/*MUST be called under the WriteLock*/ @NotNull private Map<Integer, SerializedStubTree> readOldData(final int key) throws StorageException { final Map<Integer, SerializedStubTree> result = new HashMap<Integer, SerializedStubTree>(); IndexStorage<Integer, SerializedStubTree> indexStorage = myStorage; if (indexStorage instanceof MemoryIndexStorage) { final MemoryIndexStorage<Integer, SerializedStubTree> memIndexStorage = (MemoryIndexStorage<Integer, SerializedStubTree>) indexStorage; if (!memIndexStorage.isBufferingEnabled()) { // if buffering is not enabled, use backend storage to make sure // the returned stub tree contains no data corresponding to unsaved documents. // This will ensure that correct set of old keys is used for update indexStorage = memIndexStorage.getBackendStorage(); } } try { final ValueContainer<SerializedStubTree> valueContainer = indexStorage.read(key); if (valueContainer.size() != 1) { LOG.assertTrue(valueContainer.size() == 0); return result; } result.put(key, valueContainer.getValueIterator().next()); return result; } catch (RuntimeException e) { final Throwable cause = e.getCause(); if (cause instanceof IOException) { throw new StorageException(cause); } throw e; } }