org.apache.clerezza.dataset

Class TcManager

java.lang.Object

org.apache.clerezza.dataset.TcProviderMultiplexer

org.apache.clerezza.dataset.TcManager

All Implemented Interfaces:

TcProvider, GraphStore

public class TcManager
extends TcProviderMultiplexer
implements GraphStore

This class extends TcProviderMultiplexer, delegating the actual provision and creation of Graphs or MGraphs to registered WeightedTcProviders. The class attempts to satisfy the request using the registered WeightedTcProvider in decreasing order of weight. If multiple providers have the same weight the lexicographical order of the fully qualified class name determines which one is used, namely the one that occurs earlier. If a call to a registered provider causes an IllegalArgumentException, NoSuchEntityException or UnsupportedOperationException then the call is delegated to the next provider. Only one instance of this class should exist in a system, the public no argument constructor is meant for initialization by dependency injection systems such as OSGi-DS. Applications should use the static getInstance() method if they aren't using a framework that injects them the instance. This class returns Graphs a subtype of Graph that allows read/write locks. This class also registers all Graphs as services with the property 'name' indicating there name. Security checks are done when a Graph is retrieved. The returned Graph will do no further security checks. Because of this it should not be passed to a context where different access control applies. If an Graph is retrieved without having write permission the returned graph will be read-only. If a Graphs needs to passed around across different security contexts the one retrieved from the OSGi service whiteboard should be used as this performs access control on every access.

Author:

reto, mir, hasan

Field Summary

Fields

Modifier and Type	Field and Description
static String	GENERAL_PURPOSE_TC
static String	Graph_SERVICES_ENABLED
static String	MGRAPH_CACHE_ENABLED
protected QueryEngine	queryEngine
protected SortedSet<WeightedTcProvider>	tempProviderList

Fields inherited from class org.apache.clerezza.dataset.TcProviderMultiplexer

providerList

Constructor Summary

Constructors

Constructor and Description
TcManager() the constructor sets the singleton instance to allow instantiation by OSGi-DS.

Method Summary

Modifier and Type	Method and Description
protected void	activate(org.osgi.service.component.ComponentContext componentContext)
protected void	bindGpWeightedTcProvider(WeightedTcProvider provider) Registers a provider
protected void	bindQueryEngine(QueryEngine queryEngine)
protected void	bindWeightedTcProvider(WeightedTcProvider provider) Registers a provider
Graph	createGraph(IRI name) Creates an initially empty Graph with a specified name
ImmutableGraph	createImmutableGraph(IRI name, Graph triples) Creates a ImmutableGraph with a specified name
protected void	deactivate(org.osgi.service.component.ComponentContext componentContext)
void	deleteGraph(IRI name) Deletes the ImmutableGraph or Graph of a specified name.
boolean	executeSparqlQuery(AskQuery query, Graph defaultGraph) Deprecated. Query is discontinued
ImmutableGraph	executeSparqlQuery(ConstructQuery query, Graph defaultGraph) Deprecated. Query is discontinued
ImmutableGraph	executeSparqlQuery(DescribeQuery query, Graph defaultGraph) Deprecated. Query is discontinued
Object	executeSparqlQuery(Query query, Graph defaultGraph) Deprecated. Query is discontinued
ResultSet	executeSparqlQuery(SelectQuery query, Graph defaultGraph) Deprecated. Query is discontinued
Object	executeSparqlQuery(String query, boolean forceFastlane) Executes any sparql query.
Object	executeSparqlQuery(String query, Graph defaultGraph) Executes any sparql query.
Object	executeSparqlQuery(String query, IRI defaultGraphName) Executes any sparql query.
Object	executeSparqlQuery(String query, IRI defaultGraphName, boolean forceFastlane) Executes any sparql query.
Graph	getGraph(IRI name) This method is used to get a Graph indifferently whether it's a ImmutableGraph or not.
ImmutableGraph	getImmutableGraph(IRI name) Get a ImmutableGraph by its name
static TcManager	getInstance() This returns the singleton instance.
Graph	getMGraph(IRI name) Get an Graph taht is not ImmutableGrah.
Set<IRI>	getNames(ImmutableGraph ImmutableGraph) get a set of the names of a ImmutableGraph
TcAccessController	getTcAccessController()
protected void	graphAppears(IRI name) subclasses overwrite this method to be notified when a new ImmutableGraph is available (either because it has been created or being provided by a newly added WeightedTcProvider).
boolean	isTcServicesEnabled()
Set<IRI>	listGraphs() Lists the name of the Graphs available through this TcProvider indifferently whether they are mutables or immutables, implementations may take into account the security context and omit Graphs for which access is not allowed.
Set<IRI>	listImmutableGraphs() Lists the name of the ImmutableGraphs available through this TcProvider, implementations may take into account the security context and omit ImmutableGraphs for which access is not allowed.
Set<IRI>	listMGraphs() Lists the name of the Graphs available through this TcProvider that are not ImmutableGraph, implementations may take into account the security context and omit Graphs for which access is not allowed.
Set<IRI>	listNamedGraphs() Lists the name of the named Graphs available through this GraphStore.
protected void	mGraphAppears(IRI name) subclasses overwrite this method to be notified when a new Graph is available (either because it has been created or being provided by a newly added WeightedTcProvider).
protected void	tcDisappears(IRI name) subclasses overwrite this method to be notified whenGraph is no longer available (either because it has been deleted or bacause its WeightedTcProvider was removed).
protected void	unbindGpWeightedTcProvider(WeightedTcProvider provider) Unregister a provider
protected void	unbindQueryEngine(QueryEngine queryEngine)
protected void	unbindWeightedTcProvider(WeightedTcProvider provider) Unregister a provider

