com.sleepycat.je.txn
Class Txn

java.lang.Object
  com.sleepycat.je.txn.Locker
      com.sleepycat.je.txn.Txn

All Implemented Interfaces:

LogReadable, LogWritable

Direct Known Subclasses:

AutoTxn

public class Txn

extends Locker

implements LogWritable, LogReadable

A Txn is one that's created by a call to Environment.txnBegin. This class must support multithreaded use.

Field Summary

static byte	TXN_NOSYNC
static byte	TXN_SYNC
static byte	TXN_WRITE_NOSYNC

Fields inherited from class com.sleepycat.je.txn.Locker

defaultNoWait, deleteInfo, dirtyReadDefault, envImpl, handleLockToHandleMap, handleToHandleLockMap, id, lockManager, lockTimeOutMillis, thread

Constructor Summary

Txn()
Constructor for reading from log.

Txn(EnvironmentImpl envImpl, TransactionConfig config)
Create a transaction from Environment.txnBegin.

Method Summary

long	abort() Abort this transaction.
(package private) void	addLock(Long nodeId, Lock lock, LockType type, LockGrantType grantStatus, MemoryBudget mb) Add lock to the appropriate queue.
void	addLogInfo(long nodeId, long lastLsn) Called by the log manager when logging a transaction aware object.
protected void	checkState(boolean calledByAbort) Throw an exception if the transaction is not open.
LockStats	collectStats(LockStats stats) stats
long	commit() Call commit() with the default sync configuration property.
long	commit(byte flushSyncBehavior) Commit this transaction 1.
boolean	createdNode(long nodeId)
void	dumpLog(StringBuffer sb, boolean verbose) Write the object into the string buffer for log dumping.
protected long	generateId(TxnManager txnManager) UserTxns get a new unique id for each instance.
boolean	getAbortKnownDeleted(long nodeId)
long	getAbortLsn(long nodeId)
(package private) long	getFirstActiveLsn()
(package private) int	getInMemorySize()
(package private) long	getLastLsn() Access to last LSN.
int	getLogSize()
long	getTransactionId()
boolean	isHandleLockTransferrable()
boolean	isSerializableIsolation() Is serializable isolation.
boolean	isTransactional() Is transactional.
LockResult	lock(long nodeId, LockType lockType, DatabaseImpl database) Gets a lock on this nodeId and, if it is a write lock, saves an abort lsn.
boolean	logEntryIsTransactional()
void	markDeleteAtTxnEnd(DatabaseImpl dbImpl, boolean deleteAtCommit, MemoryBudget mb) Database operations like remove and truncate leave behind residual DatabaseImpls that must be purged at transaction commit or abort.
(package private) void	moveWriteToReadLock(long nodeId, Lock lock, MemoryBudget mb) A lock is being demoted.
Locker	newInstance() Asserts false and returns null since only ThreadLocker should be cloned.
void	operationEnd() Created transactions do nothing at the end of the operation.
void	operationEnd(boolean operationOK) Created transactions do nothing at the end of the operation.
void	readFromLog(ByteBuffer logBuffer) Initialize this object from the data in itemBuf.
void	registerCursor(CursorImpl cursor) Cursors operating under this transaction are added to the collection.
(package private) void	removeLock(long nodeId, Lock lock) Remove the lock from the set owned by this transaction.
void	setHandleLockOwner(boolean operationOK, Database dbHandle, boolean dbIsClosing) Created transactions don't transfer locks until commit.
(package private) void	setOnlyAbortable() Set the state of a transaction to ONLY_ABORTABLE.
void	unRegisterCursor(CursorImpl cursor) Remove a cursor from the collection.
void	writeToLog(ByteBuffer logBuffer) Serialize this object into the buffer.

