co.cask.tephra.persist

Interface TransactionStateStorage

All Superinterfaces:

com.google.common.util.concurrent.Service

All Known Implementing Classes:

AbstractTransactionStateStorage, HDFSTransactionStateStorage, LocalFileTransactionStateStorage, NoOpTransactionStateStorage

public interface TransactionStateStorage
extends com.google.common.util.concurrent.Service

Defines the common contract for persisting transaction state changes.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service

com.google.common.util.concurrent.Service.Listener, com.google.common.util.concurrent.Service.State

Method Summary

Methods

Modifier and Type	Method and Description
TransactionLog	createLog(long timestamp) Creates a new TransactionLog.
void	deleteLogsOlderThan(long timestamp) Removes any transaction logs with a timestamp older than the given value.
long	deleteOldSnapshots(int numberToKeep) Removes any snapshots prior to the numberToKeep most recent.
TransactionSnapshot	getLatestSnapshot() Returns the most recent snapshot that has been successfully written.
String	getLocation() Returns a string representation of the location used for persistence.
List<TransactionLog>	getLogsSince(long timestamp) Returns all TransactionLogs with a timestamp greater than or equal to the given timestamp.
List<String>	listLogs() Returns the (non-qualified) names of available logs.
List<String>	listSnapshots() Returns the (non-qualified) names of available snapshots.
void	writeSnapshot(OutputStream out, TransactionSnapshot snapshot) Persists a snapshot of transaction state to an output stream.
void	writeSnapshot(TransactionSnapshot snapshot) Persists a snapshot of transaction state.

Methods inherited from interface com.google.common.util.concurrent.Service

addListener, isRunning, start, startAndWait, state, stop, stopAndWait

Method Detail

writeSnapshot

void writeSnapshot(OutputStream out,
                 TransactionSnapshot snapshot)
                   throws IOException

Persists a snapshot of transaction state to an output stream.

Throws:

IOException

writeSnapshot

void writeSnapshot(TransactionSnapshot snapshot)
                   throws IOException

Persists a snapshot of transaction state.

Throws:

IOException

getLatestSnapshot

TransactionSnapshot getLatestSnapshot()
                                      throws IOException

Returns the most recent snapshot that has been successfully written. Note that this may return null if no completed snapshot files are found.

Throws:

IOException

deleteOldSnapshots

long deleteOldSnapshots(int numberToKeep)
                        throws IOException

Removes any snapshots prior to the numberToKeep most recent.

Parameters:

numberToKeep - The number of most recent snapshots to keep.

Returns:

The timestamp of the oldest snapshot kept.

Throws:

IOException - If an error occurs while deleting old snapshots.

listSnapshots

List<String> listSnapshots()
                           throws IOException

Returns the (non-qualified) names of available snapshots.

Throws:

IOException

getLogsSince

List<TransactionLog> getLogsSince(long timestamp)
                                  throws IOException

Returns all TransactionLogs with a timestamp greater than or equal to the given timestamp. Note that the returned list is guaranteed to be sorted in ascending timestamp order.

Throws:

IOException

createLog

TransactionLog createLog(long timestamp)
                         throws IOException

Creates a new TransactionLog.

Throws:

IOException

listLogs

List<String> listLogs()
                      throws IOException

Returns the (non-qualified) names of available logs.

Throws:

IOException

deleteLogsOlderThan

void deleteLogsOlderThan(long timestamp)
                         throws IOException

Removes any transaction logs with a timestamp older than the given value. Logs must be removed based on timestamp to ensure we can fully recover state based on a given snapshot.

Parameters:

timestamp - The timestamp to delete up to. Logs with a timestamp less than this value will be removed.

Throws:

IOException - If an error occurs while removing logs.

getLocation

String getLocation()

Returns a string representation of the location used for persistence.