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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.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class CalculateAverage_rprabhu {
private static final String FILE = "./measurements.txt";
private static record Measurement(String station, double value) {
private Measurement(String[] parts) {
this(parts[0], Double.parseDouble(parts[1]));
}
}
private static record ResultRow(double min, double mean, double max) {
public String toString() {
return round(min) + "/" + round(mean) + "/" + round(max);
}
private double round(double value) {
return Math.round(value * 10.0) / 10.0;
}
};
private static class MeasurementAggregator {
private double min = Double.POSITIVE_INFINITY;
private double max = Double.NEGATIVE_INFINITY;
private double sum;
private long count;
}
private static ConcurrentHashMap<String, MeasurementAggregator> map = new ConcurrentHashMap<>();
private static final int TASK_CHUNK = 50000;
private static class TaskExecutor implements Runnable {
List<String> list;
TaskExecutor(List<String> list) {
this.list = list;
}
@Override
public void run() {
for (String str : list) {
// System.out.println(str);
// String[] values = str.split(";");
int index = str.indexOf(';');
String station = str.substring(0, index);
double val = Double.parseDouble(str.substring(index + 1));
// double val = Double.parseDouble(values[1]);
MeasurementAggregator aggr = map.getOrDefault(station, new MeasurementAggregator());
aggr.count += 1;
aggr.sum += val;
aggr.max = (val >= aggr.max) ? val : aggr.max; // Math.max(aggr.max, val);
aggr.min = (val <= aggr.min) ? val : aggr.min; // Math.min(aggr.min, val);
map.put(station, aggr);
}
}
}
private static class TaskScheduler {
ExecutorService executor;
List<String> list = new ArrayList<>(TASK_CHUNK);
TaskScheduler(ExecutorService executor) {
this.executor = executor;
}
void push(String line) {
// System.out.println("adding: " + line);
list.add(line);
if (list.size() >= TASK_CHUNK) {
executor.submit(new TaskExecutor(list));
list = new ArrayList<>(TASK_CHUNK);
}
}
void completeRemaining() {
// System.out.println("Completing remaining: " + list.size());
if (!list.isEmpty()) {
// System.out.println("Scheduling remaining");
executor.submit(new TaskExecutor(list));
}
}
}
public static void main(String[] args) throws IOException, InterruptedException, ExecutionException {
// ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
// ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
ExecutorService executor = Executors.newCachedThreadPool();
TaskScheduler scheduler = new TaskScheduler(executor);
Files.lines(Paths.get(FILE), StandardCharsets.UTF_8).forEach(line -> {
scheduler.push(line);
});
scheduler.completeRemaining();
executor.shutdown();
executor.awaitTermination(600, TimeUnit.SECONDS);
Map<String, ResultRow> sortedResult = new TreeMap<>();
map.forEach(
(key, value) -> sortedResult.put(key, new ResultRow(value.min, value.sum / value.count, value.max)));
System.out.println(sortedResult);
}
}
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