Class AllocExtent
java.lang.Object
org.apache.derby.impl.store.raw.data.AllocExtent
- All Implemented Interfaces:
Externalizable
,Serializable
An allocation extent row manages the page status of page in the extent.
AllocExtent is externalizable and is written to the AllocPage directly,
without being converted to a row first.
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final int
protected static final int
public Per Page statusprotected static final int
private long
private int
private long
private long
(package private) int
protected static final int
(package private) FormatableBitSet
private static final int
private static final int
private static final int
private static final int
private static final int
private int
private int
private long
private long
private static final int
(package private) FormatableBitSet
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Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
AllocExtent
(long offset, long start, int length, int pagesize, int maxlength) protected
AllocExtent
(AllocExtent original) -
Method Summary
Modifier and TypeMethodDescriptionprotected void
allocPage
(long pagenum) Allocate this page - this is called underneath the log recordprotected boolean
canAddFreePage
(long lastAllocatedPage) private void
checkInRange
(long pagenum) protected int
compress
(BaseContainerHandle owner, RawTransaction ntt, AllocPage alloc_page) Compress free pages at end of this extent.protected void
compressPages
(int new_highest_page, int num_pages_truncated) protected void
deallocPage
(long pagenum) Deallocate logical page pagenum - this is called underneath the log record.protected int
Get the number of used page in this extentprotected long
protected long
Get the first logical page number managed by this extent.protected long
getFreePageNumber
(long pnum) Get a page number that is freeprotected long
Get the last logical page number managed by this extent.protected long
get the last preallocated pagenumber managed by this alloc pageprotected long
protected long
getNextValidPageNumber
(long prevPageNumber) protected long
getPagenum
(int bit_pos) translate bit position in map to page number.protected long
getPageOffset
(long pagenum, int pagesize, boolean deallocOK) Get the physical offset of pagenum.protected int
getPageStatus
(long pagenum) Return the status of a particular pageprotected int
Get the total number of pages in this extentprotected int
Get the number of unfilled pages in this extentprotected long
getUnfilledPageNumber
(long pagenum) Get a page number that is unfilled, pagenum is the last page that was rejected.protected boolean
Return the status of this extentprotected static int
MAX_RANGE
(int availspace) Statically calculates how many pages this extent can manage given the availspace number of bytes to store this extent in if read/writeExternal changes, this must change tooprivate boolean
void
private void
setExtentFreePageStatus
(boolean hasFree) protected void
setLastPreallocPagenum
(long preAllocPagenum) preallocated N pages, passed in the last preallocated page number.protected String
protected boolean
trackUnfilledPage
(long pagenumber, boolean unfilled) protected void
undoCompressPages
(int new_highest_page, int num_pages_truncated) Undo the compress space operation.protected void
updateUnfilledPageInfo
(AllocExtent inputExtent) void
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Field Details
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extentOffset
private long extentOffset -
extentStart
private long extentStart -
extentEnd
private long extentEnd -
extentLength
private int extentLength -
extentStatus
int extentStatus -
preAllocLength
private int preAllocLength -
reserved1
private int reserved1 -
reserved2
private long reserved2 -
reserved3
private long reserved3 -
HAS_DEALLOCATED
private static final int HAS_DEALLOCATED- See Also:
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HAS_FREE
private static final int HAS_FREE- See Also:
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ALL_FREE
private static final int ALL_FREE- See Also:
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HAS_UNFILLED_PAGES
private static final int HAS_UNFILLED_PAGES- See Also:
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KEEP_UNFILLED_PAGES
private static final int KEEP_UNFILLED_PAGES- See Also:
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NO_DEALLOC_PAGE_MAP
private static final int NO_DEALLOC_PAGE_MAP- See Also:
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RETIRED
private static final int RETIRED- See Also:
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ALLOCATED_PAGE
protected static final int ALLOCATED_PAGEpublic Per Page status- See Also:
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DEALLOCATED_PAGE
protected static final int DEALLOCATED_PAGE- See Also:
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FREE_PAGE
protected static final int FREE_PAGE- See Also:
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freePages
FormatableBitSet freePages -
unFilledPages
FormatableBitSet unFilledPages
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Constructor Details
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AllocExtent
protected AllocExtent(long offset, long start, int length, int pagesize, int maxlength) -
AllocExtent
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AllocExtent
public AllocExtent()
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Method Details
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MAX_RANGE
protected static int MAX_RANGE(int availspace) Statically calculates how many pages this extent can manage given the availspace number of bytes to store this extent in if read/writeExternal changes, this must change too -
writeExternal
- Specified by:
writeExternal
in interfaceExternalizable
- Throws:
IOException
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readExternal
- Specified by:
readExternal
in interfaceExternalizable
- Throws:
IOException
ClassNotFoundException
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allocPage
Allocate this page - this is called underneath the log record- Throws:
StandardException
- Standard Derby error policy
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deallocPage
Deallocate logical page pagenum - this is called underneath the log record. pagenum must be a page managed by this extent and it must be valid- Throws:
StandardException
- Standard Derby error policy
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compress
protected int compress(BaseContainerHandle owner, RawTransaction ntt, AllocPage alloc_page) throws StandardException Compress free pages at end of this extent.Search backward from end of extent and prepare data structures to return pages at end of extent to the OS. Returns the lowest page that can be returned to the OS.
