/** This function may return cached copies of GoogleCloudStorageItemInfo. */
@Override
public GoogleCloudStorageItemInfo getItemInfo(StorageResourceId resourceId) throws IOException {
// Get the item from cache.
GoogleCloudStorageItemInfo item = cache.getItem(resourceId);
// If it wasn't in the cache, request it then add it.
if (item == null) {
item = super.getItemInfo(resourceId);
cache.putItem(item);
}
return item;
}
/** This function may return cached copies of GoogleCloudStorageItemInfo. */
@Override
public List<GoogleCloudStorageItemInfo> getItemInfos(List<StorageResourceId> resourceIds)
throws IOException {
List<GoogleCloudStorageItemInfo> result =
new ArrayList<GoogleCloudStorageItemInfo>(resourceIds.size());
List<StorageResourceId> request = new ArrayList<StorageResourceId>(resourceIds.size());
// Populate the result list with items in the cache, and the request list with resources that
// still need to be resolved. Null items are added to the result list to preserve ordering.
for (StorageResourceId resourceId : resourceIds) {
GoogleCloudStorageItemInfo item = cache.getItem(resourceId);
if (item == null) {
request.add(resourceId);
}
result.add(item);
}
// Resolve all the resources which were not cached, cache them, and add them to the result list.
// Null entries in the result list are replaced by the fresh entries from the underlying
// GoogleCloudStorage.
if (!request.isEmpty()) {
List<GoogleCloudStorageItemInfo> response = super.getItemInfos(request);
Iterator<GoogleCloudStorageItemInfo> responseIterator = response.iterator();
// Iterate through the result set, replacing the null entries added previously with entries
// from the response.
for (int i = 0; i < result.size() && responseIterator.hasNext(); i++) {
if (result.get(i) == null) {
GoogleCloudStorageItemInfo item = responseIterator.next();
cache.putItem(item);
result.set(i, item);
}
}
}
return result;
}
