com.graphaware.runtime.manager

Class BaseTxDrivenModuleManager<T extends TxDrivenModule>

java.lang.Object

com.graphaware.runtime.manager.BaseModuleManager<TxDrivenModuleMetadata,T>

com.graphaware.runtime.manager.BaseTxDrivenModuleManager<T>

All Implemented Interfaces:

ModuleManager<T>, TxDrivenModuleManager<T>

Direct Known Subclasses:

ProductionTxDrivenModuleManager

public abstract class BaseTxDrivenModuleManager<T extends TxDrivenModule>
extends BaseModuleManager<TxDrivenModuleMetadata,T>
implements TxDrivenModuleManager<T>

BaseModuleManager for TxDrivenModules.

Field Summary

Fields inherited from class com.graphaware.runtime.manager.BaseModuleManager

metadataRepository, modules

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseTxDrivenModuleManager(ModuleMetadataRepository metadataRepository, StatsCollector statsCollector, InstanceRoleUtils instanceRoleUtils) Construct a new manager.

Method Summary

Modifier and Type	Method and Description
protected TxDrivenModuleMetadata	acknowledgeMetadata(T module, TxDrivenModuleMetadata metadata) Acknowledge module metadata after it has been created afresh or successfully loaded from a ModuleMetadataRepository.
void	afterCommit(Map<String,Object> states) Delegate work to modules after a transaction is committed.
void	afterRollback(Map<String,Object> states) Delegate work to modules after a transaction is rolled back.
Map<String,Object>	beforeCommit(TransactionDataContainer transactionData) Delegate work to modules before a transaction is committed.
protected TxDrivenModuleMetadata	createFreshMetadata(T module) Create new metadata for a module.
protected void	handleCorruptMetadata(T module) Handle the fact that metadata for a module has been corrupted.
protected void	handleNoMetadata(T module) Handle the fact that there was no metadata for a module.
protected abstract void	initialize(T module) Initialize module.
protected abstract void	reinitialize(T module, TxDrivenModuleMetadata oldMetadata) Re-initialize module.
protected abstract void	start(T module) Start module.
void	startModules() Perform work needed to make modules start doing their job.

Methods inherited from class com.graphaware.runtime.manager.BaseModuleManager

checkNotAlreadyRegistered, cleanupMetadata, getModule, getModule, loadMetadata, registerModule, shutdownModules

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.manager.ModuleManager

checkNotAlreadyRegistered, cleanupMetadata, getModule, getModule, loadMetadata, registerModule, shutdownModules

Constructor Detail

BaseTxDrivenModuleManager

protected BaseTxDrivenModuleManager(ModuleMetadataRepository metadataRepository,
                                    StatsCollector statsCollector,
                                    InstanceRoleUtils instanceRoleUtils)

Construct a new manager.

Parameters:

metadataRepository - repository for storing module metadata.

statsCollector - stats collector.

instanceRoleUtils - instance role utils.

Method Detail

handleCorruptMetadata

protected void handleCorruptMetadata(T module)

Handle the fact that metadata for a module has been corrupted. This could be because somebody has manually messed with the storage of module metadata, or because the implementation of the module metadata has changed and the class expected is different from the class previously serialized.

After this method has returned, it is guaranteed that BaseModuleManager.createFreshMetadata(com.graphaware.runtime.module.RuntimeModule) will be called. This means that if the module doesn't heavily rely on its metadata, there is no need to override this method.

Overrides:

handleCorruptMetadata in class BaseModuleManager<TxDrivenModuleMetadata,T extends TxDrivenModule>

Parameters:

module - that had corrupted metadata.

handleNoMetadata

protected void handleNoMetadata(T module)

Handle the fact that there was no metadata for a module. This could be because it has been registered for the first time, or because somebody as manually deleted the metadata from wherever ModuleMetadataRepository stores them.

After this method has returned, it is guaranteed that BaseModuleManager.createFreshMetadata(com.graphaware.runtime.module.RuntimeModule) will be called. This means that there is no need to override this method unless there is some work that needs to be done in addition to creating new metadata.

Overrides:

handleNoMetadata in class BaseModuleManager<TxDrivenModuleMetadata,T extends TxDrivenModule>

Parameters:

module - that had no metadata.

createFreshMetadata

protected TxDrivenModuleMetadata createFreshMetadata(T module)

Create new metadata for a module.

Specified by:

createFreshMetadata in class BaseModuleManager<TxDrivenModuleMetadata,T extends TxDrivenModule>

Parameters:

module - for which to create metadata.

Returns:

fresh metadata.

acknowledgeMetadata

protected TxDrivenModuleMetadata acknowledgeMetadata(T module,
                                                     TxDrivenModuleMetadata metadata)

Acknowledge module metadata after it has been created afresh or successfully loaded from a ModuleMetadataRepository. The implementation can, for example, choose to let the module know about its own metadata. This method also gives the subclasses the opportunity to modify the metadata before it is persisted to the database.

Specified by:

acknowledgeMetadata in class BaseModuleManager<TxDrivenModuleMetadata,T extends TxDrivenModule>

Parameters:

module - for which to acknowledge metadata.

metadata - to acknowledge.

Returns:

the acknowledged metadata (possibly modified).

startModules

public void startModules()

Perform work needed to make modules start doing their job. Called exactly once each time the database is started.

Specified by:

startModules in interface ModuleManager<T extends TxDrivenModule>

Overrides:

startModules in class BaseModuleManager<TxDrivenModuleMetadata,T extends TxDrivenModule>

start

protected abstract void start(T module)

Start module. This means preparing for doing the actual work. Call in a single-thread exactly once on each module every time the runtime starts.

Parameters:

module - to be started.

initialize

protected abstract void initialize(T module)

Initialize module. This means doing any work necessary for a module that has been registered for the first time on an existing database, or that has been previously registered with different configuration.

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 for many modules, it might not be necessary to do anything.

Parameters:

module - to initialize.

reinitialize

protected abstract void reinitialize(T module,
                                     TxDrivenModuleMetadata oldMetadata)

Re-initialize module. This means cleaning up all data this module might have ever written to the graph and doing any work necessary for a module that has been registered for the first time on an existing database, or that has been previously registered with different configuration.

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 for many modules, it might not be necessary to do anything.

Parameters:

module - to initialize.

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

beforeCommit

public Map<String,Object> beforeCommit(TransactionDataContainer transactionData)

Delegate work to modules before a transaction is committed.

Specified by:

beforeCommit in interface TxDrivenModuleManager<T extends TxDrivenModule>

Parameters:

transactionData - about-to-be-committed transaction data.

Returns:

map of objects (states) returned by the modules, keyed by RuntimeModule.getId().

afterCommit

public void afterCommit(Map<String,Object> states)

Delegate work to modules after a transaction is committed.

Specified by:

afterCommit in interface TxDrivenModuleManager<T extends TxDrivenModule>

Parameters:

states - returned by TxDrivenModuleManager.beforeCommit(com.graphaware.tx.event.improved.data.TransactionDataContainer).

afterRollback

public void afterRollback(Map<String,Object> states)

Delegate work to modules after a transaction is rolled back.

Specified by:

afterRollback in interface TxDrivenModuleManager<T extends TxDrivenModule>

Parameters:

states - returned by TxDrivenModuleManager.beforeCommit(com.graphaware.tx.event.improved.data.TransactionDataContainer).