io.druid.segment

Class DimensionHandlerUtils

java.lang.Object

io.druid.segment.DimensionHandlerUtils

public final class DimensionHandlerUtils
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static ColumnCapabilities	DEFAULT_STRING_CAPABILITIES

Method Summary

Modifier and Type	Method and Description
static Float	convertObjectToFloat(Object valObj)
static Long	convertObjectToLong(Object valObj)
static <ColumnSelectorStrategyClass extends ColumnSelectorStrategy> ColumnSelectorPlus<ColumnSelectorStrategyClass>	createColumnSelectorPlus(ColumnSelectorStrategyFactory<ColumnSelectorStrategyClass> strategyFactory, DimensionSpec dimensionSpec, ColumnSelectorFactory cursor) Convenience function equivalent to calling createColumnSelectorPluses(ColumnSelectorStrategyFactory, List, ColumnSelectorFactory) with a singleton list of dimensionSpecs and then retrieving the only element in the returned array.
static <ColumnSelectorStrategyClass extends ColumnSelectorStrategy> ColumnSelectorPlus<ColumnSelectorStrategyClass>[]	createColumnSelectorPluses(ColumnSelectorStrategyFactory<ColumnSelectorStrategyClass> strategyFactory, List<DimensionSpec> dimensionSpecs, ColumnSelectorFactory cursor) Creates an array of ColumnSelectorPlus objects, selectors that handle type-specific operations within query processing engines, using a strategy factory provided by the query engine.
static ColumnValueSelector	getColumnValueSelectorFromDimensionSpec(DimensionSpec dimSpec, ColumnSelectorFactory columnSelectorFactory)
static Long	getExactLongFromDecimalString(String decimalStr) Convert a string representing a decimal value to a long.
static DimensionHandler	getHandlerFromCapabilities(String dimensionName, ColumnCapabilities capabilities, DimensionSchema.MultiValueHandling multiValueHandling)
static List<ValueType>	getValueTypesFromDimensionSpecs(List<DimensionSpec> dimSpecs)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_STRING_CAPABILITIES

public static final ColumnCapabilities DEFAULT_STRING_CAPABILITIES

Method Detail

getHandlerFromCapabilities

public static DimensionHandler getHandlerFromCapabilities(String dimensionName,
                                                          ColumnCapabilities capabilities,
                                                          DimensionSchema.MultiValueHandling multiValueHandling)

getValueTypesFromDimensionSpecs

public static List<ValueType> getValueTypesFromDimensionSpecs(List<DimensionSpec> dimSpecs)

createColumnSelectorPlus

public static <ColumnSelectorStrategyClass extends ColumnSelectorStrategy> ColumnSelectorPlus<ColumnSelectorStrategyClass> createColumnSelectorPlus(ColumnSelectorStrategyFactory<ColumnSelectorStrategyClass> strategyFactory,
                                                                                                                                                    DimensionSpec dimensionSpec,
                                                                                                                                                    ColumnSelectorFactory cursor)

Convenience function equivalent to calling createColumnSelectorPluses(ColumnSelectorStrategyFactory, List, ColumnSelectorFactory) with a singleton list of dimensionSpecs and then retrieving the only element in the returned array.

Type Parameters:

ColumnSelectorStrategyClass - The strategy type created by the provided strategy factory.

Parameters:

strategyFactory - A factory provided by query engines that generates type-handling strategies

dimensionSpec - column to generate a ColumnSelectorPlus object for

cursor - Used to create value selectors for columns.

Returns:

A ColumnSelectorPlus object

createColumnSelectorPluses

public static <ColumnSelectorStrategyClass extends ColumnSelectorStrategy> ColumnSelectorPlus<ColumnSelectorStrategyClass>[] createColumnSelectorPluses(ColumnSelectorStrategyFactory<ColumnSelectorStrategyClass> strategyFactory,
                                                                                                                                                        List<DimensionSpec> dimensionSpecs,
                                                                                                                                                        ColumnSelectorFactory cursor)

Creates an array of ColumnSelectorPlus objects, selectors that handle type-specific operations within query processing engines, using a strategy factory provided by the query engine. One ColumnSelectorPlus will be created for each column specified in dimensionSpecs. The ColumnSelectorPlus provides access to a type strategy (e.g., how to group on a float column) and a value selector for a single column. A caller should define a strategy factory that provides an interface for type-specific operations in a query engine. See GroupByStrategyFactory for a reference.

Type Parameters:

ColumnSelectorStrategyClass - The strategy type created by the provided strategy factory.

Parameters:

strategyFactory - A factory provided by query engines that generates type-handling strategies

dimensionSpecs - The set of columns to generate ColumnSelectorPlus objects for

cursor - Used to create value selectors for columns.

Returns:

An array of ColumnSelectorPlus objects, in the order of the columns specified in dimensionSpecs

getColumnValueSelectorFromDimensionSpec

public static ColumnValueSelector getColumnValueSelectorFromDimensionSpec(DimensionSpec dimSpec,
                                                                          ColumnSelectorFactory columnSelectorFactory)

convertObjectToLong

public static Long convertObjectToLong(Object valObj)

convertObjectToFloat

public static Float convertObjectToFloat(Object valObj)

getExactLongFromDecimalString

@Nullable
public static Long getExactLongFromDecimalString(String decimalStr)

Convert a string representing a decimal value to a long. If the decimal value is not an exact integral value (e.g. 42.0), or if the decimal value is too large to be contained within a long, this function returns null.

Parameters:

decimalStr - string representing a decimal value

Returns:

long equivalent of decimalStr, returns null for non-integral decimals and integral decimal values outside of the values representable by longs