com.sleepycat.je.log
Class FileHeader

java.lang.Object
  extended by com.sleepycat.je.log.FileHeader
All Implemented Interfaces:
LoggableObject, LogReadable, LogWritable

public class FileHeader
extends Object
implements LoggableObject, LogReadable

A FileHeader embodies the header information at the beginning of each log file.


Constructor Summary
FileHeader()
          For logging only.
FileHeader(long fileNum, long lastEntryInPrevFileOffset)
           
 
Method Summary
 boolean countAsObsoleteWhenLogged()
          Returns true if this item should be counted as obsoleted when logged.
 void dumpLog(StringBuffer sb, boolean verbose)
          Write the object into the string buffer for log dumping.
(package private) static int entrySize()
          A header is always a known size.
(package private)  long getLastEntryInPrevFileOffset()
           
 int getLogSize()
           
 LogEntryType getLogType()
          All objects that are reponsible for a generating a type of log entry must implement this.
 long getTransactionId()
           
 boolean logEntryIsTransactional()
           
 boolean marshallOutsideWriteLatch()
          Return true if this item can be marshalled outside the log write latch.
 void postLogWork(long justLoggedLsn)
          Do any processing we need to do after logging, while under the logging latch.
 void readFromLog(ByteBuffer logBuffer, byte entryTypeVersion)
          Initialize this object from the data in itemBuf.
 String toString()
          Print in xml format
(package private)  boolean validate(String fileName, long expectedFileNum)
           
 void writeToLog(ByteBuffer logBuffer)
          Serialize this object into the buffer.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

FileHeader

FileHeader(long fileNum,
           long lastEntryInPrevFileOffset)

FileHeader

public FileHeader()
For logging only.

Method Detail

validate

boolean validate(String fileName,
                 long expectedFileNum)
           throws DatabaseException
Returns:
whether the file header has an old version number.
Throws:
DatabaseException - if the header isn't valid.

getLastEntryInPrevFileOffset

long getLastEntryInPrevFileOffset()
Returns:
the offset of the last entry in the previous file.

getLogType

public LogEntryType getLogType()
Description copied from interface: LoggableObject
All objects that are reponsible for a generating a type of log entry must implement this.

Specified by:
getLogType in interface LoggableObject
Returns:
the type of log entry
See Also:
LoggableObject.getLogType()

marshallOutsideWriteLatch

public boolean marshallOutsideWriteLatch()
Description copied from interface: LoggableObject
Return true if this item can be marshalled outside the log write latch.

Specified by:
marshallOutsideWriteLatch in interface LoggableObject
See Also:
Can be marshalled outside the log write latch.

countAsObsoleteWhenLogged

public boolean countAsObsoleteWhenLogged()
Description copied from interface: LoggableObject
Returns true if this item should be counted as obsoleted when logged. This currently applies to deleted LNs only.

Specified by:
countAsObsoleteWhenLogged in interface LoggableObject
See Also:
LoggableObject.countAsObsoleteWhenLogged()

postLogWork

public void postLogWork(long justLoggedLsn)
                 throws DatabaseException
Description copied from interface: LoggableObject
Do any processing we need to do after logging, while under the logging latch.

Specified by:
postLogWork in interface LoggableObject
Throws:
DatabaseException
See Also:
LoggableObject.postLogWork(long)

entrySize

static int entrySize()
A header is always a known size.


getLogSize

public int getLogSize()
Specified by:
getLogSize in interface LogWritable
Returns:
number of bytes used to store this object
See Also:
LogWritable.getLogSize()

writeToLog

public void writeToLog(ByteBuffer logBuffer)
Description copied from interface: LogWritable
Serialize this object into the buffer.

Specified by:
writeToLog in interface LogWritable
Parameters:
logBuffer - is the destination buffer
See Also:
Serialize this object into the buffer. Update cksum with all the bytes used by this object

readFromLog

public void readFromLog(ByteBuffer logBuffer,
                        byte entryTypeVersion)
                 throws LogException
Description copied from interface: LogReadable
Initialize this object from the data in itemBuf.

Specified by:
readFromLog in interface LogReadable
Parameters:
itemBuf - the source buffer
Throws:
LogException
See Also:
Initialize this object from the data in itemBuf.

dumpLog

public void dumpLog(StringBuffer sb,
                    boolean verbose)
Description copied from interface: LogReadable
Write the object into the string buffer for log dumping. Each object should be dumped without indentation or new lines and should be valid XML.

Specified by:
dumpLog in interface LogReadable
Parameters:
sb - destination string buffer
verbose - if true, dump the full, verbose version
See Also:
LogReadable.dumpLog(java.lang.StringBuffer, boolean)

logEntryIsTransactional

public boolean logEntryIsTransactional()
Specified by:
logEntryIsTransactional in interface LogReadable
Returns:
true if the LogEntry is a transactional log entry type.
See Also:
LogReadable.logEntryIsTransactional()

getTransactionId

public long getTransactionId()
Specified by:
getTransactionId in interface LogReadable
Returns:
return the transaction id if this log entry is transactional, 0 otherwise.
See Also:
LogReadable.getTransactionId()

toString

public String toString()
Print in xml format

Overrides:
toString in class Object


Copyright 2004-2005 Sleepycat, Inc. All Rights Reserved.