org.apache.druid.segment

Class ColumnProcessors

java.lang.Object

org.apache.druid.segment.ColumnProcessors

public class ColumnProcessors
extends Object

Creates "column processors", which are objects that wrap a single input column and provide some functionality on top of it.

See Also:

which this may eventually replace, which creates similar, vectorized processors; may eventually be moved into this class.

Constructor Summary

Constructors

Constructor and Description
ColumnProcessors()

Method Summary

Modifier and Type	Method and Description
static <T> T	makeProcessor(DimensionSpec dimensionSpec, ColumnProcessorFactory<T> processorFactory, ColumnSelectorFactory selectorFactory) Make a processor for a particular DimensionSpec.
static <T> T	makeProcessor(Expr expr, ValueType exprTypeHint, ColumnProcessorFactory<T> processorFactory, ColumnSelectorFactory selectorFactory) Make a processor for a particular expression.
static <T> T	makeProcessor(String column, ColumnProcessorFactory<T> processorFactory, ColumnSelectorFactory selectorFactory) Make a processor for a particular named column.

Methods inherited from class java.lang.Object

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

Constructor Detail

ColumnProcessors

public ColumnProcessors()

Method Detail

makeProcessor

public static <T> T makeProcessor(String column,
                                  ColumnProcessorFactory<T> processorFactory,
                                  ColumnSelectorFactory selectorFactory)

Make a processor for a particular named column.

Type Parameters:

T - processor type

Parameters:

column - the column

processorFactory - the processor factory

selectorFactory - the column selector factory

makeProcessor

public static <T> T makeProcessor(DimensionSpec dimensionSpec,
                                  ColumnProcessorFactory<T> processorFactory,
                                  ColumnSelectorFactory selectorFactory)

Make a processor for a particular DimensionSpec.

Type Parameters:

T - processor type

Parameters:

dimensionSpec - the dimension spec

processorFactory - the processor factory

selectorFactory - the column selector factory

makeProcessor

public static <T> T makeProcessor(Expr expr,
                                  ValueType exprTypeHint,
                                  ColumnProcessorFactory<T> processorFactory,
                                  ColumnSelectorFactory selectorFactory)

Make a processor for a particular expression. If the expression is a simple identifier, this behaves identically to makeProcessor(String, ColumnProcessorFactory, ColumnSelectorFactory) and accesses the column directly. Otherwise, it uses an expression selector of type exprTypeHint.

Type Parameters:

T - processor type

Parameters:

expr - the parsed expression

exprTypeHint - expression selector type to use for exprs that are not simple identifiers

processorFactory - the processor factory

selectorFactory - the column selector factory