/**
* Copyright 2011 JogAmp Community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are those of the
* authors and should not be interpreted as representing official policies, either expressed
* or implied, of JogAmp Community.
*/
package jogamp.android.launcher;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import android.content.Context;
public class LauncherTempFileCache {
private static final boolean DEBUG = true;
// Lifecycle: For all JVMs, ClassLoader and times.
private static final String tmpSubDir = "jogamp";
private static final String tmpDirPrefix = "file_cache";
// Get the value of the tmproot system property
// Lifecycle: For all JVMs and ClassLoader
/* package */ static final String tmpRootPropName = "jnlp.jogamp.tmp.cache.root";
// Flag indicating that we got a fatal error in the static initializer.
private static boolean staticInitError = false;
private static File tmpBaseDir;
// String representing the name of the temp root directory relative to the
// tmpBaseDir. Its value is "jlnNNNNN", which is the unique filename created
// by File.createTempFile() without the ".tmp" extension.
//
// Lifecycle: For all JVMs and ClassLoader
//
private static String tmpRootPropValue;
private static File tmpRootDir;
// Flag indicating that we got a fatal error in the initializer.
private boolean initError = false;
private File individualTmpDir;
/**
* Documented way to kick off static initialization
* @return true is static initialization was successful
*/
public static synchronized boolean initSingleton(final Context ctx) {
if(null == tmpRootDir && !staticInitError) {
// Create / initialize the temp root directory, starting the Reaper
// thread to reclaim old installations if necessary. If we get an
// exception, set an error code.
try {
initTmpRoot(ctx);
} catch (final Exception ex) {
ex.printStackTrace();
staticInitError = true;
}
}
return !staticInitError;
}
/**
* This method is called by the static initializer to create / initialize
* the temp root directory that will hold the temp directories for this
* instance of the JVM. This is done as follows:
*
* 1. Synchronize on a global lock. Note that for this purpose we will
* use System.out in the absence of a true global lock facility.
* We are careful not to hold this lock too long.
*
* 2. Check for the existence of the "jnlp.applet.launcher.tmproot"
* system property.
*
* a. If set, then some other thread in a different ClassLoader has
* already created the tmprootdir, so we just need to
* use it. The remaining steps are skipped.
* However, we check the existence of the tmpRootDir
* and if non existent, we assume a new launch and continue.
*
* b. If not set, then we are the first thread in this JVM to run,
* and we need to create the the tmprootdir.
*
* 3. Create the tmprootdir, along with the appropriate locks.
* Note that we perform the operations in the following order,
* prior to creating tmprootdir itself, to work around the fact that
* the file creation and file lock steps are not atomic, and we need
* to ensure that a newly-created tmprootdir isn't reaped by a
* concurrently running JVM.
*
* create jlnNNNN.tmp using File.createTempFile()
* lock jlnNNNN.tmp
* create jlnNNNN.lck while holding the lock on the .tmp file
* lock jlnNNNN.lck
*
* Since the Reaper thread will enumerate the list of *.lck files
* before starting, we can guarantee that if there exists a *.lck file
* for an active process, then the corresponding *.tmp file is locked
* by that active process. This guarantee lets us avoid reaping an
* active process' files.
*
* 4. Set the "jnlp.applet.launcher.tmproot" system property.
*
* 5. Add a shutdown hook to cleanup jlnNNNN.lck and jlnNNNN.tmp. We
* don't actually expect that this shutdown hook will ever be called,
* but the act of doing this, ensures that the locks never get
* garbage-collected, which is necessary for correct behavior when
* the first ClassLoader is later unloaded, while subsequent Applets
* are still running.
*
* 6. Start the Reaper thread to cleanup old installations.
