DefinitionCollectingModelWalker.java
/*
* Portions of this software was developed by employees of the National Institute
* of Standards and Technology (NIST), an agency of the Federal Government and is
* being made available as a public service. Pursuant to title 17 United States
* Code Section 105, works of NIST employees are not subject to copyright
* protection in the United States. This software may be subject to foreign
* copyright. Permission in the United States and in foreign countries, to the
* extent that NIST may hold copyright, to use, copy, modify, create derivative
* works, and distribute this software and its documentation without fee is hereby
* granted on a non-exclusive basis, provided that this notice and disclaimer
* of warranty appears in all copies.
*
* THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
* EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
* THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
* INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
* SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT
* SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
* INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
* OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
* CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
* PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
* OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
*/
package gov.nist.secauto.metaschema.core.model;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Objects;
import java.util.Set;
import java.util.function.Function;
import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
/**
* Supports walking a portion of a metaschema model collecting a set of
* definitions that match the provided filter. For a definition to be collected,
* the filter must return {@code true}.
*/
public abstract class DefinitionCollectingModelWalker
extends ModelWalker<Void> {
private static final Logger LOGGER = LogManager.getLogger(DefinitionCollectingModelWalker.class);
private final Function<IDefinition, Boolean> filter;
@NonNull
private final Set<IDefinition> definitions = new LinkedHashSet<>();
@Override
protected Void getDefaultData() { // NOPMD - intentional
return null;
}
/**
* Construct a new walker using the provided filter.
*
* @param filter
* the filter to match definitions against
*/
protected DefinitionCollectingModelWalker(Function<IDefinition, Boolean> filter) {
Objects.requireNonNull(filter, "filter");
this.filter = filter;
}
/**
* Retrieves the filter used for matching.
*
* @return the filter
*/
protected Function<IDefinition, Boolean> getFilter() {
return filter;
}
/**
* Return the collection of definitions matching the configured filter.
*
* @return the collection of definitions
*/
@NonNull
@SuppressFBWarnings(value = "EI_EXPOSE_REP", justification = "interface doesn't allow modification")
public Collection<? extends IDefinition> getDefinitions() {
return definitions;
}
@Override
protected void visit(IFlagDefinition def, Void data) {
if (LOGGER.isTraceEnabled()) {
LOGGER.trace("visiting flag definition '{}'", def.toCoordinates());
}
if (getFilter().apply(def)) {
definitions.add(def);
}
}
@Override
protected boolean visit(IFieldDefinition def, Void data) {
if (LOGGER.isTraceEnabled()) {
LOGGER.trace("visiting field definition '{}'", def.toCoordinates());
}
boolean retval;
if (definitions.contains(def)) {
// no need to visit, since this has already been seen
retval = false;
} else {
if (getFilter().apply(def)) {
definitions.add(def);
}
retval = true;
}
return retval;
}
@Override
protected boolean visit(IAssemblyDefinition def, Void data) {
if (LOGGER.isTraceEnabled()) {
LOGGER.trace("visiting assembly definition '{}'", def.toCoordinates());
}
boolean retval;
if (definitions.contains(def)) {
// no need to visit, since this has already been seen
retval = false;
} else {
if (getFilter().apply(def)) {
definitions.add(def);
}
retval = true;
}
return retval;
}
}