com.sleepycat.je.log.entry

Class TraceLogEntry

java.lang.Object

com.sleepycat.je.log.entry.SingleItemEntry<T>

com.sleepycat.je.log.entry.TraceLogEntry

All Implemented Interfaces:

LogEntry, ReplicableLogEntry, Cloneable

public class TraceLogEntry
extends SingleItemEntry<T>

Log entry for a trace object.

Constructor Summary

Constructors

Constructor and Description
TraceLogEntry() Construct a log entry for reading a Trace object.
TraceLogEntry(Trace trace) Construct a log entry for writing a Trace object.

Method Summary

Modifier and Type	Method and Description
LogEntry	clone()
Collection<VersionedWriteLoggable>	getEmbeddedLoggables() Returns all possible VersionedWriteLoggable objects that may be embedded in the binary data of this log entry.
int	getLastFormatChange() Returns the log version of the most recent format change for this log entry.
Class<T>	getLogClass() Returns the class of the contained loggable item or items, or null if the instance was created to write an entry.
LogEntryType	getLogType()
Object	getResolvedItem(DatabaseImpl dbImpl) By default, this log entry is complete and does not require fetching additional entries.
int	getSize(int logVersion, boolean forReplication) Returns the number of bytes needed to store this entry in the format for the specified log version.
boolean	hasReplicationFormat() Returns whether this format has a variant that is optimized for replication.
boolean	isDeleted() Returns whether this is a deleted LN.
boolean	isImmediatelyObsolete(DatabaseImpl dbImpl) Returns true if this item should be counted as obsolete when logged.
boolean	isReplicationFormatWorthwhile(ByteBuffer logBuffer, int srcVersion, int destVersion) Returns whether it is worthwhile to materialize and then re-serialize a log entry in a format optimized for replication.
void	postFetchInit(DatabaseImpl dbImpl)
void	postLogWork(LogEntryHeader header, long justLoggedLsn, VLSN vlsn) Do any processing we need to do after logging, while under the logging latch.
void	setLogType(LogEntryType entryType) Inform a BaseEntry instance of its corresponding LogEntryType.
static void	setTestPriorItem(Loggable priorItem) Specify an object to write instead of the enclosed item when asked to write this entry in the log format prior to the last changed version, for testing.
String	toString()
void	writeEntry(ByteBuffer destBuffer, int logVersion, boolean forReplication) Serializes this object into the specified buffer in the format for the the specified log version.

Methods inherited from class com.sleepycat.je.log.entry.SingleItemEntry

create, create, dumpEntry, dumpRep, getDbId, getMainItem, getSize, getTransactionId, logicalEquals, readEntry, writeEntry

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.sleepycat.je.log.entry.LogEntry

clone, dumpEntry, dumpRep, getDbId, getLogType, getMainItem, getResolvedItem, getSize, getTransactionId, isDeleted, isImmediatelyObsolete, logicalEquals, postLogWork, readEntry, setLogType, writeEntry

Constructor Detail

TraceLogEntry

public TraceLogEntry()

Construct a log entry for reading a Trace object.

TraceLogEntry

public TraceLogEntry(Trace trace)

Construct a log entry for writing a Trace object.

Method Detail

setTestPriorItem

public static void setTestPriorItem(Loggable priorItem)

Specify an object to write instead of the enclosed item when asked to write this entry in the log format prior to the last changed version, for testing.

getLastFormatChange

public int getLastFormatChange()

Description copied from interface: ReplicableLogEntry

Returns the log version of the most recent format change for this log entry.

Returns:

the log version of the most recent format change

getSize

public int getSize(int logVersion,
                   boolean forReplication)

Returns the number of bytes needed to store this entry in the format for the specified log version. Earlier log versions only need to be supported for log entries with format changes made in LogEntryType.LOG_VERSION_REPLICATE_OLDER or greater.

This implementation provides additional behavior for testing.

Specified by:

getSize in interface ReplicableLogEntry

Parameters:

logVersion - the log version

forReplication - whether the entry will be sent over the wire, and not written to the log.

Returns:

the number of bytes to store this entry for the log version

writeEntry

public void writeEntry(ByteBuffer destBuffer,
                       int logVersion,
                       boolean forReplication)

Serializes this object into the specified buffer in the format for the the specified log version. Earlier log versions only need to be supported for log entries with format changes made in LogEntryType.LOG_VERSION_REPLICATE_OLDER or greater.

