/**
* 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).
*
* @pre: builder is set.
* @param patterns the patterns to be matched.
* @throws RetePatternBuildException if construction fails.
*/
public synchronized void buildMatchersCoalesced(final Collection<PatternDescription> patterns)
throws RetePatternBuildException {
context.modelReadLock();
try {
if (parallelExecutionEnabled) reteNet.getStructuralChangeLock().lock();
try {
try {
context.coalesceTraversals(
new Callable<Void>() {
@Override
public Void call() throws RetePatternBuildException {
for (PatternDescription gtPattern : patterns) {
boundary.accessProduction(gtPattern);
}
return null;
}
});
} catch (InvocationTargetException ex) {
final Throwable cause = ex.getCause();
if (cause instanceof RetePatternBuildException) throw (RetePatternBuildException) cause;
if (cause instanceof RuntimeException) throw (RuntimeException) cause;
assert (false);
}
} finally {
if (parallelExecutionEnabled) reteNet.getStructuralChangeLock().unlock();
}
settle();
} finally {
context.modelReadUnLock();
}
}
/**
* Accesses the patternmatcher for a given pattern, constructs one if a matcher is not available
* yet.
*
* @pre: builder is set.
* @param gtPattern the pattern to be matched.
* @return a patternmatcher object that can match occurences of the given pattern.
* @throws RetePatternBuildException if construction fails.
*/
public synchronized RetePatternMatcher accessMatcher(final PatternDescription gtPattern)
throws RetePatternBuildException {
RetePatternMatcher matcher;
// String namespace = gtPattern.getNamespace().getName();
// String name = gtPattern.getName();
// String fqn = namespace + "." + name;
matcher = matchers.get(gtPattern);
if (matcher == null) {
context.modelReadLock();
try {
if (parallelExecutionEnabled) reteNet.getStructuralChangeLock().lock();
try {
try {
context.coalesceTraversals(
new Callable<Void>() {
@Override
public Void call() throws RetePatternBuildException {
Address<? extends Production> prodNode;
prodNode = boundary.accessProduction(gtPattern);
RetePatternMatcher retePatternMatcher =
new RetePatternMatcher(ReteEngine.this, prodNode);
retePatternMatcher.setTag(gtPattern);
matchers.put(gtPattern, retePatternMatcher);
return null;
}
});
} catch (InvocationTargetException ex) {
final Throwable cause = ex.getCause();
if (cause instanceof RetePatternBuildException) throw (RetePatternBuildException) cause;
if (cause instanceof RuntimeException) throw (RuntimeException) cause;
assert (false);
}
} finally {
if (parallelExecutionEnabled) reteNet.getStructuralChangeLock().unlock();
settle();
}
} finally {
context.modelReadUnLock();
}
// reteNet.flushUpdates();
matcher = matchers.get(gtPattern);
}
return matcher;
}
/**
* Returns an indexer that groups the contents of this Production node by their projections to a
* given mask. Designed to be called by a RetePatternMatcher.
*
* @param production the production node to be indexed.
* @param mask the mask that defines the projection.
* @return the Indexer.
*/
synchronized Indexer accessProjection(Production production, TupleMask mask) {
Library library = reteNet.getHeadContainer().getLibrary();
Indexer result = library.peekProjectionIndexer(production, mask);
if (result == null) {
context.modelReadLock();
try {
if (parallelExecutionEnabled) reteNet.getStructuralChangeLock().lock();
try {
result = library.accessProjectionIndexerOnetime(production, mask);
} finally {
if (parallelExecutionEnabled) reteNet.getStructuralChangeLock().unlock();
}
} finally {
context.modelReadUnLock();
}
}
return result;
}
/** deconstructs engine components */
private synchronized void deconstructEngine() {
reteNet.kill();
for (Disconnectable disc : disconnectables) {
disc.disconnect();
}
this.matchers = null;
this.disconnectables = null;
this.reteNet = null;
this.boundary = null;
// this.machineListener = new MachineListener(this); // prerequisite:
// framework, disconnectables
this.manipulationListener = null;
this.traceListener = null;
}
/**
* 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.
*
* @param action the action to be run when reaching the steady-state.
*/
public void settle(Runnable action) {
reteNet.waitForReteTermination(action);
}
/** Waits until the pattern matcher is in a steady state and output can be retrieved. */
public void settle() {
reteNet.waitForReteTermination();
}
