io.druid.query.topn

Interface Historical1AggPooledTopNScanner<DimensionSelectorType extends HistoricalDimensionSelector,MetricSelectorType extends ColumnValueSelector,BufferAggregatorType extends BufferAggregator>

All Known Implementing Classes:

Historical1SimpleDoubleAggPooledTopNScannerPrototype, HistoricalSingleValueDimSelector1SimpleDoubleAggPooledTopNScannerPrototype

public interface Historical1AggPooledTopNScanner<DimensionSelectorType extends HistoricalDimensionSelector,MetricSelectorType extends ColumnValueSelector,BufferAggregatorType extends BufferAggregator>

Method Summary

Modifier and Type	Method and Description
long	scanAndAggregate(DimensionSelectorType dimensionSelector, MetricSelectorType metricSelector, BufferAggregatorType aggregator, int aggregatorSize, HistoricalCursor cursor, int[] positions, ByteBuffer resultsBuffer)

Method Detail

scanAndAggregate

long scanAndAggregate(DimensionSelectorType dimensionSelector,
                      MetricSelectorType metricSelector,
                      BufferAggregatorType aggregator,
                      int aggregatorSize,
                      HistoricalCursor cursor,
                      int[] positions,
                      ByteBuffer resultsBuffer)

Parameters:

aggregatorSize - number of bytes required by aggregator for a single aggregation

positions - a cache for positions in resultsBuffer, where specific (indexed) dimension values are aggregated

Returns:

number of scanned rows, i. e. number of steps made with the given cursor