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| Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
| CacheEntry.java | 58.3% | 68% | 81.2% | 67.8% |
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| 1 | /* | |
| 2 | * Copyright (c) 2002-2003 by OpenSymphony | |
| 3 | * All rights reserved. | |
| 4 | */ | |
| 5 | package com.opensymphony.oscache.base; | |
| 6 | ||
| 7 | import com.opensymphony.oscache.web.filter.ResponseContent; | |
| 8 | ||
| 9 | import java.io.Serializable; | |
| 10 | ||
| 11 | import java.util.Collection; | |
| 12 | import java.util.HashSet; | |
| 13 | import java.util.Set; | |
| 14 | ||
| 15 | /** | |
| 16 | * A CacheEntry instance represents one entry in the cache. It holds the object that | |
| 17 | * is being cached, along with a host of information about that entry such as the | |
| 18 | * cache key, the time it was cached, whether the entry has been flushed or not and | |
| 19 | * the groups it belongs to. | |
| 20 | * | |
| 21 | * @version $Revision: 1.1 $ | |
| 22 | * @author <a href="mailto:mike@atlassian.com">Mike Cannon-Brookes</a> | |
| 23 | * @author <a href="mailto:tgochenour@peregrine.com">Todd Gochenour</a> | |
| 24 | * @author <a href="mailto:fbeauregard@pyxis-tech.com">Francois Beauregard</a> | |
| 25 | */ | |
| 26 | public class CacheEntry implements Serializable { | |
| 27 | /** | |
| 28 | * Default initialization value for the creation time and the last | |
| 29 | * update time. This is a placeholder that indicates the value has | |
| 30 | * not been set yet. | |
| 31 | */ | |
| 32 | private static final byte NOT_YET = -1; | |
| 33 | ||
| 34 | /** | |
| 35 | * Specifying this as the refresh period for the | |
| 36 | * {@link #needsRefresh(int)} method will ensure | |
| 37 | * an entry does not become stale until it is | |
| 38 | * either explicitly flushed or a custom refresh | |
| 39 | * policy causes the entry to expire. | |
| 40 | */ | |
| 41 | public static final int INDEFINITE_EXPIRY = -1; | |
| 42 | ||
| 43 | /** | |
| 44 | * The entry refresh policy object to use for this cache entry. This is optional. | |
| 45 | */ | |
| 46 | private EntryRefreshPolicy policy = null; | |
| 47 | ||
| 48 | /** | |
| 49 | * The actual content that is being cached. Wherever possible this object | |
| 50 | * should be serializable. This allows <code>PersistenceListener</code>s | |
| 51 | * to serialize the cache entries to disk or database. | |
| 52 | */ | |
| 53 | private Object content = null; | |
| 54 | ||
| 55 | /** | |
| 56 | * The set of cache groups that this cache entry belongs to, if any. | |
| 57 | */ | |
| 58 | private Set groups = null; | |
| 59 | ||
| 60 | /** | |
| 61 | * The unique cache key for this entry | |
| 62 | */ | |
| 63 | private String key; | |
| 64 | ||
| 65 | /** | |
| 66 | * <code>true</code> if this entry was flushed | |
| 67 | */ | |
| 68 | private boolean wasFlushed = false; | |
| 69 | ||
| 70 | /** | |
| 71 | * The time this entry was created. | |
| 72 | */ | |
| 73 | private long created = NOT_YET; | |
| 74 | ||
| 75 | /** | |
| 76 | * The time this emtry was last updated. | |
| 77 | */ | |
| 78 | private long lastUpdate = NOT_YET; | |
| 79 | ||
| 80 | /** | |
| 81 | * Construct a new CacheEntry using the key provided. | |
| 82 | * | |
| 83 | * @param key The key of this CacheEntry | |
| 84 | */ | |
| 85 | 28 | public CacheEntry(String key) { |
| 86 | 28 | this(key, null); |
| 87 | } | |
| 88 | ||
| 89 | /** | |
| 90 | * Construct a CacheEntry. | |
| 91 | * | |
| 92 | * @param key The unique key for this <code>CacheEntry</code>. | |
| 93 | * @param policy Object that implements refresh policy logic. This parameter | |
| 94 | * is optional. | |
| 95 | */ | |
| 96 | 20354 | public CacheEntry(String key, EntryRefreshPolicy policy) { |
| 97 | 20353 | this(key, policy, null); |
| 98 | } | |
| 99 | ||
| 100 | /** | |
| 101 | * Construct a CacheEntry. | |
| 102 | * | |
