/*
* Copyright 2016 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.parser;
import static com.google.common.base.Preconditions.checkArgument;
import static java.util.Objects.requireNonNull;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.commons.compress.archivers.ArchiveException;
import org.apache.commons.compress.archivers.ArchiveStreamFactory;
import org.apache.commons.compress.compressors.CompressorException;
import org.apache.commons.compress.compressors.CompressorStreamFactory;
import org.tukaani.xz.XZInputStream;
/**
* A skeletal implementation that reads the trace files into a data stream.
*
* @author ben.manes@gmail.com (Ben Manes)
*/
public abstract class AbstractTraceReader implements TraceReader {
private static final int BUFFER_SIZE = 1 << 16;
protected final List<String> filePaths;
public AbstractTraceReader(List<String> filePaths) {
this.filePaths = requireNonNull(filePaths);
}
/** Returns the input stream of the trace data. */
protected InputStream readFiles() throws IOException {
List<InputStream> inputs = new ArrayList<>(filePaths.size());
for (String filePath : filePaths) {
inputs.add(readFile(filePath));
}
return new SequenceInputStream(Collections.enumeration(inputs));
}
/** Returns the input stream, decompressing if required. */
private InputStream readFile(String filePath) throws IOException {
BufferedInputStream input = new BufferedInputStream(openFile(filePath), BUFFER_SIZE);
input.mark(100);
try {
return new XZInputStream(input);
} catch (IOException e) {
input.reset();
}
try {
return new CompressorStreamFactory().createCompressorInputStream(input);
} catch (CompressorException e) {
input.reset();
}
try {
return new ArchiveStreamFactory().createArchiveInputStream(input);
} catch (ArchiveException e) {
input.reset();
}
return input;
}
/** Returns the input stream for the raw file. */
private InputStream openFile(String filePath) throws IOException {
File file = new File(filePath);
if (file.exists()) {
return new FileInputStream(file);
}
InputStream input = getClass().getResourceAsStream(filePath);
checkArgument(input != null, "Could not find file: " + filePath);
return input;
}
}