/*******************************************************************************
* Copyright 2009, 2010 Innovation Gate GmbH. All Rights Reserved.
*
* This file is part of the OpenWGA server platform.
*
* OpenWGA is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* In addition, a special exception is granted by the copyright holders
* of OpenWGA called "OpenWGA plugin exception". You should have received
* a copy of this exception along with OpenWGA in file COPYING.
* If not, see <http://www.openwga.com/gpl-plugin-exception>.
*
* OpenWGA 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with OpenWGA in file COPYING.
* If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/
package de.innovationgate.wgpublisher.cache;
import java.io.IOException;
import java.io.Serializable;
import java.io.Writer;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import org.apache.log4j.Logger;
import de.innovationgate.utils.WGUtils;
import de.innovationgate.utils.cache.Cache;
import de.innovationgate.utils.cache.CacheException;
import de.innovationgate.utils.cache.CacheFactory;
import de.innovationgate.webgate.api.WGException;
/**
* A wrapper around a generic cache object to use it as WebTML cache
*/
public class WebTMLCache {
private int _capacity;
public static class CacheEntry implements Serializable {
private String _code;
private Date _date;
public CacheEntry(String code, Date date) {
super();
_code = code;
_date = date;
}
public String getCode() {
return _code;
}
public Date getDate() {
return _date;
}
}
public static class CacheKey {
private String _dbKey;
private String _tagId;
private String _expressionKey;
public CacheKey(String dbKey, String tag, String expressionKey) {
super();
_dbKey = dbKey;
_tagId = tag;
_expressionKey = expressionKey;
}
public CacheKey(String stringKey) {
super();
List<String> elements = WGUtils.deserializeCollection(stringKey, "//");
_dbKey = elements.get(0);
_tagId = elements.get(1);
_expressionKey = elements.get(2);
}
public String getExpressionKey() {
return _expressionKey;
}
public String getTagId() {
return _tagId;
}
public String toString() {
return _dbKey + "//" +_tagId + "//" + _expressionKey;
}
public String getDbKey() {
return _dbKey;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((_dbKey == null) ? 0 : _dbKey.hashCode());
result = prime * result + ((_expressionKey == null) ? 0 : _expressionKey.hashCode());
result = prime * result + ((_tagId == null) ? 0 : _tagId.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
CacheKey other = (CacheKey) obj;
if (_dbKey == null) {
if (other._dbKey != null)
return false;
}
else if (!_dbKey.equals(other._dbKey))
return false;
if (_expressionKey == null) {
if (other._expressionKey != null)
return false;
}
else if (!_expressionKey.equals(other._expressionKey))
return false;
if (_tagId == null) {
if (other._tagId != null)
return false;
}
else if (!_tagId.equals(other._tagId))
return false;
return true;
}
}
private Cache _cache;
private int _cacheIndex;
public void clear() throws CacheException {
init();
}
public void clearForDatabase(String dbKey) throws CacheException {
_cache.flushGroup(dbKey);
}
public void close() throws CacheException {
_cache.destroy();
}
public void dump(Writer out) throws IOException {
out.write("DBKEY;TAGID;CACHEKEY;TIME;SIZE\n");
DateFormat dateFormat = new SimpleDateFormat();
try {
Iterator keys = _cache.getEntryKeys().iterator();
while (keys.hasNext()) {
String keyString = (String) keys.next();
CacheKey key = new CacheKey(keyString);
try {
CacheEntry entry = (CacheEntry) _cache.readEntry(keyString);
out.write(key.getDbKey());
out.write(";");
out.write(key.getTagId());
out.write(";");
out.write(key.getExpressionKey());
out.write(";");
out.write(dateFormat.format(entry.getDate()));
out.write(";");
out.write(String.valueOf(((String) entry.getCode()).length()));
out.write("\n");
}
catch (CacheException e) {
out.write("Exception reading cache entry " + key.toString() + ": " + e.getClass().getName() + " - " + e.getMessage() + "\n");
}
}
}
catch (CacheException e) {
throw new IOException("Cache Exception: " + e.getMessage());
}
}
public String getCache(String dbKey, String tagid, String key, Date dblastmod) throws CacheException {
CacheKey cacheKey = new CacheKey(dbKey, tagid, key);
CacheEntry entry = (CacheEntry) _cache.readEntry(cacheKey.toString());
if (entry == null) {
return null;
}
if (entry.getDate().getTime() < dblastmod.getTime()) {
return null;
}
return (String) entry.getCode();
}
public void removeCache(String dbKey, String tagid, String key) throws CacheException {
CacheKey cacheKey = new CacheKey(dbKey, tagid, key);
_cache.flushEntry(cacheKey.toString());
}
public long getEntriesCount() {
try {
return _cache.getSize();
}
catch (CacheException e) {
return 0;
}
}
public WebTMLCache(int capacity) throws CacheException {
setCapacity(capacity);
init();
}
private synchronized void init() throws CacheException {
Cache oldCache = _cache;
_cache = CacheFactory.createCache("WebTMLCache-" + increaseCacheIndex(), _capacity, null);
if (oldCache != null) {
oldCache.destroy();
}
}
private int increaseCacheIndex() {
_cacheIndex++;
return _cacheIndex;
}
public void putCache(String dbKey, String tagid, String key, String content, Date cacheDate, int latency) throws CacheException {
CacheKey cacheKey = new CacheKey(dbKey, tagid, key);
CacheEntry cacheEntry = new CacheEntry(content, cacheDate);
_cache.writeEntry(cacheKey.toString(), cacheEntry, dbKey, latency);
}
public int getCapacity() {
return _capacity;
}
public void setCapacity(int capacity) {
_capacity = capacity;
}
public Cache getCache() {
return _cache;
}
}