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.
  • Method Details

    • getDatabasePath

      String getDatabasePath()
      Get the database path.
      Returns:
      the database path
    • openFile

      FileStore openFile(String name, 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() throws DbException
      Check if the simulated power failure occurred. This call will decrement the countdown.
      Throws:
      DbException - if the simulated power failure occurred
    • checkWritingAllowed

      void checkWritingAllowed() throws DbException
      Check if writing is allowed.
      Throws:
      DbException - if it is not allowed
    • getMaxLengthInplaceLob

      int getMaxLengthInplaceLob()
      Get the maximum length of a in-place large object
      Returns:
      the maximum size
    • getTempFileDeleter

      TempFileDeleter getTempFileDeleter()
      Get the temp file deleter mechanism.
      Returns:
      the temp file deleter
    • getLobSyncObject

      Object getLobSyncObject()
      Get the synchronization object for lob operations.
      Returns:
      the synchronization object
    • getLobFileListCache

      SmallLRUCache<String,String[]> getLobFileListCache()
      Get the lob file list cache if it is used.
      Returns:
      the cache or null
    • getLobStorage

      LobStorageInterface getLobStorage()
      Get the lob storage mechanism to use.
      Returns:
      the lob storage mechanism
    • readLob

      int readLob(long lobId, byte[] hmac, long offset, byte[] buff, int off, int length)
      Read from a lob.
      Parameters:
      lobId - the lob id
      hmac - the message authentication code
      offset - the offset within the lob
      buff - the target buffer
      off - the offset within the target buffer
      length - the number of bytes to read
      Returns:
      the number of bytes read
    • getCompareMode

      CompareMode getCompareMode()
      Return compare mode.
      Returns:
      Compare mode.