/*
* Copyright 2015 Ben Manes. All Rights Reserved.
*
* 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 com.github.benmanes.caffeine.cache.simulator.report;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.TimeUnit;
import com.github.benmanes.caffeine.cache.simulator.BasicSettings;
import com.github.benmanes.caffeine.cache.simulator.policy.PolicyStats;
import com.google.common.io.Files;
import com.typesafe.config.Config;
/**
* A skeletal plain text implementation applicable for printing to the console or a file.
*
* @author ben.manes@gmail.com (Ben Manes)
*/
public abstract class TextReporter implements Reporter {
private static final String[] HEADERS = {
"Policy", "Hit rate", "Hits", "Misses", "Requests",
"Evictions", "Admit rate", "Steps", "Time"};
private final List<PolicyStats> results;
private final BasicSettings settings;
public TextReporter(Config config) {
settings = new BasicSettings(config);
results = new ArrayList<>();
}
/** Returns the column headers. */
protected String[] headers() {
return HEADERS.clone();
}
/** Adds the result of a policy simulation. */
@Override
public void add(PolicyStats policyStats) {
results.add(policyStats);
}
/** Writes the report to the output destination. */
@Override
public void print() throws IOException {
results.sort(comparator());
String report = assemble(results);
String output = settings.report().output();
if (output.equalsIgnoreCase("console")) {
System.out.println(report);
} else {
File file = Paths.get(output).toFile();
Files.write(report, file, StandardCharsets.UTF_8);
}
}
/** Assembles an aggregated report. */
protected abstract String assemble(List<PolicyStats> results);
/** Returns a comparator that sorts by the specified column. */
private Comparator<PolicyStats> comparator() {
Comparator<PolicyStats> comparator = makeComparator();
return settings.report().ascending() ? comparator : comparator.reversed();
}
private Comparator<PolicyStats> makeComparator() {
switch (settings.report().sortBy().toLowerCase()) {
case "policy":
return Comparator.comparing(PolicyStats::name);
case "hit rate":
return Comparator.comparingDouble(PolicyStats::hitRate);
case "hits":
return Comparator.comparingLong(PolicyStats::hitCount);
case "misses":
return Comparator.comparingLong(PolicyStats::missCount);
case "evictions":
return Comparator.comparingLong(PolicyStats::evictionCount);
case "admit rate":
return Comparator.comparingLong(PolicyStats::admissionCount);
case "steps":
return Comparator.comparingLong(PolicyStats::operationCount);
case "time":
return Comparator.comparingLong(stats -> stats.stopwatch().elapsed(TimeUnit.NANOSECONDS));
default:
throw new IllegalArgumentException("Unknown sort order: " + settings.report().sortBy());
}
}
}