Methods inherited from class com.sleepycat.je.txn.Locker

addDeleteInfo, addToHandleMaps, demoteLock, dumpLockTable, getId, getLockTimeout, getTxnStartMillis, getTxnTimeOut, getWaitingFor, isDirtyReadDefault, isTimedOut, operationEnd, releaseLock, rememberHandleWriteLock, setLockTimeout, setTxnTimeout, setWaitingFor, sharesLocksWith, toString, transferHandleLock, transferHandleLockToHandle, unregisterHandle

Methods inherited from class java.lang.Object

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

Field Detail

TXN_NOSYNC

public static final byte TXN_NOSYNC

See Also:

Constant Field Values

TXN_WRITE_NOSYNC

public static final byte TXN_WRITE_NOSYNC

See Also:

Constant Field Values

TXN_SYNC

public static final byte TXN_SYNC

See Also:

Constant Field Values

Constructor Detail

Txn

public Txn(EnvironmentImpl envImpl,
           TransactionConfig config)
    throws DatabaseException

Create a transaction from Environment.txnBegin.

Txn

public Txn()

Constructor for reading from log.

Method Detail

generateId

protected long generateId(TxnManager txnManager)

UserTxns get a new unique id for each instance.

Specified by:

generateId in class Locker

getLastLsn

long getLastLsn()

Access to last LSN.

lock

public LockResult lock(long nodeId,
                       LockType lockType,
                       DatabaseImpl database)
                throws DatabaseException

Gets a lock on this nodeId and, if it is a write lock, saves an abort lsn. Caller will set the abortLsn later, after the write lock has been obtained.

Specified by:

lock in class Locker

Throws:

DatabaseException

commit

public long commit()
            throws DatabaseException

Call commit() with the default sync configuration property.

Throws:

DatabaseException

commit

public long commit(byte flushSyncBehavior)
            throws DatabaseException

Commit this transaction 1. Releases read locks 2. Writes a txn commit record into the log 3. Flushes the log to disk. 4. Add deleted LN info to IN compressor queue 5. Release all write locks If any step of this fails, we must convert this transaction to an abort.

Throws:

DatabaseException

abort

public long abort()
           throws DatabaseException

Abort this transaction. Steps are: 1. Release LN read locks. 2. Write a txn abort entry to the log. This is only for log file cleaning optimization and there's no need to guarantee a flush to disk. 3. Find the last LN log entry written for this txn, and use that to traverse the log looking for nodes to undo. For each node, use the same undo logic as recovery to rollback the transaction. Note that we walk the log in order to undo in reverse order of the actual operations. For example, suppose the txn did this: delete K1/D1 (in LN 10) create K1/D1 (in LN 20) If we process LN10 before LN 20, we'd inadvertently create a duplicate tree of "K1", which would be fatal for the mapping tree. 4. Release the write lock for this LN.

Throws:

DatabaseException

addLogInfo

public void addLogInfo(long nodeId,
                       long lastLsn)
                throws DatabaseException

Called by the log manager when logging a transaction aware object. This method is synchronized by the caller, by being called within the log latch. Record the last LSN for this transaction, to create the transaction chain, and also record the LSN in the write info for abort logic.

Throws:

DatabaseException

getFirstActiveLsn

long getFirstActiveLsn()
                 throws DatabaseException

Returns:

first logged LSN, to aid recovery rollback.

Throws:

DatabaseException

markDeleteAtTxnEnd

public void markDeleteAtTxnEnd(DatabaseImpl dbImpl,
                               boolean deleteAtCommit,
                               MemoryBudget mb)
                        throws DatabaseException

Description copied from class: Locker

Database operations like remove and truncate leave behind residual DatabaseImpls that must be purged at transaction commit or abort.

Specified by:

markDeleteAtTxnEnd in class Locker

Parameters:

dbImpl - databaseImpl to remove

deleteAtCommit - true if this databaseImpl should be cleaned on commit, false if it should be cleaned on abort.

mb - environment memory budget.

Throws:

DatabaseException

addLock

void addLock(Long nodeId,
             Lock lock,
             LockType type,
             LockGrantType grantStatus,
             MemoryBudget mb)
       throws DatabaseException

Add lock to the appropriate queue.

Specified by:

addLock in class Locker

Throws:

DatabaseException

removeLock

void removeLock(long nodeId,
                Lock lock)
          throws DatabaseException

Remove the lock from the set owned by this transaction. If specified to LockManager.release, the lock manager will call this when its releasing a lock. Usually done because the transaction doesn't need to really keep the lock, i.e for a deleted record.

