ai.grakn.factory

Class SystemKeyspace<M extends GraknGraph,T extends org.apache.tinkerpop.gremlin.structure.Graph>

java.lang.Object

ai.grakn.factory.SystemKeyspace<M,T>

Type Parameters:

M -

T -

public class SystemKeyspace<M extends GraknGraph,T extends org.apache.tinkerpop.gremlin.structure.Graph>
extends Object

Manages the system keyspace.

Used to populate the system ontology the first time the system keyspace is created.

Used to populate the system keyspace with all newly create keyspaces as a user opens them. We have no way to determining whether a keyspace with a given name already exists or not. We maintain the list in our Grakn system keyspace. An element is added to that list when there is an attempt to create a graph from a factory bound to the keyspace name. The list is simply the instances of the system entity type 'keyspace'. Nothing is ever removed from that list. The set of known keyspaces is maintained in a static map so we don't connect to the system keyspace every time a factory produces a new graph. That means that we can't have several different factories (e.g. Titan and in-memory Tinkerpop) at the same time sharing keyspace names. We can't identify the factory builder by engineUrl and config because we don't know what's inside the config, which is residing remotely at the engine!

Author:

borislav

Field Summary

Fields

Modifier and Type	Field and Description
static String	KEYSPACE_ENTITY
static String	KEYSPACE_RESOURCE
protected org.slf4j.Logger	LOG
static String	SYSTEM_GRAPH_NAME
static String	SYSTEM_ONTOLOGY_FILE

Constructor Summary

Constructors

Constructor and Description
SystemKeyspace(String engineUrl, String config)

Method Summary

Modifier and Type	Method and Description
SystemKeyspace<M,T>	keyspaceOpened(String keyspace) Notify that we just opened a keyspace with the same engineUrl & config.
void	loadSystemOntology() Load the system ontology into a newly created system keyspace.

Methods inherited from class java.lang.Object

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

Field Detail

SYSTEM_GRAPH_NAME

public static final String SYSTEM_GRAPH_NAME

See Also:

Constant Field Values

SYSTEM_ONTOLOGY_FILE

public static final String SYSTEM_ONTOLOGY_FILE

See Also:

Constant Field Values

KEYSPACE_ENTITY

public static final String KEYSPACE_ENTITY

See Also:

Constant Field Values

KEYSPACE_RESOURCE

public static final String KEYSPACE_RESOURCE

See Also:

Constant Field Values

LOG

protected final org.slf4j.Logger LOG

Constructor Detail

SystemKeyspace

public SystemKeyspace(String engineUrl,
                      String config)

Method Detail

keyspaceOpened

public SystemKeyspace<M,T> keyspaceOpened(String keyspace)

Notify that we just opened a keyspace with the same engineUrl & config.

loadSystemOntology

public void loadSystemOntology()

Load the system ontology into a newly created system keyspace. Because the ontology only consists of types, the inserts are idempotent and it is safe to load it multiple times.