounds, so no index check
while (buffer[start] != '\n') {
start++;
}
return new LineInfo(semicolonIndex, start + 1);
}
}
private record LineInfo(int semicolonIndex, int nextStart) {
}
}