Package com.sleepycat.db

Class LogCursor

java.lang.Object
com.sleepycat.db.LogCursor
public class LogCursor extends Object
The LogCursor object is the handle for a cursor into the log files, supporting sequential access to the records stored in log files.

The handle is not free-threaded. Once the LogCursor.close method is called, the handle may not be accessed again, regardless of that method's success or failure.

  • Method Details

    • close

      public void close() throws DatabaseException
      Discard the log cursor. After close() has been called, regardless of its return, the cursor handle may not be used again.
      Throws:
      DatabaseException

    • getCurrent

      public OperationStatus getCurrent(LogSequenceNumber lsn, DatabaseEntry data) throws DatabaseException
      Return the LogSequenceNumber and log record to which the log cursor currently refers.

      Parameters:
      lsn - The returned LogSequenceNumber.

      data - The returned log record. The data field is set to the record retrieved, and the size field indicates the number of bytes in the record.

      Returns:
      The status of the operation.

      Throws:
      DatabaseException - if a failure occurs.

    • getNext

      public OperationStatus getNext(LogSequenceNumber lsn, DatabaseEntry data) throws DatabaseException
      Return the next LogSequenceNumber and log record.

      The current log position is advanced to the next record in the log, and its LogSequenceNumber and data are returned. If the cursor has not been initialized, the first available log record in the log will be returned.

      Parameters:
      lsn - The returned LogSequenceNumber.

      data - The returned log record.

      Returns:
      The status of the operation; a return of NOTFOUND indicates the last log record has already been returned or the log is empty.

      Throws:
      DatabaseException - if a failure occurs.

    • getFirst

      public OperationStatus getFirst(LogSequenceNumber lsn, DatabaseEntry data) throws DatabaseException
      Return the first LogSequenceNumber and log record.

      The current log position is set to the first record in the log, and its LogSequenceNumber and data are returned.

      Parameters:
      lsn - The returned LogSequenceNumber.

      data - The returned log record.

      Returns:
      The status of the operation; a return of NOTFOUND indicates the log is empty.

      Throws:
      DatabaseException - if a failure occurs.

    • getLast

      public OperationStatus getLast(LogSequenceNumber lsn, DatabaseEntry data) throws DatabaseException
      Return the last LogSequenceNumber and log record.

      The current log position is set to the last record in the log, and its LogSequenceNumber and data are returned.

      Parameters:
      lsn - The returned LogSequenceNumber.

      data - The returned log record.

      Returns:
      The status of the operation; a return of NOTFOUND indicates the log is empty.

      Throws:
      DatabaseException - if a failure occurs.

    • getPrev

      public OperationStatus getPrev(LogSequenceNumber lsn, DatabaseEntry data) throws DatabaseException
      Return the previous LogSequenceNumber and log record.

      The current log position is advanced to the previous record in the log, and its LogSequenceNumber and data are returned. If the cursor has not been initialized, the last available log record in the log will be returned.

      Parameters:
      lsn - The returned LogSequenceNumber.

      data - The returned log record.

      Returns:
      The status of the operation; a return of NOTFOUND indicates the first log record has already been returned or the log is empty.

      Throws:
      DatabaseException - if a failure occurs.

    • set

      public OperationStatus set(LogSequenceNumber lsn, DatabaseEntry data) throws DatabaseException
      Return a specific log record.

      The current log position is set to the specified record in the log, and its data is returned.

      Parameters:
      lsn - The specified LogSequenceNumber.

      data - The returned log record.

      Returns:
      The status of the operation.

      Throws:
      DatabaseException - if a failure occurs.

    • version

      public int version() throws DatabaseException
      Get the log file version.

      Returns:
      The log file version.

      Throws:
      DatabaseException - if a failure occurs.