Package org.apache.druid.query.groupby.epinephelinae.column

Class KeyMappingMultiValueGroupByColumnSelectorStrategy.DictionaryBuilding

    • Constructor Detail

      • DictionaryBuilding

        public DictionaryBuilding()

    • Method Detail

      • processValueFromGroupingKey

        public void processValueFromGroupingKey​(GroupByColumnSelectorPlus selectorPlus,
                                        ByteBuffer key,
                                        ResultRow resultRow,
                                        int keyBufferPosition)
        Description copied from interface: GroupByColumnSelectorStrategy
        Read a value from a grouping key and add it to the group by query result row, using the output name specified in a DimensionSpec. An implementation may choose to not add anything to the result row (e.g., as the String implementation does for empty rows) selectorPlus provides access to: - the keyBufferPosition offset from which to read the value - the dimension value selector - the DimensionSpec for this dimension from the query
        Parameters:
        selectorPlus - dimension info containing the key offset, value selector, and dimension spec
        key - grouping key
        resultRow - result row for the group by query being served
        keyBufferPosition - buffer position for the grouping key, added to support chaining multiple ColumnSelectorStrategy

      • initColumnValues

        public int initColumnValues​(ColumnValueSelector selector,
                            int columnIndex,
                            Object[] valuess)
        Description copied from interface: GroupByColumnSelectorStrategy
        Retrieve a row object from the ColumnValueSelector and put it in valuess at columnIndex.
        Parameters:
        selector - Value selector for a column.
        columnIndex - Index of the column within the row values array
        valuess - Row values array, one index per column
        Returns:
        estimated increase in internal state footprint, in bytes, as a result of this operation. May be zero if memory did not increase as a result of this operation. Will not be negative.

      • writeToKeyBuffer

        public int writeToKeyBuffer​(int keyBufferPosition,
                            ColumnValueSelector selector,
                            ByteBuffer keyBuffer)
        Description copied from interface: GroupByColumnSelectorStrategy
        Write a single object from the given selector to the keyBuffer at keyBufferPosition. The reading column must have a single value. The position of the keyBuffer may be modified.
        Parameters:
        keyBufferPosition - starting offset for this column's value within the grouping key
        selector - selector to retrieve row value object from
        keyBuffer - grouping key
        Returns:
        estimated increase in internal state footprint, in bytes, as a result of this operation. May be zero if memory did not increase as a result of this operation. Will not be negative.

      • bufferComparator

        public Grouper.BufferComparator bufferComparator​(int keyBufferPosition,
                                                 @Nullable
                                                 StringComparator stringComparator)
        Description copied from interface: GroupByColumnSelectorStrategy
        Return BufferComparator for values written using this strategy when limit is pushed down to segment scan.
        Parameters:
        keyBufferPosition - starting offset for this column's value within the grouping key
        stringComparator - stringComparator from LimitSpec for this column. If this is null, implementations will use the StringComparators.LEXICOGRAPHIC comparator.
        Returns:
        BufferComparator for comparing values written