org.apache.calcite.runtime

Class EnumeratorCursor<T>

java.lang.Object

org.apache.calcite.avatica.util.AbstractCursor

org.apache.calcite.avatica.util.PositionedCursor<T>

org.apache.calcite.runtime.EnumeratorCursor<T>

Type Parameters:

T - Element type

All Implemented Interfaces:

Closeable, AutoCloseable, Cursor

Direct Known Subclasses:

ArrayEnumeratorCursor, RecordEnumeratorCursor

public abstract class EnumeratorCursor<T>
extends PositionedCursor<T>

Implementation of Cursor on top of an Enumerator that returns a record for each row. The returned record is cached to avoid multiple computations of current row. For instance, EnumerableCalc computes result just in current() method, thus it makes sense to cache the result and make it available for all the accessors.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.calcite.avatica.util.PositionedCursor

PositionedCursor.ArrayGetter, PositionedCursor.FieldGetter, PositionedCursor.ListGetter, PositionedCursor.MapGetter<K>, PositionedCursor.ObjectGetter

Nested classes/interfaces inherited from class org.apache.calcite.avatica.util.AbstractCursor

AbstractCursor.AbstractGetter, AbstractCursor.Getter

Nested classes/interfaces inherited from interface org.apache.calcite.avatica.util.Cursor

Cursor.Accessor

Field Summary

Fields inherited from class org.apache.calcite.avatica.util.AbstractCursor

wasNull

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	EnumeratorCursor(Enumerator<T> enumerator) Creates a EnumeratorCursor

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
protected T	current()
boolean	next()

Methods inherited from class org.apache.calcite.avatica.util.AbstractCursor

createAccessor, createAccessors, createGetter, wasNull

Methods inherited from class java.lang.Object

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

Constructor Detail

EnumeratorCursor

protected EnumeratorCursor(Enumerator<T> enumerator)

Creates a EnumeratorCursor

Parameters:

enumerator - input enumerator

Method Detail

current

protected T current()

Specified by:

current in class PositionedCursor<T>

next

public boolean next()

Specified by:

next in interface Cursor

Specified by:

next in class AbstractCursor

close

public void close()