artpar's attempt

* artpar's attempt

* artpar's attempt

* remove int -> Integer conversions, custom parsing for measurements

* remove allocations by caching station names
also remove Integer and use int instead to remove valueOf calls

* Fix result mismatch errors

* parse int instead of double

* reduce time spent reading the mapped buffer

* cleanup unused memory

* less is faster ? vector addition doesn't look worth it

* backout from virtual threads as well

* Fix breaking tests
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Parth Mudgal 2024-01-06 03:58:38 +05:30 committed by GitHub
parent d3e88219f0
commit 72ad94d6c2
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calculate_average_artpar.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.
#
JAVA_OPTS="--add-modules=jdk.incubator.vector"
time java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_artpar

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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 java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.time.Instant;
import java.util.*;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.stream.Collectors;
public class CalculateAverage_artpar {
public static final int N_THREADS = 8;
private static final String FILE = "./measurements.txt";
// private static final VectorSpecies<Integer> SPECIES = IntVector.SPECIES_PREFERRED;
// final int VECTOR_SIZE = 512;
// final int VECTOR_SIZE_1 = VECTOR_SIZE - 1;
final int SIZE = 1024 * 1024;
public CalculateAverage_artpar() throws IOException {
long start = Instant.now().toEpochMilli();
Path measurementFile = Paths.get(FILE);
long fileSize = Files.size(measurementFile);
long expectedChunkSize = Math.max(fileSize / 8, 1024);
ExecutorService threadPool = Executors.newFixedThreadPool(N_THREADS);
long chunkStartPosition = 0;
RandomAccessFile fis = new RandomAccessFile(measurementFile.toFile(), "r");
List<Future<Map<String, MeasurementAggregator>>> futures = new ArrayList<>();
long bytesReadCurrent = 0;
try (FileChannel fileChannel = FileChannel.open(measurementFile, StandardOpenOption.READ)) {
for (int i = 0; i < 8; i++) {
long chunkSize = expectedChunkSize;
chunkSize = fis.skipBytes(Math.toIntExact(chunkSize));
bytesReadCurrent += chunkSize;
while (((char) fis.read()) != '\n' && bytesReadCurrent < fileSize) {
chunkSize++;
bytesReadCurrent++;
}
// System.out.println("[" + chunkStartPosition + "] - [" + (chunkStartPosition + chunkSize) + " bytes");
if (chunkStartPosition + chunkSize >= fileSize) {
chunkSize = fileSize - chunkStartPosition;
}
if (chunkSize < 1) {
break;
}
if (chunkSize > Integer.MAX_VALUE) {
chunkSize = Integer.MAX_VALUE;
}
MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, chunkStartPosition,
chunkSize);
ReaderRunnable readerRunnable = new ReaderRunnable(mappedByteBuffer);
Future<Map<String, MeasurementAggregator>> future = threadPool.submit(readerRunnable::run);
// System.out.println("Added future [" + chunkStartPosition + "][" + chunkSize + "]");
futures.add(future);
chunkStartPosition = chunkStartPosition + chunkSize + 1;
}
}
fis.close();
Map<String, MeasurementAggregator> globalMap = futures.parallelStream()
.flatMap(future -> {
try {
return future.get().entrySet().stream();
}
catch (InterruptedException | ExecutionException e) {
throw new RuntimeException(e);
}
}).parallel().collect(Collectors.toMap(
Map.Entry::getKey, Map.Entry::getValue,
MeasurementAggregator::combine));
Map<String, ResultRow> results = globalMap.entrySet().stream().parallel()
.collect(Collectors.toMap(Map.Entry::getKey, e -> e.getValue().finish()));
threadPool.shutdown();
Map<String, ResultRow> measurements = new TreeMap<>(results);
PrintStream printStream = new PrintStream(new BufferedOutputStream(System.out));
// PrintStream printStream = System.out;
printStream.print("{");
boolean isFirst = true;
for (Map.Entry<String, ResultRow> stringResultRowEntry : measurements.entrySet()) {
if (!isFirst) {
printStream.print(", ");
printStream.flush();
}
printStream.flush();
printStream.print(stringResultRowEntry.getKey());
printStream.flush();
printStream.print("=");
printStream.flush();
stringResultRowEntry.getValue().printTo(printStream);
printStream.flush();
isFirst = false;
}
System.out.print("}\n");
// long end = Instant.now().toEpochMilli();
// System.out.println((end - start) / 1000);
}
public static void main(String[] args) throws IOException {
new CalculateAverage_artpar();
}
public static int hashCode(byte[] array, int length) {
int h = 1;
int i = 0;
for (; i + 7 < length; i += 8) {
h = 31 * 31 * 31 * 31 * 31 * 31 * 31 * 31 * h + 31 * 31 * 31 * 31
* 31 * 31 * 31 * array[i] + 31 * 31 * 31 * 31 * 31 * 31
* array[i + 1]
+ 31 * 31 * 31 * 31 * 31 * array[i + 2] + 31
* 31 * 31 * 31 * array[i + 3]
+ 31 * 31 * 31 * array[i + 4]
+ 31 * 31 * array[i + 5] + 31 * array[i + 6] + array[i + 7];
}
for (; i + 3 < length; i += 4) {
h = 31 * 31 * 31 * 31 * h + 31 * 31 * 31 * array[i] + 31 * 31
* array[i + 1] + 31 * array[i + 2] + array[i + 3];
}
for (; i < length; i++) {
