/**
* Fetches a single change package fragment.
*
* @param sessionId the {@link SessionId} representing the requesting user
* @param proxyId the ID that identifies the list of stored fragments
* @param fragmentIndex allows to request different change package fragments
* @return a {@link ChangePackageEnvelope} containing the change package fragment
* @throws ESException in case the mandatory session adapter is missing
*/
@ESMethod(MethodId.DOWNLOADCHANGEPACKAGEFRAGMENT)
public ChangePackageEnvelope downloadChangePackageFragment(
SessionId sessionId, String proxyId, int fragmentIndex) throws ESException {
final ESSessionId resolvedSession =
getAccessControl().getSessions().resolveSessionById(sessionId.getId());
final SessionId session = APIUtil.toInternal(SessionId.class, resolvedSession);
final Optional<ChangePackageFragmentProviderAdapter> maybeAdapter =
ESCollections.find(session.eAdapters(), ChangePackageFragmentProviderAdapter.class);
if (!maybeAdapter.isPresent()) {
throw new ESException(
Messages.VersionSubInterfaceImpl_ChangePackageFragmentProviderAdapterMissing + sessionId);
}
final ChangePackageFragmentProviderAdapter adapter = maybeAdapter.get();
final ChangePackageEnvelope envelope =
VersioningFactory.eINSTANCE.createChangePackageEnvelope();
final List<String> fragment = adapter.getFragment(proxyId, fragmentIndex);
envelope.getFragment().addAll(fragment);
envelope.setFragmentCount(adapter.getFragmentSize(proxyId));
envelope.setFragmentIndex(fragmentIndex);
if (envelope.isLast()) {
adapter.markAsConsumed(proxyId);
}
return envelope;
}