2 * Copyright (C) 2001, 2002 The Mir-coders group
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4 * This file is part of Mir.
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6 * Mir is free software; you can redistribute it and/or modify
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7 * it under the terms of the GNU General Public License as published by
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8 * the Free Software Foundation; either version 2 of the License, or
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9 * (at your option) any later version.
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11 * Mir is distributed in the hope that it will be useful,
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12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 * GNU General Public License for more details.
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16 * You should have received a copy of the GNU General Public License
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17 * along with Mir; if not, write to the Free Software
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18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 * In addition, as a special exception, The Mir-coders gives permission to link
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21 * the code of this program with the com.oreilly.servlet library, any library
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22 * licensed under the Apache Software License, The Sun (tm) Java Advanced
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23 * Imaging library (JAI), The Sun JIMI library (or with modified versions of
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24 * the above that use the same license as the above), and distribute linked
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25 * combinations including the two. You must obey the GNU General Public
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26 * License in all respects for all of the code used other than the above
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27 * mentioned libraries. If you modify this file, you may extend this exception
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28 * to your version of the file, but you are not obligated to do so. If you do
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29 * not wish to do so, delete this exception statement from your version.
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32 package mir.storage.store;
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35 * Title: StoreContainer
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37 * Description: This is the bucket object for one type of StorableObjects,
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38 * mainy a linked list of StoreIdenfiers. On use or creation
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39 * an object stored in StoreIdentifier is put to head of the
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40 * list. if maximum size of the list is reached, the
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41 * StoreIdentifier at the end of the list is released.
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43 * Copyright: Copyright (c) 2002
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49 import java.util.LinkedList;
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50 import java.util.ListIterator;
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52 import javax.servlet.http.HttpServletRequest;
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54 import mir.misc.StringUtil;
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56 public class StoreContainer {
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57 private final static int DEFAULT_SIZE = 10;
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58 private static int uniqueCounter = 10000;
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60 private LinkedList container;
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61 private StoreContainerType stocType;
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62 private int maxSize = DEFAULT_SIZE, uniqueId;
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63 private int addCount = 0, removeCount = 0, storeOutCount;
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64 private int hitCount = 0, missCount = 0;
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65 private static ObjectStore o_store = ObjectStore.getInstance();
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67 // avoid construction without parameters
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68 private StoreContainer() {};
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70 public StoreContainer(StoreContainerType stoc_type) {
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71 this.uniqueId = ++uniqueCounter;
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72 this.stocType = stoc_type;
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73 this.container = new LinkedList();
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74 int defaultSize = stoc_type.getDefaultSize();
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75 String confProperty = stoc_type.getConfPrefix() + ".DefaultSize";
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76 String confedSize = o_store.getConfProperty(confProperty);
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77 if (confedSize != null) {
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78 this.maxSize = StringUtil.parseInt(confedSize, defaultSize);
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82 public StoreContainer(StoreContainerType stoc_type, int maxSize) {
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84 this.maxSize = maxSize;
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87 public synchronized StorableObject use(StoreIdentifier sid) {
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88 int hit = container.indexOf(sid);
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90 StoreIdentifier hitSid = (StoreIdentifier) container.get(hit);
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91 if (hitSid != null) {
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93 return hitSid.use();
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100 public boolean has(StoreIdentifier sid) {
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101 return container.contains(sid);
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104 public void add(StoreIdentifier sid) {
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105 if (sid != null && sid.hasReference()) {
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108 System.err.println("OBJECTStore: tried to add sid " + sid.toString() +
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109 " that was already in store.");
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112 container.addFirst(sid);
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113 shrinkIfNecessary();
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120 * Method: invalidate(StorableObject sto)
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121 * Description: finds @see StorableObject, propagates invalidation to
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122 * @see StoreIdentifier and removes StoreIdentifier from
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125 public synchronized void invalidate(StoreIdentifier search_sid) {
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126 if (search_sid != null) {
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127 int hit = container.indexOf(search_sid);
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129 StoreIdentifier sid = (StoreIdentifier) container.get(hit);
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130 container.remove(sid);
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137 public synchronized void invalidate() {
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138 StoreIdentifier sid;
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139 while (container.size() > 0) {
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140 sid = (StoreIdentifier) container.getLast();
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141 container.removeLast();
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148 * Description: readjusts StoreContainer size to value.
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151 public void setSize(int size) {
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154 shrinkToSize(size);
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155 this.maxSize = size;
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158 private void shrinkIfNecessary() {
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159 shrinkToSize(maxSize);
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162 private void shrinkToSize(int size) {
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163 if (size < container.size()) {
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165 while (size < container.size()) {
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166 StoreIdentifier sid = (StoreIdentifier) container.getLast();
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167 container.remove(sid);
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174 private synchronized void moveToHead(StoreIdentifier sid) {
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176 container.remove(sid);
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177 container.addFirst(sid);
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182 * Method: toString()
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183 * Description: gives out statistical Information, viewable via
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184 * @see ServletStoreInfo.
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188 public String toString() {
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189 return toHtml(null);
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192 public String toHtml(HttpServletRequest req) {
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193 boolean showingContent = false;
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194 float hitRatio = 0;
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195 long divisor = hitCount + missCount;
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197 hitRatio = (float) hitCount / (float) divisor;
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200 StringBuffer sb = new StringBuffer("StoreContainer id: ");
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201 sb.append(uniqueId).append(" for ");
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202 sb.append(stocType.toString());
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204 String show = req.getParameter("stoc_show");
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205 if (show != null && show.equals("" + uniqueId)) {
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206 // show all entries in container
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207 sb.append(" [<b>showing</b>]");
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208 showingContent = true;
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211 sb.append(" [<a href=\"?stoc_show=" + uniqueId + "\">show</a>]");
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213 sb.append("\n [current/maximum size: ");
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214 sb.append(container.size()).append("/").append(maxSize);
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215 sb.append("]\n [added/stored out/removed: ").append(addCount).append("/");
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216 sb.append(storeOutCount).append("/").append(removeCount).append(
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217 "]\n [hit/miss/ratio: ");
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218 sb.append(hitCount).append("/").append(missCount).append("/");
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219 sb.append(hitRatio).append("%]\n");
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221 if (showingContent) {
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222 sb.append(" <b>Container contains following references:</b>\n ");
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223 ListIterator it = container.listIterator();
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224 while (it.hasNext()) {
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225 StoreIdentifier sid = (StoreIdentifier) it.next();
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226 sb.append(sid.toString()).append("\n ");
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228 sb.append("<b>End of List</b>\n\n");
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232 return sb.toString();
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