/**
* Caches result locally for the given storage under given hash.
*
* @param localStorageData {@link LocalStorageData}
* @param results Results to cache
* @param hash Hash to use
*/
private void cacheQueryResultLocally(
LocalStorageData localStorageData, List<E> results, int hash) {
try {
storageManager.cacheStorageData(localStorageData, results, hash);
} catch (IOException | SerializationException e) { // NOPMD NOCHK
// ignore also if caching fails
}
}
/**
* This method executes the query in way that it first checks if wanted data is already cached. If
* not method has the ability to load the data via the HTTP or locally and aggregate the data if
* the {@link IAggregator} is provided. If the {@link IAggregator} is not provided, the data will
* be returned not aggregated.
*
* <p>In addition it will try to cache the results if they are not yet cached.
*
* <p>This method should be used by all subclasses, because it guards against massive data loading
* that can make out of memory exceptions on the UI.
*
* @param storageIndexQuery Query.
* @param aggregator {@link IAggregator}
* @param comparator If supplied the final result list will be sorted by this comparator.
* @param limit Limit the number of results by given number. Value <code>-1</code> means no limit.
* @return Return results of a query.
*/
protected List<E> executeQuery(
StorageIndexQuery storageIndexQuery,
IAggregator<E> aggregator,
Comparator<? super E> comparator,
int limit) {
List<E> returnList = null;
// check if this can be cached
if (storageManager.canBeCached(storageIndexQuery, aggregator)) {
int hash = storageManager.getCachedDataHash(storageIndexQuery, aggregator);
if (!localStorageData.isFullyDownloaded()) {
// check if it s cached on the CMR
StorageData storageData = new StorageData(localStorageData);
try {
returnList =
dataRetriever.getCachedDataViaHttp(getCmrRepositoryDefinition(), storageData, hash);
} catch (BusinessException | IOException | SerializationException e) { // NOPMD // NOCHK
// ignore cause we can still load results in other way
}
if (null == returnList) {
// if not we load data regular way
returnList = loadData(storageIndexQuery, aggregator);
// and cache it on the CMR if we get something
if (CollectionUtils.isNotEmpty(returnList)) {
cacheQueryResultOnCmr(getCmrRepositoryDefinition(), storageData, returnList, hash);
}
}
} else {
try {
returnList = dataRetriever.getCachedDataLocally(localStorageData, hash);
} catch (IOException | SerializationException e) { // NOPMD NOCHK
// ignore cause we can still load results in other way
}
if (null == returnList) {
// if not we load data regular way
returnList = loadData(storageIndexQuery, aggregator);
// and cache it locally if we get something
if (CollectionUtils.isNotEmpty(returnList)) {
cacheQueryResultLocally(localStorageData, returnList, hash);
}
}
}
} else {
returnList = loadData(storageIndexQuery, aggregator);
}
// sort if needed
if (null != comparator) {
Collections.sort(returnList, comparator);
}
// limit the size if needed
if ((limit > -1) && (returnList.size() > limit)) {
returnList = returnList.subList(0, limit);
}
return returnList;
}
