io.druid.query.groupby.epinephelinae.column

Class DictionaryBuildingStringGroupByColumnSelectorStrategy

java.lang.Object

io.druid.query.groupby.epinephelinae.column.StringGroupByColumnSelectorStrategy

io.druid.query.groupby.epinephelinae.column.DictionaryBuildingStringGroupByColumnSelectorStrategy

All Implemented Interfaces:

ColumnSelectorStrategy, GroupByColumnSelectorStrategy

public class DictionaryBuildingStringGroupByColumnSelectorStrategy
extends StringGroupByColumnSelectorStrategy

A String strategy that builds an internal String<->Integer dictionary for DimensionSelectors that return false for nameLookupPossibleInAdvance()

Constructor Summary

Constructors

Constructor and Description
DictionaryBuildingStringGroupByColumnSelectorStrategy()

Method Summary

Modifier and Type	Method and Description
Object	getOnlyValue(ColumnValueSelector selector) Retrieve a single object using the ColumnValueSelector.
void	initColumnValues(ColumnValueSelector selector, int columnIndex, Object[] valuess) Retrieve a row object from the ColumnValueSelector and put it in valuess at columnIndex.
void	processValueFromGroupingKey(GroupByColumnSelectorPlus selectorPlus, ByteBuffer key, Map<String,Object> resultMap) Read a value from a grouping key and add it to the group by query result map, using the output name specified in a DimensionSpec.

Methods inherited from class io.druid.query.groupby.epinephelinae.column.StringGroupByColumnSelectorStrategy

checkRowIndexAndAddValueToGroupingKey, getGroupingKeySize, initGroupingKeyColumnValue, writeToKeyBuffer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DictionaryBuildingStringGroupByColumnSelectorStrategy

public DictionaryBuildingStringGroupByColumnSelectorStrategy()

Method Detail

processValueFromGroupingKey

public void processValueFromGroupingKey(GroupByColumnSelectorPlus selectorPlus,
                                        ByteBuffer key,
                                        Map<String,Object> resultMap)

Description copied from interface: GroupByColumnSelectorStrategy

Read a value from a grouping key and add it to the group by query result map, using the output name specified in a DimensionSpec. An implementation may choose to not add anything to the result map (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

Specified by:

processValueFromGroupingKey in interface GroupByColumnSelectorStrategy

Overrides:

processValueFromGroupingKey in class StringGroupByColumnSelectorStrategy

Parameters:

selectorPlus - dimension info containing the key offset, value selector, and dimension spec

key - grouping key

resultMap - result map for the group by query being served

initColumnValues

public void 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.

Specified by:

initColumnValues in interface GroupByColumnSelectorStrategy

Overrides:

initColumnValues in class StringGroupByColumnSelectorStrategy

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

getOnlyValue

public Object getOnlyValue(ColumnValueSelector selector)

Description copied from interface: GroupByColumnSelectorStrategy

Retrieve a single object using the ColumnValueSelector. The reading column must have a single value.

Specified by:

getOnlyValue in interface GroupByColumnSelectorStrategy

Overrides:

getOnlyValue in class StringGroupByColumnSelectorStrategy

Parameters:

selector - Value selector for a column

Returns:

an object retrieved from the column