Specified by:

removeLock in class Locker

Throws:

DatabaseException

moveWriteToReadLock

void moveWriteToReadLock(long nodeId,
                         Lock lock,
                         MemoryBudget mb)

A lock is being demoted. Move it from the write collection into the read collection.

Specified by:

moveWriteToReadLock in class Locker

createdNode

public boolean createdNode(long nodeId)
                    throws DatabaseException

Specified by:

createdNode in class Locker

Returns:

true if this transaction created this node. We know that this is true if the node is write locked and has a null abort LSN.

Throws:

DatabaseException

getAbortLsn

public long getAbortLsn(long nodeId)
                 throws DatabaseException

Specified by:

getAbortLsn in class Locker

Returns:

the abortLsn for this node.

Throws:

DatabaseException

getAbortKnownDeleted

public boolean getAbortKnownDeleted(long nodeId)
                             throws DatabaseException

Specified by:

getAbortKnownDeleted in class Locker

Returns:

the abortKnownDeleted for this node.

Throws:

DatabaseException

isTransactional

public boolean isTransactional()

Is transactional.

Specified by:

isTransactional in class Locker

isSerializableIsolation

public boolean isSerializableIsolation()

Is serializable isolation.

Specified by:

isSerializableIsolation in class Locker

newInstance

public Locker newInstance()
                   throws DatabaseException

Asserts false and returns null since only ThreadLocker should be cloned.

Specified by:

newInstance in class Locker

Throws:

DatabaseException

operationEnd

public void operationEnd()
                  throws DatabaseException

Created transactions do nothing at the end of the operation.

Specified by:

operationEnd in class Locker

Throws:

DatabaseException

operationEnd

public void operationEnd(boolean operationOK)
                  throws DatabaseException

Created transactions do nothing at the end of the operation.

Specified by:

operationEnd in class Locker

Parameters:

operationOK - is whether the operation succeeded, since that may impact ending behavior. (i.e for AutoTxn)

Throws:

DatabaseException

setHandleLockOwner

public void setHandleLockOwner(boolean operationOK,
                               Database dbHandle,
                               boolean dbIsClosing)
                        throws DatabaseException

Created transactions don't transfer locks until commit.

Specified by:

setHandleLockOwner in class Locker

Throws:

DatabaseException

registerCursor

public void registerCursor(CursorImpl cursor)
                    throws DatabaseException

Cursors operating under this transaction are added to the collection.

Specified by:

registerCursor in class Locker

Throws:

DatabaseException

unRegisterCursor

public void unRegisterCursor(CursorImpl cursor)
                      throws DatabaseException

Remove a cursor from the collection.

Specified by:

unRegisterCursor in class Locker

Throws:

DatabaseException

isHandleLockTransferrable

public boolean isHandleLockTransferrable()

Overrides:

isHandleLockTransferrable in class Locker

Returns:

true if this txn is willing to give up the handle lock to another txn before this txn ends.

collectStats

public LockStats collectStats(LockStats stats)
                       throws DatabaseException

stats

Specified by:

collectStats in class Locker

Throws:

DatabaseException

setOnlyAbortable

void setOnlyAbortable()

Set the state of a transaction to ONLY_ABORTABLE.

Overrides:

setOnlyAbortable in class Locker

checkState

protected void checkState(boolean calledByAbort)
                   throws DatabaseException

Throw an exception if the transaction is not open. acquireLatch is overloaded. If it's false, it means we're being called from abort().

Specified by:

checkState in class Locker

Throws:

DatabaseException

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:

LogWritable.writeToLog(java.nio.ByteBuffer)

readFromLog

public void readFromLog(ByteBuffer logBuffer)

Description copied from interface: LogReadable

Initialize this object from the data in itemBuf.

Specified by:

readFromLog in interface LogReadable

See Also:

It's ok for FindBugs to whine about id not being synchronized.

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)

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()

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()

getInMemorySize

int getInMemorySize()