RingbufferService (Hazelcast Root 3.12.9 API)

java.lang.Object
- com.hazelcast.ringbuffer.impl.RingbufferService

All Implemented Interfaces:

FragmentedMigrationAwareService, ManagedService, MigrationAwareService, QuorumAwareService, RemoteService, SplitBrainHandlerService
```
public class RingbufferService
extends Object
implements ManagedService, RemoteService, FragmentedMigrationAwareService, QuorumAwareService, SplitBrainHandlerService
```
The SPI Service that deals with the Ringbuffer.

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`SERVICE_NAME` The ringbuffer service name which defines it in the node engine.
`static String`	`TOPIC_RB_PREFIX` Prefix of ringbuffers that are created for topics.

Constructor Summary

Constructors
Constructor and Description

RingbufferService(NodeEngineImpl nodeEngine)

Constructors
Constructor and Description
`RingbufferService(NodeEngineImpl nodeEngine)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addRingbuffer(int partitionId, RingbufferContainer ringbuffer, RingbufferConfig config)`
`void`	`beforeMigration(PartitionMigrationEvent partitionMigrationEvent)` Called before migration process starts, on both source and destination members.
`void`	`commitMigration(PartitionMigrationEvent event)` Commits the migration process for this service, on both source and destination members.
`DistributedObject`	`createDistributedObject(String objectName)` Creates a distributed object.
`void`	`destroyContainer(int partitionId, ObjectNamespace namespace)`
`void`	`destroyDistributedObject(String name)` Destroys a distributed object.
`void`	`ensureQuorumPresent(String distributedObjectName, QuorumType requiredQuorumPermissionType)`
`Collection<ServiceNamespace>`	`getAllServiceNamespaces(PartitionReplicationEvent event)` Returns all known namespaces for given replication event.
`<T,E> RingbufferContainer<T,E>`	`getContainerOrNull(int partitionId, ObjectNamespace namespace)` Returns the ringbuffer container if it already exists for the given `partitionId` and `namespace`.
`ConcurrentMap<Integer,Map<ObjectNamespace,RingbufferContainer>>`	`getContainers()`
`<T,E> RingbufferContainer<T,E>`	`getOrCreateContainer(int partitionId, ObjectNamespace namespace, RingbufferConfig config)` Return the ringbuffer containter for the specified `namespace`.
`String`	`getQuorumName(String name)` Gets the name of the quorum associated with specified operation name.
`RingbufferConfig`	`getRingbufferConfig(String name)`
`static ObjectNamespace`	`getRingbufferNamespace(String name)`
`int`	`getRingbufferPartitionId(String ringbufferName)`
`void`	`init(NodeEngine nodeEngine, Properties properties)` Initializes this service.
`boolean`	`isKnownServiceNamespace(ServiceNamespace namespace)` Returns true if namespace is known by this service, false otherwise
`Runnable`	`prepareMergeRunnable()` When the two separate clusters merge (resolve a split-brain), this method is called to return a `Runnable`, that will merge the clusters.
`Operation`	`prepareReplicationOperation(PartitionReplicationEvent event)` Returns an operation to replicate service data and/or state for a specific partition replica on another cluster member.
`Operation`	`prepareReplicationOperation(PartitionReplicationEvent event, Collection<ServiceNamespace> namespaces)` Returns an operation to replicate service data and/or state for a specific partition replica and namespaces on another cluster member.
`void`	`reset()` Resets this service back to its initial state.
`void`	`rollbackMigration(PartitionMigrationEvent event)` Rollback the migration process for this service, on both source and destination members.
`void`	`shutdown(boolean terminate)` Shuts down this service.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - TOPIC_RB_PREFIX
```
public static final String TOPIC_RB_PREFIX
```
    Prefix of ringbuffers that are created for topics. Using a prefix prevents users accidentally retrieving the ringbuffer.
    
    See Also:
    
    Constant Field Values
  - SERVICE_NAME
```
public static final String SERVICE_NAME
```
    The ringbuffer service name which defines it in the node engine.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - RingbufferService
```
public RingbufferService(NodeEngineImpl nodeEngine)
```
- Method Detail
  - init
```
public void init(NodeEngine nodeEngine,
                 Properties properties)
```
    Description copied from interface: ManagedService
    
    Initializes this service.
    
