com.graphaware.runtime

Interface GraphAwareRuntime

public interface GraphAwareRuntime

Runtime that delegates to registered RuntimeModules to perform useful work. There must be exactly one instance of this runtime for a single GraphDatabaseService.

After all desired modules have been registered, start() can be called in order to initialize the runtime and all its modules before the database is exposed to callers. No more modules can be registered thereafter.

If not called explicitly, the start() method shall be called automatically by the runtime upon first transaction received from callers. In such case, all other transaction will be blocked until the runtime and all its modules have been initialized.

Every new RuntimeModule whose configuration has changed since the last run will be forced to (re-)initialize, which can lead to very long startup times, as (re-)initialization could be a global graph operation. Re-initialization will also be automatically performed for all modules, for which it has been detected that something is out-of-sync (module threw a com.graphaware.runtime.module.NeedsInitializationException).

The runtime might use special nodes for internal data storage and prevent the deletion of those nodes.

Method Summary

Methods

Modifier and Type	Method and Description
RuntimeConfiguration	getConfiguration() Get the configuration of this runtime.
DatabaseWriter	getDatabaseWriter() Get an instance of database writer associated with this runtime.
<T extends RuntimeModule> T	getModule(String moduleId, Class<T> clazz) Get a module registered with the runtime.
void	registerModule(RuntimeModule module) Register a RuntimeModule.
void	start() Start the Runtime.
void	start(boolean skipLoadingMetadata) Start the runtime, optionally skipping the metadata loading phase.
void	waitUntilStarted() Blocks until this runtime has been started and is ready to use.

Method Detail

registerModule

void registerModule(RuntimeModule module)

Register a RuntimeModule. Note that modules are delegated to in the order they are registered. Must be called before the Runtime is started.

Parameters:

module - to register.

start

void start()

Start the Runtime. Must be called before anything gets written into the database, but will be called automatically if not called explicitly. Automatic invocation means that first transactions run against the database will have to wait for the Runtime to be started and modules initialized.

waitUntilStarted

void waitUntilStarted()

Blocks until this runtime has been started and is ready to use.

getModule

<T extends RuntimeModule> T getModule(String moduleId,
                                    Class<T> clazz)
                                  throws org.neo4j.graphdb.NotFoundException

Get a module registered with the runtime.

Type Parameters:

T - type of the class above.

Parameters:

moduleId - module ID.

clazz - expected class of the module.

Returns:

module.

Throws:

org.neo4j.graphdb.NotFoundException - in case no such module has been registered.

getConfiguration

RuntimeConfiguration getConfiguration()

Get the configuration of this runtime.

Returns:

config.

start

void start(boolean skipLoadingMetadata)

Start the runtime, optionally skipping the metadata loading phase. It is not recommended to skip metadata loading; modules without metadata might not behave correctly.

Parameters:

skipLoadingMetadata - true for skipping the metadata loading phase.

getDatabaseWriter

DatabaseWriter getDatabaseWriter()

Get an instance of database writer associated with this runtime. Modules should use this writer to execute database modifications. This allows the framework (and its configuration) to optimize write throughput.

Returns:

writer associated with this runtime.