Package org.h2.store
Interface DataHandler
- All Known Implementing Classes:
Database
,Recover
,SessionRemote
public interface DataHandler
A data handler contains a number of callback methods, mostly related to CLOB
and BLOB handling. The most important implementing class is a database.
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Method Summary
Modifier and TypeMethodDescriptionvoid
Check if the simulated power failure occurred.void
Check if writing is allowed.Return compare mode.Get the database path.Get the lob file list cache if it is used.Get the lob storage mechanism to use.Get the synchronization object for lob operations.int
Get the maximum length of a in-place large objectGet the temp file deleter mechanism.Open a file at the given location.int
readLob
(long lobId, byte[] hmac, long offset, byte[] buff, int off, int length) Read from a lob.
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Method Details
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getDatabasePath
String getDatabasePath()Get the database path.- Returns:
- the database path
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openFile
Open a file at the given location.- Parameters:
name
- the file namemode
- the modemustExist
- whether the file must already exist- Returns:
- the file
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checkPowerOff
Check if the simulated power failure occurred. This call will decrement the countdown.- Throws:
DbException
- if the simulated power failure occurred
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checkWritingAllowed
Check if writing is allowed.- Throws:
DbException
- if it is not allowed
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getMaxLengthInplaceLob
int getMaxLengthInplaceLob()Get the maximum length of a in-place large object- Returns:
- the maximum size
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getTempFileDeleter
TempFileDeleter getTempFileDeleter()Get the temp file deleter mechanism.- Returns:
- the temp file deleter
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getLobSyncObject
Object getLobSyncObject()Get the synchronization object for lob operations.- Returns:
- the synchronization object
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getLobFileListCache
SmallLRUCache<String,String[]> getLobFileListCache()Get the lob file list cache if it is used.- Returns:
- the cache or null
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getLobStorage
LobStorageInterface getLobStorage()Get the lob storage mechanism to use.- Returns:
- the lob storage mechanism
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readLob
int readLob(long lobId, byte[] hmac, long offset, byte[] buff, int off, int length) Read from a lob.- Parameters:
lobId
- the lob idhmac
- the message authentication codeoffset
- the offset within the lobbuff
- the target bufferoff
- the offset within the target bufferlength
- the number of bytes to read- Returns:
- the number of bytes read
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getCompareMode
CompareMode getCompareMode()Return compare mode.- Returns:
- Compare mode.
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