Initial 1brc version by plbpietrz (#219)
* Initial version * Small result merge optimisation * Switched from reading bytes to longs * Reading into internal buffer, test fixes * Licence and minor string creation optimisation * Hash collision fix
This commit is contained in:
Bartłomiej Pietrzyk
GitHub
parent
d18b10708b
commit
c926aab444
20
calculate_average_plbpietrz.sh
Executable file
20
calculate_average_plbpietrz.sh
Executable file
@ -0,0 +1,20 @@
|
||||
#!/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 -Xmx99m --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_plbpietrz
|
||||
273
src/main/java/dev/morling/onebrc/CalculateAverage_plbpietrz.java
Normal file
273
src/main/java/dev/morling/onebrc/CalculateAverage_plbpietrz.java
Normal file
@ -0,0 +1,273 @@
|
||||
/*
|
||||
* 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.PrintWriter;
|
||||
import java.io.RandomAccessFile;
|
||||
import java.io.UncheckedIOException;
|
||||
import java.nio.MappedByteBuffer;
|
||||
import java.nio.channels.FileChannel;
|
||||
import java.nio.charset.Charset;
|
||||
import java.nio.file.Path;
|
||||
import java.util.ArrayList;
|
||||
import java.util.Arrays;
|
||||
import java.util.Comparator;
|
||||
import java.util.HashMap;
|
||||
import java.util.List;
|
||||
import java.util.Map;
|
||||
import java.util.stream.Collectors;
|
||||
|
||||
public class CalculateAverage_plbpietrz {
|
||||
|
||||
private static final String FILE = "./measurements.txt";
|
||||
private static final int READ_SIZE = 1024;
|
||||
private static final int CPU_COUNT = Runtime.getRuntime().availableProcessors();
|
||||
|
||||
private static class TemperatureStats {
|
||||
double min = 999, max = -999d;
|
||||
double accumulated;
|
||||
int count;
|
||||
|
||||
public void update(double temp) {
|
||||
this.min = Math.min(this.min, temp);
|
||||
this.max = Math.max(this.max, temp);
|
||||
this.accumulated += temp;
|
||||
this.count++;
|
||||
}
|
||||
}
|
||||
|
||||
private record FilePart(long pos, long size) {
|
||||
}
|
||||
|
||||
private static class WeatherStation {
|
||||
private int length;
|
||||
private int nameHash;
|
||||
private byte[] nameBytes;
|
||||
private String string;
|
||||
|
||||
public WeatherStation() {
|
||||
nameBytes = new byte[128];
|
||||
}
|
||||
|
||||
public WeatherStation(WeatherStation station) {
|
||||
this.nameBytes = Arrays.copyOf(station.nameBytes, station.length);
|
||||
this.length = station.length;
|
||||
this.nameHash = station.nameHash;
|
||||
}
|
||||
|
||||
@Override
|
||||
public int hashCode() {
|
||||
return nameHash;
|
||||
}
|
||||
|
||||
@Override
|
||||
public boolean equals(Object o) {
|
||||
if (this == o)
|
||||
return true;
|
||||
if (o instanceof WeatherStation s) {
|
||||
return this.nameHash == s.nameHash && Arrays.equals(this.nameBytes, 0, this.length, s.nameBytes, 0, s.length);
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
if (string == null)
|
||||
string = new String(nameBytes, 0, length, Charset.defaultCharset());
|
||||
return string;
|
||||
}
|
||||
|
||||
public void appendByte(byte b) {
|
||||
string = null;
|
||||
nameBytes[length++] = b;
|
||||
nameHash = nameHash * 31 + b;
|
||||
}
|
||||
|
||||
public void clear() {
|
||||
this.length = 0;
|
||||
this.nameHash = 0;
|
||||
this.string = null;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
public static void main(String[] args) throws IOException {
|
||||
Path inputFilePath = Path.of(FILE);
|
||||
Map<WeatherStation, TemperatureStats> results;
|
||||
try (RandomAccessFile inputFile = new RandomAccessFile(inputFilePath.toFile(), "r")) {
|
||||
var parsedBuffers = partitionInput(inputFile)
|
||||
.stream()
|
||||
.parallel()
|
||||
.map(fp -> getMappedByteBuffer(fp, inputFile))
|
||||
.map(CalculateAverage_plbpietrz::parseBuffer);
|
||||
results = parsedBuffers.flatMap(m -> m.entrySet().stream())
|
||||
.collect(
|
||||
Collectors.groupingBy(
|
||||
Map.Entry::getKey,
|
||||
Collectors.reducing(
|
||||
new TemperatureStats(),
|
||||
Map.Entry::getValue,
|
||||
CalculateAverage_plbpietrz::mergeTemperatureStats)));
|
||||
try (PrintWriter pw = new PrintWriter(new BufferedOutputStream(System.out))) {
|
||||
formatResults(pw, results);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private static List<FilePart> partitionInput(RandomAccessFile inputFile) throws IOException {
|
||||
List<FilePart> fileParts = new ArrayList<>();
|
||||
long fileLength = inputFile.length();