*/
private static void initTmpRoot(final Context ctx) throws IOException {
if (DEBUG) {
System.err.println("TempFileCache: Static Initialization ----------------------------------------------");
System.err.println("TempFileCache: Thread: "+Thread.currentThread().getName()+", CL 0x"+Integer.toHexString(LauncherTempFileCache.class.getClassLoader().hashCode()));
}
synchronized (System.out) {
// Get the name of the tmpbase directory.
{
final File tmpRoot = ctx.getDir("temp", Context.MODE_WORLD_READABLE);
tmpBaseDir = new File(new File(tmpRoot, tmpSubDir), tmpDirPrefix);
}
tmpRootPropValue = System.getProperty(tmpRootPropName);
if (tmpRootPropValue != null) {
// Make sure that the property is not set to an illegal value
if (tmpRootPropValue.indexOf('/') >= 0 ||
tmpRootPropValue.indexOf(File.separatorChar) >= 0) {
throw new IOException("Illegal value of: " + tmpRootPropName);
}
// Set tmpRootDir = ${tmpbase}/${jnlp.applet.launcher.tmproot}
if (DEBUG) {
System.err.println("TempFileCache: Trying existing value of: " +
tmpRootPropName + "=" + tmpRootPropValue);
}
tmpRootDir = new File(tmpBaseDir, tmpRootPropValue);
if (DEBUG) {
System.err.println("TempFileCache: Trying tmpRootDir = " + tmpRootDir.getAbsolutePath());
}
if (tmpRootDir.isDirectory()) {
if (!tmpRootDir.canWrite()) {
throw new IOException("Temp root directory is not writable: " + tmpRootDir.getAbsolutePath());
}
} else {
// It is possible to move to a new GlueGen version within the same JVM
// In case tmpBaseDir has changed, we should assume a new tmpRootDir.
System.err.println("TempFileCache: None existing tmpRootDir = " + tmpRootDir.getAbsolutePath()+", assuming new path due to update");
tmpRootPropValue = null;
tmpRootDir = null;
System.clearProperty(tmpRootPropName);
}
}
if (tmpRootPropValue == null) {
// Create the tmpbase directory if it doesn't already exist
tmpBaseDir.mkdirs();
if (!tmpBaseDir.isDirectory()) {
throw new IOException("Cannot create directory " + tmpBaseDir);
}
// Create ${tmpbase}/jlnNNNN.tmp then lock the file
final File tmpFile = File.createTempFile("jln", ".tmp", tmpBaseDir);
if (DEBUG) {
System.err.println("TempFileCache: tmpFile = " + tmpFile.getAbsolutePath());
}
final FileOutputStream tmpOut = new FileOutputStream(tmpFile);
final FileChannel tmpChannel = tmpOut.getChannel();
final FileLock tmpLock = tmpChannel.lock();
// Strip off the ".tmp" to get the name of the tmprootdir
final String tmpFileName = tmpFile.getAbsolutePath();
final String tmpRootName = tmpFileName.substring(0, tmpFileName.lastIndexOf(".tmp"));
// create ${tmpbase}/jlnNNNN.lck then lock the file
final String lckFileName = tmpRootName + ".lck";
final File lckFile = new File(lckFileName);
if (DEBUG) {
System.err.println("TempFileCache: lckFile = " + lckFile.getAbsolutePath());
}
lckFile.createNewFile();
final FileOutputStream lckOut = new FileOutputStream(lckFile);
final FileChannel lckChannel = lckOut.getChannel();
final FileLock lckLock = lckChannel.lock();
// Create tmprootdir
tmpRootDir = new File(tmpRootName);
if (DEBUG) {
System.err.println("TempFileCache: tmpRootDir = " + tmpRootDir.getAbsolutePath());
}
if (!tmpRootDir.mkdir()) {
throw new IOException("Cannot create " + tmpRootDir);
}
// Add shutdown hook to cleanup the OutputStream, FileChannel,
// and FileLock for the jlnNNNN.lck and jlnNNNN.lck files.
// We do this so that the locks never get garbage-collected.
