com.tangosol.net.cache
Class SerializationPagedCache.PagedBinaryStore

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.net.cache.SerializationPagedCache.PagedBinaryStore

All Implemented Interfaces:

BinaryStore

Enclosing class:

SerializationPagedCache

public class SerializationPagedCache.PagedBinaryStore
extends Base
implements BinaryStore

A virtual BinaryStore implementation that aggregates a sequence (newest to oldest) of periodic BinaryStore objects.

Constructor Summary

SerializationPagedCache.PagedBinaryStore(int cPages)
Construct a PagedBinaryStore.

Method Summary

protected SerializationPagedCache.WrapperBinaryStore	advanceCurrentPage(SerializationPagedCache.WrapperBinaryStore store) Advance the current page, using the passed BinaryStore as the store for the new current page, and returning the oldest active page, if the maximum number of active pages is exceeded by the advancing of the current page.
void	close() Release underlying resources.
void	erase(Binary binKey) Remove the specified key from the underlying store if present.
void	eraseAll() Remove all data from the underlying store.
SerializationPagedCache.WrapperBinaryStore[]	getActivePageArray() Get the array of BinaryStore objects, one for each active page.
int	getActivePageCount() Determine the number of pages that the PagedBinaryStore is currently managing.
protected SerializationPagedCache.WrapperBinaryStore	getCurrentPage() Obtain the page to which current updates are being performed.
int	getCurrentPageNumber() Determine the number of pages that the PagedBinaryStore has managed in total, including those it is currently managing.
int	getMaximumPages() Determine the maximum number of pages that the cache will manage, beyond which the oldest pages are destroyed.
protected SerializationPagedCache.WrapperBinaryStore	getOldestActivePage() Obtain the oldest active page.
SerializationPagedCache.WrapperBinaryStore	getPage(int nPage) Get the BinaryStore for the page specified by the passed page number.
protected Map	getPagedKeyMap() Obtain the map that manages the mapping from Binary keys to BinaryStore objects.
int	getTotalPageCount() Determine the number of pages that the PagedBinaryStore has managed in total, including those it is currently managing.
boolean	isPageActive(int nPage) Determine if the specified page number is active.
Iterator	keys() Iterate all keys in the underlying store.
Binary	load(Binary binKey) Return the value associated with the specified key, or null if the key does not have an associated value in the underlying store.
protected void	logException(Throwable e, String sMethod) Helper to log ignored exceptions.
void	store(Binary binKey, Binary binValue) Store the specified value under the specific key in the underlying store.
protected int	toPageIndex(int nPage) Translate a page number to an index into the PageArray.

Constructor Detail

SerializationPagedCache.PagedBinaryStore

public SerializationPagedCache.PagedBinaryStore(int cPages)

Construct a PagedBinaryStore.

Parameters:

cPages - the maximum number of pages to have active at a time

Method Detail

load

public Binary load(Binary binKey)

Return the value associated with the specified key, or null if the key does not have an associated value in the underlying store.

Specified by:

load in interface BinaryStore

Parameters:

binKey - key whose associated value is to be returned

Returns:

the value associated with the specified key, or null if no value is available for that key

store

public void store(Binary binKey,
                  Binary binValue)

Store the specified value under the specific key in the underlying store. This method is intended to support both key/value creation and value update for a specific key.

Specified by:

store in interface BinaryStore

Parameters:

binKey - key to store the value under

binValue - value to be stored

erase

public void erase(Binary binKey)

Remove the specified key from the underlying store if present.

Specified by:

erase in interface BinaryStore

Parameters:

binKey - key whose mapping is to be removed from the map

eraseAll

public void eraseAll()

Remove all data from the underlying store.

Specified by:

eraseAll in interface BinaryStore

keys

public Iterator keys()

Iterate all keys in the underlying store.

Specified by:

keys in interface BinaryStore

Returns:

a read-only iterator of the keys in the underlying store

close

public void close()

Release underlying resources.

getMaximumPages

public int getMaximumPages()

Determine the maximum number of pages that the cache will manage, beyond which the oldest pages are destroyed.

Returns:

the maximum number of pages that the cache will manage

getActivePageCount

public int getActivePageCount()

Determine the number of pages that the PagedBinaryStore is currently managing. This is the "active" page count.

Returns:

the number of pages that the PagedBinaryStore is currently managing

getTotalPageCount

public int getTotalPageCount()

Determine the number of pages that the PagedBinaryStore has managed in total, including those it is currently managing.

Returns:

the total number of pages ever managed by the PagedBinaryStore

getCurrentPageNumber

public int getCurrentPageNumber()

Determine the number of pages that the PagedBinaryStore has managed in total, including those it is currently managing.

Returns:

the total number of pages ever managed by the PagedBinaryStore

isPageActive

public boolean isPageActive(int nPage)

Determine if the specified page number is active. A page is active if it is either the current page, or a page that has not aged to the point that it has been discarded.

Parameters:

nPage - the page number to test

Returns:

if the specified page is active

getActivePageArray

public SerializationPagedCache.WrapperBinaryStore[] getActivePageArray()

Get the array of BinaryStore objects, one for each active page. The array is indexed by "page indexes" and not page numbers. Page numbers are sequential page ids; they can be translated to page indices by using the toPageIndex method.

Returns:

the array of active BinaryStore objects

getPage

public SerializationPagedCache.WrapperBinaryStore getPage(int nPage)

Get the BinaryStore for the page specified by the passed page number. The page number is basically the infinitely increasing counter of pages; the first page is 0, the second is 1, and so on.

Parameters:

nPage - the page number

Returns:

the correspodning BinaryStore, or null if the specified page number is not active

getCurrentPage

protected SerializationPagedCache.WrapperBinaryStore getCurrentPage()

Obtain the page to which current updates are being performed. This page is referred to as the "current" page.

Returns:

the BinaryStore that holds the current page's data

getOldestActivePage

protected SerializationPagedCache.WrapperBinaryStore getOldestActivePage()

Obtain the oldest active page.

Returns:

the BinaryStore that holds the oldest active page's data

toPageIndex

protected int toPageIndex(int nPage)

Translate a page number to an index into the PageArray.

Parameters:

nPage - the page number

Returns:

an index into the PageArray, or -1 if the page number is no longer valid

getPagedKeyMap

protected Map getPagedKeyMap()

Obtain the map that manages the mapping from Binary keys to BinaryStore objects. The BinaryStore objects are actually wrappers around the real BinaryStore objects that each manage one "page" of data.

Returns:

the map of Binary key to BinaryStore

advanceCurrentPage

protected SerializationPagedCache.WrapperBinaryStore advanceCurrentPage(SerializationPagedCache.WrapperBinaryStore store)

Advance the current page, using the passed BinaryStore as the store for the new current page, and returning the oldest active page, if the maximum number of active pages is exceeded by the advancing of the current page.

Parameters:

store - the BinaryStore to use for the new current page

Returns:

the oldest active page, if keeping it would exceed the maximum number of pages; otherwise null

logException

protected void logException(Throwable e,
                            String sMethod)

Helper to log ignored exceptions.

Parameters:

e - the throwable object

sMethod - the calling method name