org.apache.ignite.internal.pagemem.impl

Class PageMemoryNoStoreImpl

java.lang.Object

org.apache.ignite.internal.pagemem.impl.PageMemoryNoStoreImpl

All Implemented Interfaces:

PageIdAllocator, PageMemory, PageSupport, LifecycleAware

public class PageMemoryNoStoreImpl
extends Object
implements PageMemory

Page header structure is described by the following diagram. When page is not allocated (in a free list):

 +--------+--------+---------------------------------------------+
 |8 bytes |8 bytes |     PAGE_SIZE + PAGE_OVERHEAD - 16 bytes    |
 +--------+--------+---------------------------------------------+
 |Next ptr|Rel ptr |              Empty                          |
 +--------+--------+---------------------------------------------+
 

When page is allocated and is in use:

 +--------+--------+--------+--------+---------------------------+
 |8 bytes |8 bytes |8 bytes |8 bytes |        PAGE_SIZE          |
 +--------+--------+--------+--------+---------------------------+
 | Marker |Page ID |Pin CNT |  Lock  |        Page data          |
 +--------+--------+--------+--------+---------------------------+
 

Note that first 8 bytes of page header are used either for page marker or for next relative pointer depending on whether the page is in use or not.

Field Summary

Fields

Modifier and Type	Field and Description
static int	LOCK_OFFSET Page pin counter offset.
static int	PAGE_ID_OFFSET Page ID offset.
static long	PAGE_MARKER
static int	PAGE_OVERHEAD Need a 8-byte pointer for linked list, 8 bytes for internal needs (flags), 4 bytes cache ID, 8 bytes timestamp.

Fields inherited from interface org.apache.ignite.internal.pagemem.PageIdAllocator

FLAG_DATA, FLAG_IDX, INDEX_PARTITION, MAX_PARTITION_ID

Constructor Summary

Constructors

Constructor and Description
PageMemoryNoStoreImpl(IgniteLogger log, DirectMemoryProvider directMemoryProvider, GridCacheSharedContext<?,?> sharedCtx, int pageSize, DataRegionConfiguration dataRegionCfg, DataRegionMetricsImpl memMetrics, boolean trackAcquiredPages)

Method Summary

Modifier and Type	Method and Description
long	acquiredPages()
long	acquirePage(int cacheId, long pageId) Gets the page absolute pointer associated with the given page ID.
long	allocatePage(int cacheId, int partId, byte flags) Allocates a page from the space for the given partition ID and the given flags.
int	checkpointBufferPagesCount() Number of pages used in checkpoint buffer.
boolean	freePage(int cacheId, long pageId) The given page is free now.
boolean	isDirty(int cacheId, long pageId, long page)
long	loadedPages()
ByteBuffer	pageBuffer(long pageAddr)
int	pageIndex(int seqNo)
int	pageSequenceNumber(int pageIdx)
int	pageSize()
long	readLock(int cacheId, long pageId, long page)
long	readLockForce(int cacheId, long pageId, long page) Obtains read lock without checking page tag.
void	readUnlock(int cacheId, long pageId, long page) Releases locked page.
void	releasePage(int cacheId, long pageId, long page)
void	start() Starts grid component, called on grid start.
void	stop() Stops grid component, called on grid shutdown.
int	systemPageSize()
int	totalPages()
long	tryWriteLock(int cacheId, long pageId, long page)
long	writeLock(int cacheId, long pageId, long page)
void	writeUnlock(int cacheId, long pageId, long page, Boolean walPlc, boolean dirtyFlag) Releases locked page.

Methods inherited from class java.lang.Object

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

Field Detail

PAGE_MARKER

public static final long PAGE_MARKER

See Also:

Constant Field Values

PAGE_ID_OFFSET

public static final int PAGE_ID_OFFSET

Page ID offset.

See Also:

Constant Field Values

LOCK_OFFSET

public static final int LOCK_OFFSET

Page pin counter offset.

See Also:

Constant Field Values

PAGE_OVERHEAD

public static final int PAGE_OVERHEAD

Need a 8-byte pointer for linked list, 8 bytes for internal needs (flags), 4 bytes cache ID, 8 bytes timestamp.

See Also:

Constant Field Values

Constructor Detail

PageMemoryNoStoreImpl

public PageMemoryNoStoreImpl(IgniteLogger log,
                             DirectMemoryProvider directMemoryProvider,
                             GridCacheSharedContext<?,?> sharedCtx,
                             int pageSize,
                             DataRegionConfiguration dataRegionCfg,
                             DataRegionMetricsImpl memMetrics,
                             boolean trackAcquiredPages)

Parameters:

log - Logger.

directMemoryProvider - Memory allocator to use.

sharedCtx - Cache shared context.

pageSize - Page size.

dataRegionCfg - Data region configuration.

memMetrics - Memory Metrics.

trackAcquiredPages - If true tracks number of allocated pages (for tests purpose only).

