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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.AbstractMap;
import java.util.Comparator;
import java.util.Map;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.stream.Collectors;
public class CalculateAverage_patrick {
private static final String FILE = "./measurements.txt";
private record Measurement(long count, double sum, double min, double max) {
Measurement(double value) {
this(1, value, value, value);
}
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append(round(min));
builder.append("/");
builder.append(round(sum/count));
builder.append("/");
builder.append(round(max));
return builder.toString();
}
private double round(double value) {
return Math.round(value * 10.0) / 10.0;
}
}
public static void main(String[] args) throws IOException {
Map<String, Measurement> resultMap = Files.lines(Path.of(FILE)).parallel()
.map(line -> {
int separatorIndex = line.indexOf(";");
String key = line.substring(0, separatorIndex);
double value = Double.parseDouble(line.substring(separatorIndex + 1));
return new AbstractMap.SimpleEntry<>(key, value);
})
.collect(Collectors.toConcurrentMap(
entry -> entry.getKey(),
entry -> new Measurement(entry.getValue()),
((measurement1, measurement2) -> new Measurement(
measurement1.count + measurement2.count,
measurement1.sum + measurement2.sum,
Math.min(measurement1.min, measurement2.min),
Math.max(measurement1.max, measurement2.max)))));
System.out.print(
resultMap.entrySet().stream().sorted(Map.Entry.comparingByKey()).map(Object::toString).collect(Collectors.joining(", ", "{", "}")));
}
}
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