Class DirStorageFactory

java.lang.Object
org.apache.derby.impl.io.BaseStorageFactory
org.apache.derby.impl.io.DirStorageFactory
All Implemented Interfaces:
StorageFactory, WritableStorageFactory
public class DirStorageFactory extends BaseStorageFactory implements WritableStorageFactory
This class provides a disk based implementation of the StorageFactory interface. It is used by the database engine to access persistent data and transaction logs under the directory (default) subsubprotocol.

  • Constructor Details

    • DirStorageFactory

      public DirStorageFactory()

  • Method Details

    • newStorageFile

      public final StorageFile newStorageFile(String path)
      Construct a StorageFile from a path name.
      Specified by:
      newStorageFile in interface StorageFactory
      Overrides:
      newStorageFile in class BaseStorageFactory
      Parameters:
      path - The path name of the file
      Returns:
      A corresponding StorageFile object

    • newStorageFile

      public final StorageFile newStorageFile(String directoryName, String fileName)
      Construct a StorageFile from a directory and file name.
      Specified by:
      newStorageFile in interface StorageFactory
      Overrides:
      newStorageFile in class BaseStorageFactory
      Parameters:
      directoryName - The directory part of the path name.
      fileName - The name of the file within the directory.
      Returns:
      A corresponding StorageFile object

    • newStorageFile

      public final StorageFile newStorageFile(StorageFile directoryName, String fileName)
      Construct a StorageFile from a directory and file name.
      Specified by:
      newStorageFile in interface StorageFactory
      Overrides:
      newStorageFile in class BaseStorageFactory
      Parameters:
      directoryName - The directory part of the path name.
      fileName - The name of the file within the directory.
      Returns:
      A corresponding StorageFile object

    • newPersistentFile

      StorageFile newPersistentFile(String path)
      Construct a persistent StorageFile from a path name.
      Specified by:
      newPersistentFile in class BaseStorageFactory
      Parameters:
      path - The path name of the file. Guaranteed not to be in the temporary file directory. If null then the database directory should be returned.
      Returns:
      A corresponding StorageFile object

    • newPersistentFile

      StorageFile newPersistentFile(String directoryName, String fileName)
      Construct a persistent StorageFile from a directory and path name.
      Specified by:
      newPersistentFile in class BaseStorageFactory
      Parameters:
      directoryName - The path name of the directory. Guaranteed not to be in the temporary file directory. Guaranteed not to be null
      fileName - The name of the file within the directory. Guaranteed not to be null.
      Returns:
      A corresponding StorageFile object

    • newPersistentFile

      StorageFile newPersistentFile(StorageFile directoryName, String fileName)
      Construct a persistent StorageFile from a directory and path name.
      Specified by:
      newPersistentFile in class BaseStorageFactory
      Parameters:
      directoryName - The path name of the directory. Guaranteed not to be to be null. Guaranteed to be created by a call to one of the newPersistentFile methods.
      fileName - The name of the file within the directory. Guaranteed not to be null.
      Returns:
      A corresponding StorageFile object

    • sync

      public void sync(OutputStream stream, boolean metaData) throws IOException, SyncFailedException
      Force the data of an output stream out to the underlying storage. That is, ensure that it has been made persistent. If the database is to be transient, that is, if the database does not survive a restart, then the sync method implementation need not do anything.
      Specified by:
      sync in interface WritableStorageFactory
      Parameters:
      stream - The stream to be synchronized.
      metaData - If true then this method must force both changes to the file's contents and metadata to be written to storage; if false, it need only force file content changes to be written. The implementation is allowed to ignore this parameter and always force out metadata changes.
      Throws:
      IOException - if an I/O error occurs.
      SyncFailedException - Thrown when the buffers cannot be flushed, or because the system cannot guarantee that all the buffers have been synchronized with physical media.

    • supportsWriteSync

      public boolean supportsWriteSync()
      This method tests whether the "rws" and "rwd" modes are implemented. If the "rws" and "rwd" modes are supported then the database engine will conclude that the write methods of "rws"/"rwd" mode StorageRandomAccessFiles are slow but the sync method is fast and optimize accordingly.
      Specified by:
      supportsWriteSync in interface WritableStorageFactory
      Returns:
      true if an StIRandomAccess file opened with "rws" or "rwd" modes immediately writes data to the underlying storage, false if not.

    • isReadOnlyDatabase

      public boolean isReadOnlyDatabase()
      Description copied from interface: StorageFactory
      Determine whether the database is read only. The database engine supports read-only databases, even in file systems that are writable.
      Specified by:
      isReadOnlyDatabase in interface StorageFactory
      Overrides:
      isReadOnlyDatabase in class BaseStorageFactory
      Returns:
      true if the storage is read only, false if it is writable.

    • supportsRandomAccess

      public boolean supportsRandomAccess()
      Determine whether the storage supports random access. If random access is not supported then it will only be accessed using InputStreams and OutputStreams (if the database is writable).
      Specified by:
      supportsRandomAccess in interface StorageFactory
      Overrides:
      supportsRandomAccess in class BaseStorageFactory
      Returns:
      true if the storage supports random access, false if it is writable.

    • doInit

      void doInit() throws IOException
      Specified by:
      doInit in class BaseStorageFactory
      Throws:
      IOException