Methods inherited from class org.apache.clerezza.dataset.TcProviderMultiplexer

addWeightedTcProvider, getProviderList, isCachingEnabled, removeWeightedTcProvider, setCachingEnabled

Methods inherited from class java.lang.Object

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

Field Detail

GENERAL_PURPOSE_TC

public static final String GENERAL_PURPOSE_TC

See Also:

Constant Field Values

Graph_SERVICES_ENABLED

public static final String Graph_SERVICES_ENABLED

See Also:

Constant Field Values

MGRAPH_CACHE_ENABLED

public static final String MGRAPH_CACHE_ENABLED

See Also:

Constant Field Values

queryEngine

protected QueryEngine queryEngine

tempProviderList

protected SortedSet<WeightedTcProvider> tempProviderList

Constructor Detail

TcManager

public TcManager()

the constructor sets the singleton instance to allow instantiation by OSGi-DS. This constructor should not be called except by OSGi-DS, otherwise the static getInstance method should be used.

Method Detail

getInstance

public static TcManager getInstance()

This returns the singleton instance. If an instance has been previously created (e.g. by OSGi declarative services) this instance is returned, otherwise a new instance is created and providers are injected using the service provider interface (META-INF/services/)

Returns:

the singleton instance

activate

protected void activate(org.osgi.service.component.ComponentContext componentContext)

deactivate

protected void deactivate(org.osgi.service.component.ComponentContext componentContext)

getImmutableGraph

public ImmutableGraph getImmutableGraph(IRI name)
                                 throws NoSuchEntityException

Description copied from interface: TcProvider

Get a ImmutableGraph by its name

Specified by:

getImmutableGraph in interface TcProvider

Overrides:

getImmutableGraph in class TcProviderMultiplexer

Parameters:

name - the name of the ImmutableGraph

Returns:

the ImmutableGraph with the specified name

Throws:

NoSuchEntityException - if there is no ImmutableGraph with the specified name

getMGraph

public Graph getMGraph(IRI name)

Description copied from interface: TcProvider

Get an Graph taht is not ImmutableGrah. The instances returned in different invocations are equals.

Specified by:

getMGraph in interface TcProvider

Overrides:

getMGraph in class TcProviderMultiplexer

Parameters:

name - the name of the Graph

Returns:

Graph with the specified name

getGraph

public Graph getGraph(IRI name)

Description copied from interface: TcProvider

This method is used to get a Graph indifferently whether it's a ImmutableGraph or not. If the name names an Graph the result is the same as when invoking getMGraph with that argument, analogously for ImmutableGraphS the method returns an instance equals to what getImmutableGraph would return.

Specified by:

getGraph in interface TcProvider

Overrides:

getGraph in class TcProviderMultiplexer

Parameters:

name - the name of the ImmutableGraph or Graph

Returns:

the ImmutableGraph or Graph

createGraph

public Graph createGraph(IRI name)
                  throws UnsupportedOperationException

Description copied from interface: TcProvider

Creates an initially empty Graph with a specified name

Specified by:

createGraph in interface TcProvider

Overrides:

createGraph in class TcProviderMultiplexer

Parameters:

name - names the new Graph

Returns:

the newly created Graph

Throws:

UnsupportedOperationException - if this provider doesn't support creating GraphS

createImmutableGraph

public ImmutableGraph createImmutableGraph(IRI name,
                                           Graph triples)

Description copied from interface: TcProvider

Creates a ImmutableGraph with a specified name

Specified by:

createImmutableGraph in interface TcProvider

Overrides:

createImmutableGraph in class TcProviderMultiplexer

Parameters:

name - the name of the ImmutableGraph to be created

triples - the triples of the new ImmutableGraph

Returns:

the newly created ImmutableGraph

deleteGraph

public void deleteGraph(IRI name)

Description copied from interface: TcProvider

Deletes the ImmutableGraph or Graph of a specified name. If name references a ImmutableGraph and the ImmutableGraph has other names, it will still be available with those other names.