Runtime.getRuntime().addShutdownHook(new Thread() {
/* @Override */
public void run() {
// NOTE: we don't really expect that this code will ever
// be called. If it does, we will close the output
// stream, which will in turn close the channel.
// We will then release the lock.
try {
tmpOut.close();
tmpLock.release();
lckOut.close();
lckLock.release();
} catch (final IOException ex) {
// Do nothing
}
}
});
// Set the system property...
tmpRootPropValue = tmpRootName.substring(tmpRootName.lastIndexOf(File.separator) + 1);
System.setProperty(tmpRootPropName, tmpRootPropValue);
if (DEBUG) {
System.err.println("TempFileCache: Setting " + tmpRootPropName + "=" + tmpRootPropValue);
}
// Start a new Reaper thread to do stuff...
final Thread reaperThread = new Thread() {
/* @Override */
public void run() {
deleteOldTempDirs();
}
};
reaperThread.setName("TempFileCache-Reaper");
reaperThread.start();
}
}
if (DEBUG) {
System.err.println("------------------------------------------------------------------ (static ok: "+(!staticInitError)+")");
}
}
/**
* Called by the Reaper thread to delete old temp directories
* Only one of these threads will run per JVM invocation.
*/
private static void deleteOldTempDirs() {
if (DEBUG) {
System.err.println("TempFileCache: *** Reaper: deleteOldTempDirs in " +
tmpBaseDir.getAbsolutePath());
}
// enumerate list of jnl*.lck files, ignore our own jlnNNNN file
final String ourLockFile = tmpRootPropValue + ".lck";
final FilenameFilter lckFilter = new FilenameFilter() {
/* @Override */
public boolean accept(final File dir, final String name) {
return name.endsWith(".lck") && !name.equals(ourLockFile);
}
};
// For each file <file>.lck in the list we will first try to lock
// <file>.tmp if that succeeds then we will try to lock <file>.lck
// (which should always succeed unless there is a problem). If we can
// get the lock on both files, then it must be an old installation, and
// we will delete it.
final String[] fileNames = tmpBaseDir.list(lckFilter);
if (fileNames != null) {
for (int i = 0; i < fileNames.length; i++) {
final String lckFileName = fileNames[i];
final String tmpDirName = lckFileName.substring(0, lckFileName.lastIndexOf(".lck"));
final String tmpFileName = tmpDirName + ".tmp";
final File lckFile = new File(tmpBaseDir, lckFileName);
final File tmpFile = new File(tmpBaseDir, tmpFileName);
final File tmpDir = new File(tmpBaseDir, tmpDirName);
if (lckFile.exists() && tmpFile.exists() && tmpDir.isDirectory()) {
FileOutputStream tmpOut = null;
FileChannel tmpChannel = null;
FileLock tmpLock = null;
try {
tmpOut = new FileOutputStream(tmpFile);
tmpChannel = tmpOut.getChannel();
tmpLock = tmpChannel.tryLock();
} catch (final Exception ex) {
// Ignore exceptions
if (DEBUG) {
ex.printStackTrace();
}
}
if (tmpLock != null) {
FileOutputStream lckOut = null;
FileChannel lckChannel = null;
FileLock lckLock = null;
try {
lckOut = new FileOutputStream(lckFile);
lckChannel = lckOut.getChannel();
lckLock = lckChannel.tryLock();
} catch (final Exception ex) {
if (DEBUG) {
ex.printStackTrace();
}
}
if (lckLock != null) {
// Recursively remove the old tmpDir and all of
// its contents
removeAll(tmpDir);
// Close the streams and delete the .lck and .tmp
// files. Note that there is a slight race condition
// in that another process could open a stream at
// the same time we are trying to delete it, which will
// prevent deletion, but we won't worry about it, since
// the worst that will happen is we might have an
// occasional 0-byte .lck or .tmp file left around
try {
lckOut.close();
} catch (final IOException ex) {
}
lckFile.delete();
try {
tmpOut.close();
} catch (final IOException ex) {
}
tmpFile.delete();
} else {
try {
// Close the file and channel for the *.lck file
if (lckOut != null) {
lckOut.close();
}
// Close the file/channel and release the lock
// on the *.tmp file
tmpOut.close();
tmpLock.release();
} catch (final IOException ex) {
if (DEBUG) {
ex.printStackTrace();
}
}
}
}
} else {
if (DEBUG) {
System.err.println("TempFileCache: Skipping: " + tmpDir.getAbsolutePath());
}
}
}
}
}
/**
* Remove the specified file or directory. If "path" is a directory, then
* recursively remove all entries, then remove the directory itself.