h = 31 * h + array[i];
}
return h;
}
private record ResultRow(double min, double mean, double max) {
public String toString() {
return round(min / 10) + "/" + round(mean / 10) + "/" + round(max / 10);
}
private double round(double value) {
return Math.round(value * 10.0) / 10.0;
}
public void printTo(PrintStream out) {
out.printf("%.1f/%.1f/%.1f", min / 10, mean / 10, max / 10);
}
}
private static class MeasurementAggregator {
private double min = Double.POSITIVE_INFINITY;
private double max = Double.NEGATIVE_INFINITY;
private double sum;
private long count;
public MeasurementAggregator() {
}
// public MeasurementAggregator(double min, double max, double sum, long count) {
// this.min = min;
// this.max = max;
// this.sum = sum;
// this.count = count;
// }
MeasurementAggregator combine(MeasurementAggregator other) {
min = Math.min(min, other.min);
max = Math.max(max, other.max);
sum += other.sum;
count += other.count;
return this;
}
// MeasurementAggregator combine(double otherMin, double otherMax, double otherSum, long otherCount) {
// min = Math.min(min, otherMin);
// max = Math.max(max, otherMax);
// sum += otherSum;
// count += otherCount;
// return this;
// }
MeasurementAggregator combine(double value) {
min = Math.min(min, value);
max = Math.max(max, value);
sum += value;
count += 1;
return this;
}
ResultRow finish() {
double mean = (count > 0) ? sum / count : 0;
return new ResultRow(min, mean, max);
}
}
static class StationName {
public final int hash;
private final String name;
// private final int index;
public int count = 0;
// public int[] values = new int[VECTOR_SIZE];
public MeasurementAggregator measurementAggregator = new MeasurementAggregator();
public StationName(String name, int hash) {
this.name = name;
// this.index = index;
this.hash = hash;
}
}
private class ReaderRunnable {
private final MappedByteBuffer mappedByteBuffer;
StationNameMap stationNameMap = new StationNameMap();
// double[][] stationValueMap = new double[SIZE][];
private ReaderRunnable(MappedByteBuffer mappedByteBuffer) {
this.mappedByteBuffer = mappedByteBuffer;
}
public Map<String, MeasurementAggregator> run() {
// System.out.println("Started future - " + mappedByteBuffer.position());
int doubleValue;
long start = Date.from(Instant.now()).getTime();
// int totalBytesRead = 0;
// ByteBuffer nameBuffer = ByteBuffer.allocate(128);
int MAPPED_BYTE_BUFFER_SIZE = 8192;
byte[] rawBuffer = new byte[32];
int rawBufferReadIndex = 0;
StationName matchedStation = null;
boolean expectedName = true;
byte[] mappedBytes = new byte[MAPPED_BYTE_BUFFER_SIZE];
int mappedBytesReadIndex;
boolean negative = false;
int start1 = 0;
int result = 0;
while (mappedByteBuffer.hasRemaining()) {
int remaining = mappedByteBuffer.remaining();
int bytesToRead = Math.min(remaining, MAPPED_BYTE_BUFFER_SIZE);
mappedByteBuffer.get(mappedBytes, 0, bytesToRead);
remaining = mappedByteBuffer.remaining();
mappedBytesReadIndex = 0;
while (mappedBytesReadIndex < bytesToRead) {
byte b = mappedBytes[mappedBytesReadIndex];
mappedBytesReadIndex++;
if (expectedName) {
if (b != ';') {
rawBuffer[rawBufferReadIndex] = b;
rawBufferReadIndex++;
continue;
}
else {
expectedName = false;
matchedStation = stationNameMap.getOrCreate(rawBuffer, rawBufferReadIndex);
rawBufferReadIndex = 0;
negative = false;
start1 = 0;
result = 0;
continue;
}
}
while (b != '\n') {
rawBuffer[rawBufferReadIndex] = b;
rawBufferReadIndex++;
if (mappedBytesReadIndex < bytesToRead) {
b = mappedBytes[mappedBytesReadIndex];
mappedBytesReadIndex++;
}
else {
break;
}
}
if (b != '\n') {
if (mappedBytesReadIndex == bytesToRead && remaining > 0) {
continue;
}
}
// Check for negative numbers
if (rawBuffer[0] == '-') {
negative = true;
start1++;
}
for (int i = start1; i < rawBufferReadIndex; i++) {
byte c = rawBuffer[i];
if (c != '.') {
result = result * 10 + (c - '0');
}
}
doubleValue = negative ? -result : result;
rawBufferReadIndex = 0;
matchedStation.measurementAggregator.combine(doubleValue);
matchedStation.count++;
expectedName = true;
}
}
long end = Date.from(Instant.now()).getTime();
// System.out.println("Took [" + ((end - start) / 1000) + "s for " + totalBytesRead / 1024 + " kb");
return Arrays.stream(stationNameMap.names).parallel().filter(Objects::nonNull)
.collect(Collectors.toMap(e -> e.name, e -> e.measurementAggregator));
// return groupedMeasurements;
}
}
class StationNameMap {
int[] indexes = new int[SIZE];
StationName[] names = new StationName[SIZE];
int currentIndex = 0;
public StationName getOrCreate(byte[] stationNameBytes, int length) {
int hash = CalculateAverage_artpar.hashCode(stationNameBytes, length);
int position = Math.abs(hash) % SIZE;
while (indexes[position] != 0 && names[indexes[position]].hash != hash) {
position = ++position % SIZE;
}
if (indexes[position] != 0) {
return names[indexes[position]];
}
StationName stationName = new StationName(
new String(stationNameBytes, 0, length, StandardCharsets.UTF_8), hash);
indexes[position] = ++currentIndex;
names[indexes[position]] = stationName;
return stationName;
}
}
}