Class ReadOnly

java.lang.Object
org.apache.derby.impl.store.raw.log.ReadOnly
All Implemented Interfaces:
ModuleSupportable, Corruptable, LogFactory
public class ReadOnly extends Object implements LogFactory, ModuleSupportable
A read-only version of the log factory. It doesn't do anything, it doesn't check that the database needs recovery or not.

It doesn't handle undo. No recovery.

Multithreading considerations:
This class must be MT-safe.

  • Field Details

    • logArchiveDirectory

      private String logArchiveDirectory

  • Constructor Details

    • ReadOnly

      public ReadOnly()

  • Method Details

    • getLogger

      public Logger getLogger()
      Specified by:
      getLogger in interface LogFactory

    • createDataWarningFile

      public void createDataWarningFile() throws StandardException
      Not applicable in readonly databases
      Specified by:
      createDataWarningFile in interface LogFactory
      Throws:
      StandardException

    • setRawStoreFactory

      public void setRawStoreFactory(RawStoreFactory rsf)
      Not applicable in readonly databases
      Specified by:
      setRawStoreFactory in interface LogFactory

    • recover

      public void recover(DataFactory dataFactory, TransactionFactory transactionFactory) throws StandardException
      MT - not needed, no work is done
      Specified by:
      recover in interface LogFactory
      Parameters:
      dataFactory - - the data factory
      transactionFactory - - the transaction factory
      Throws:
      StandardException - Standard Derby Error Policy

    • checkpoint

      public boolean checkpoint(RawStoreFactory rawStoreFactory, DataFactory dataFactory, TransactionFactory transactionFactory, boolean wait)
      MT - not needed, no work is done
      Specified by:
      checkpoint in interface LogFactory
      Parameters:
      rawStoreFactory - - the raw store
      dataFactory - - the data factory
      transactionFactory - - the transaction factory
      wait - - if true waits for any existing checkpoint to complete and then executes and waits for another checkpoint. if false if another thead is executing a checkpoint routine will return immediately.
      Returns:
      true if checkpoint is successful, Will return false if wait is false and the routine finds another thread executing a checkpoint.

    • markCorrupt

      public StandardException markCorrupt(StandardException originalError)
      Description copied from interface: Corruptable
      Mark the module as corrupt. It is safe to call this multiple times.
      Specified by:
      markCorrupt in interface Corruptable
      Returns:
      Must always return its parameter.

    • flush

      public void flush(LogInstant where) throws StandardException
      Description copied from interface: LogFactory
      Flush all unwritten log record up to the log instance indicated to disk.
      Specified by:
      flush in interface LogFactory
      Parameters:
      where - flush log up to here
      Throws:
      StandardException - cannot flush log file due to sync error

    • canSupport

      public boolean canSupport(Properties startParams)
      Description copied from interface: ModuleSupportable
      See if this implementation can support any attributes that are listed in properties. This call may be made on a newly created instance before the boot() method has been called, or after the boot method has been called for a running module.

      The module can check for attributes in the properties to see if it can fulfill the required behaviour. E.g. the raw store may define an attribute called RawStore.Recoverable. If a temporary raw store is required the property RawStore.recoverable=false would be added to the properties before calling bootServiceModule. If a raw store cannot support this attribute its canSupport method would return null. Also see the Monitor class's prologue to see how the identifier is used in looking up properties.
      Actually a better way maybe to have properties of the form RawStore.Attributes.mandatory=recoverable,smallfootprint and RawStore.Attributes.requested=oltp,fast

      Specified by:
      canSupport in interface ModuleSupportable
      Returns:
      true if this instance can be used, false otherwise.

    • setTruncationLWM

      public LogInstant setTruncationLWM(UUID name, LogInstant instant, RawStoreFactory rawStoreFactory, TransactionFactory transFactory) throws StandardException
      Throws:
      StandardException

    • setTruncationLWM

      public void setTruncationLWM(UUID name, LogInstant instant) throws StandardException
      Throws:
      StandardException - functionality not implemented

    • removeTruncationLWM

      public void removeTruncationLWM(UUID name, RawStoreFactory rawStoreFactory, TransactionFactory transFactory) throws StandardException
      Throws:
      StandardException - functionality not implemented

    • getTruncationLWM

      public LogInstant getTruncationLWM(UUID name) throws StandardException
      Throws:
      StandardException - functionality not implemented

    • removeTruncationLWM

      public void removeTruncationLWM(UUID name) throws StandardException
      Throws:
      StandardException - functionality not implemented

    • openFlushedScan

      public ScanHandle openFlushedScan(DatabaseInstant i, int groupsIWant) throws StandardException
      Description copied from interface: LogFactory
      Get a ScanHandle to scan flushed records from the log.