*/
private static void removeAll(final File path) {
if (DEBUG) {
System.err.println("TempFileCache: removeAll(" + path + ")");
}
if (path.isDirectory()) {
// Recursively remove all files/directories in this directory
final File[] list = path.listFiles();
if (list != null) {
for (int i = 0; i < list.length; i++) {
removeAll(list[i]);
}
}
}
path.delete();
}
public LauncherTempFileCache () {
if (DEBUG) {
System.err.println("TempFileCache: new TempFileCache() --------------------- (static ok: "+(!staticInitError)+")");
System.err.println("TempFileCache: Thread: "+Thread.currentThread().getName()+", CL 0x"+Integer.toHexString(LauncherTempFileCache.class.getClassLoader().hashCode())+", this 0x"+Integer.toHexString(hashCode()));
}
if(!staticInitError) {
try {
createTmpDir();
} catch (final Exception ex) {
ex.printStackTrace();
initError = true;
}
}
if (DEBUG) {
System.err.println("tempDir: "+individualTmpDir+" (ok: "+(!initError)+")");
System.err.println("----------------------------------------------------------");
}
}
/**
* @return true is static and object initialization was successful
*/
public boolean isValid() { return !staticInitError && !initError; }
/**
* Base temp directory used by TempFileCache.
* Lifecycle: For all JVMs, ClassLoader and times.
*
* This is set to:
*
* ${java.io.tmpdir}/<tmpDirPrefix>
*
*
* @return
*/
public File getBaseDir() { return tmpBaseDir; }
/**
* Root temp directory for this JVM instance. Used to store individual
* directories.
*
* Lifecycle: For all JVMs and ClassLoader
*
* <tmpBaseDir>/<tmpRootPropValue>
*
* Use Case: Per ClassLoader files, eg. native libraries.
*
* Old temp directories are cleaned up the next time a JVM is launched that
* uses TempFileCache.
*
*
* @return
*/
public File getRootDir() { return tmpRootDir; }
/**
* Temporary directory for individual files (eg. native libraries of one ClassLoader instance).
* The directory name is:
*
* Lifecycle: Within each JVM .. use case dependent, ie. per ClassLoader
*
* <tmpRootDir>/jlnMMMMM
*
* where jlnMMMMM is the unique filename created by File.createTempFile()
* without the ".tmp" extension.
*
*
* @return
*/
public File getTempDir() { return individualTmpDir; }
/**
* Create the temp directory in tmpRootDir. To do this, we create a temp
* file with a ".tmp" extension, and then create a directory of the
* same name but without the ".tmp". The temp file, directory, and all
* files in the directory will be reaped the next time this is started.
* We avoid deleteOnExit, because it doesn't work reliably.
*/
private void createTmpDir() throws IOException {
final File tmpFile = File.createTempFile("jln", ".tmp", tmpRootDir);
final String tmpFileName = tmpFile.getAbsolutePath();
final String tmpDirName = tmpFileName.substring(0, tmpFileName.lastIndexOf(".tmp"));
individualTmpDir = new File(tmpDirName);
if (!individualTmpDir.mkdir()) {
throw new IOException("Cannot create " + individualTmpDir);
}
}
}