com.orientechnologies.orient.core.storage.cache

Interface OWriteCache

All Known Implementing Classes:

ODirectMemoryOnlyDiskCache, OWOWCache

public interface OWriteCache

Method Summary

Modifier and Type	Method and Description
void	addBackgroundExceptionListener(OBackgroundExceptionListener listener) Adds listener which is triggered if exception is cast inside background flush data thread.
long	addFile(String fileName)
long	addFile(String fileName, long fileId)
void	addLowDiskSpaceListener(OLowDiskSpaceListener listener)
void	addPageIsBrokenListener(OPageIsBrokenListener listener) Adds listener which is called by cache if corruption of file page is detected.
int	allocateNewPage(long fileId)
long	bookFileId(String fileName)
void	checkCacheOverflow()
boolean	checkLowDiskSpace()
OPageDataVerificationError[]	checkStoredPages(OCommandOutputListener commandOutputListener)
long[]	close()
void	close(long fileId, boolean flush)
long[]	delete()
void	deleteFile(long fileId)
boolean	exists(long fileId)
boolean	exists(String fileName)
long	externalFileId(int fileId) Converts unique internal file id to external one.
long	fileIdByName(String fileName) Returns id associated with given file or value < 0 if such file does not exist.
boolean	fileIdsAreEqual(long firsId, long secondId) DO NOT DELETE THIS METHOD IT IS USED IN ENTERPRISE STORAGE
String	fileNameById(long fileId)
Map<String,Long>	files()
void	flush()
void	flush(long fileId)
void	flushTillSegment(long segmentId)
long	getExclusiveWriteCachePagesSize()
long	getFilledUpTo(long fileId)
int	getId()
Long	getMinimalNotFlushedSegment()
Path	getRootDirectory() Directory which contains all files managed by write cache.
int	internalFileId(long fileId) Returns internal file id which is unique and always the same for given file in contrary to external id which changes over close/open cycle of cache.
OCachePointer[]	load(long fileId, long startPageIndex, int pageCount, OModifiableBoolean cacheHit, boolean verifyChecksums)
long	loadFile(String fileName) Registers new file in write cache and returns file id assigned to this file.
void	makeFuzzyCheckpoint(long segmentId)
String	nativeFileNameById(long fileId) Obtains native file name by the given file id.
int	pageSize() DO NOT DELETE THIS METHOD IT IS USED IN ENTERPRISE STORAGE
void	removeBackgroundExceptionListener(OBackgroundExceptionListener listener) Removes listener which is triggered if exception is cast inside background flush data thread.
void	removeLowDiskSpaceListener(OLowDiskSpaceListener listener)
void	removePageIsBrokenListener(OPageIsBrokenListener listener) Removes listener which is called by cache if corruption of file page is detected.
void	renameFile(long fileId, String newFileName)
void	replaceFileContentWith(long fileId, Path newContentFile) Replaces the file content with the content of the provided file.
String	restoreFileById(long fileId) Finds if there was file in write cache with given id which is deleted right now.
void	store(long fileId, long pageIndex, OCachePointer dataPointer)
void	truncateFile(long fileId)
void	updateDirtyPagesTable(OCachePointer pointer, OLogSequenceNumber startLSN)

Method Detail

addPageIsBrokenListener

void addPageIsBrokenListener(OPageIsBrokenListener listener)

Adds listener which is called by cache if corruption of file page is detected.

removePageIsBrokenListener

void removePageIsBrokenListener(OPageIsBrokenListener listener)

Removes listener which is called by cache if corruption of file page is detected.

addLowDiskSpaceListener

void addLowDiskSpaceListener(OLowDiskSpaceListener listener)

removeLowDiskSpaceListener

void removeLowDiskSpaceListener(OLowDiskSpaceListener listener)

bookFileId

long bookFileId(String fileName)

loadFile

long loadFile(String fileName)
       throws IOException

Registers new file in write cache and returns file id assigned to this file.

File id consist of two parts:

1. Internal id is permanent and can not be changed during life of storage internalFileId(long)
2. Write cache id which is changed between storage open/close cycles

If file with the same name is deleted and then new file is created this file with have the same internal id.

Parameters:

fileName - Name of file to register inside storage.

Returns:

Id of registered file

Throws:

IOException

addFile

long addFile(String fileName)
      throws IOException

Throws:

IOException

addFile

long addFile(String fileName,
             long fileId)
      throws IOException

Throws:

IOException

fileIdByName

long fileIdByName(String fileName)

Returns id associated with given file or value < 0 if such file does not exist.

Parameters:

fileName - File name id of which has to be returned.

