Interface Txn

All Known Implementing Classes:

TxnReadUncommitted, TxnSerializable

public interface Txn

A transaction can hold locks to several resources. The resources (potentially) locked by a transaction can be accessed using streamAccessedResourcePaths(). References to resources can be acquired via

invalid reference

#getResourceApi(String[])

. TODO Consider replace of String[] with Array; the former is a pain to use with e.g. guava cache TODO Consider replace of Stream with Flowable; the former does not have proper resource management

Author:

raven

Method Summary

Modifier and Type	Method	Description
void	addCommit()
void	addFinalize()
void	addRollback()
boolean	claim()	Instruct this TxnMgr to try to claim (i.e.
void	cleanUpTxn()
Instant	getActivityDate()
Instant	getCreationDate()
TemporalAmount	getDurationToNextHeartbeat()
String	getId()	Get the id of this transaction
Instant	getMostRecentHeartbeat()
TxnResourceApi	getResourceApi(Path<String> resRelPath)	Get access to a resource as seen from this txn
TxnMgr	getTxnMgr()
boolean	isCommit()
boolean	isFinalize()
boolean	isRollback()
boolean	isStale()	Whether the transaction has become stale
boolean	isWrite()
Stream<TxnResourceApi>	listVisibleFiles(Path<String> prefix)
void	promote()	Promote a read transaction to write.
void	setActivityDate(Instant instant)	Update the transaction's most recent activity timestamp to given timestamp; Used to prevent other processes from considering the transaction stale.
Stream<Path<String>>	streamAccessedResourcePaths()
default Instant	updateActivityDate()	Update the transaction's most recent activity timestamp to the current time; Used to prevent other processes from considering the transaction stale.
void	updateHeartbeat()

Method Details

getTxnMgr

TxnMgr getTxnMgr()

getId

String getId()

Get the id of this transaction

getResourceApi

TxnResourceApi getResourceApi(Path<String> resRelPath)

Get access to a resource as seen from this txn

listVisibleFiles

Stream<TxnResourceApi> listVisibleFiles(Path<String> prefix)

streamAccessedResourcePaths

Stream<Path<String>> streamAccessedResourcePaths()
                                          throws IOException

Throws:

IOException

isStale

boolean isStale()
         throws IOException

Whether the transaction has become stale

Throws:

IOException

claim

boolean claim()
       throws IOException

Instruct this TxnMgr to try to claim (i.e. take ownership) of this txn. Should only be used on stale transactions. A claim fails - indicated by a return value of false - if the txn's heartbeat timeout has not been reached. This condition also occurs if another thread won the competition for claiming a txn.

Throws:

IOException

isWrite

boolean isWrite()

addCommit

void addCommit()
        throws IOException

Throws:

IOException

addFinalize

void addFinalize()
          throws IOException

Throws:

IOException

addRollback

void addRollback()
          throws IOException

Throws:

IOException

isCommit

boolean isCommit()
          throws IOException

Throws:

IOException

isRollback

boolean isRollback()
            throws IOException

Throws:

IOException

isFinalize

boolean isFinalize()
            throws IOException

Throws:

IOException

cleanUpTxn

void cleanUpTxn()
         throws IOException

Throws:

IOException

promote

void promote()

Promote a read transaction to write.

getCreationDate

Instant getCreationDate()

updateHeartbeat

void updateHeartbeat()
              throws IOException

Throws:

IOException

getMostRecentHeartbeat

Instant getMostRecentHeartbeat()
                        throws IOException

Throws:

IOException

getDurationToNextHeartbeat

TemporalAmount getDurationToNextHeartbeat()
                                   throws IOException

Throws:

IOException

setActivityDate

void setActivityDate(Instant instant)
              throws IOException

Update the transaction's most recent activity timestamp to given timestamp; Used to prevent other processes from considering the transaction stale.

Throws:

IOException

getActivityDate

Instant getActivityDate()
                 throws IOException

Throws:

IOException

updateActivityDate

default Instant updateActivityDate()
                            throws IOException

Update the transaction's most recent activity timestamp to the current time; Used to prevent other processes from considering the transaction stale.

Throws:

IOException