PageMemory (Ignite 2.17.0)

All Superinterfaces:

PageIdAllocator, PageSupport

All Known Subinterfaces:

PageMemoryEx

All Known Implementing Classes:

PageMemoryImpl, PageMemoryNoStoreImpl
```
public interface PageMemory
extends PageIdAllocator, PageSupport
```

Field Summary
- Fields inherited from interface org.apache.ignite.internal.pagemem.PageIdAllocator
  FLAG_AUX, FLAG_DATA, FLAG_IDX, INDEX_PARTITION, MAX_PARTITION_ID, META_PAGE_ID

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`int`	`checkpointBufferPagesCount()`	Number of pages used in checkpoint buffer.
`long`	`loadedPages()`
`DataRegionMetricsImpl`	`metrics()`	Metrics of the data region this memory is associated with.
`ByteBuffer`	`pageBuffer(long pageAddr)`
`int`	`pageSize()`
`int`	`realPageSize(int grpId)`
`void`	`start()`	Start page memory.
`void`	`stop(boolean deallocate)`	Stop page memory.
`int`	`systemPageSize()`

Methods inherited from interface org.apache.ignite.internal.pagemem.PageIdAllocator
allocatePage, freePage

Methods inherited from interface org.apache.ignite.internal.pagemem.PageSupport
acquirePage, acquirePage, isDirty, readLock, readLockForce, readUnlock, releasePage, tryWriteLock, writeLock, writeUnlock

- Method Detail
  - start
```
void start()
    throws IgniteException
```
    Start page memory.
    
    Throws:
    
    IgniteException
  - stop
```
void stop(boolean deallocate)
   throws IgniteException
```
    Stop page memory.
    
    Parameters:
    
    deallocate - True to deallocate memory, false to allow memory reuse on subsequent start()
    
    Throws:
    
    IgniteException
  - pageSize
```
int pageSize()
```
    Returns:
    
    Page size in bytes.
  - realPageSize
```
int realPageSize(int grpId)
```
    Parameters:
    
    grpId - Group id.
    
    Returns:
    
    Page size without encryption overhead.
  - systemPageSize
```
int systemPageSize()
```
    Returns:
    
    Page size with system overhead, in bytes.
  - pageBuffer
```
ByteBuffer pageBuffer(long pageAddr)
```
    Parameters:
    
    pageAddr - Page address.
    
    Returns:
    
    Page byte buffer.
  - loadedPages
```
long loadedPages()
```
    Returns:
    
    Total number of loaded pages in memory.
  - checkpointBufferPagesCount
```
int checkpointBufferPagesCount()
```
    Number of pages used in checkpoint buffer.
  - metrics
```
DataRegionMetricsImpl metrics()
```
    Metrics of the data region this memory is associated with.