Package org.apache.druid.query.rowsandcols

Class StorageAdapterRowsAndColumns

java.lang.Object

org.apache.druid.query.rowsandcols.StorageAdapterRowsAndColumns

All Implemented Interfaces:

Closeable, AutoCloseable, RowsAndColumns, CloseableShapeshifter

public class StorageAdapterRowsAndColumns
extends Object
implements CloseableShapeshifter, RowsAndColumns

Provides RowsAndColumns on top of a StorageAdapter.

Constructor Summary

Constructors

Constructor	Description
StorageAdapterRowsAndColumns(StorageAdapter storageAdapter)

Method Summary

Modifier and Type	Method	Description
<T> T	as(Class<T> clazz)	Asks the Object to return itself as a concrete implementation of a specific interface.
void	close()
Column	findColumn(String name)	Finds a column by name.
Collection<String>	getColumnNames()	The set of column names available from the RowsAndColumns
protected RowsAndColumns	getRealRAC()
int	numRows()	The number of rows in the RowsAndColumns object

Methods inherited from class java.lang.Object

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

Constructor Detail

StorageAdapterRowsAndColumns

public StorageAdapterRowsAndColumns(StorageAdapter storageAdapter)

Method Detail

as

public <T> T as(Class<T> clazz)

Description copied from interface: CloseableShapeshifter

Asks the Object to return itself as a concrete implementation of a specific interface. The interface asked for will tend to be a semantically-meaningful interface.

Specified by:

as in interface CloseableShapeshifter

Specified by:

as in interface RowsAndColumns

Type Parameters:

T - The interface that the calling code wants a concrete implementation of

Parameters:

clazz - A class object representing the interface that the calling code wants a concrete implementation of

Returns:

A concrete implementation of the interface, or null if there is no meaningful optimization to be had through a local implementation of the interface.

getColumnNames

public Collection<String> getColumnNames()

Description copied from interface: RowsAndColumns

The set of column names available from the RowsAndColumns

Specified by:

getColumnNames in interface RowsAndColumns

Returns:

The set of column names available from the RowsAndColumns

numRows

public int numRows()

Description copied from interface: RowsAndColumns

The number of rows in the RowsAndColumns object

Specified by:

numRows in interface RowsAndColumns

Returns:

the integer number of rows

findColumn

public Column findColumn(String name)

Description copied from interface: RowsAndColumns

Finds a column by name. null is returned if the column is not found. The RowsAndColumns object should not attempt to default not-found columns to pretend as if they exist, instead the user of the RowsAndColumns object should decide the correct semantic interpretation of a column that does not exist. It is expected that most locations will choose to believe that the column does exist and is always null, but there are often optimizations that can effect this same assumption without doing a lot of extra work if the calling code knows that it does not exist.

Specified by:

findColumn in interface RowsAndColumns

Parameters:

name - the name of the column to find

Returns:

the Column, if found. null if not found.

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

getRealRAC

protected RowsAndColumns getRealRAC()