      MT- read only

      Specified by:
      openFlushedScan in interface LogFactory
      Parameters:
      i - - the LogInstant where we start our scan. null means start at the beginning of the log. This function raises an error if startAt is a LogInstant which is not in the log.
      groupsIWant - - log record groups the scanner wants.
      Returns:
      the LogScan.
      Throws:
      StandardException - functionality not implemented

    • openForwardsScan

      public LogScan openForwardsScan(LogInstant startAt, LogInstant stopAt) throws StandardException
      Description copied from interface: LogFactory
      Get a LogScan to scan the log in a forward direction.

      MT- read only

      Specified by:
      openForwardsScan in interface LogFactory
      Parameters:
      startAt - - the LogInstant where we start our scan. null means start at the beginning of the log. This function raises an error if startAt is a LogInstant which is not in the log.
      stopAt - - the LogInstant where we stop our scan. null means stop at the end of the log. This function raises an error if stopAt is a LogInstant which is not in the log.
      Returns:
      the LogScan.
      Throws:
      StandardException - functionality not implemented

    • getFirstUnflushedInstant

      public LogInstant getFirstUnflushedInstant()
      Description copied from interface: LogFactory
      Get the instant for the last record in the log.
      Specified by:
      getFirstUnflushedInstant in interface LogFactory

    • getFirstUnflushedInstantAsLong

      public long getFirstUnflushedInstantAsLong()
      Description copied from interface: LogFactory
      Get the log instant long value of the first log record that has not been flushed. Only works after recover() has finished, or (if in slave replication mode) after calling initializeReplicationSlaveRole.
      Specified by:
      getFirstUnflushedInstantAsLong in interface LogFactory
      Returns:
      the log instant long value of the first log record that has not been flushed

    • openForwardsFlushedScan

      public LogScan openForwardsFlushedScan(LogInstant startAt) throws StandardException
      Description copied from interface: LogFactory
      Get a LogScan to scan flushed records from the log.

      MT- read only

      Specified by:
      openForwardsFlushedScan in interface LogFactory
      Parameters:
      startAt - - the LogInstant where we start our scan. null means start at the beginning of the log. This function raises an error if startAt is a LogInstant which is not in the log.
      Returns:
      the LogScan.
      Throws:
      StandardException - functionality not implemented

    • freezePersistentStore

      public void freezePersistentStore() throws StandardException
      Backup restore - stop sending log record to the log stream
      Specified by:
      freezePersistentStore in interface LogFactory
      Throws:
      StandardException - Standard Derby error policy

    • unfreezePersistentStore

      public void unfreezePersistentStore() throws StandardException
      Backup restore - start sending log record to the log stream
      Specified by:
      unfreezePersistentStore in interface LogFactory
      Throws:
      StandardException - Standard Derby error policy

    • logArchived

      public boolean logArchived()
      Backup restore - is the log being archived to some directory? if RawStore.LOG_ARCHIVAL_DIRECTORY is set to some value, that means the log is meant to be archived. Else, log not archived.
      Specified by:
      logArchived in interface LogFactory
      Returns:
      true if the log is being archived.

    • getLogFactoryProperties

      public void getLogFactoryProperties(PersistentSet set)
      Get JBMS properties relevant to the log factory
      Specified by:
      getLogFactoryProperties in interface LogFactory

    • getLogDirectory

      public StorageFile getLogDirectory()
      Description copied from interface: LogFactory
      Return the location of the log directory.
      Specified by:
      getLogDirectory in interface LogFactory

    • getCanonicalLogPath

      public String getCanonicalLogPath()
      Description copied from interface: LogFactory
      Return the canonical directory of the PARENT of the log directory. The log directory live in the "log" subdirectory of this path. If the log is at the default location (underneath the database directory), this returns null. Should only be called after the log factory is booted.
      Specified by:
      getCanonicalLogPath in interface LogFactory