    Specified by:
    
    init in interface ManagedService
    
    Parameters:
    
    nodeEngine - the NodeEngine that this service belongs to
    
    properties - the Properties (can be used to pass settings to the service)
  - getContainers
```
public ConcurrentMap<Integer,Map<ObjectNamespace,RingbufferContainer>> getContainers()
```
  - createDistributedObject
```
public DistributedObject createDistributedObject(String objectName)
```
    Description copied from interface: RemoteService
    
    Creates a distributed object.
    
    Specified by:
    
    createDistributedObject in interface RemoteService
    
    Parameters:
    
    objectName - the name for the created distributed object
    
    Returns:
    
    the created distributed object
  - destroyDistributedObject
```
public void destroyDistributedObject(String name)
```
    Description copied from interface: RemoteService
    
    Destroys a distributed object.
    
    Specified by:
    
    destroyDistributedObject in interface RemoteService
    
    Parameters:
    
    name - the name of the distributed object to destroy
  - destroyContainer
```
public void destroyContainer(int partitionId,
                             ObjectNamespace namespace)
```
  - reset
```
public void reset()
```
    Description copied from interface: ManagedService
    
    Resets this service back to its initial state.
    TODO: what is the purpose of reset
    
    Specified by:
    
    reset in interface ManagedService
  - shutdown
```
public void shutdown(boolean terminate)
```
    Description copied from interface: ManagedService
    
    Shuts down this service.
    TODO: what is the purpose of the terminate variable
    
    Specified by:
    
    shutdown in interface ManagedService
    
    Parameters:
    
    terminate - true to shut down this service
  - getOrCreateContainer
```
public <T,E> RingbufferContainer<T,E> getOrCreateContainer(int partitionId,
                                                           ObjectNamespace namespace,
                                                           RingbufferConfig config)
```
    Return the ringbuffer containter for the specified namespace. If there is no ringbuffer container, create it using the config.
    
    Parameters:
    
    namespace - the ringbuffer container namespace
    
    config - the ringbuffer config. Used to create the container when the container doesn't exist
    
    Returns:
    
    the ringbuffer container
    
    Throws:
    
    NullPointerException - if the config is null
  - getContainerOrNull
```
public <T,E> RingbufferContainer<T,E> getContainerOrNull(int partitionId,
                                                         ObjectNamespace namespace)
```
    Returns the ringbuffer container if it already exists for the given partitionId and namespace. Returns null if it doesn't exist.
    
    Type Parameters:
    
    T - the type of items in the ringbuffer container
    
    E - the type of items in the ringbuffer
    
    Parameters:
    
    partitionId - the partition ID of the ringbuffer container
    
    namespace - the namespace of the ringbuffer container
    
    Returns:
    
    the ringbuffer container or null if it has not been created
  - getRingbufferConfig
```
public RingbufferConfig getRingbufferConfig(String name)
```
  - getRingbufferNamespace
```
public static ObjectNamespace getRingbufferNamespace(String name)
```
  - getRingbufferPartitionId
```
public int getRingbufferPartitionId(String ringbufferName)
```
  - addRingbuffer
```
public void addRingbuffer(int partitionId,
                          RingbufferContainer ringbuffer,
                          RingbufferConfig config)
```
  - beforeMigration
```
public void beforeMigration(PartitionMigrationEvent partitionMigrationEvent)
```
    Description copied from interface: MigrationAwareService
    
    Called before migration process starts, on both source and destination members.
    Service can take actions required before migration. Migration process will block until this method returns. If this method fails by throwing an exception, migration process for specific partition will fail and will be rolled back.
    
    Specified by:
    
    beforeMigration in interface MigrationAwareService
    
    Parameters:
    
    partitionMigrationEvent - migration event
  - prepareReplicationOperation
```
public Operation prepareReplicationOperation(PartitionReplicationEvent event)
```
    Description copied from interface: MigrationAwareService
    
    Returns an operation to replicate service data and/or state for a specific partition replica on another cluster member.
    This method will be called on source member whenever partitioning system requires to copy/replicate a partition replica. Returned operation will be executed on destination member. If operation fails by throwing exception, migration process will fail and will be rolled back.
    Returning null is allowed and means service does not have anything to replicate.
    
    Specified by:
    
    prepareReplicationOperation in interface MigrationAwareService
    
    Parameters:
    
    event - replication
    
    Returns:
    
    replication operation or null if nothing will be replicated
  - prepareReplicationOperation
```
public Operation prepareReplicationOperation(PartitionReplicationEvent event,
                                             Collection<ServiceNamespace> namespaces)
```
    Description copied from interface: FragmentedMigrationAwareService
    
    Returns an operation to replicate service data and/or state for a specific partition replica and namespaces on another cluster member. This method is very similar to MigrationAwareService.prepareReplicationOperation(PartitionReplicationEvent), instead of copying whole partition replica, allows copying only some portion of replica, specified by given namespaces.
    This method will be called on source member whenever partitioning system requires to copy/replicate a partition replica. Returned operation will be executed on destination member. If operation fails by throwing exception, migration process will fail and will be rolled back.
    Returning null is allowed and means service does not have anything to replicate.
    
