org.eclipse.viatra.query.runtime.rete.matcher

Class ReteEngine

java.lang.Object

org.eclipse.viatra.query.runtime.rete.matcher.ReteEngine

All Implemented Interfaces:

IQueryBackend

public class ReteEngine
extends java.lang.Object
implements IQueryBackend

Field Summary

Fields

Modifier and Type	Field and Description
protected ReteBoundary	boundary
protected ReteRecipeCompiler	compiler
protected java.util.Collection<Disconnectable>	disconnectables
protected java.util.Map<PQuery,RetePatternMatcher>	matchers
protected boolean	parallelExecutionEnabled
protected Network	reteNet
protected int	reteThreads
protected IQueryRuntimeContext	runtimeContext

Constructor Summary

Constructors

Constructor and Description
ReteEngine(IQueryBackendContext context, int reteThreads)

Method Summary

Modifier and Type	Method and Description
RetePatternMatcher	accessMatcher(PQuery query) Accesses the patternmatcher for a given pattern, constructs one if a matcher is not available yet.
void	addDisconnectable(Disconnectable disc)
void	buildMatchersCoalesced(java.util.Collection<PQuery> specifications) Constructs RETE pattern matchers for a collection of patterns, if they are not available yet.
void	dispose() Disposes the query backend.
void	flushUpdates() Propagates all pending updates in this query backend.
IQueryBackendContext	getBackendContext()
ReteBoundary	getBoundary()
ReteRecipeCompiler	getCompiler()
IQueryBackendHintProvider	getHintConfiguration()
org.apache.log4j.Logger	getLogger()
IQueryResultProvider	getResultProvider(PQuery query) Returns a result provider for a given query.
IQueryResultProvider	getResultProvider(PQuery query, QueryEvaluationHint hints) Returns a result provider for a given query.
Network	getReteNet()
IQueryRuntimeContext	getRuntimeContext()
boolean	isCaching()
boolean	isParallelExecutionEnabled()
void	killEngine() Deconstructs the engine to get rid of it finally
IQueryResultProvider	peekExistingResultProvider(PQuery query) Returns an existing result provider for a given query, if it was previously constructed, returns null otherwise.
void	reset() Resets the engine to an after-initialization phase
void	setCompiler(ReteRecipeCompiler builder)
void	settle() Waits until the pattern matcher is in a steady state and output can be retrieved.
void	settle(java.lang.Runnable action) Waits until the pattern matcher is in a steady state and output can be retrieved.

Methods inherited from class java.lang.Object

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

Field Detail

reteNet

protected Network reteNet

reteThreads

protected final int reteThreads

boundary

protected ReteBoundary boundary

runtimeContext

protected IQueryRuntimeContext runtimeContext

disconnectables

protected java.util.Collection<Disconnectable> disconnectables

matchers

protected java.util.Map<PQuery,RetePatternMatcher> matchers

compiler

protected ReteRecipeCompiler compiler

parallelExecutionEnabled

protected final boolean parallelExecutionEnabled

Constructor Detail

ReteEngine

public ReteEngine(IQueryBackendContext context,
                  int reteThreads)

Parameters:

context - the context of the pattern matcher, conveying all information from the outside world.

reteThreads - the number of threads to operate the RETE network with; 0 means single-threaded operation, 1 starts an asynchronous thread to operate the RETE net, >1 uses multiple RETE containers.

Method Detail

getBackendContext

public IQueryBackendContext getBackendContext()

Since:

1.6

flushUpdates

public void flushUpdates()

Description copied from interface: IQueryBackend

Propagates all pending updates in this query backend. The implementation of this method is optional, and it can be ignored entirely if the backend does not delay updates.

Specified by:

flushUpdates in interface IQueryBackend

killEngine

public void killEngine()

Deconstructs the engine to get rid of it finally

reset

public void reset()

Resets the engine to an after-initialization phase

accessMatcher

public RetePatternMatcher accessMatcher(PQuery query)
                                 throws QueryProcessingException

Accesses the patternmatcher for a given pattern, constructs one if a matcher is not available yet.

Parameters:

query - the pattern to be matched.

Returns:

a patternmatcher object that can match occurences of the given pattern.

Throws:

RetePatternBuildException - if construction fails.

QueryProcessingException

buildMatchersCoalesced

public void buildMatchersCoalesced(java.util.Collection<PQuery> specifications)
                            throws QueryProcessingException

Constructs RETE pattern matchers for a collection of patterns, if they are not available yet. Model traversal during the whole construction period is coalesced (which may have an effect on performance, depending on the matcher context).

Parameters:

specifications - the patterns to be matched.

Throws:

RetePatternBuildException - if construction fails.

QueryProcessingException

settle

public void settle()

Waits until the pattern matcher is in a steady state and output can be retrieved.

settle

public void settle(java.lang.Runnable action)

Waits until the pattern matcher is in a steady state and output can be retrieved. When steady state is reached, a retrieval action is executed before the steady state ceases.

Parameters:

action - the action to be run when reaching the steady-state.

getReteNet

public Network getReteNet()

Returns:

the reteNet

getBoundary

public ReteBoundary getBoundary()

Returns:

the boundary

setCompiler

public void setCompiler(ReteRecipeCompiler builder)

Parameters:

builder - the pattern matcher builder to set

addDisconnectable

public void addDisconnectable(Disconnectable disc)

Parameters:

disc - the new Disconnectable adapter.

isParallelExecutionEnabled

public boolean isParallelExecutionEnabled()

Returns:

the parallelExecutionEnabled

getLogger

public org.apache.log4j.Logger getLogger()

getRuntimeContext

public IQueryRuntimeContext getRuntimeContext()

getCompiler

public ReteRecipeCompiler getCompiler()

getResultProvider

public IQueryResultProvider getResultProvider(PQuery query)
                                       throws QueryProcessingException

Description copied from interface: IQueryBackend

Returns a result provider for a given query. Repeated calls may return the same instance.

Specified by:

getResultProvider in interface IQueryBackend

Throws:

QueryProcessingException

getResultProvider

public IQueryResultProvider getResultProvider(PQuery query,
                                              QueryEvaluationHint hints)
                                       throws QueryProcessingException

Description copied from interface: IQueryBackend

Returns a result provider for a given query. Repeated calls may return the same instance.

Specified by:

getResultProvider in interface IQueryBackend

Throws:

QueryProcessingException

Since:

1.4

peekExistingResultProvider

public IQueryResultProvider peekExistingResultProvider(PQuery query)

Description copied from interface: IQueryBackend

Returns an existing result provider for a given query, if it was previously constructed, returns null otherwise. Will not construct and initialize new result providers.

Specified by:

peekExistingResultProvider in interface IQueryBackend

dispose

public void dispose()

Description copied from interface: IQueryBackend

Disposes the query backend.

Specified by:

dispose in interface IQueryBackend

isCaching

public boolean isCaching()

Specified by:

isCaching in interface IQueryBackend

Returns:

true iff this backend is incremental, i.e. it caches the results of queries for quick retrieval, and can provide update notifications on result set changes.

getHintConfiguration

public IQueryBackendHintProvider getHintConfiguration()

Since:

1.5

No Reference:

Internal API, subject to change