    • enableLogArchiveMode

      public void enableLogArchiveMode()
      Specified by:
      enableLogArchiveMode in interface LogFactory

    • disableLogArchiveMode

      public void disableLogArchiveMode()
      Specified by:
      disableLogArchiveMode in interface LogFactory

    • deleteOnlineArchivedLogFiles

      public void deleteOnlineArchivedLogFiles()
      Specified by:
      deleteOnlineArchivedLogFiles in interface LogFactory

    • inRFR

      public boolean inRFR()
      Specified by:
      inRFR in interface LogFactory

    • checkpointInRFR

      public void checkpointInRFR(LogInstant cinstant, long redoLWM, long undoLWM, DataFactory df) throws StandardException
      Perform a checkpoint during rollforward recovery.
      Specified by:
      checkpointInRFR in interface LogFactory
      Parameters:
      cinstant - The LogInstant of the checkpoint
      redoLWM - Redo Low Water Mark in the check point record
      undoLWM - Undo Low Water Mark in the checkpoint
      df - - the data factory
      Throws:
      StandardException

    • startLogBackup

      public void startLogBackup(File toDir) throws StandardException
      Specified by:
      startLogBackup in interface LogFactory
      Throws:
      StandardException

    • endLogBackup

      public void endLogBackup(File toDir) throws StandardException
      Specified by:
      endLogBackup in interface LogFactory
      Throws:
      StandardException

    • abortLogBackup

      public void abortLogBackup()
      Specified by:
      abortLogBackup in interface LogFactory

    • setDatabaseEncrypted

      public void setDatabaseEncrypted(boolean isEncrypted, boolean flushLog)
      Sets whether the database is encrypted.

      Read-only database can not be re-encrypted, nothing to do in this case.

      Specified by:
      setDatabaseEncrypted in interface LogFactory
      Parameters:
      isEncrypted - true if the database is encrypted, false if not
      flushLog - true if log needs to be flushed, false otherwise

    • startNewLogFile

      public void startNewLogFile() throws StandardException
      Specified by:
      startNewLogFile in interface LogFactory
      Throws:
      StandardException

    • isCheckpointInLastLogFile

      public boolean isCheckpointInLastLogFile() throws StandardException
      Specified by:
      isCheckpointInLastLogFile in interface LogFactory
      Throws:
      StandardException

    • deleteLogFileAfterCheckpointLogFile

      public void deleteLogFileAfterCheckpointLogFile() throws StandardException
      Specified by:
      deleteLogFileAfterCheckpointLogFile in interface LogFactory
      Throws:
      StandardException

    • checkVersion

      public boolean checkVersion(int requiredMajorVersion, int requiredMinorVersion, String feature) throws StandardException
      Check to see if a database has been upgraded to the required level in order to use a store feature. This method is generally used to prevent writes to data/log file by a particular store feature until the database is upgraded to the required version. In read-only database writes are not allowed, so nothing to do for this method in this implementation of the log factory.
      Specified by:
      checkVersion in interface LogFactory
      Parameters:
      requiredMajorVersion - required database Engine major version
      requiredMinorVersion - required database Engine minor version
      feature - Non-null to throw an exception, null to return the state of the version match.
      Returns:
      true if the database has been upgraded to the required level, false otherwise.
      Throws:
      StandardException - not implemented exception is thrown

    • startReplicationMasterRole

      public void startReplicationMasterRole(MasterFactory masterFactory) throws StandardException
      Replication not applicable on readonly databases
      Specified by:
      startReplicationMasterRole in interface LogFactory
      Parameters:
      masterFactory - The MasterFactory service responsible for controlling the master side replication behaviour.
      Throws:
      StandardException - always thrown, indicating that ReadOnly databases can not be replicated

    • inReplicationMasterMode

      public boolean inReplicationMasterMode()
      Replication not applicable on readonly databases.
      Specified by:
      inReplicationMasterMode in interface LogFactory
      Returns:
      false always since replication is not applicable here.

    • stopReplicationMasterRole

      public void stopReplicationMasterRole()
      Replication not applicable on readonly databases
      Specified by:
      stopReplicationMasterRole in interface LogFactory