Method Detail

start

public void start()
           throws IgniteException

Starts grid component, called on grid start.

Specified by:

start in interface LifecycleAware

Throws:

IgniteException - If failed.

stop

public void stop()
          throws IgniteException

Stops grid component, called on grid shutdown.

Specified by:

stop in interface LifecycleAware

Throws:

IgniteException - If failed.

pageBuffer

public ByteBuffer pageBuffer(long pageAddr)

Specified by:

pageBuffer in interface PageMemory

Parameters:

pageAddr - Page address.

Returns:

Page byte buffer.

allocatePage

public long allocatePage(int cacheId,
                         int partId,
                         byte flags)

Allocates a page from the space for the given partition ID and the given flags.

Specified by:

allocatePage in interface PageIdAllocator

partId - Partition ID.

Returns:

Allocated page ID.

freePage

public boolean freePage(int cacheId,
                        long pageId)

The given page is free now.

Specified by:

freePage in interface PageIdAllocator

Parameters:

cacheId - Cache ID.

pageId - Page ID.

pageSize

public int pageSize()

Specified by:

pageSize in interface PageMemory

Returns:

Page size in bytes.

systemPageSize

public int systemPageSize()

Specified by:

systemPageSize in interface PageMemory

Returns:

Page size with system overhead, in bytes.

loadedPages

public long loadedPages()

Specified by:

loadedPages in interface PageMemory

Returns:

Total number of loaded pages in memory.

totalPages

public int totalPages()

Returns:

Total number of pages may be allocated for this instance.

acquiredPages

public long acquiredPages()

Returns:

Total number of acquired pages.

acquirePage

public long acquirePage(int cacheId,
                        long pageId)

Gets the page absolute pointer associated with the given page ID. Each page obtained with this method must be released by calling PageSupport.releasePage(int, long, long). This method will allocate page with given ID if it doesn't exist.

Specified by:

acquirePage in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

Returns:

Page pointer.

releasePage

public void releasePage(int cacheId,
                        long pageId,
                        long page)

Specified by:

releasePage in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID to release.

page - Page pointer.

readLock

public long readLock(int cacheId,
                     long pageId,
                     long page)

Specified by:

readLock in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

page - Page pointer.

Returns:

Pointer for reading the page.

readLockForce

public long readLockForce(int cacheId,
                          long pageId,
                          long page)

Obtains read lock without checking page tag.

Specified by:

readLockForce in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

page - Page pointer.

Returns:

Pointer for reading the page.

readUnlock

public void readUnlock(int cacheId,
                       long pageId,
                       long page)

Releases locked page.

Specified by:

readUnlock in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

page - Page pointer.

writeLock

public long writeLock(int cacheId,
                      long pageId,
                      long page)

Specified by:

writeLock in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

page - Page pointer.

Returns:

Address of a buffer with contents of the given page or 0L if attempt to take the write lock failed.

tryWriteLock

public long tryWriteLock(int cacheId,
                         long pageId,
                         long page)

Specified by:

tryWriteLock in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

page - Page pointer.

Returns:

Address of a buffer with contents of the given page or 0L if attempt to take the write lock failed.

writeUnlock

public void writeUnlock(int cacheId,
                        long pageId,
                        long page,
                        Boolean walPlc,
                        boolean dirtyFlag)

Releases locked page.

Specified by:

writeUnlock in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

page - Page pointer.

walPlc - True if page should be recorded to WAL, false if the page must not be recorded and null for the default behavior.

dirtyFlag - Determines whether the page was modified since the last checkpoint.

isDirty

public boolean isDirty(int cacheId,
                       long pageId,
                       long page)

Specified by:

isDirty in interface PageSupport

Parameters:

cacheId - Cache group ID.

pageId - Page ID.

page - Page pointer.

Returns:

True if the page is dirty.

pageSequenceNumber

public int pageSequenceNumber(int pageIdx)

Parameters:

pageIdx - Page index.

Returns:

Total page sequence number.

pageIndex

public int pageIndex(int seqNo)

Parameters:

seqNo - Page sequence number.

Returns:

Page index.

checkpointBufferPagesCount

public int checkpointBufferPagesCount()

Number of pages used in checkpoint buffer.

Specified by:

checkpointBufferPagesCount in interface PageMemory