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
65 import javax.servlet.http.*;
66 import javax.servlet.*;
67 import mir.misc.Logfile;
69 public class ObjectStore {
71 private final static ObjectStore INSTANCE=new ObjectStore();
72 private final static HashMap containerMap=new HashMap(); // StoreContainerType/StoreContainer
73 private static Logfile storeLog;
74 private static long storeHit=0,storeMiss=0;
75 private ResourceBundle ostoreConf;
77 private ObjectStore() {
78 ostoreConf = ResourceBundle.getBundle("objectstore");
79 if ( ostoreConf == null )
80 System.err.println("FATAL: could not find objectstore.properties");
82 public static ObjectStore getInstance() { return INSTANCE; }
87 * Description: The ObjectStore tries to find the @see StoreIdentifier sid
88 * and returns the stored Object.
90 * @return StorableObject is null when no StorableObject for the
91 * StoreIdentifier sid is found.
93 public StorableObject use(StoreIdentifier sid) {
95 StorableObject storeObject=null;
96 StoreContainer stoc = getStoreContainerForSid( sid );
97 if (stoc!=null) storeObject=stoc.use(sid);
98 else System.out.println("Warning: container not found for: " + sid.toString());
99 if (storeObject!=null) {
104 storeMiss++; return null;
110 * Description: A StoreIdentifier is added to the ObjectStore, if it
111 * contains a reference to a @see StorableObject.
113 public void add(StoreIdentifier sid) {
114 if ( sid!=null && sid.hasReference() ) {
115 // find the right StoreContainer for sid
116 StoreContainer stoc = getStoreContainerForSid(sid);
118 // we have to make new StoreContainer
119 StoreContainerType stocType = sid.getStoreContainerType();
120 stoc = new StoreContainer(stocType);
121 containerMap.put(stocType, stoc);
128 * Method: invalidate(StorableObject sto)
129 * Description: ObjectStore is notified of change of a @see StorableObject
130 * sto and invalidates all relevant cache entries.
133 public void invalidate(StoreIdentifier sid) {
134 // propagate invalidation to StoreContainer
136 StoreContainer stoc = getStoreContainerForSid(sid);
137 stoc.invalidate(sid);
142 * Method: invalidate(StoreContainerType)
143 * Description: serves to invalidate a whole StoreContainer
147 public void invalidate(StoreContainerType stoc_type) {
148 if ( stoc_type != null ) {
149 /** @todo invalidates too much:
150 * improvement: if instanceof StoreContainerEntity && EntityList
151 * then invalidate only StoreIdentifier matching the right table
153 StoreContainer stoc = getStoreContainerForStocType(stoc_type);
160 // internal methods for StoreContainer managment
163 * Method: getStoreContainerForSid
164 * Description: private method to find the right @see StoreContainer for
165 * the @see StoreIdentifier sid.
167 * @return StoreContainer is null when no Container is found.
169 private StoreContainer getStoreContainerForSid(StoreIdentifier sid){
170 // find apropriate container for a specific sid
172 StoreContainerType stoc_type = sid.getStoreContainerType();
173 return getStoreContainerForStocType(stoc_type);
178 private StoreContainer getStoreContainerForStocType(StoreContainerType stoc_type) {
179 if ( stoc_type!=null && containerMap.containsKey(stoc_type) )
180 return (StoreContainer)containerMap.get(stoc_type);
184 private boolean has(StoreIdentifier sid) {
185 StoreContainer stoc = getStoreContainerForSid( sid );
186 return ( stoc != null && stoc.has(sid) ) ? true:false;
189 public String getConfProperty(String name) {
191 String returnValue="";
193 return ostoreConf.getString(name);
195 catch (MissingResourceException e) {
196 System.err.println("ObjectStore: " + e.toString());
204 * Description: Displays statistical information about the ObjectStore.
205 * Further information is gathered from all @see StoreContainer
209 public String toString() {
213 public String toHtml(HttpServletRequest req) {
215 long divisor=storeHit+storeMiss;
216 if (divisor>0) hitRatio=(float)storeHit/(float)divisor;
219 StringBuffer sb = new StringBuffer("Mir-ObjectStore ");
220 sb.append( ((req!=null) ? html_version():version()) ).append("\n");
221 sb.append("ObjectStore overall hits/misses/ratio: ").append(storeHit);
222 sb.append("/").append(storeMiss).append("/").append(hitRatio);
223 sb.append("%\nCurrently ").append(containerMap.size());
224 sb.append(" StoreContainer in use - listing information:\n");
226 // ask container for information
227 StoreContainer currentStoc;
228 for(Iterator it=containerMap.keySet().iterator();it.hasNext();) {
229 currentStoc=(StoreContainer)containerMap.get(it.next());
230 sb.append(currentStoc.toHtml(req));
233 return sb.toString();
238 * Method: html_version()
239 * Description: returns ObjectStore version as String for HTML representation
243 private String html_version() { return "<i>"+version()+"</i>"; }
247 * Description: returns ObjectStore version as String
251 private String version() { return "v_sstart3__1.0"; }