org.apache.derby.impl.store.raw.log
Class ReadOnly

java.lang.Object
  org.apache.derby.impl.store.raw.log.ReadOnly

All Implemented Interfaces:

ModuleSupportable, Corruptable, LogFactory

public class ReadOnly
extends java.lang.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 Summary

private java.lang.String

logArchiveDirectory

Fields inherited from interface org.apache.derby.iapi.store.raw.log.LogFactory

LOG_DIRECTORY_NAME, MODULE, RT_READONLY, RUNTIME_ATTRIBUTES

Constructor Summary

ReadOnly()

Method Summary

void	abortLogBackup()
boolean	canSupport(java.util.Properties startParams) See if this implementation can support any attributes that are listed in properties.
boolean	checkpoint(RawStoreFactory rawStoreFactory, DataFactory dataFactory, TransactionFactory transactionFactory, boolean wait) MT - not needed, no work is done
void	checkpointInRFR(LogInstant cinstant, long redoLWM, long undoLWM, DataFactory df) Perform a checkpoint during rollforward recovery.
boolean	checkVersion(int requiredMajorVersion, int requiredMinorVersion, java.lang.String feature) Check to see if a database has been upgraded to the required level in order to use a store feature.
void	createDataWarningFile() Not applicable in readonly databases
void	deleteLogFileAfterCheckpointLogFile()
void	deleteOnlineArchivedLogFiles()
void	disableLogArchiveMode()
void	enableLogArchiveMode()
void	endLogBackup(java.io.File toDir)
void	flush(LogInstant where) Flush all unwritten log record up to the log instance indicated to disk.
void	freezePersistentStore() Backup restore - stop sending log record to the log stream
java.lang.String	getCanonicalLogPath() Return the canonical directory of the PARENT of the log directory.
LogInstant	getFirstUnflushedInstant() Get the instant for the last record in the log.
long	getFirstUnflushedInstantAsLong() Get the log instant long value of the first log record that has not been flushed.
StorageFile	getLogDirectory() Return the location of the log directory.
void	getLogFactoryProperties(PersistentSet set) Get JBMS properties relevant to the log factory
Logger	getLogger()
LogInstant	getTruncationLWM(UUID name)
boolean	inReplicationMasterMode() Replication not applicable on readonly databases.
boolean	inRFR()
boolean	isCheckpointInLastLogFile()
boolean	logArchived() Backup restore - is the log being archived to some directory?
StandardException	markCorrupt(StandardException originalError) Mark the module as corrupt.
ScanHandle	openFlushedScan(DatabaseInstant i, int groupsIWant) Get a ScanHandle to scan flushed records from the log.
LogScan	openForwardsFlushedScan(LogInstant startAt) Get a LogScan to scan flushed records from the log.
LogScan	openForwardsScan(LogInstant startAt, LogInstant stopAt) Get a LogScan to scan the log in a forward direction.
void	recover(DataFactory dataFactory, TransactionFactory transactionFactory) MT - not needed, no work is done
void	removeTruncationLWM(UUID name)
void	removeTruncationLWM(UUID name, RawStoreFactory rawStoreFactory, TransactionFactory transFactory)
void	setDatabaseEncrypted(boolean isEncrypted, boolean flushLog) Sets whether the database is encrypted.
void	setRawStoreFactory(RawStoreFactory rsf) Not applicable in readonly databases
void	setTruncationLWM(UUID name, LogInstant instant)
LogInstant	setTruncationLWM(UUID name, LogInstant instant, RawStoreFactory rawStoreFactory, TransactionFactory transFactory)
void	startLogBackup(java.io.File toDir)
void	startNewLogFile()
void	startReplicationMasterRole(MasterFactory masterFactory) Replication not applicable on readonly databases
void	stopReplicationMasterRole() Replication not applicable on readonly databases
void	unfreezePersistentStore() Backup restore - start sending log record to the log stream

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

logArchiveDirectory

private java.lang.String logArchiveDirectory

Constructor Detail

ReadOnly

public ReadOnly()

Method Detail

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(java.util.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 java.lang.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(java.io.File toDir)
                    throws StandardException

Specified by:

startLogBackup in interface LogFactory

Throws:

StandardException

endLogBackup

public void endLogBackup(java.io.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,
                            java.lang.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