Examples with Predicate org.neo4j.helpers.Predicate used on opensource projects

Example 6 with Predicate

use of org.neo4j.helpers.Predicate in project graphdb by neo4j-attic.

the class ExactDepthPathFinder method paths.

private Iterator<Path> paths(final Node start, final Node end) {
    TraversalDescription base = Traversal.description().uniqueness(Uniqueness.RELATIONSHIP_PATH).order(new BranchOrderingPolicy() {

        public BranchSelector create(TraversalBranch startSource) {
            return new LiteDepthFirstSelector(startSource, startThreshold);
        }
    });
    final int firstHalf = onDepth / 2;
    Traverser startTraverser = base.prune(Traversal.pruneAfterDepth(firstHalf)).expand(expander).filter(new Predicate<Path>() {

        public boolean accept(Path item) {
            return item.length() == firstHalf;
        }
    }).traverse(start);
    final int secondHalf = onDepth - firstHalf;
    Traverser endTraverser = base.prune(Traversal.pruneAfterDepth(secondHalf)).expand(expander.reversed()).filter(new Predicate<Path>() {

        public boolean accept(Path item) {
            return item.length() == secondHalf;
        }
    }).traverse(end);
    final Iterator<Path> startIterator = startTraverser.iterator();
    final Iterator<Path> endIterator = endTraverser.iterator();
    final Map<Node, Visit> visits = new HashMap<Node, Visit>();
    return new PrefetchingIterator<Path>() {

        @Override
        protected Path fetchNextOrNull() {
            Path[] found = null;
            while (found == null && (startIterator.hasNext() || endIterator.hasNext())) {
                found = goOneStep(start, startIterator, visits);
                if (found == null) {
                    found = goOneStep(end, endIterator, visits);
                }
            }
            return found != null ? toPath(found, start) : null;
        }
    };
}

Example 7 with Predicate

use of org.neo4j.helpers.Predicate in project graphdb by neo4j-attic.

the class ExperimentalAStar method findAllPaths.

public Iterable<WeightedPath> findAllPaths(Node start, final Node end) {
    Predicate<Path> filter = new Predicate<Path>() {

        public boolean accept(Path position) {
            return position.endNode().equals(end);
        }
    };
    final Traverser traverser = traversalDescription.order(new SelectorFactory(end)).filter(filter).traverse(start);
    return new Iterable<WeightedPath>() {

        public Iterator<WeightedPath> iterator() {
            return new StopAfterWeightIterator(traverser.iterator(), costEvaluator);
        }
    };
}

Example 8 with Predicate

use of org.neo4j.helpers.Predicate in project graphdb by neo4j-attic.

the class MasterImpl method commitSingleResourceTransaction.

public Response<Long> commitSingleResourceTransaction(SlaveContext context, String resource, TxExtractor txGetter) {
    Transaction otherTx = suspendOtherAndResumeThis(context);
    try {
        XaDataSource dataSource = graphDbConfig.getTxModule().getXaDataSourceManager().getXaDataSource(resource);
        final long txId = dataSource.applyPreparedTransaction(txGetter.extract());
        Predicate<Long> notThisTx = new Predicate<Long>() {

            public boolean accept(Long item) {
                return item != txId;
            }
        };
        return packResponse(context, txId, notThisTx);
    } catch (IOException e) {
        e.printStackTrace();
        return new FailedResponse<Long>();
    } finally {
        suspendThisAndResumeOther(otherTx, context);
    }
}