java.lang.Object
- org.apache.druid.segment.ForwardingRowIterator

All Implemented Interfaces:

Closeable, AutoCloseable, RowIterator, TimeAndDimsIterator, TransformableRowIterator
```
public abstract class ForwardingRowIterator
extends Object
implements TransformableRowIterator
```
Implementation of TransformableRowIterator that just delegates all methods to some baseIterator (adapter pattern). Subclass should override some methods.

Field Summary

Fields
Modifier and Type Field Description

protected TransformableRowIterator baseIterator

Constructor Summary

Constructors
Modifier Constructor Description

protected ForwardingRowIterator(TransformableRowIterator baseIterator)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	Closes any resources, associated with this iterator.
`TimeAndDimsPointer`	`getMarkedPointer()`	Returns a pointer to the row, that was the current row when `RowIterator.mark()` was called for the last time.
`RowPointer`	`getPointer()`	Returns a pointer to the current row.
`boolean`	`hasTimeAndDimsChangedSinceMark()`	Compares the "memoized" data point from the last `RowIterator.mark()` call with the data point, to which `RowIterator.getPointer()` currently points.
`void`	`mark()`	"Memoizes" the data point, to which `RowIterator.getPointer()` currently points.
`boolean`	`moveToNext()`	Moves iterator to the next data point.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - baseIterator
```
protected final TransformableRowIterator baseIterator
```
- Constructor Detail
  - ForwardingRowIterator
```
protected ForwardingRowIterator(TransformableRowIterator baseIterator)
```
- Method Detail
  - mark
```
public void mark()
```
    Description copied from interface: RowIterator
    
    "Memoizes" the data point, to which RowIterator.getPointer() currently points. If the last call to TimeAndDimsIterator.moveToNext() returned false, the behaviour of this method is undefined, e. g. it may throw a runtime exception.
    
    Specified by:
    
    mark in interface RowIterator
  - getMarkedPointer
```
public TimeAndDimsPointer getMarkedPointer()
```
    Description copied from interface: TransformableRowIterator
    
    Returns a pointer to the row, that was the current row when RowIterator.mark() was called for the last time. This method always returns the same object, but pointing to different rows after each RowIterator.mark() call. This method must not be called before ever calling to TimeAndDimsIterator.moveToNext(). If the very first call to TimeAndDimsIterator.moveToNext() returned false, the behaviour of this method is undefined (it may return a "wrong" pointer, null, throw an exception, etc.). This method could be called before the first call to RowIterator.mark() (it should return the same object as it is required to return after all subsequent RowIterator.mark() calls), but the data of the returned pointer should not be accessed before the first call to RowIterator.mark(). This method is used in RowCombiningTimeAndDimsIterator implementation. getMarkedPointer() returns TimeAndDimsPointer instead of RowPointer (like TransformableRowIterator.getPointer()) merely because RowCombiningTimeAndDimsIterator doesn't need this method to return anything more specific than TimeAndDimsPointer.
    
    Specified by:
    
    getMarkedPointer in interface TransformableRowIterator
  - hasTimeAndDimsChangedSinceMark
```
public boolean hasTimeAndDimsChangedSinceMark()
```
    Description copied from interface: RowIterator
    
    Compares the "memoized" data point from the last RowIterator.mark() call with the data point, to which RowIterator.getPointer() currently points. Comparison is made in terms of TimeAndDimsPointer.compareTo(org.apache.druid.segment.TimeAndDimsPointer) contract. If RowIterator.mark() has never been called, or the last call to TimeAndDimsIterator.moveToNext() returned false, the behaviour of this method is undefined: it may arbitrarily return true, or false, or throw a runtime exception.
    
    Specified by:
    
    hasTimeAndDimsChangedSinceMark in interface RowIterator
  - getPointer
```
public RowPointer getPointer()
```
    Description copied from interface: TransformableRowIterator
    
    Returns a pointer to the current row. This method _always returns the same object_, but pointing to different row after each TimeAndDimsIterator.moveToNext() call that returns {@link true}. Other aspects of the behaviour of this method are the same as in the generic RowIterator.getPointer() contract.
    
    Specified by:
    
    getPointer in interface RowIterator
    
    Specified by:
    
    getPointer in interface TimeAndDimsIterator
    
    Specified by:
    
    getPointer in interface TransformableRowIterator
  - moveToNext
```
public boolean moveToNext()
```
    Description copied from interface: TimeAndDimsIterator
    
    Moves iterator to the next data point. This method must be called before the first use of TimeAndDimsIterator.getPointer(). As long as this method returns true, TimeAndDimsIterator.getPointer() could be safely called; after this method returned false, this iterator is done, TimeAndDimsIterator.getPointer() must _not_ be called, and TimeAndDimsIterator.close() should be called.
    
    Specified by:
    
    moveToNext in interface TimeAndDimsIterator
  - close
```
public void close()
```
    Description copied from interface: TimeAndDimsIterator
    
    Closes any resources, associated with this iterator.
    
    Specified by:
    
    close in interface AutoCloseable
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface TimeAndDimsIterator

Class ForwardingRowIterator

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

baseIterator

Constructor Detail

ForwardingRowIterator

Method Detail

mark

getMarkedPointer

hasTimeAndDimsChangedSinceMark

getPointer

moveToNext

close