- Returns:
- Return bit of page where all pages that follow can be returned to the OS.
- Throws:
StandardException
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compressPages
protected void compressPages(int new_highest_page, int num_pages_truncated) -
undoCompressPages
protected void undoCompressPages(int new_highest_page, int num_pages_truncated) Undo the compress space operation.Undo of this operation doesn't really "undo" the operation, it just makes sure the data structures are ok after the undo. We are guaranteed at the point of the transaction doing the Undo of the compress space operation fixes up the bit maps to only point at pages within the new_highest_page range.
Prior to logging the compress space operation all pages greater than There are only 2 possibilities at this point: 1) the truncate of pages greater than new_highest_page happened before the abort took place. W 2)
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getExtentEnd
protected long getExtentEnd() -
getFreePageNumber
protected long getFreePageNumber(long pnum) Get a page number that is free -
getPageOffset
protected long getPageOffset(long pagenum, int pagesize, boolean deallocOK) throws StandardException Get the physical offset of pagenum. If deallocOK is true, then even if pagenum is deallocated, it is OK. If deallocOK is false, then an exception is thrown if pagenum is deallocated. An exception is always thrown if pagenum is a free page- Throws:
StandardException
- Standard Derby error policy
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isRetired
protected boolean isRetired()Return the status of this extent -
mayHaveFreePage
private boolean mayHaveFreePage() -
setExtentFreePageStatus
private void setExtentFreePageStatus(boolean hasFree) -
canAddFreePage
protected boolean canAddFreePage(long lastAllocatedPage) -
getPageStatus
protected int getPageStatus(long pagenum) Return the status of a particular page -
getFirstPagenum
protected long getFirstPagenum()Get the first logical page number managed by this extent. -
getLastPagenum
protected long getLastPagenum()Get the last logical page number managed by this extent. -
getPagenum
protected long getPagenum(int bit_pos) translate bit position in map to page number.- Returns:
- The page number of this "bit" in the extent map.
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getLastPreallocPagenum
protected long getLastPreallocPagenum()get the last preallocated pagenumber managed by this alloc page -
setLastPreallocPagenum
protected void setLastPreallocPagenum(long preAllocPagenum) preallocated N pages, passed in the last preallocated page number. -
getNextValidPageNumber
protected long getNextValidPageNumber(long prevPageNumber) -
getLastValidPageNumber
protected long getLastValidPageNumber() -
checkInRange
private void checkInRange(long pagenum) -
updateUnfilledPageInfo
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trackUnfilledPage
protected boolean trackUnfilledPage(long pagenumber, boolean unfilled) -
getUnfilledPageNumber
protected long getUnfilledPageNumber(long pagenum) Get a page number that is unfilled, pagenum is the last page that was rejected. -
getAllocatedPageCount
protected int getAllocatedPageCount()Get the number of used page in this extent -
getUnfilledPageCount
protected int getUnfilledPageCount()Get the number of unfilled pages in this extent -
getTotalPageCount
protected int getTotalPageCount()Get the total number of pages in this extent -
toDebugString
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