com.sleepycat.je.log.entry

Class ErasedLogEntry

java.lang.Object

com.sleepycat.je.log.entry.ErasedLogEntry

All Implemented Interfaces:

LogEntry, Cloneable

public class ErasedLogEntry
extends Object
implements LogEntry

When a log entry is erase, it is overwritten in place. Its type is set to LogEntryType.LOG_ERASED and its item bytes are set to zero. However, an entry may be partially erased, in which case isAllZeros() returns false. The original entry type is lost, but the other fields of the header are left in place. The item size, previous offset, VLSN and flags are left intact. The checksum field is left intact, but is no longer valid.

See Also:

DataEraser

Constructor Summary

Constructors

Constructor and Description
ErasedLogEntry()

Method Summary

Modifier and Type	Method and Description
ErasedLogEntry	clone()
StringBuilder	dumpEntry(StringBuilder sb, boolean verbose) Print out the contents of an entry.
void	dumpRep(StringBuilder sb) Dump the contents of the log entry that are interesting for replication.
DatabaseId	getDbId()
LogEntryType	getLogType()
Object	getMainItem()
Object	getResolvedItem(DatabaseImpl dbImpl) Construct a complete item from a item entry, fetching additional log entries as needed to ensure that a usable main object is available.
int	getSize()
long	getTransactionId()
boolean	isAllZeros() Returns whether the item bytes are all zeros, meaning that erasure of this entry is complete.
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	logicalEquals(LogEntry other)
void	postLogWork(LogEntryHeader header, long justLoggedLsn, VLSN vlsn) Do any processing we need to do after logging, while under the logging latch.
void	readEntry(EnvironmentImpl envImpl, LogEntryHeader header, ByteBuffer entryBuffer) Read in a log entry.
void	setLogType(LogEntryType entryType) Inform a LogEntry instance of its corresponding LogEntryType.
void	writeEntry(ByteBuffer logBuffer) Serialize this object into the buffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

ErasedLogEntry

public ErasedLogEntry()

Method Detail

getSize

public int getSize()

Specified by:

getSize in interface LogEntry

Returns:

size of byte buffer needed to store this entry.

writeEntry

public void writeEntry(ByteBuffer logBuffer)

Description copied from interface: LogEntry

Serialize this object into the buffer.

Specified by:

writeEntry in interface LogEntry

Parameters:

logBuffer - is the destination buffer

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)

Description copied from interface: LogEntry

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

Specified by:

postLogWork in interface LogEntry

clone

public ErasedLogEntry clone()

Specified by:

clone in interface LogEntry

Overrides:

clone in class Object

Returns:

a shallow clone.

setLogType

public void setLogType(LogEntryType entryType)

Description copied from interface: LogEntry

Inform a LogEntry 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

readEntry

public void readEntry(EnvironmentImpl envImpl,
                      LogEntryHeader header,
                      ByteBuffer entryBuffer)

Description copied from interface: LogEntry

Read in a log entry.

Specified by:

readEntry in interface LogEntry

dumpEntry

public StringBuilder dumpEntry(StringBuilder sb,
                               boolean verbose)

Description copied from interface: LogEntry

Print out the contents of an entry.

Specified by:

dumpEntry in interface LogEntry

isAllZeros

public boolean isAllZeros()

Returns whether the item bytes are all zeros, meaning that erasure of this entry is complete. A partially erased entry can occur when a crash occurs between writing the header type byte persistently and writing the item bytes persistently.

getMainItem

public Object getMainItem()

Specified by:

getMainItem in interface LogEntry

Returns:

the first item of the log entry

getResolvedItem

public Object getResolvedItem(DatabaseImpl dbImpl)

Description copied from interface: LogEntry

Construct a complete item from a item entry, fetching additional log entries as needed to ensure that a usable main object is available. For an OldBINDeltaLogEntry, fetches the full BIN and merges the delta information. This is necessary to return a Node main object. However, for the new BINDeltaLogEntry, the full BIN is not fetched, since the partial BIN (the delta) is usable as a Node.

Specified by:

getResolvedItem in interface LogEntry

getDbId

public DatabaseId getDbId()

Specified by:

getDbId in interface LogEntry

Returns:

the ID of the database containing this entry, or null if this entry type is not part of a database.

getTransactionId

public long getTransactionId()

Specified by:

getTransactionId in interface LogEntry

Returns:

return the transaction id if this log entry is transactional, 0 otherwise.

logicalEquals

public boolean logicalEquals(LogEntry other)

Specified by:

logicalEquals in interface LogEntry

Returns:

true if these two log entries are logically the same. Used for replication.

dumpRep

public void dumpRep(StringBuilder sb)

Description copied from interface: LogEntry

Dump the contents of the log entry that are interesting for replication.

Specified by:

dumpRep in interface LogEntry