com.graphaware.runtime.module

Class BaseTxDrivenModule<T>

java.lang.Object

com.graphaware.runtime.module.BaseRuntimeModule

com.graphaware.runtime.module.BaseTxDrivenModule<T>

Type Parameters:

T - The type of a state object that the module can use to pass information from the TxDrivenModule.beforeCommit(com.graphaware.tx.event.improved.api.ImprovedTransactionData) method to the afterCommit(Object) method.

All Implemented Interfaces:

RuntimeModule, TxDrivenModule<T>

Direct Known Subclasses:

ThirdPartyIntegrationModule

public abstract class BaseTxDrivenModule<T>
extends BaseRuntimeModule
implements TxDrivenModule<T>

Base class for TxDrivenModule implementations.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseTxDrivenModule(String moduleId) Construct a new module.

Method Summary

Modifier and Type	Method and Description
void	afterCommit(T state) Perform the core business logic of this module after a transaction commits.
void	afterRollback(T state) Cleanup if needed after a transaction rolled back.
TxDrivenModuleConfiguration	getConfiguration() Return the configuration of this module.
void	initialize(org.neo4j.graphdb.GraphDatabaseService database) Initialize this module.
void	reinitialize(org.neo4j.graphdb.GraphDatabaseService database, TxDrivenModuleMetadata oldMetadata) Re-initialize this module.
void	shutdown()
void	start(org.neo4j.graphdb.GraphDatabaseService database) Start the module.

Methods inherited from class com.graphaware.runtime.module.BaseRuntimeModule

getId

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.graphaware.runtime.module.TxDrivenModule

beforeCommit

Methods inherited from interface com.graphaware.runtime.module.RuntimeModule

getId

Constructor Detail

BaseTxDrivenModule

protected BaseTxDrivenModule(String moduleId)

Construct a new module.

Parameters:

moduleId - ID of this module. Must not be null.

Method Detail

getConfiguration

public TxDrivenModuleConfiguration getConfiguration()

Return the configuration of this module. Each module must encapsulate its entire configuration in an instance of a TxDrivenModuleConfiguration implementation. Use NullTxDrivenModuleConfiguration if this module needs no configuration.

Specified by:

getConfiguration in interface TxDrivenModule<T>

Returns:

module configuration.

start

public void start(org.neo4j.graphdb.GraphDatabaseService database)

Start the module. This method must bring the module to a usable state, i.e. after it returns, the module must be able to handle multi-threaded requests. This method is guaranteed to be called exactly once every time the runtime/database starts.

Specified by:

start in interface TxDrivenModule<T>

Parameters:

database - to start this module against.

initialize

public void initialize(org.neo4j.graphdb.GraphDatabaseService database)

Initialize this module. This method must bring the module to a state equivalent to a state of the same module that has been registered at all times since the database was empty. It can perform global-graph operations to achieve this. It must manage its own transactions.

For example, a module that performs some in-graph caching needs to write information into the graph so that when the method returns, the graph is in the same state as it would be if the module has been running all the time since the graph was empty.

Note that the implementation in this base class doesn't do anything and can be safely overridden without calling super.

Specified by:

initialize in interface TxDrivenModule<T>

Parameters:

database - to initialize this module for.

reinitialize

public void reinitialize(org.neo4j.graphdb.GraphDatabaseService database,
                         TxDrivenModuleMetadata oldMetadata)

Re-initialize this module. This method must remove all metadata written to the graph by this module and bring the module to a state equivalent to a state of the same module that has been registered at all times since the database was empty. It can perform global-graph operations to achieve this. It must manage its own transactions.

Specified by:

reinitialize in interface TxDrivenModule<T>

Parameters:

database - to re-initialize this module for.

oldMetadata - metadata stored for this module from its previous run. Can be null in case metadata was corrupt or there was no metadata.

shutdown

public void shutdown()

Note that the implementation in this base class doesn't do anything and can be safely overridden without calling super.

Specified by:

shutdown in interface RuntimeModule

afterCommit

public void afterCommit(T state)

Perform the core business logic of this module after a transaction commits.

Specified by:

afterCommit in interface TxDrivenModule<T>

Parameters:

state - returned by TxDrivenModule.beforeCommit(com.graphaware.tx.event.improved.api.ImprovedTransactionData). Will be null if TxDrivenModule.beforeCommit(com.graphaware.tx.event.improved.api.ImprovedTransactionData) threw an exception but the transaction still committed. This is the case for all exceptions except DeliberateTransactionRollbackException.

afterRollback

public void afterRollback(T state)

Cleanup if needed after a transaction rolled back. Will only be called if this module's TxDrivenModule.beforeCommit(com.graphaware.tx.event.improved.api.ImprovedTransactionData) method was called.

Specified by:

afterRollback in interface TxDrivenModule<T>

Parameters:

state - returned by TxDrivenModule.beforeCommit(com.graphaware.tx.event.improved.api.ImprovedTransactionData). Will be null if it is this module that caused the rollback by throwing DeliberateTransactionRollbackException. Will also be null if TxDrivenModule.beforeCommit(com.graphaware.tx.event.improved.api.ImprovedTransactionData) threw a non-rollback-causing exception, but some other module caused rollback after that.