com.sleepycat.je.log.entry

Class NameLNLogEntry

java.lang.Object

com.sleepycat.je.log.entry.LNLogEntry<NameLN>

com.sleepycat.je.log.entry.NameLNLogEntry

All Implemented Interfaces:

LogEntry, ReplicableLogEntry, Cloneable

public class NameLNLogEntry
extends LNLogEntry<NameLN>

NameLNLogEntry contains all the regular LNLogEntry fields and additional information about the database operation which instigated the logging of this NameLN. This additional information is used to support replication of database operations in a replication group. Database operations pose a special problem for replication because unlike data record put and get calls, they can result in multiple log entries that are not all members of a single transaction. Create and truncate are the problem operations because they end up logging new MapLNs, and our implementation does not treat MapLNs as transactional. Database operations challenge two replication assumptions: (a) that all logical operations can be repeated on the client node based on the contents of a single log entry, and (b) that non-txnal log entries like MapLNs need not be replicated. Specifically, here's what is logged for database operations. create: 1. new NameLN_TX 2. new MapLN, which has the database config info. 3. txn commit of autocommit or user txn. rename: 1. deleted NameLN_TX 2. new NameLN_TX 3. txn commit from autocommit or user txn truncate: 1. new MapLN w/new id 2. modify the existing NameLN with new id (old database is deleted by usual commit-time processing) 3. txn commit from autocommit or user txn delete 1. deleted NameLN_TX (old database gets deleted by usual commit-time processing) 2. txn commit from autocommit or user txn Extra information is needed for create and truncate, which both log information within the MapLN. Rename and delete only log NameLNs, so they can be replicated on the client using the normal replication messages. The extra fields which follow the usual LNLogEntry fields are: operationType - the type of database operation. In a single node system, this is local information implicit in the code path. databaseConfig (optional) - For creates, database configuration info databaseId (optional)- For truncates, the old db id, so we know which MapLN to delete.

Field Summary

Fields inherited from class com.sleepycat.je.log.entry.LNLogEntry

MIN_LOG_SIZE

Constructor Summary

Constructors

Constructor and Description
NameLNLogEntry() Constructor to read an entry.
NameLNLogEntry(LogEntryType entryType, DatabaseId dbId, Txn txn, long abortLsn, boolean abortKD, byte[] key, NameLN nameLN, int priorSize, long priorLsn, ReplicationContext repContext) Constructor to write this entry.

Method Summary

Modifier and Type	Method and Description
LogEntry	clone()
StringBuilder	dumpEntry(StringBuilder sb, boolean verbose) Extends its super class to dump database operation information.
void	dumpRep(StringBuilder sb) Dump the contents of the log entry that are interesting for replication.
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()
DbOperationType	getOperationType()
ReplicatedDatabaseConfig	getReplicatedCreateConfig()
Object	getResolvedItem(DatabaseImpl dbImpl) By default, this log entry is complete and does not require fetching additional entries.
int	getSize()
int	getSize(int logVersion, boolean forReplication) Returns the number of bytes needed to store this entry in the format for the specified log version.
DatabaseId	getTruncateOldDbId()
boolean	logicalEquals(LogEntry other)
void	readEntry(EnvironmentImpl envImpl, LogEntryHeader header, ByteBuffer entryBuffer) Extends its super class to read in database operation information.
void	setLogType(LogEntryType entryType) Inform a BaseEntry instance of its corresponding LogEntryType.
String	toString()
void	writeEntry(ByteBuffer destBuffer) Serialize this object into the buffer.
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.LNLogEntry

countPriorVersionObsolete, create, getAbortData, getAbortExpiration, getAbortKey, getAbortKnownDeleted, getAbortLsn, getAbortVLSN, getData, getDbId, getEmbeddedData, getExpiration, getKey, getLN, getMainItem, getPriorVersionLsn, getPriorVersionSize, getTransactionId, getTxnId, getUnconvertedDataLength, getUnconvertedKeyLength, getUserKeyData, getUserTxn, hasReplicationFormat, isAbortExpirationInHours, isDeleted, isEmbeddedLN, isExpirationInHours, isImmediatelyObsolete, isReplicationFormatWorthwhile, postFetchInit, postFetchInit, postLogWork

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, getLogType, getResolvedItem, setLogType

Constructor Detail

NameLNLogEntry

public NameLNLogEntry()

Constructor to read an entry.

NameLNLogEntry

public NameLNLogEntry(LogEntryType entryType,
                      DatabaseId dbId,
                      Txn txn,
                      long abortLsn,
                      boolean abortKD,
                      byte[] key,
                      NameLN nameLN,
                      int priorSize,
                      long priorLsn,
                      ReplicationContext repContext)

Constructor to write this entry.

Method Detail

readEntry

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

Extends its super class to read in database operation information.

Specified by:

readEntry in interface LogEntry

Overrides:

readEntry in class LNLogEntry<NameLN>

dumpEntry

public StringBuilder dumpEntry(StringBuilder sb,
                               boolean verbose)

Extends its super class to dump database operation information.

Specified by:

dumpEntry in interface LogEntry

Overrides:

dumpEntry in class LNLogEntry<NameLN>

getLastFormatChange

public int getLastFormatChange()

Description copied from interface: ReplicableLogEntry

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

Specified by:

getLastFormatChange in interface ReplicableLogEntry

Overrides:

getLastFormatChange in class LNLogEntry<NameLN>

Returns:

the log version of the most recent format change

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

Overrides:

getEmbeddedLoggables in class LNLogEntry<NameLN>

getSize

public int getSize(int logVersion,
                   boolean forReplication)

Description copied from interface: ReplicableLogEntry

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.

Specified by:

getSize in interface ReplicableLogEntry

Overrides:

getSize in class LNLogEntry<NameLN>

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)

Description copied from interface: ReplicableLogEntry

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.

Specified by:

writeEntry in interface ReplicableLogEntry

Overrides:

writeEntry in class LNLogEntry<NameLN>

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.

logicalEquals

public boolean logicalEquals(LogEntry other)

Specified by:

logicalEquals in interface LogEntry

Overrides:

logicalEquals in class LNLogEntry<NameLN>

Returns:

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

getOperationType

public DbOperationType getOperationType()

getReplicatedCreateConfig

public ReplicatedDatabaseConfig getReplicatedCreateConfig()

getTruncateOldDbId

public DatabaseId getTruncateOldDbId()

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

Overrides:

dumpRep in class LNLogEntry<NameLN>

writeEntry

public void writeEntry(ByteBuffer destBuffer)

Description copied from interface: LogEntry

Serialize this object into the buffer.

Specified by:

writeEntry in interface LogEntry

Parameters:

destBuffer - is the destination buffer

getSize

public int getSize()

Specified by:

getSize in interface LogEntry

Returns:

size of byte buffer needed to store this entry.

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

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