org.h2.store
Interface DataHandler

All Known Implementing Classes:

Database, Recover, RunScriptCommand, ScriptCommand, SessionRemote, TestDataPage, TestFile, TestValueHashMap, TestValueMemory

public interface DataHandler

A data handler contains a number of callback methods. The most important implementing class is a database.

Method Summary

void	checkPowerOff() Check if the simulated power failure occurred.
void	checkWritingAllowed() Check if writing is allowed.
void	freeUpDiskSpace() Free up disk space if possible.
java.lang.String	getDatabasePath() Get the database path.
java.lang.String	getLobCompressionAlgorithm(int type) Get the compression algorithm used for large objects.
java.sql.Connection	getLobConnection() Get a database connection to be used for LOB access.
SmallLRUCache<java.lang.String,java.lang.String[]>	getLobFileListCache() Get the lob file list cache if it is used.
LobStorage	getLobStorage() Get the lob storage mechanism to use.
java.lang.Object	getLobSyncObject() Get the synchronization object for lob operations.
int	getMaxLengthInplaceLob() Get the maximum length of a in-place large object
TempFileDeleter	getTempFileDeleter() Get the temp file deleter mechanism.
FileStore	openFile(java.lang.String name, java.lang.String mode, boolean mustExist) Open a file at the given location.

Method Detail

getDatabasePath

java.lang.String getDatabasePath()

Get the database path.

Returns:

the database path

openFile

FileStore openFile(java.lang.String name,
                   java.lang.String mode,
                   boolean mustExist)

Open a file at the given location.

Parameters:

name - the file name

mode - the mode

mustExist - whether the file must already exist

Returns:

the file

checkPowerOff

void checkPowerOff()

Check if the simulated power failure occurred. This call will decrement the countdown.

Throws:

SQLException - if the simulated power failure occurred

checkWritingAllowed

void checkWritingAllowed()

Check if writing is allowed.

Throws:

SQLException - if it is not allowed

freeUpDiskSpace

void freeUpDiskSpace()

Free up disk space if possible. This method is called if more space is needed.

Throws:

SQLException - if no more space could be freed

getMaxLengthInplaceLob

int getMaxLengthInplaceLob()

Get the maximum length of a in-place large object

Returns:

the maximum size

getLobCompressionAlgorithm

java.lang.String getLobCompressionAlgorithm(int type)

Get the compression algorithm used for large objects.

Parameters:

type - the data type (CLOB or BLOB)

Returns:

the compression algorithm, or null

getTempFileDeleter

TempFileDeleter getTempFileDeleter()

Get the temp file deleter mechanism.

Returns:

the temp file deleter

getLobSyncObject

java.lang.Object getLobSyncObject()

Get the synchronization object for lob operations.

Returns:

the synchronization object

getLobFileListCache

SmallLRUCache<java.lang.String,java.lang.String[]> getLobFileListCache()

Get the lob file list cache if it is used.

Returns:

the cache or null

getLobStorage

LobStorage getLobStorage()

Get the lob storage mechanism to use.

Returns:

the lob storage mechanism

getLobConnection

java.sql.Connection getLobConnection()

Get a database connection to be used for LOB access.

Returns:

the connection or null