/**
* Copyright 2011 Florian Schmaus
*
* 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.jivesoftware.smackx.entitycaps.cache;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.provider.IQProvider;
import org.jivesoftware.smack.util.Base32Encoder;
import org.jivesoftware.smack.util.Base64Encoder;
import org.jivesoftware.smack.util.StringEncoder;
import org.jivesoftware.smackx.entitycaps.EntityCapsManager;
import org.jivesoftware.smackx.packet.DiscoverInfo;
import org.jivesoftware.smackx.provider.DiscoverInfoProvider;
import org.xmlpull.mxp1.MXParser;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
/**
* Simple implementation of an EntityCapsPersistentCache that uses a directory
* to store the Caps information for every known node. Every node is represented
* by an file.
*
* @author Florian Schmaus
*
*/
public class SimpleDirectoryPersistentCache implements EntityCapsPersistentCache {
private File cacheDir;
private StringEncoder filenameEncoder;
/**
* Creates a new SimpleDirectoryPersistentCache Object. Make sure that the
* cacheDir exists and that it's an directory.
* <p>
* Default filename encoder {@link Base32Encoder}, as this will work on all
* filesystems, both case sensitive and case insensitive. It does however
* produce longer filenames.
*
* @param cacheDir
*/
public SimpleDirectoryPersistentCache(File cacheDir) {
this(cacheDir, Base32Encoder.getInstance());
}
/**
* Creates a new SimpleDirectoryPersistentCache Object. Make sure that the
* cacheDir exists and that it's an directory.
*
* If your cacheDir is case insensitive then make sure to set the
* StringEncoder to {@link Base32Encoder} (which is the default).
*
* @param cacheDir The directory where the cache will be stored.
* @param filenameEncoder Encodes the node string into a filename.
*/
public SimpleDirectoryPersistentCache(File cacheDir, StringEncoder filenameEncoder) {
if (!cacheDir.exists())
throw new IllegalStateException("Cache directory \"" + cacheDir + "\" does not exist");
if (!cacheDir.isDirectory())
throw new IllegalStateException("Cache directory \"" + cacheDir + "\" is not a directory");
this.cacheDir = cacheDir;
this.filenameEncoder = filenameEncoder;
}
@Override
public void addDiscoverInfoByNodePersistent(String node, DiscoverInfo info) {
String filename = filenameEncoder.encode(node);
File nodeFile = new File(cacheDir, filename);
try {
if (nodeFile.createNewFile())
writeInfoToFile(nodeFile, info);
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void replay() throws IOException {
File[] files = cacheDir.listFiles();
for (File f : files) {
String node = filenameEncoder.decode(f.getName());
DiscoverInfo info = restoreInfoFromFile(f);
if (info == null)
continue;
EntityCapsManager.addDiscoverInfoByNode(node, info);
}
}
public void emptyCache() {
File[] files = cacheDir.listFiles();
for (File f : files) {
f.delete();
}
}
/**
* Writes the DiscoverInfo packet to an file
*
* @param file
* @param info
* @throws IOException
*/
private static void writeInfoToFile(File file, DiscoverInfo info) throws IOException {
DataOutputStream dos = new DataOutputStream(new FileOutputStream(file));
try {
dos.writeUTF(info.toXML());
} finally {
dos.close();
}
}
/**
* Tries to restore an DiscoverInfo packet from a file.
*
* @param file
* @return
* @throws IOException
*/
private static DiscoverInfo restoreInfoFromFile(File file) throws IOException {
DataInputStream dis = new DataInputStream(new FileInputStream(file));
String fileContent = null;
String id;
String from;
String to;
try {
fileContent = dis.readUTF();
} finally {
dis.close();
}
if (fileContent == null)
return null;
Reader reader = new StringReader(fileContent);
XmlPullParser parser;
try {
parser = new MXParser();
parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, true);
parser.setInput(reader);
} catch (XmlPullParserException xppe) {
xppe.printStackTrace();
return null;
}
DiscoverInfo iqPacket;
IQProvider provider = new DiscoverInfoProvider();
// Parse the IQ, we only need the id
try {
parser.next();
id = parser.getAttributeValue("", "id");
from = parser.getAttributeValue("", "from");
to = parser.getAttributeValue("", "to");
parser.next();
} catch (XmlPullParserException e1) {
return null;
}
try {
iqPacket = (DiscoverInfo) provider.parseIQ(parser);
} catch (Exception e) {
return null;
}
iqPacket.setPacketID(id);
iqPacket.setFrom(from);
iqPacket.setTo(to);
iqPacket.setType(IQ.Type.RESULT);
return iqPacket;
}
}