2 * Copyright (C) 2001, 2002 The Mir-coders group
4 * This file is part of Mir.
6 * Mir is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * Mir is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with Mir; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 * In addition, as a special exception, The Mir-coders gives permission to link
21 * the code of this program with the com.oreilly.servlet library, any library
22 * licensed under the Apache Software License, The Sun (tm) Java Advanced
23 * Imaging library (JAI), The Sun JIMI library (or with modified versions of
24 * the above that use the same license as the above), and distribute linked
25 * combinations including the two. You must obey the GNU General Public
26 * License in all respects for all of the code used other than the above
27 * mentioned libraries. If you modify this file, you may extend this exception
28 * to your version of the file, but you are not obligated to do so. If you do
29 * not wish to do so, delete this exception statement from your version.
32 package mir.storage.store;
35 * Title: ObjectStore for StorableObjects
36 * Description: ObjectStore holds a Map of @see StoreContainer for all possible
37 * @see StoreIdentifier.
39 * @see StorageIdentifier - identitfies one object in the ObjectStore
40 * i.e. in its apropriate bucket. It holds a unique identifier
41 * of a StorableObject and a reference on the StorableObject.
43 * @see StoreContainer - "Buckets" to store different types of Objects
44 * in one Container. These buckets are cofigurable via
47 * @see StoreContainerType - is a signature for all StoreContainer
48 * and StoreIdentifier.
50 * @see StorableObjects - Interface Object have to implement to
51 * be handled by the ObjectStore
53 * @see ServletStoreInfo - Maintenance Servlet for ObjectStore.
54 * Displays information about current content of the
58 * Copyright: Copyright (c) 2002
64 import java.io.BufferedInputStream;
65 import java.io.FileInputStream;
66 import java.util.HashMap;
67 import java.util.Iterator;
69 import java.util.MissingResourceException;
70 import java.util.Properties;
72 import javax.servlet.http.HttpServletRequest;
74 import mir.config.MirPropertiesConfiguration;
75 import mir.log.LoggerWrapper;
77 public class ObjectStore {
79 private final static ObjectStore INSTANCE = new ObjectStore();
80 private final static Map containerMap = new HashMap(); // StoreContainerType/StoreContainer
81 private static long storeHit = 0, storeMiss = 0;
82 private Properties ostoreConf;
83 private LoggerWrapper logger;
85 private ObjectStore() {
86 String confName = null;
88 logger = new LoggerWrapper("Database.ObjectStore");
89 Properties conf = new Properties();
93 MirPropertiesConfiguration.instance().getString("Home") +
94 "etc/objectstore.properties";
95 conf.load(new BufferedInputStream(new FileInputStream(confName)));
97 catch (java.io.FileNotFoundException fnfe) {
98 logger.error("could not read config file. not found: " + confName);
100 catch (Throwable t) {
101 logger.error("could not get config: " + t.getMessage());
106 public static ObjectStore getInstance() {
112 * Description: The ObjectStore tries to find the @see StoreIdentifier sid
113 * and returns the stored Object.
115 * @return StorableObject is null when no StorableObject for the
116 * StoreIdentifier sid is found.
118 public StorableObject use(StoreIdentifier sid) {
120 StorableObject storeObject = null;
121 StoreContainer stoc = getStoreContainerForSid(sid);
123 storeObject = stoc.use(sid);
125 logger.warn("container not found for: " + sid.toString());
126 if (storeObject != null) {
138 * Description: A StoreIdentifier is added to the ObjectStore, if it
139 * contains a reference to a @see StorableObject.
141 public void add(StoreIdentifier sid) {
142 if (sid != null && sid.hasReference()) {
143 // find the right StoreContainer for sid
144 StoreContainer stoc = getStoreContainerForSid(sid);
146 // we have to make new StoreContainer
147 StoreContainerType stocType = sid.getStoreContainerType();
148 stoc = new StoreContainer(stocType);
149 containerMap.put(stocType, stoc);
156 * Method: invalidate(StorableObject sto)
157 * Description: ObjectStore is notified of change of a @see StorableObject
158 * sto and invalidates all relevant cache entries.
161 public void invalidate(StoreIdentifier sid) {
162 // propagate invalidation to StoreContainer
164 StoreContainer stoc = getStoreContainerForSid(sid);
165 stoc.invalidate(sid);
170 * Method: invalidate(StoreContainerType)
171 * Description: serves to invalidate a whole StoreContainer
175 public void invalidate(StoreContainerType stoc_type) {
176 if (stoc_type != null) {
177 /** @todo invalidates too much:
178 * improvement: if instanceof StoreContainerEntity && EntityList
179 * then invalidate only StoreIdentifier matching the right table
181 StoreContainer stoc = getStoreContainerForStocType(stoc_type);
188 // internal methods for StoreContainer managment
191 * Method: getStoreContainerForSid
192 * Description: private method to find the right @see StoreContainer for
193 * the @see StoreIdentifier sid.
195 * @return StoreContainer is null when no Container is found.
197 private StoreContainer getStoreContainerForSid(StoreIdentifier sid) {
198 // find apropriate container for a specific sid
200 StoreContainerType stoc_type = sid.getStoreContainerType();
201 return getStoreContainerForStocType(stoc_type);
206 private StoreContainer getStoreContainerForStocType(StoreContainerType
208 if (stoc_type != null && containerMap.containsKey(stoc_type))
209 return (StoreContainer) containerMap.get(stoc_type);
213 private boolean has(StoreIdentifier sid) {
214 StoreContainer stoc = getStoreContainerForSid(sid);
215 return (stoc != null && stoc.has(sid)) ? true : false;
218 public String getConfProperty(String name) {
220 String returnValue = "";
222 return ostoreConf.getProperty(name);
224 catch (MissingResourceException e) {
225 logger.error("getConfProperty: " + e.toString());
233 * Description: Displays statistical information about the ObjectStore.
234 * Further information is gathered from all @see StoreContainer
238 public String toString() {
242 public String toHtml(HttpServletRequest req) {
244 long divisor = storeHit + storeMiss;
246 hitRatio = (float) storeHit / (float) divisor;
249 StringBuffer sb = new StringBuffer("Mir-ObjectStore ");
250 sb.append( ( (req != null) ? html_version() : version())).append("\n");
251 sb.append("ObjectStore overall hits/misses/ratio: ").append(storeHit);
252 sb.append("/").append(storeMiss).append("/").append(hitRatio);
253 sb.append("%\nCurrently ").append(containerMap.size());
254 sb.append(" StoreContainer in use - listing information:\n");
256 // ask container for information
257 StoreContainer currentStoc;
258 for (Iterator it = containerMap.keySet().iterator(); it.hasNext(); ) {
259 currentStoc = (StoreContainer) containerMap.get(it.next());
260 sb.append(currentStoc.toHtml(req));
263 return sb.toString();
267 * Method: html_version()
268 * Description: returns ObjectStore version as String for HTML representation
272 private String html_version() {
273 return "<i>" + version() + "</i>";
278 * Description: returns ObjectStore version as String
282 private String version() {
283 return "v_sstart3__1.0";