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* Copyright (c) 2008, 2016, 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. Oracle designates this
* particular file as subject to the Classpath exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* 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.
*
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package com.sun.btrace.agent;
import com.sun.btrace.DebugSupport;
import com.sun.btrace.SharedSettings;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* This class represents various strategies available for dumping BTrace
* output to a file.
*
* @author Jaroslav Bachorik
*/
abstract class TraceOutputWriter extends Writer {
final protected DebugSupport debug;
protected TraceOutputWriter(SharedSettings settings) {
debug = new DebugSupport(settings);
}
static private class SimpleFileOutput extends TraceOutputWriter {
final private FileWriter delegate;
@SuppressWarnings("DefaultCharset")
public SimpleFileOutput(File output, SharedSettings settings) throws IOException {
super(settings);
try {
File parent = output.getParentFile();
if (parent != null) {
output.getParentFile().mkdirs();
}
delegate = new FileWriter(output);
} catch (IOException e) {
debug.debug(e);
throw e;
}
}
@Override
public void close() throws IOException {
delegate.close();
}
@Override
public void flush() throws IOException {
delegate.flush();
}
@Override
public void write(char[] cbuf, int off, int len) throws IOException {
delegate.write(cbuf, off, len);
}
}
@SuppressWarnings("DefaultCharset")
static abstract private class RollingFileWriter extends TraceOutputWriter {
final private ReentrantReadWriteLock writerLock = new ReentrantReadWriteLock();
// @GuardedBy writerLock
private FileWriter currentFileWriter;
private final String path, baseName;
private int counter = 1;
protected final SharedSettings settings;
public RollingFileWriter(File output, SharedSettings settings) throws IOException {
super(settings);
try {
output.getParentFile().mkdirs();
currentFileWriter = new FileWriter(output);
path = output.getParentFile().getAbsolutePath();
baseName = output.getName();
this.settings = settings;
} catch (IOException e) {
debug.debug(e);
throw e;
}
}
@Override
final public void close() throws IOException {
try {
writerLock.readLock().lock();
currentFileWriter.close();
} finally {
writerLock.readLock().unlock();
}
}
@Override
final public void flush() throws IOException {
try {
writerLock.readLock().lock();
currentFileWriter.flush();
} finally {
writerLock.readLock().unlock();
}
if (needsRoll()) {
nextWriter();
}
}
@Override
final public void write(char[] cbuf, int off, int len) throws IOException {
try {
writerLock.readLock().lock();
currentFileWriter.write(cbuf, off, len);
} finally {
writerLock.readLock().unlock();
}
}
private void nextWriter() {
try {
writerLock.writeLock().lock();
currentFileWriter = getNextWriter();
} catch (IOException e) {
debug.debug(e);
} finally {
writerLock.writeLock().unlock();
}
}
private FileWriter getNextWriter() throws IOException {
currentFileWriter.close();
File scriptOutputFile_renameFrom = new File(path + File.separator + baseName);
File scriptOutputFile_renameTo = new File(path + File.separator + baseName + "." + (counter++));
if (scriptOutputFile_renameTo.exists()) {
scriptOutputFile_renameTo.delete();
}
scriptOutputFile_renameFrom.renameTo(scriptOutputFile_renameTo);
scriptOutputFile_renameFrom = new File(path + File.separator + baseName);
if (counter > settings.getFileRollMaxRolls()) {
counter = 1;
}
return new FileWriter(scriptOutputFile_renameFrom);
}
abstract protected boolean needsRoll();
}
static private class TimeBasedRollingFileWriter extends RollingFileWriter {
private long lastTimeStamp = System.currentTimeMillis();
private final TimeUnit unit = TimeUnit.MILLISECONDS;
public TimeBasedRollingFileWriter(File output, SharedSettings settings) throws IOException {
super(output, settings);
}
@Override
protected boolean needsRoll() {
long currTime = System.currentTimeMillis();
long myInterval = currTime - lastTimeStamp;
if (unit.convert(myInterval, TimeUnit.MILLISECONDS) >= settings.getFileRollMilliseconds()) {
lastTimeStamp = currTime;
return true;
}
return false;
}
}
/**
* Plain file writer - all output will go to one specified file
* @param output The file to put the output to
* @param settings The settings storage
* @return Returns an appropriate {@linkplain TraceOutputWriter} instance or NULL
*/
public static TraceOutputWriter fileWriter(File output, SharedSettings settings) {
TraceOutputWriter instance = null;
try {
instance = new SimpleFileOutput(output, settings);
} catch (IOException e) {
// ignore
}
return instance;
}
/**
* Time based rolling file writer. Defaults to 100 allowed output chunks.
* @param output The file to put the output to
* @param settings The shared settings
* @return Returns an appropriate {@linkplain TraceOutputWriter} instance or NULL
*/
public static TraceOutputWriter rollingFileWriter(File output, SharedSettings settings) {
TraceOutputWriter instance = null;
try {
instance = new TimeBasedRollingFileWriter(output, settings);
} catch (IOException e) {
// ignore
}
return instance;
}
private static void ensurePathExists(File f) {
if (f == null || f.exists()) return;
ensurePathExists(f.getParentFile());
if (!f.getName().endsWith(".btrace")) { // not creating the actual file
try {
f.createNewFile();
} catch (IOException e) {
e.printStackTrace();
// ignore and continue
}
}
}
}