| 103 | * @param key The unique key for this <code>CacheEntry</code>. | |
| 104 | * @param policy The object that implements the refresh policy logic. This | |
| 105 | * parameter is optional. | |
| 106 | * @param groups The groups that this <code>CacheEntry</code> belongs to. This | |
| 107 | * parameter is optional. | |
| 108 | */ | |
| 109 | 20353 | public CacheEntry(String key, EntryRefreshPolicy policy, String[] groups) { |
| 110 | 20353 | this.key = key; |
| 111 | ||
| 112 | 20353 | if (groups != null) { |
| 113 | 0 | this.groups = new HashSet(groups.length); |
| 114 | ||
| 115 | 0 | for (int i = 0; i < groups.length; i++) { |
| 116 | 0 | this.groups.add(groups[i]); |
| 117 | } | |
| 118 | } | |
| 119 | ||
| 120 | 20354 | this.policy = policy; |
| 121 | 20355 | this.created = System.currentTimeMillis(); |
| 122 | } | |
| 123 | ||
| 124 | /** | |
| 125 | * Sets the actual content that is being cached. Wherever possible this | |
| 126 | * object should be <code>Serializable</code>, however it is not an | |
| 127 | * absolute requirement when using a memory-only cache. Being <code>Serializable</code> | |
| 128 | * allows <code>PersistenceListener</code>s to serialize the cache entries to disk | |
| 129 | * or database. | |
| 130 | * | |
| 131 | * @param value The content to store in this CacheEntry. | |
| 132 | */ | |
| 133 | 12299 | public synchronized void setContent(Object value) { |
| 134 | 12299 | content = value; |
| 135 | 12300 | lastUpdate = System.currentTimeMillis(); |
| 136 | 12300 | wasFlushed = false; |
| 137 | } | |
| 138 | ||
| 139 | /** | |
| 140 | * Get the cached content from this CacheEntry. | |
| 141 | * | |
| 142 | * @return The content of this CacheEntry. | |
| 143 | */ | |
| 144 | 2012406 | public Object getContent() { |
| 145 | 2012406 | return content; |
| 146 | } | |
| 147 | ||
| 148 | /** | |
| 149 | * Get the date this CacheEntry was created. | |
| 150 | * | |
| 151 | * @return The date this CacheEntry was created. | |
| 152 | */ | |
| 153 | 4 | public long getCreated() { |
| 154 | 4 | return created; |
| 155 | } | |
| 156 | ||
| 157 | /** | |
| 158 | * Sets the cache groups for this entry. | |
| 159 | * | |
| 160 | * @param groups A string array containing all the group names | |
| 161 | */ | |
| 162 | 12283 | public synchronized void setGroups(String[] groups) { |
| 163 | 12283 | if (groups != null) { |
| 164 | 84 | this.groups = new HashSet(groups.length); |
| 165 | ||
| 166 | 84 | for (int i = 0; i < groups.length; i++) { |
| 167 | 132 | this.groups.add(groups[i]); |
| 168 | } | |
| 169 | } else { | |
| 170 | 12199 | this.groups = null; |
| 171 | } | |
| 172 | ||
| 173 | 12283 | lastUpdate = System.currentTimeMillis(); |
| 174 | } | |
| 175 | ||
| 176 | /** | |
| 177 | * Sets the cache groups for this entry | |
| 178 | * | |
| 179 | * @param groups A collection containing all the group names | |
| 180 | */ | |
| 181 | 0 | public void setGroups(Collection groups) { |
| 182 | 0 | if (groups != null) { |
| 183 | 0 | this.groups = new HashSet(groups); |
| 184 | } else { | |
| 185 | 0 | this.groups = null; |
| 186 | } | |
| 187 | ||
| 188 | 0 | lastUpdate = System.currentTimeMillis(); |
| 189 | } | |
| 190 | ||
| 191 | /** | |
| 192 | * Gets the cache groups that this cache entry belongs to. | |
| 193 | * These returned groups should be treated as immuatable. | |
| 194 | * | |
| 195 | * @return A set containing the names of all the groups that | |
| 196 | * this cache entry belongs to. | |
| 197 | */ | |
| 198 | 16475 | public Set getGroups() { |
| 199 | 16475 | return groups; |
| 200 | } | |
| 201 | ||
| 202 | /** | |
| 203 | * Get the key of this CacheEntry | |
| 204 | * | |
| 205 | * @return The key of this CacheEntry | |
| 206 | */ | |
| 207 | 310 | public String getKey() { |
| 208 | 310 | return key; |
| 209 | } | |
| 210 | ||
| 211 | /** | |
| 212 | * Set the date this CacheEntry was last updated. | |
| 213 | * | |