    Specified by:
    
    prepareReplicationOperation in interface FragmentedMigrationAwareService
    
    Parameters:
    
    event - replication event
    
    namespaces - replica fragment namespaces to replicate
    
    Returns:
    
    replication operation or null if nothing will be replicated
    
    See Also:
    
    MigrationAwareService.prepareReplicationOperation(PartitionReplicationEvent)
  - commitMigration
```
public void commitMigration(PartitionMigrationEvent event)
```
    Description copied from interface: MigrationAwareService
    
    Commits the migration process for this service, on both source and destination members. This method will be called after all replication operations are executed successfully on destination and master member receives success response from all participants.
    Commit is not expected to fail at this point, all exceptions will be suppressed and logged. Implementations of this method must be thread safe as this method may be called concurrently for different migrations on different partitions.
    
    Specified by:
    
    commitMigration in interface MigrationAwareService
    
    Parameters:
    
    event - migration event
  - rollbackMigration
```
public void rollbackMigration(PartitionMigrationEvent event)
```
    Description copied from interface: MigrationAwareService
    
    Rollback the migration process for this service, on both source and destination members. This method will be called when migration process fails at any moment. Reasons for failure may be an exception thrown on any migration step or failure(s) of any of the migration participants; either master or source or destination.
    Rollback is not expected to fail at this point, all exceptions will be suppressed and logged. Implementations of this method must be thread safe as this method may be called concurrently for different migrations on different partitions.
    
    Specified by:
    
    rollbackMigration in interface MigrationAwareService
    
    Parameters:
    
    event - migration event
  - getAllServiceNamespaces
```
public Collection<ServiceNamespace> getAllServiceNamespaces(PartitionReplicationEvent event)
```
    Description copied from interface: FragmentedMigrationAwareService
    
    Returns all known namespaces for given replication event.
    
    Specified by:
    
    getAllServiceNamespaces in interface FragmentedMigrationAwareService
    
    Parameters:
    
    event - replication event
    
    Returns:
    
    all known service namespaces for the replication
  - isKnownServiceNamespace
```
public boolean isKnownServiceNamespace(ServiceNamespace namespace)
```
    Description copied from interface: FragmentedMigrationAwareService
    
    Returns true if namespace is known by this service, false otherwise
    
    Specified by:
    
    isKnownServiceNamespace in interface FragmentedMigrationAwareService
    
    Parameters:
    
    namespace - namespace
    
    Returns:
    
    true if namespace is known by this service, false otherwise
  - getQuorumName
```
public String getQuorumName(String name)
```
    Description copied from interface: QuorumAwareService
    
    Gets the name of the quorum associated with specified operation name.
    
    Specified by:
    
    getQuorumName in interface QuorumAwareService
    
    Parameters:
    
    name - the operation name for which the quorum name is retured
    
    Returns:
    
    name of the associated quorum, null if there is no associated quorum
  - ensureQuorumPresent
```
public void ensureQuorumPresent(String distributedObjectName,
                                QuorumType requiredQuorumPermissionType)
```
  - prepareMergeRunnable
```
public Runnable prepareMergeRunnable()
```
    Description copied from interface: SplitBrainHandlerService
    
    When the two separate clusters merge (resolve a split-brain), this method is called to return a Runnable, that will merge the clusters.
    
    Specified by:
    
    prepareMergeRunnable in interface SplitBrainHandlerService
    
    Returns:
    
    a Runnable that will merge the clusters

Class RingbufferService

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

TOPIC_RB_PREFIX

SERVICE_NAME

Constructor Detail

RingbufferService

Method Detail

init

getContainers

createDistributedObject

destroyDistributedObject

destroyContainer

reset

shutdown

getOrCreateContainer

getContainerOrNull

getRingbufferConfig

getRingbufferNamespace

getRingbufferPartitionId

addRingbuffer

beforeMigration

prepareReplicationOperation

prepareReplicationOperation

commitMigration

rollbackMigration

getAllServiceNamespaces

isKnownServiceNamespace

getQuorumName

ensureQuorumPresent

prepareMergeRunnable