Returns:

id associated with given file or value < 0 if such file does not exist.

checkLowDiskSpace

boolean checkLowDiskSpace()
                   throws IOException

Throws:

IOException

makeFuzzyCheckpoint

void makeFuzzyCheckpoint(long segmentId)
                  throws IOException

Throws:

IOException

flushTillSegment

void flushTillSegment(long segmentId)

exists

boolean exists(String fileName)

exists

boolean exists(long fileId)

store

void store(long fileId,
           long pageIndex,
           OCachePointer dataPointer)

checkCacheOverflow

void checkCacheOverflow()
                 throws InterruptedException

Throws:

InterruptedException

allocateNewPage

int allocateNewPage(long fileId)
             throws IOException

Throws:

IOException

load

OCachePointer[] load(long fileId,
                     long startPageIndex,
                     int pageCount,
                     OModifiableBoolean cacheHit,
                     boolean verifyChecksums)
              throws IOException

Throws:

IOException

flush

void flush(long fileId)

flush

void flush()

getFilledUpTo

long getFilledUpTo(long fileId)

getExclusiveWriteCachePagesSize

long getExclusiveWriteCachePagesSize()

deleteFile

void deleteFile(long fileId)
         throws IOException

Throws:

IOException

truncateFile

void truncateFile(long fileId)
           throws IOException

Throws:

IOException

renameFile

void renameFile(long fileId,
                String newFileName)
         throws IOException

Throws:

IOException

replaceFileContentWith

void replaceFileContentWith(long fileId,
                            Path newContentFile)
                     throws IOException

Replaces the file content with the content of the provided file.

Parameters:

fileId - the file id of the file to replace the content of.

newContentFile - the new content file to replace the current content with.

Throws:

IOException

close

long[] close()
      throws IOException

Throws:

IOException

close

void close(long fileId,
           boolean flush)

checkStoredPages

OPageDataVerificationError[] checkStoredPages(OCommandOutputListener commandOutputListener)

delete

long[] delete()
       throws IOException

Throws:

IOException

fileNameById

String fileNameById(long fileId)

nativeFileNameById

String nativeFileNameById(long fileId)

Obtains native file name by the given file id.

Native file name is a file name of a "physical" on-disk file, it may differ from the "virtual" logical file name.

Parameters:

fileId - the file id to obtain the native file name of.

Returns:

the obtained native file name or null if the passed file id doesn't correspond to any file.

getId

int getId()

files

Map<String,Long> files()

pageSize

int pageSize()

DO NOT DELETE THIS METHOD IT IS USED IN ENTERPRISE STORAGE

Returns:

Size of page inside of cache.

fileIdsAreEqual

boolean fileIdsAreEqual(long firsId,
                        long secondId)

DO NOT DELETE THIS METHOD IT IS USED IN ENTERPRISE STORAGE

Takes two ids and checks whether they are equal from point of view of write cache. In other words methods checks whether two ids in reality contain the same internal ids.

restoreFileById

String restoreFileById(long fileId)
                throws IOException

Finds if there was file in write cache with given id which is deleted right now. If such file exists it creates new file with the same name at it was in deleted file.

Parameters:

fileId - If of file which should be restored

Returns:

Name of restored file or null if such name does not exist

Throws:

IOException

addBackgroundExceptionListener

void addBackgroundExceptionListener(OBackgroundExceptionListener listener)

Adds listener which is triggered if exception is cast inside background flush data thread.

Parameters:

listener - Listener to trigger

removeBackgroundExceptionListener

void removeBackgroundExceptionListener(OBackgroundExceptionListener listener)

Removes listener which is triggered if exception is cast inside background flush data thread.

Parameters:

listener - Listener to remove

getRootDirectory

Path getRootDirectory()

Directory which contains all files managed by write cache.

Returns:

Directory which contains all files managed by write cache or null in case of in memory database.

internalFileId

int internalFileId(long fileId)

Returns internal file id which is unique and always the same for given file in contrary to external id which changes over close/open cycle of cache.

Parameters:

fileId - External file id.

Returns:

Internal file id.

externalFileId

long externalFileId(int fileId)

Converts unique internal file id to external one. External id is combination of internal id and write cache id, which changes every time when cache is closed and opened again.

Parameters:

fileId - Internal file id.

Returns:

External file id.

See Also:

internalFileId(long), getId()

getMinimalNotFlushedSegment

Long getMinimalNotFlushedSegment()

updateDirtyPagesTable

void updateDirtyPagesTable(OCachePointer pointer,
                           OLogSequenceNumber startLSN)