/**
* Clear everything including cache, session, files.
*
* @throws TimeoutException
* @throws ExecutionException
* @throws InterruptedException
*/
public void clear() {
// clear stuff on the server
staticStateManagerService.clearClient(staticStateIdentifierManager.getIdentifier());
// remove cookie and session
staticStateIdentifierManager.clearIdentifier();
}
/**
* Creates or restores a new file.
*
* @param uuid
* @return
* @throws IOException
*/
private T createOrRestore(UUID uuid) throws IOException {
// restore cache from file:
File uuidFileParent = staticStateDirectoryManager.getUUIDFileParent();
// if that file is scheduled for deletion, we do not restore it
if (fileDeleter.deletionQueueContains(uuidFileParent)) {
log.debug("trying to restore from state a file that is scheduled for deletion");
// invalidate identifier
staticStateIdentifierManager.clearIdentifier();
// get a new one
// and recreate file
uuidFileParent = staticStateDirectoryManager.getUUIDFileParent();
}
File uuidFile = new File(uuidFileParent, FILENAME);
T entity = null;
if (uuidFile.exists()) {
log.debug("No value in the cache for uuid " + uuid + ". Filling cache from file.");
try {
entity = read(uuidFile);
} catch (Exception e) {
log.error(
"Cache cannot be restored from "
+ uuidFile.getAbsolutePath()
+ "."
+ "The file might be empty or the model has changed since last time: "
+ e.getMessage(),
e);
}
} else {
log.debug(
"No value in the cache for uuid "
+ uuid
+ " and no value in the file. Creating a new one.");
// create the file
try {
uuidFile.createNewFile();
} catch (IOException e) {
log.error("cannot create model file: " + e.getMessage(), e);
throw e;
}
// and persist an entity
try {
entity = getEntityType().newInstance();
} catch (InstantiationException e) {
throw new RuntimeException(e);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
staticStateManagerService.writeEntity(uuidFile, entity);
}
// then return entity
return entity;
}
public void clearFile(final UUID fileId) {
staticStateManagerService.clearFile(staticStateIdentifierManager.getIdentifier(), fileId);
}
/**
* Persist modifications to file and cache.
*
* @param entity
* @return
* @throws ExecutionException
*/
public void updateEntity(T entity) {
UUID uuid = staticStateIdentifierManager.getIdentifier();
staticStateManagerService.updateEntity(uuid, entity);
}
/**
* Retrieves the entity from cache or null if this entity is not present.
*
* @return
*/
public StaticStatePersistedOnFileSystemEntity getEntityIfPresent() {
return staticStateManagerService.getEntityIfPresent(
staticStateIdentifierManager.getIdentifier());
}
