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/*
* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 4823133
* @summary optimize RandomAccessFile.length() and length() is thread safe now.
*/
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
/**
*
* @author vyom.tewari@oracle.com
*/
public class FileLengthTest {
private static final int BUF_SIZE = 4096;
private static RandomAccessFile randomAccessFile;
private static Thread fileLengthCaller;
private static Thread fileContentReader;
private static StringBuilder fileContents;
private static volatile boolean isFailed = false;
/**
* this thread will call length() in loop
*/
private static void startLengthThread() {
if (randomAccessFile == null) {
return;
}
fileLengthCaller = new Thread(() -> {
while (true) {
try {
long length = randomAccessFile.length();
if (length < 0) {
return;
}
} catch (IOException ex) {
return;
}
}
});
fileLengthCaller.setName("RandomAccessFile-length-caller");
fileLengthCaller.setDaemon(true);
fileLengthCaller.start();
}
/**
* this thread will call read() and store the content in internal buffer.
*/
private static void startReaderThread() {
if (randomAccessFile == null) {
return;
}
fileContentReader = new Thread(() -> {
StringBuilder sb = new StringBuilder(BUF_SIZE);
int i;
byte arr[] = new byte[8];
try {
while ((i = randomAccessFile.read(arr)) != -1) {
sb.append(new String(arr, 0, i));
}
if (!sb.toString().equals(fileContents.toString())) {
isFailed = true;
}
} catch (IOException ex) {
}
});
fileContentReader.setName("RandomAccessFile-content-reader");
fileContentReader.setDaemon(true);
fileContentReader.start();
}
public static void main(String args[]) {
byte arr[] = new byte[BUF_SIZE];
String testFile = "testfile.txt";
try {
createDummyFile(testFile);
File file = new File(testFile);
file.deleteOnExit();
randomAccessFile = new RandomAccessFile(file, "r");
int count = randomAccessFile.read(arr);
randomAccessFile.seek(0);
fileContents = new StringBuilder(BUF_SIZE);
fileContents.append(new String(arr, 0, count));
startLengthThread();
startReaderThread();
fileContentReader.join();
} catch (FileNotFoundException | InterruptedException ex) {
} catch (IOException ex) {
} finally {
try {
randomAccessFile.close();
} catch (IOException ex) {
}
}
if (isFailed) {
throw new RuntimeException("RandomAccessFile.length() changed the underlying file pointer.");
}
}
private static void createDummyFile(String fileName) throws FileNotFoundException, IOException {
try (FileOutputStream outputStream = new FileOutputStream(new File(fileName))) {
String str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
int count = 0;
while ((count + str.length()) < BUF_SIZE) {
outputStream.write(str.getBytes());
count += str.length();
}
outputStream.flush();
}
}
}
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