Examples with Cursor io.druid.segment.Cursor used on opensource projects

Example 31 with Cursor

use of io.druid.segment.Cursor in project druid by druid-io.

the class GroupByQueryEngine method process.

public Sequence<Row> process(final GroupByQuery query, final StorageAdapter storageAdapter) {
    if (storageAdapter == null) {
        throw new ISE("Null storage adapter found. Probably trying to issue a query against a segment being memory unmapped.");
    }
    final List<Interval> intervals = query.getQuerySegmentSpec().getIntervals();
    if (intervals.size() != 1) {
        throw new IAE("Should only have one interval, got[%s]", intervals);
    }
    Filter filter = Filters.convertToCNFFromQueryContext(query, Filters.toFilter(query.getDimFilter()));
    final Sequence<Cursor> cursors = storageAdapter.makeCursors(filter, intervals.get(0), query.getVirtualColumns(), query.getGranularity(), false);
    final ResourceHolder<ByteBuffer> bufferHolder = intermediateResultsBufferPool.take();
    return Sequences.concat(Sequences.withBaggage(Sequences.map(cursors, new Function<Cursor, Sequence<Row>>() {

        @Override
        public Sequence<Row> apply(final Cursor cursor) {
            return new BaseSequence<>(new BaseSequence.IteratorMaker<Row, RowIterator>() {

                @Override
                public RowIterator make() {
                    return new RowIterator(query, cursor, bufferHolder.get(), config.get());
                }

                @Override
                public void cleanup(RowIterator iterFromMake) {
                    CloseQuietly.close(iterFromMake);
                }
            });
        }
    }), new Closeable() {

        @Override
        public void close() throws IOException {
            CloseQuietly.close(bufferHolder);
        }
    }));
}