|
||||
|
||||
long blockSize = Math.min(fileLength, Math.max(READ_SIZE, fileLength / CPU_COUNT));
|
||||
|
||||
for (long start = 0, end; start < fileLength; start = end) {
|
||||
end = findMinBlockOffset(inputFile, start, blockSize);
|
||||
fileParts.add(new FilePart(start, end - start));
|
||||
}
|
||||
return fileParts;
|
||||
}
|
||||
|
||||
private static long findMinBlockOffset(RandomAccessFile file, long startPosition, long minBlockSize) throws IOException {
|
||||
long length = file.length();
|
||||
if (startPosition + minBlockSize < length) {
|
||||
file.seek(startPosition + minBlockSize);
|
||||
while (file.readByte() != '\n') {
|
||||
}
|
||||
return file.getFilePointer();
|
||||
}
|
||||
else {
|
||||
return length;
|
||||
}
|
||||
}
|
||||
|
||||
private static MappedByteBuffer getMappedByteBuffer(FilePart fp, RandomAccessFile inputFile) {
|
||||
try {
|
||||
return inputFile.getChannel().map(FileChannel.MapMode.READ_ONLY, fp.pos, fp.size);
|
||||
}
|
||||
catch (IOException e) {
|
||||
throw new UncheckedIOException(e);
|
||||
}
|
||||
}
|
||||
|
||||
private static Map<WeatherStation, TemperatureStats> parseBuffer(MappedByteBuffer buffer) {
|
||||
byte[] readLong = new byte[READ_SIZE];
|
||||
byte[] temperature = new byte[32];
|
||||
int temperatureLineLenght = 0;
|
||||
|
||||
int limit = buffer.limit();
|
||||
boolean readingName = true;
|
||||
Map<WeatherStation, TemperatureStats> temperatures = new HashMap<>();
|
||||
WeatherStation station = new WeatherStation();
|
||||
|
||||
int bytesToRead = Math.min(READ_SIZE, limit - buffer.position());
|
||||
while (bytesToRead > 0) {
|
||||
if (bytesToRead == READ_SIZE) {
|
||||
buffer.get(readLong);
|
||||
}
|
||||
else {
|
||||
for (int j = 0; j < bytesToRead; ++j)
|
||||
readLong[j] = buffer.get();
|
||||
}
|
||||
|
||||
for (int i = 0; i < bytesToRead; ++i) {
|
||||
byte aChar = readLong[i];
|
||||
if (readingName) {
|
||||
if (aChar != ';') {
|
||||
if (aChar != '\n') {
|
||||
station.appendByte(aChar);
|
||||
}
|
||||
}
|
||||
else {
|
||||
readingName = false;
|
||||
}
|
||||
}
|
||||
else {
|
||||
if (aChar != '\n') {
|
||||
temperature[temperatureLineLenght++] = aChar;
|
||||
}
|
||||
else {
|
||||
double temp = parseTemperature(temperature, temperatureLineLenght);
|
||||
|
||||
if (!temperatures.containsKey(station)) {
|
||||
temperatures.put(new WeatherStation(station), new TemperatureStats());
|
||||
}
|
||||
TemperatureStats weatherStats = temperatures.get(station);
|
||||
weatherStats.update(temp);
|
||||
|
||||
station.clear();
|
||||
temperatureLineLenght = 0;
|
||||
readingName = true;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
bytesToRead = Math.min(READ_SIZE, limit - buffer.position());
|
||||
}
|
||||
return temperatures;
|
||||
}
|
||||
|
||||
private static double parseTemperature(byte[] temperature, int temperatureSize) {
|
||||
double sign = 1;
|
||||
double manitssa = 0;
|
||||
double exponent = 1;
|
||||
for (int i = 0; i < temperatureSize; ++i) {
|
||||
byte c = temperature[i];
|
||||
switch (c) {
|
||||
case '-':
|
||||
sign = -1;
|
||||
break;
|
||||
case '.':
|
||||
for (int j = i; j < temperatureSize - 1; ++j)
|
||||
exponent *= 0.1;
|
||||
break;
|
||||
default:
|
||||
manitssa = manitssa * 10 + (c - 48);
|
||||
}
|
||||
}
|
||||
return sign * manitssa * exponent;
|
||||
}
|
||||
|
||||
private static TemperatureStats mergeTemperatureStats(TemperatureStats v1, TemperatureStats v2) {
|
||||
TemperatureStats acc = new TemperatureStats();
|
||||
acc.min = Math.min(v1.min, v2.min);
|
||||
acc.max = Math.max(v1.max, v2.max);
|
||||
acc.accumulated = v1.accumulated + v2.accumulated;
|
||||
acc.count = v1.count + v2.count;
|
||||
return acc;
|
||||
}
|
||||
|
||||
private static void formatResults(PrintWriter pw, Map<WeatherStation, TemperatureStats> resultsMap) {
|
||||
pw.print('{');
|
||||
var results = new ArrayList<>(resultsMap.entrySet());
|
||||
results.sort(Comparator.comparing(e -> e.getKey().toString()));
|
||||
var iterator = results.iterator();
|
||||
while (iterator.hasNext()) {
|
||||
var entry = iterator.next();
|
||||
TemperatureStats stats = entry.getValue();
|
||||
pw.printf("%s=%.1f/%.1f/%.1f",
|
||||
entry.getKey(),
|
||||
stats.min,
|
||||
stats.accumulated / stats.count,
|
||||
stats.max);
|
||||
if ((iterator.hasNext()))
|
||||
pw.print(", ");
|
||||
}
|
||||
pw.println('}');
|
||||
}
|
||||
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user