public EntityIterator getIteratorImpl()

in entity-store/src/main/java/jetbrains/exodus/entitystore/iterate/SortIterable.java [124:157]
31 lines of code
13 McCabe index (conditional complexity)

    public EntityIterator getIteratorImpl(@NotNull final PersistentStoreTransaction txn) {
        if (propIndex == EntityIterableBase.EMPTY) {
            return new EntityTypeFilteredIterator(source, sourceTypeId);
        }
        final PersistentEntityStoreImpl store = getStore();
        final EntityIterableCache entityIterableCache = store.getEntityIterableCache();
        final EntityIterableBase cachedPropertyIndex = entityIterableCache.putIfNotCached(propIndex);

        if (propIndex.nonCachedHasFastCountAndIsEmpty() && store.getConfig().isDebugAllowInMemorySort()) {
            // if property index is much greater than source then it makes sense to sort source in-memory (XD-609)
            final long sourceSize = entityIterableCache.isDispatcherThread() ? -1 : source.getRoughCount();
            if (sourceSize >= 0) {
                final long indexSize = cachedPropertyIndex.size();
                final long log2IndexSize = MathUtil.longLogarithm(indexSize);
                final long sizeMulLog = sourceSize * log2IndexSize;
                final boolean isCachedInstance = cachedPropertyIndex.isCachedInstance();
                if ((isCachedInstance && sizeMulLog * sourceSize < indexSize) ||
                    (!isCachedInstance && sizeMulLog * log2IndexSize < indexSize)) {
                    return new OptionallyStableInMemorySortIterator((int) sourceSize, stableSort);
                }
            }
        }

        final EntityIterator propIterator = ascending ?
            cachedPropertyIndex.getIteratorImpl(txn) : cachedPropertyIndex.getReverseIteratorImpl(txn);
        if (propIterator == EntityIteratorBase.EMPTY) {
            return new EntityTypeFilteredIterator(source, sourceTypeId);
        }
        if (stableSort) {
            final StableSortIterator itr = new StableSortIterator((PropertyValueIterator) propIterator);
            return new PropertyValueIteratorFixingDecorator(this, itr, itr);
        }
        return new EntityIteratorFixingDecorator(this, new NonStableSortIterator(txn, propIterator));
    }