Specified by:

deleteGraph in interface TcProvider

Overrides:

deleteGraph in class TcProviderMultiplexer

Parameters:

name - the entity to be removed

getNames

public Set<IRI> getNames(ImmutableGraph ImmutableGraph)

Description copied from interface: TcProvider

get a set of the names of a ImmutableGraph

Specified by:

getNames in interface TcProvider

Overrides:

getNames in class TcProviderMultiplexer

Returns:

the set names of ImmutableGraph, the set is empty if ImmutableGraph is unknown

listNamedGraphs

public Set<IRI> listNamedGraphs()

Description copied from interface: GraphStore

Lists the name of the named Graphs available through this GraphStore.

Specified by:

listNamedGraphs in interface GraphStore

Returns:

the list of named Graphs

listGraphs

public Set<IRI> listGraphs()

Description copied from interface: TcProvider

Lists the name of the Graphs available through this TcProvider indifferently whether they are mutables or immutables, implementations may take into account the security context and omit Graphs for which access is not allowed.

Specified by:

listGraphs in interface TcProvider

Specified by:

listGraphs in interface GraphStore

Overrides:

listGraphs in class TcProviderMultiplexer

Returns:

the list of Graphs

listMGraphs

public Set<IRI> listMGraphs()

Description copied from interface: TcProvider

Lists the name of the Graphs available through this TcProvider that are not ImmutableGraph, implementations may take into account the security context and omit Graphs for which access is not allowed.

Specified by:

listMGraphs in interface TcProvider

Overrides:

listMGraphs in class TcProviderMultiplexer

Returns:

the list of Graphs

listImmutableGraphs

public Set<IRI> listImmutableGraphs()

Description copied from interface: TcProvider

Lists the name of the ImmutableGraphs available through this TcProvider, implementations may take into account the security context and omit ImmutableGraphs for which access is not allowed.

Specified by:

listImmutableGraphs in interface TcProvider

Overrides:

listImmutableGraphs in class TcProviderMultiplexer

Returns:

the list of ImmutableGraphs

executeSparqlQuery

public Object executeSparqlQuery(String query,
                                 Graph defaultGraph)
                          throws ParseException

Executes any sparql query. The type of the result object will vary depending on the type of the query. If the defaultGraph is available in this TcManages executeSparqlQuery(String, UriRef) should be used instead.

Parameters:

query - the sparql query to execute

defaultGraph - the default ImmutableGraph against which to execute the query if no FROM clause is present

Returns:

the resulting ResultSet, ImmutableGraph or Boolean value

Throws:

ParseException

executeSparqlQuery

public Object executeSparqlQuery(String query,
                                 boolean forceFastlane)
                          throws ParseException

Executes any sparql query. The type of the result object will vary depending on the type of the query. Note that this method only works for queries that do not need a default ImmutableGraph.

Parameters:

query - the sparql query to execute

forceFastlane - indicate whether to force fastlane usage.

Returns:

the resulting ResultSet, ImmutableGraph or Boolean value

Throws:

ParseException

executeSparqlQuery

public Object executeSparqlQuery(String query,
                                 IRI defaultGraphName)
                          throws ParseException

Executes any sparql query. The type of the result object will vary depending on the type of the query. If the defaultGraph is available in this TcManages executeSparqlQuery(String, UriRef) should be used instead.

Parameters:

query - the sparql query to execute

defaultGraphName - the ImmutableGraph to be used as default ImmutableGraph in the Sparql ImmutableGraph Store

Returns:

the resulting ResultSet, ImmutableGraph or Boolean value

Throws:

ParseException

executeSparqlQuery

public Object executeSparqlQuery(String query,
                                 IRI defaultGraphName,
                                 boolean forceFastlane)
                          throws ParseException

Executes any sparql query. The type of the result object will vary depending on the type of the query. If the defaultGraph is available in this TcManages executeSparqlQuery(String, UriRef) should be used instead.