This implementation provides additional behavior for testing.

Specified by:

writeEntry in interface ReplicableLogEntry

Parameters:

destBuffer - the destination buffer

logVersion - the log version

forReplication - whether the entry will be sent over the wire, and not written to the log.

getEmbeddedLoggables

public Collection<VersionedWriteLoggable> getEmbeddedLoggables()

Description copied from interface: ReplicableLogEntry

Returns all possible VersionedWriteLoggable objects that may be embedded in the binary data of this log entry.

This is used by tests to ensure that for each X:Y pair, where X is a ReplicableLogEntry and Y is a VersionedWriteLoggable, and X embeds Y either directly or indirectly, X.getLastFormatChange is greater than or equal to Y.getLastFormatChange.

Each ReplicableLogEntry and VersionedWriteLoggable class typically has a LAST_FORMAT_CHANGE constant that is returned by its getLastFormatChange method. When bumping this constant for an object X embedded by an log entry Y, Y.LAST_FORMAT_CHANGE should also be set to the minimum of its current value and X.LAST_FORMAT_CHANGE.

Enforcing this rule in a general way is made possible by the getEmbeddedLoggables method of each ReplicableLogEntry and VersionedWriteLoggable. Note that this method is not intended to be called outside of tests.

Specified by:

getEmbeddedLoggables in interface ReplicableLogEntry

hasReplicationFormat

public boolean hasReplicationFormat()

Description copied from interface: ReplicableLogEntry

Returns whether this format has a variant that is optimized for replication.

Specified by:

hasReplicationFormat in interface ReplicableLogEntry

isReplicationFormatWorthwhile

public boolean isReplicationFormatWorthwhile(ByteBuffer logBuffer,
                                             int srcVersion,
                                             int destVersion)

Description copied from interface: ReplicableLogEntry

Returns whether it is worthwhile to materialize and then re-serialize a log entry in a format optimized for replication. Implementations should attempt to check efficiently, without instantiating the log entry object. Some implementations will simply return false.

WARNING: The logBuffer position must not be changed by this method.

WARNING: The shared LogEntry object is used for calling this method, and this method must not change any of the fields in the object.

Specified by:

isReplicationFormatWorthwhile in interface ReplicableLogEntry

Parameters:

logBuffer - contains the entry that would be re-serialized.

srcVersion - the log version of entry in logBuffer.

destVersion - the version that would be used for re-serialization.

getLogClass

public Class<T> getLogClass()

Returns the class of the contained loggable item or items, or null if the instance was created to write an entry.

Returns:

the loggable class or null

setLogType

public void setLogType(LogEntryType entryType)

Inform a BaseEntry instance of its corresponding LogEntryType.

Specified by:

setLogType in interface LogEntry

getLogType

public LogEntryType getLogType()

Specified by:

getLogType in interface LogEntry

Returns:

the type of log entry

getResolvedItem

public Object getResolvedItem(DatabaseImpl dbImpl)

By default, this log entry is complete and does not require fetching additional entries. This method is overridden by BINDeltaLogEntry.

Specified by:

getResolvedItem in interface LogEntry

isImmediatelyObsolete

public boolean isImmediatelyObsolete(DatabaseImpl dbImpl)

Description copied from interface: LogEntry

Returns true if this item should be counted as obsolete when logged.

Specified by:

isImmediatelyObsolete in interface LogEntry

isDeleted

public boolean isDeleted()

Description copied from interface: LogEntry

Returns whether this is a deleted LN.

Specified by:

isDeleted in interface LogEntry

postLogWork

public void postLogWork(LogEntryHeader header,
                        long justLoggedLsn,
                        VLSN vlsn)

Do any processing we need to do after logging, while under the logging latch.

Specified by:

postLogWork in interface LogEntry

Throws:

DatabaseException - from subclasses.

postFetchInit

public void postFetchInit(DatabaseImpl dbImpl)

clone

public LogEntry clone()

Specified by:

clone in interface LogEntry

Overrides:

clone in class Object

Returns:

a shallow clone.

toString

public String toString()

Overrides:

toString in class Object