/**
* NOTE: this returns an unmodifiable copy of the keySet, so removing from here won't have an
* effect, and calling a remove while iterating through the set will not cause a concurrent
* modification exception. This behavior is necessary for now for the persisted cache feature.
*/
public Set<? extends K> getCacheLineKeys() {
// note that this must be a HashSet and not a FastSet in order to have a null value
Set<Object> keys;
if (fileTable != null) {
keys = new HashSet<Object>();
try {
synchronized (this) {
addAllFileTableKeys(keys);
}
} catch (IOException e) {
Debug.logError(e, module);
}
if (keys.remove(ObjectType.NULL)) {
keys.add(null);
}
} else {
if (memoryTable.containsKey(ObjectType.NULL)) {
keys = new HashSet<Object>(memoryTable.keySet());
keys.remove(ObjectType.NULL);
keys.add(null);
} else {
keys = memoryTable.keySet();
}
}
return Collections.unmodifiableSet(UtilGenerics.<Set<? extends K>>cast(keys));
}
/**
* Gets an element from the cache according to the specified key.
*
* @param key The key for the element, used to reference it in the hastables and LRU linked list
* @return The value of the element specified by the key
*/
public V get(Object key) {
boolean countGet = true;
Object nulledKey = fromKey(key);
CacheLine<V> line = memoryTable.get(nulledKey);
if (line == null) {
if (fileTable != null) {
V value;
try {
synchronized (this) {
value = fileTable.get(nulledKey);
}
} catch (IOException e) {
Debug.logError(e, module);
value = null;
}
if (value == null) {
missCountNotFound.incrementAndGet();
return null;
} else {
hitCount.incrementAndGet();
}
memoryTable.put(
nulledKey, createCacheLine(UtilGenerics.<K>cast(key), value, expireTimeNanos));
return value;
} else {
missCountNotFound.incrementAndGet();
}
} else {
if (countGet) hitCount.incrementAndGet();
}
return line != null ? line.getValue() : null;
}
protected synchronized void removeInternal(Object key, CacheLine<V> existingCacheLine) {
Object nulledKey = fromKey(key);
cancel(existingCacheLine);
if (!memoryTable.remove(nulledKey, existingCacheLine)) {
return;
}
if (fileTable != null) {
try {
synchronized (this) {
fileTable.remove(nulledKey);
jdbmMgr.commit();
}
} catch (IOException e) {
Debug.logError(e, module);
}
}
noteRemoval(UtilGenerics.<K>cast(key), existingCacheLine.getValue());
}