|
|||||||||||||||||||
| Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
| CacheEntry.java | 58,3% | 68% | 81,2% | 67,8% |
|
||||||||||||||
| 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 | 21 |
public CacheEntry(String key) {
|
| 86 | 21 |
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 | 212 |
public CacheEntry(String key, EntryRefreshPolicy policy) {
|
| 97 | 212 |
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 | 212 |
public CacheEntry(String key, EntryRefreshPolicy policy, String[] groups) {
|
| 110 | 212 |
this.key = key;
|
| 111 |
|
|
| 112 | 212 |
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 | 212 |
this.policy = policy;
|
| 121 | 212 |
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 | 213 |
public synchronized void setContent(Object value) { |
| 134 | 213 |
content = value; |
| 135 | 213 |
lastUpdate = System.currentTimeMillis(); |
| 136 | 213 |
wasFlushed = false;
|
| 137 |
} |
|
| 138 |
|
|
| 139 |
/**
|
|
| 140 |
* Get the cached content from this CacheEntry.
|
|
| 141 |
*
|
|
| 142 |
* @return The content of this CacheEntry.
|
|
| 143 |
*/
|
|
| 144 | 297 |
public Object getContent() {
|
| 145 | 297 |
return content;
|
| 146 |
} |
|
| 147 |
|
|
| 148 |
/**
|
|
| 149 |
* Get the date this CacheEntry was created.
|
|
| 150 |
*
|
|
| 151 |
* @return The date this CacheEntry was created.
|
|
| 152 |
*/
|
|
| 153 | 3 |
public long getCreated() { |
| 154 | 3 |
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 | 201 |
public synchronized void setGroups(String[] groups) { |
| 163 | 201 |
if (groups != null) { |
| 164 | 54 |
this.groups = new HashSet(groups.length); |
| 165 |
|
|
| 166 | 54 |
for (int i = 0; i < groups.length; i++) { |
| 167 | 87 |
this.groups.add(groups[i]);
|
| 168 |
} |
|
| 169 |
} else {
|
|
| 170 | 147 |
this.groups = null; |
| 171 |
} |
|
| 172 |
|
|
| 173 | 201 |
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 | 324 |
public Set getGroups() {
|
| 199 | 324 |
return groups;
|
| 200 |
} |
|
| 201 |
|
|
| 202 |
/**
|
|
| 203 |
* Get the key of this CacheEntry
|
|
| 204 |
*
|
|
| 205 |
* @return The key of this CacheEntry
|
|
| 206 |
*/
|
|
| 207 | 191 |
public String getKey() {
|
| 208 | 191 |
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 | 3 |
public long getLastUpdate() { |
| 226 | 3 |
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 | 360 |
public boolean isNew() { |
| 236 | 360 |
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 | 48 |
public void flush() { |
| 271 | 48 |
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 | 386 |
public boolean needsRefresh(int refreshPeriod) { |
| 286 | 386 |
boolean needsRefresh;
|
| 287 |
|
|
| 288 |
// needs a refresh if it has never been updated
|
|
| 289 | 386 |
if (lastUpdate == NOT_YET) {
|
| 290 | 27 |
needsRefresh = true;
|
| 291 |
} |
|
| 292 |
// Was it flushed from cache?
|
|
| 293 | 359 |
else if (wasFlushed) { |
| 294 | 74 |
needsRefresh = true;
|
| 295 | 285 |
} else if (refreshPeriod == 0) { |
| 296 | 63 |
needsRefresh = true;
|
| 297 |
} |
|
| 298 |
// check what the policy has to say if there is one
|
|
| 299 | 222 |
else if (policy != null) { |
| 300 | 6 |
needsRefresh = policy.needsRefresh(this);
|
| 301 |
} |
|
| 302 |
// check if the last update + update period is in the past
|
|
| 303 | 216 |
else if ((refreshPeriod >= 0) && (System.currentTimeMillis() >= (lastUpdate + (refreshPeriod * 1000L)))) { |
| 304 | 0 |
needsRefresh = true;
|
| 305 |
} else {
|
|
| 306 | 216 |
needsRefresh = false;
|
| 307 |
} |
|
| 308 |
|
|
| 309 | 386 |
return needsRefresh;
|
| 310 |
} |
|
| 311 |
} |
|
| 312 |
|
|
||||||||||