/*
* ModeShape (http://www.modeshape.org)
*
* 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 org.modeshape.jcr.value.binary;
import java.io.File;
import org.modeshape.common.SystemFailureException;
import org.modeshape.common.annotation.ThreadSafe;
import org.modeshape.common.util.FileUtil;
import org.modeshape.jcr.JcrI18n;
import org.modeshape.jcr.value.BinaryKey;
/**
* A {@link BinaryStore} implementation that does not persist the binary values beyond the lifetime of the virtual machine. This
* implementation extends {@link FileSystemBinaryStore} and uses a temporary directory. Thus, the binary values are not stored
* in-memory.
*/
@ThreadSafe
public final class TransientBinaryStore extends FileSystemBinaryStore {
private static final String JAVA_IO_TMPDIR = "java.io.tmpdir";
private static final String JBOSS_SERVER_TMPDIR = "jboss.server.temp.dir";
private static final TransientBinaryStore INSTANCE = new TransientBinaryStore();
protected static final File TRANSIENT_STORE_DIRECTORY = INSTANCE.getDirectory();
/**
* Obtain a shared {@link TransientBinaryStore} instance.
*
* @return the instance; never null
*/
public static TransientBinaryStore get() {
return INSTANCE;
}
/**
* Obtain a new temporary directory that can be used by a transient binary store. Note that none of the directories are
* actually created at this time, but are instead created (if needed) during {@link #initializeStorage(File)}.
*
* @return the new directory; never null
*/
private static File newTempDirectory() {
String tempDirName = System.getProperty(JBOSS_SERVER_TMPDIR);
if (tempDirName == null) {
tempDirName = System.getProperty(JAVA_IO_TMPDIR);
}
if (tempDirName == null) {
throw new SystemFailureException(JcrI18n.tempDirectorySystemPropertyMustBeSet.text(JAVA_IO_TMPDIR));
}
File tempDir = new File(tempDirName);
// Create a temporary directory in the "java.io.tmpdir" directory ...
return new File(tempDir, "modeshape-binary-store");
}
/**
* Create a new transient binary store.
*/
private TransientBinaryStore() {
super(newTempDirectory());
}
@Override
public void start() {
logger.debug("ModeShape repositories will use the following directory for transient storage of binary values unless repository configurations specify otherwise: {0}",
getDirectory().getAbsolutePath());
// request the folder be deleted on VM exit; this may or may not work, which is why we also try to clear it on initialize
getDirectory().deleteOnExit();
}
/**
* Ensures that the directory used by this binary store exists and can be both read and written to.
*
* @throws BinaryStoreException if the directory cannot be written to, read, or (if needed) created
*/
@Override
protected void initializeStorage( File directory ) throws BinaryStoreException {
// make sure the directory doesn't exist
FileUtil.delete(directory);
if (!directory.exists()) {
logger.debug("Creating temporary directory for transient binary store: {0}", directory.getAbsolutePath());
directory.mkdirs();
}
if (!directory.canRead()) {
throw new BinaryStoreException(JcrI18n.unableToReadTemporaryDirectory.text(directory.getAbsolutePath(),
JAVA_IO_TMPDIR));
}
if (!directory.canWrite()) {
throw new BinaryStoreException(JcrI18n.unableToWriteTemporaryDirectory.text(directory.getAbsolutePath(),
JAVA_IO_TMPDIR));
}
}
@Override
protected void moveFileExclusively( File original, File destination, BinaryKey key ) throws BinaryStoreException {
super.moveFileExclusively(original, destination, key);
// on certain OSes there is no guarantee that the files from java.io.tmpdir are cleaned up, so we need to make sure of that here
destination.deleteOnExit();
}
}