Page.PageReference

java.lang.Object
- org.h2.mvstore.Page.PageReference<K,V>

Enclosing class:

Page<K,V>
```
public static final class Page.PageReference<K,V>
extends java.lang.Object
```
A pointer to a page, either in-memory or using a page position.

Field Summary

Fields
Modifier and Type	Field	Description
`(package private) long`	`count`	The descendant count for this child page.
`(package private) static Page.PageReference`	`EMPTY`	Singleton object used when arrays of PageReference have not yet been filled.
`private Page<K,V>`	`page`	The page, if in memory, or null.
`private long`	`pos`	The position, if known, or 0.

Constructor Summary

Constructors
Modifier	Constructor	Description
`(package private)`	`PageReference(long pos, long count)`
	`PageReference(Page<K,V> page)`
`private`	`PageReference(Page<K,V> page, long pos, long count)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) void`	`clearPageReference()`	Clear if necessary, reference to the actual child Page object, so it can be garbage collected if not actively used elsewhere.
`static <X,Y> Page.PageReference<X,Y>`	`empty()`	Get an empty page reference.
`Page<K,V>`	`getPage()`
`(package private) long`	`getPos()`
`(package private) void`	`resetPos()`	Re-acquire position from in-memory page.
`java.lang.String`	`toString()`

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

- Field Detail
  - EMPTY
```
static final Page.PageReference EMPTY
```
    Singleton object used when arrays of PageReference have not yet been filled.
  - pos
```
private long pos
```
    The position, if known, or 0.
  - page
```
private Page<K,V> page
```
    The page, if in memory, or null.
  - count
```
final long count
```
    The descendant count for this child page.
- Constructor Detail
  - PageReference
```
public PageReference(Page<K,V> page)
```
  - PageReference
```
PageReference(long pos,
              long count)
```
  - PageReference
```
private PageReference(Page<K,V> page,
                      long pos,
                      long count)
```
- Method Detail
  - empty
```
public static <X,Y> Page.PageReference<X,Y> empty()
```
    Get an empty page reference.
    
    Type Parameters:
    
    X - the key class
    
    Y - the value class
    
    Returns:
    
    the page reference
  - getPage
```
public Page<K,V> getPage()
```
  - clearPageReference
```
void clearPageReference()
```
    Clear if necessary, reference to the actual child Page object, so it can be garbage collected if not actively used elsewhere. Reference is cleared only if corresponding page was already saved on a disk.
  - getPos
```
long getPos()
```
  - resetPos
```
void resetPos()
```
    Re-acquire position from in-memory page.
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object