Parameters:

query - the sparql query to execute

defaultGraphName - the ImmutableGraph to be used as default ImmutableGraph in the Sparql ImmutableGraph Store

forceFastlane - indicate whether to force fastlane usage.

Returns:

the resulting ResultSet, ImmutableGraph or Boolean value

Throws:

ParseException

executeSparqlQuery

@Deprecated
public Object executeSparqlQuery(Query query,
                                             Graph defaultGraph)

Deprecated. Query is discontinued

Executes any sparql query. The type of the result object will vary depending on the type of the query.

Parameters:

query - the sparql query to execute

defaultGraph - the default ImmutableGraph against which to execute the query if no FROM clause is present

Returns:

the resulting ResultSet, ImmutableGraph or Boolean value

executeSparqlQuery

@Deprecated
public ResultSet executeSparqlQuery(SelectQuery query,
                                                Graph defaultGraph)

Deprecated. Query is discontinued

Executes a sparql SELECT query.

Parameters:

query - the sparql SELECT query to execute

defaultGraph - the default ImmutableGraph against which to execute the query if not FROM clause is present

Returns:

the resulting ResultSet

executeSparqlQuery

@Deprecated
public boolean executeSparqlQuery(AskQuery query,
                                              Graph defaultGraph)

Deprecated. Query is discontinued

Executes a sparql ASK query.

Parameters:

query - the sparql ASK query to execute

defaultGraph - the default ImmutableGraph against which to execute the query if not FROM clause is present

Returns:

the boolean value this query evaluates to

executeSparqlQuery

@Deprecated
public ImmutableGraph executeSparqlQuery(DescribeQuery query,
                                                     Graph defaultGraph)

Deprecated. Query is discontinued

Executes a sparql DESCRIBE query.

Parameters:

query - the sparql DESCRIBE query to execute

defaultGraph - the default ImmutableGraph against which to execute the query if not FROM clause is present

Returns:

the resulting ImmutableGraph

executeSparqlQuery

@Deprecated
public ImmutableGraph executeSparqlQuery(ConstructQuery query,
                                                     Graph defaultGraph)

Deprecated. Query is discontinued

Executes a sparql CONSTRUCT query.

Parameters:

query - the sparql CONSTRUCT query to execute

defaultGraph - the default ImmutableGraph against which to execute the query if not FROM clause is present

Returns:

the resulting ImmutableGraph

getTcAccessController

public TcAccessController getTcAccessController()

Returns:

the TcAccessController that can be used to set the permissions needed to access a Triple Collection

bindWeightedTcProvider

protected void bindWeightedTcProvider(WeightedTcProvider provider)

Registers a provider

Parameters:

provider - the provider to be registered

unbindWeightedTcProvider

protected void unbindWeightedTcProvider(WeightedTcProvider provider)

Unregister a provider

Parameters:

provider - the provider to be deregistered

bindGpWeightedTcProvider

protected void bindGpWeightedTcProvider(WeightedTcProvider provider)

Registers a provider

Parameters:

provider - the provider to be registered

unbindGpWeightedTcProvider

protected void unbindGpWeightedTcProvider(WeightedTcProvider provider)

Unregister a provider

Parameters:

provider - the provider to be deregistered

bindQueryEngine

protected void bindQueryEngine(QueryEngine queryEngine)

unbindQueryEngine

protected void unbindQueryEngine(QueryEngine queryEngine)

mGraphAppears

protected void mGraphAppears(IRI name)

Description copied from class: TcProviderMultiplexer

subclasses overwrite this method to be notified when a new Graph is available (either because it has been created or being provided by a newly added WeightedTcProvider). The default implementation does nothing.

Overrides:

mGraphAppears in class TcProviderMultiplexer

graphAppears

protected void graphAppears(IRI name)

Description copied from class: TcProviderMultiplexer

subclasses overwrite this method to be notified when a new ImmutableGraph is available (either because it has been created or being provided by a newly added WeightedTcProvider). The default implementation does nothing.

Overrides:

graphAppears in class TcProviderMultiplexer

tcDisappears

protected void tcDisappears(IRI name)

Description copied from class: TcProviderMultiplexer

subclasses overwrite this method to be notified whenGraph is no longer available (either because it has been deleted or bacause its WeightedTcProvider was removed). The default implementation does nothing. for implementational reasons even for name of Graph not previously registered.

Overrides:

tcDisappears in class TcProviderMultiplexer

isTcServicesEnabled

public boolean isTcServicesEnabled()