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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.nio.file.Files;
import java.nio.file.Path;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;
public class CalculateAverage_kuduwa_keshavram {
private static final String FILE = "./measurements.txt";
private record Measurement(double min, double max, double sum, long count) {
Measurement(double initialMeasurement) {
this(initialMeasurement, initialMeasurement, initialMeasurement, 1);
}
public static Measurement combineWith(Measurement m1, Measurement m2) {
return new Measurement(
m1.min < m2.min ? m1.min : m2.min,
m1.max > m2.max ? m1.max : m2.max,
m1.sum + m2.sum,
m1.count + m2.count);
}
public String toString() {
return round(min) + "/" + round(sum / count) + "/" + round(max);
}
private double round(double value) {
return Math.round(value * 10.0) / 10.0;
}
}
public static void main(String[] args) throws IOException {
// long before = System.currentTimeMillis();
Map<String, Measurement> resultMap = new ConcurrentHashMap<>();
Files.lines(Path.of(FILE))
.parallel()
.forEach(
line -> {
int pivot = line.indexOf(";");
String key = line.substring(0, pivot);
Measurement measured = new Measurement(Double.parseDouble(line.substring(pivot + 1)));
Measurement existingMeasurement = resultMap.get(key);
if (existingMeasurement != null) {
resultMap.put(key, Measurement.combineWith(existingMeasurement, measured));
}
else {
resultMap.put(key, measured);
}
});
System.out.print("{");
System.out.print(
resultMap.entrySet().stream()
.map(Object::toString)
.sorted()
.collect(Collectors.joining(", ")));
System.out.println("}");
// System.out.println("Took: " + (System.currentTimeMillis() - before));
}
}
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