| 214 | * @param update The time (in milliseconds) this CacheEntry was last updated. | |
| 215 | */ | |
| 216 | 0 | public void setLastUpdate(long update) { |
| 217 | 0 | lastUpdate = update; |
| 218 | } | |
| 219 | ||
| 220 | /** | |
| 221 | * Get the date this CacheEntry was last updated. | |
| 222 | * | |
| 223 | * @return The date this CacheEntry was last updated. | |
| 224 | */ | |
| 225 | 4 | public long getLastUpdate() { |
| 226 | 4 | return lastUpdate; |
| 227 | } | |
| 228 | ||
| 229 | /** | |
| 230 | * Indicates whether this CacheEntry is a freshly created one and | |
| 231 | * has not yet been assigned content or placed in a cache. | |
| 232 | * | |
| 233 | * @return <code>true</code> if this entry is newly created | |
| 234 | */ | |
| 235 | 2061984 | public boolean isNew() { |
| 236 | 2061984 | return lastUpdate == NOT_YET; |
| 237 | } | |
| 238 | ||
| 239 | /** | |
| 240 | * Get the size of the cache entry in bytes (roughly).<p> | |
| 241 | * | |
| 242 | * Currently this method only handles <code>String<code>s and | |
| 243 | * {@link ResponseContent} objects. | |
| 244 | * | |
| 245 | * @return The approximate size of the entry in bytes, or -1 if the | |
| 246 | * size could not be estimated. | |
| 247 | */ | |
| 248 | 0 | public int getSize() { |
| 249 | // a char is two bytes | |
| 250 | 0 | int size = (key.length() * 2) + 4; |
| 251 | ||
| 252 | 0 | if (content.getClass() == String.class) { |
| 253 | 0 | size += ((content.toString().length() * 2) + 4); |
| 254 | 0 | } else if (content instanceof ResponseContent) { |
| 255 | 0 | size += ((ResponseContent) content).getSize(); |
| 256 | } else { | |
| 257 | 0 | return -1; |
| 258 | } | |
| 259 | ||
| 260 | //add created, lastUpdate, and wasFlushed field sizes (1, 8, and 8) | |
| 261 | 0 | return size + 17; |
| 262 | } | |
| 263 | ||
| 264 | /** | |
| 265 | * Flush the entry from cache. | |
| 266 | * note that flushing the cache doesn't actually remove the cache contents | |
| 267 | * it just tells the CacheEntry that it needs a refresh next time it is asked | |
| 268 | * this is so that the content is still there for a <usecached />. | |
| 269 | */ | |
| 270 | 62 | public void flush() { |
| 271 | 62 | wasFlushed = true; |
| 272 | } | |
| 273 | ||
| 274 | /** | |
| 275 | * Check if this CacheEntry needs to be refreshed. | |
| 276 | * | |
| 277 | * @param refreshPeriod The period of refresh (in seconds). Passing in | |
| 278 | * {@link #INDEFINITE_EXPIRY} will result in the content never becoming | |
| 279 | * stale unless it is explicitly flushed, or expired by a custom | |
| 280 | * {@link EntryRefreshPolicy}. Passing in 0 will always result in a | |
| 281 | * refresh being required. | |
| 282 | * | |
| 283 | * @return Whether or not this CacheEntry needs refreshing. | |
| 284 | */ | |
| 285 | 2012499 | public boolean needsRefresh(int refreshPeriod) { |
| 286 | 2012500 | boolean needsRefresh; |
| 287 | ||
| 288 | // needs a refresh if it has never been updated | |
| 289 | 2012500 | if (lastUpdate == NOT_YET) { |
| 290 | 8042 | needsRefresh = true; |
| 291 | } | |
| 292 | // Was it flushed from cache? | |
| 293 | 2004457 | else if (wasFlushed) { |
| 294 | 86 | needsRefresh = true; |
| 295 | 2004372 | } else if (refreshPeriod == 0) { |
| 296 | 2003685 | needsRefresh = true; |
| 297 | } | |
| 298 | // check what the policy has to say if there is one | |
| 299 | 287 | else if (policy != null) { |
| 300 | 8 | needsRefresh = policy.needsRefresh(this); |
| 301 | } | |
| 302 | // check if the last update + update period is in the past | |
| 303 | 279 | else if ((refreshPeriod >= 0) && (System.currentTimeMillis() >= (lastUpdate + (refreshPeriod * 1000L)))) { |
| 304 | 0 | needsRefresh = true; |
| 305 | } else { | |
| 306 | 279 | needsRefresh = false; |
| 307 | } | |
| 308 | ||
| 309 | 2012502 | return needsRefresh; |
| 310 | } | |
| 311 | } |
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