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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.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.ThreadLocalRandom;
public class CreateMeasurements {
private static final String FILE = "./measurements.txt";
private record WeatherStation(String id, double meanTemperature) {
double measurement() {
double m = ThreadLocalRandom.current().nextGaussian(meanTemperature, 10);
return Math.round(m * 10.0) / 10.0;
}
}
public static void main(String[] args) throws Exception {
long start = System.currentTimeMillis();
if (args.length != 1) {
System.out.println("Usage: create_measurements.sh <number of records to create>");
System.exit(1);
}
int size = 0;
try {
size = Integer.parseInt(args[0]);
}
catch (NumberFormatException e) {
System.out.println("Invalid value for <number of records to create>");
System.out.println("Usage: CreateMeasurements <number of records to create>");
System.exit(1);
}
List<WeatherStation> stations = Arrays.asList(
new WeatherStation("auckland", 15.2),
new WeatherStation("concordia", -51.7),
new WeatherStation("lima", 19.2),
new WeatherStation("hamburg", 9.4),
new WeatherStation("hammerfest", 2.7),
new WeatherStation("maui", 15.2),
new WeatherStation("miami", 24.5),
new WeatherStation("nairobi", 17.8),
new WeatherStation("newdelhi", 25.3),
new WeatherStation("tokio", 15.8));
File measurements = new File(FILE);
try (FileOutputStream fos = new FileOutputStream(measurements); BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(fos));) {
for (int i = 0; i < size; i++) {
if (i > 0 && i % 50_000_000 == 0) {
System.out.println("Wrote %,d measurements in %s ms".formatted(i, System.currentTimeMillis() - start));
}
WeatherStation station = stations.get(ThreadLocalRandom.current().nextInt(stations.size()));
bw.write(station.id());
bw.write(";" + station.measurement());
bw.newLine();
}
bw.flush();
System.out.println("Created file with %,d measurements in %s ms".formatted(size, System.currentTimeMillis() - start));
}
}
}
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