Top Description Methods

org.apache.derby.impl.store.raw.data

public Interface AllocationActions

Known Direct Implementers: org.apache.derby.impl.store.raw.data.DirectAllocActions, org.apache.derby.impl.store.raw.data.LoggableAllocActions
Imports: org.apache.derby.iapi.store.raw.xact.RawTransaction, org.apache.derby.shared.common.error.StandardException

This interface describe the operations that has to do with page allocation/deallocation. This interface is used for a special allocation page that records the allocation information and dispense the allocation policy.

Method Summary

Modifier and Type	Method and Description
public void	actionAllocatePage(RawTransaction The transaction t, BasePage the allocation page allocPage, long the page to allocation or deallocation pageNumber, int set the allocation status of the page this value doStatus, int on undo, set the allocation status of the page this value undoStatus) Set the allocation status of pageNumber to doStatus.
public void	actionChainAllocPage(RawTransaction The transaction t, BasePage the allocation page whose next page chain needs to be changed allocPage, long the next allocation page's number pageNumber, long the next allocation page's page offset pageOffset) Chain one allocation page to the next.
public void	actionCompressSpaceOperation(RawTransaction The transaction t, BasePage the allocation page to do compress on. allocPage, int The new highest page on this allocation page. The number is the offset of the page in the array of pages maintained by this allocation page, for instance a value of 0 indicates all page except the first one are to be truncated. If all pages are truncated then the offset is set to -1. new_highest_page, int The number of allocated pages in this allocation page prior to the truncate. Note that all pages from NewHighestPage+1 through newHighestPage+num_pages_truncated should be FREE. num_pages_truncated) Compress free pages.

Method Detail

actionAllocatePage	back to summary
public void actionAllocatePage(RawTransaction t, BasePage allocPage, long pageNumber, int doStatus, int undoStatus) throws StandardException Set the allocation status of pageNumber to doStatus. To undo this operation, set the allocation status of pageNumber to undoStatus Parameters t:RawTransaction The transaction allocPage:BasePage the allocation page pageNumber:long the page to allocation or deallocation doStatus:int set the allocation status of the page this value undoStatus:int on undo, set the allocation status of the page this value Exceptions StandardException: Standard Derby error policy

actionChainAllocPage	back to summary
public void actionChainAllocPage(RawTransaction t, BasePage allocPage, long pageNumber, long pageOffset) throws StandardException Chain one allocation page to the next. Parameters t:RawTransaction The transaction allocPage:BasePage the allocation page whose next page chain needs to be changed pageNumber:long the next allocation page's number pageOffset:long the next allocation page's page offset Exceptions StandardException: Standard Derby error policy

actionCompressSpaceOperation	back to summary
public void actionCompressSpaceOperation(RawTransaction t, BasePage allocPage, int new_highest_page, int num_pages_truncated) throws StandardException Compress free pages. Compress the free pages at the end of the range maintained by this allocation page. All pages being compressed should be FREE. Only pages in the last allocation page can be compressed. Parameters t:RawTransaction The transaction allocPage:BasePage the allocation page to do compress on. new_highest_page:int The new highest page on this allocation page. The number is the offset of the page in the array of pages maintained by this allocation page, for instance a value of 0 indicates all page except the first one are to be truncated. If all pages are truncated then the offset is set to -1. num_pages_truncated:int The number of allocated pages in this allocation page prior to the truncate. Note that all pages from NewHighestPage+1 through newHighestPage+num_pages_truncated should be FREE. Exceptions StandardException: Standard exception policy.