Improved version based on rafaelmerino (#511)

* files created by create_fork.sh

* use indexOf

* improved implementation based on rafaelmerino

---------

Co-authored-by: Yann Moisan <yann@zen.ly>
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Yann Moisan 2024-01-20 20:33:14 +01:00 committed by GitHub
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19
calculate_average_YannMoisan.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=""
java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_YannMoisan

20
prepare_YannMoisan.sh Executable file
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#!/bin/bash
#
# 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.
#
# Uncomment below to use sdk
# source "$HOME/.sdkman/bin/sdkman-init.sh"
# sdk use java 21.0.1-graal 1>&2

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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.IOException;
import java.io.UncheckedIOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.*;
import java.util.concurrent.ForkJoinPool;
import java.util.function.Supplier;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
/**
* based on imrafaelmerino
* ./calculate_average_imrafaelmerino.sh 129.10s user 4.73s system 1395% cpu 9.591 total
*
* ./calculate_average_baseline.sh 193.27s user 5.81s system 100% cpu 3:17.85 total
*
* addition to copied implementation
* - use a Location object as a key in the Map to avoid String instantiations.
* ./calculate_average_YannMoisan.sh 118.36s user 5.72s system 1425% cpu 8.705 total
*
* Model Name: MacBook Pro
* Chip: Intel Core i9
* Total Number of Cores: 8
* Memory: 64 GB
* */
public class CalculateAverage_YannMoisan {
private static final String FILE = "./measurements.txt";
private static final int FIELD_SIZE = 128;
public static void main(String[] args) throws IOException {
var chunkSize = 1024 * 1024 * 50L; // Long.parseLong(args[0].trim());
var result = calculateStats(FILE, chunkSize);
System.out.println(result);
}
private static Map<String, Stat> calculateStats(String file,
long chunkSize)
throws IOException {
try (var fileChannel = FileChannel.open(Paths.get(file),
StandardOpenOption.READ)) {
var stats = fileMemoryStream(fileChannel, chunkSize)
.parallel()
.map(p -> ManagedComputation.compute(() -> parse(p)))
.reduce(Collections.emptyMap(),
(stat1, stat2) -> combine(stat1, stat2));
var tm = new TreeMap<String, Stat>();
stats.forEach((k, v) -> tm.put(new String(k.value, 0, k.value.length), v));
return tm;
}
}
private static Map<Location, Stat> combine(Map<Location, Stat> xs,
Map<Location, Stat> ys) {
Map<Location, Stat> result = new HashMap<>();
for (var key : xs.keySet()) {
var m1 = xs.get(key);
var m2 = ys.get(key);
var combined = (m2 == null) ? m1 : (m1 == null) ? m2 : Stat.combine(m1, m2);
result.put(key, combined);
}
for (var key : ys.keySet())
result.putIfAbsent(key, ys.get(key));
return result;
}
private static Map<Location, Stat> parse(ByteBuffer bb) {
Map<Location, Stat> stats = new HashMap<>();
var limit = bb.limit();
var field = new byte[FIELD_SIZE];
while (bb.position() < limit) {
var fieldCurrentIndex = 0;
field[fieldCurrentIndex++] = bb.get();
while (bb.position() < limit) {
var fieldByte = bb.get();
if (fieldByte == ';')
break;
field[fieldCurrentIndex++] = fieldByte;
}
var dst = new byte[fieldCurrentIndex];
System.arraycopy(field, 0, dst, 0, fieldCurrentIndex);
var fieldStr = new Location(dst);
// System.arraycopy(field, 0, dst, 0, fieldCurrentIndex);
var number = 0;
var sign = 1;
while (bb.position() < limit) {
var numberByte = bb.get();
if (numberByte == '-')
sign = -1;
else if (numberByte == '\n')
break;
else if (numberByte != '.')
number = number * 10 + (numberByte - '0');
}
stats.computeIfAbsent(fieldStr,
k -> new Stat())
.update(sign * number);
}
return stats;
}
private static Stream<ByteBuffer> fileMemoryStream(FileChannel fileChannel,
long chunkSize)
throws IOException {
var spliterator = Spliterators.spliteratorUnknownSize(fileMemoryIterator(fileChannel,
chunkSize),
Spliterator.IMMUTABLE);
return StreamSupport.stream(spliterator,
false);
}
private static Iterator<ByteBuffer> fileMemoryIterator(FileChannel fileChannel, long chunkSize) throws IOException {
return new Iterator<>() {
private final long size = fileChannel.size();
private long start = 0;
@Override
public boolean hasNext() {
return start < size;
}
@Override
public ByteBuffer next() {
try {
var buffer = fileChannel.map(MapMode.READ_ONLY,
start,
Math.min(chunkSize,
size - start));
var limmit = buffer.limit() - 1;
while (buffer.get(limmit) != '\n')
limmit--;
limmit++;
buffer.limit(limmit);
start += limmit;
return buffer;
}
catch (IOException ex) {
throw new UncheckedIOException(ex);
}
}
};
}
private static final class Location {
public final byte[] value;
public Location(byte[] value) {
this.value = value;
}
@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (o == null || getClass() != o.getClass())
return false;
Location location = (Location) o;
return Arrays.equals(value, location.value);
}
@Override
public int hashCode() {
return Arrays.hashCode(value);
}
}
private static final class Stat {
private int min = Integer.MAX_VALUE;
private int max = Integer.MIN_VALUE;
private long sum = 0L;
private long count = 0L;
public static Stat combine(Stat m1,
Stat m2) {
var stat = new Stat();
stat.min = Math.min(m1.min, m2.min);
stat.max = Math.max(m1.max, m2.max);
stat.sum = m1.sum + m2.sum;
stat.count = m1.count + m2.count;
return stat;
}
private void update(int value) {
this.min = Math.min(this.min, value);
this.max = Math.max(this.max, value);
this.sum += value;
this.count++;
}
@Override
public String toString() {
return round(min / 10.0) + "/" + round((sum / 10.0) / count) + "/" + round(max / 10.0);
}
private double round(double value) {
return Math.round(value * 10.0) / 10.0;
}
}
private static final class ManagedComputation {
static <T> T compute(final Supplier<T> supplier) {
var managedBlocker = new ManagedSupplier<>(supplier);
try {
ForkJoinPool.managedBlock(managedBlocker);
return managedBlocker.getResult();
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
}
private static class ManagedSupplier<T> implements ForkJoinPool.ManagedBlocker {
private final Supplier<T> task;
private T result;
private boolean isDone = false;
private ManagedSupplier(final Supplier<T> supplier) {
task = supplier;
}
@Override
public boolean block() {
result = task.get();
isDone = true;
return true;
}
@Override
public boolean isReleasable() {
return isDone;
}
T getResult() {
return result;
}
}
}
}