StandardQueryCachepublic class StandardQueryCache extends Object implements QueryCache| The standard implementation of the Hibernate QueryCache interface. This
implementation is very good at recognizing stale query results and
and re-running queries when it detects this condition, recaching the new
results. |
| Fields Summary |
|---|
| private static final Log | log | | private Cache | queryCache | | private UpdateTimestampsCache | updateTimestampsCache | | private final String | regionName |
| Constructors Summary |
|---|
public StandardQueryCache(org.hibernate.cfg.Settings settings, Properties props, UpdateTimestampsCache updateTimestampsCache, String regionName)
if ( regionName == null ) {
regionName = StandardQueryCache.class.getName();
}
String prefix = settings.getCacheRegionPrefix();
if ( prefix != null ) {
regionName = prefix + '." + regionName;
}
log.info( "starting query cache at region: " + regionName );
this.queryCache = settings.getCacheProvider().buildCache(regionName, props);
this.updateTimestampsCache = updateTimestampsCache;
this.regionName = regionName;
|
| Methods Summary |
|---|
| public void | clear()
queryCache.clear();
| | public void | destroy()
try {
queryCache.destroy();
}
catch (Exception e) {
log.warn("could not destroy query cache: " + regionName, e);
}
| | public java.util.List | get(QueryKey key, org.hibernate.type.Type[] returnTypes, boolean isNaturalKeyLookup, java.util.Set spaces, org.hibernate.engine.SessionImplementor session)
if ( log.isDebugEnabled() ) {
log.debug("checking cached query results in region: " + regionName);
}
List cacheable = (List) queryCache.get(key);
if (cacheable==null) {
log.debug("query results were not found in cache");
return null;
}
Long timestamp = (Long) cacheable.get(0);
if ( !isNaturalKeyLookup && !isUpToDate(spaces, timestamp) ) {
log.debug("cached query results were not up to date");
return null;
}
log.debug("returning cached query results");
for ( int i=1; i<cacheable.size(); i++ ) {
if ( returnTypes.length==1 ) {
returnTypes[0].beforeAssemble( (Serializable) cacheable.get(i), session );
}
else {
TypeFactory.beforeAssemble( (Serializable[]) cacheable.get(i), returnTypes, session );
}
}
List result = new ArrayList( cacheable.size()-1 );
for ( int i=1; i<cacheable.size(); i++ ) {
try {
if ( returnTypes.length==1 ) {
result.add( returnTypes[0].assemble( (Serializable) cacheable.get(i), session, null ) );
}
else {
result.add( TypeFactory.assemble( (Serializable[]) cacheable.get(i), returnTypes, session, null ) );
}
}
catch (UnresolvableObjectException uoe) {
if (isNaturalKeyLookup) {
//TODO: not really completely correct, since
// the uoe could occur while resolving
// associations, leaving the PC in an
// inconsistent state
log.debug("could not reassemble cached result set");
queryCache.remove(key);
return null;
}
else {
throw uoe;
}
}
}
return result;
| | public Cache | getCache()
return queryCache;
| | public java.lang.String | getRegionName()
return regionName;
| | protected boolean | isUpToDate(java.util.Set spaces, java.lang.Long timestamp)
if ( log.isDebugEnabled() ) {
log.debug("Checking query spaces for up-to-dateness: " + spaces);
}
return updateTimestampsCache.isUpToDate(spaces, timestamp);
| | public boolean | put(QueryKey key, org.hibernate.type.Type[] returnTypes, java.util.List result, boolean isNaturalKeyLookup, org.hibernate.engine.SessionImplementor session)
if ( isNaturalKeyLookup && result.size()==0 ) {
return false;
}
else {
Long ts = new Long( session.getTimestamp() );
if ( log.isDebugEnabled() ) {
log.debug( "caching query results in region: " + regionName + "; timestamp=" + ts );
}
List cacheable = new ArrayList( result.size()+1 );
cacheable.add( ts );
for ( int i=0; i<result.size(); i++ ) {
if ( returnTypes.length==1 ) {
cacheable.add( returnTypes[0].disassemble( result.get(i), session, null ) );
}
else {
cacheable.add( TypeFactory.disassemble( (Object[]) result.get(i), returnTypes, null, session, null ) );
}
}
queryCache.put(key, cacheable);
return true;
}
| | public java.lang.String | toString()
return "StandardQueryCache(" + regionName + ')";
|
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