Examples with LazyAnswerIterator ai.grakn.graql.internal.reasoner.iterator.LazyAnswerIterator used on opensource projects

Example 6 with LazyAnswerIterator

use of ai.grakn.graql.internal.reasoner.iterator.LazyAnswerIterator in project grakn by graknlabs.

the class LazyQueryCache method getAnswerStreamWithUnifier.

@Override
public Pair<Stream<Answer>, MultiUnifier> getAnswerStreamWithUnifier(Q query) {
    CacheEntry<Q, LazyAnswerIterator> match = this.getEntry(query);
    if (match != null) {
        Q equivalentQuery = match.query();
        MultiUnifier multiUnifier = equivalentQuery.getMultiUnifier(query);
        Stream<Answer> unified = match.cachedElement().stream().flatMap(a -> a.unify(multiUnifier));
        return new Pair<>(unified, multiUnifier);
    }
    Stream<Answer> answerStream = record(query, query.getQuery().stream().map(a -> a.explain(new LookupExplanation(query))));
    return new Pair<>(answerStream, new MultiUnifierImpl());
}

Example 7 with LazyAnswerIterator

use of ai.grakn.graql.internal.reasoner.iterator.LazyAnswerIterator in project grakn by graknlabs.

the class LazyQueryCache method recordRetrieveLazy.

/**
 * record answer stream for a specific query and retrieve the updated stream in a lazy iterator
 * @param query to be recorded
 * @param answers answer stream of the query
 * @return lazy iterator of updated answers
 */
public LazyAnswerIterator recordRetrieveLazy(Q query, Stream<Answer> answers) {
    CacheEntry<Q, LazyAnswerIterator> match = this.getEntry(query);
    if (match != null) {
        Q equivalentQuery = match.query();
        MultiUnifier multiUnifier = query.getMultiUnifier(equivalentQuery);
        Stream<Answer> unifiedStream = answers.flatMap(a -> a.unify(multiUnifier));
        // NB: entry overwrite
        this.putEntry(match.query(), match.cachedElement().merge(unifiedStream));
        return getAnswerIterator(query);
    }
    LazyAnswerIterator liter = new LazyAnswerIterator(answers);
    this.putEntry(query, liter);
    return liter;
}

Example 8 with LazyAnswerIterator

use of ai.grakn.graql.internal.reasoner.iterator.LazyAnswerIterator in project grakn by graknlabs.

the class QueryAnswerStream method join.

/**
 * lazy stream join with quasi- sideways information propagation
 * @param stream left stream operand
 * @param stream2 right stream operand
 * @param joinVars intersection on variables of two streams
 * @return joined stream
 */
public static Stream<Answer> join(Stream<Answer> stream, Stream<Answer> stream2, ImmutableSet<Var> joinVars) {
    LazyAnswerIterator l2 = new LazyAnswerIterator(stream2);
    return stream.flatMap(a1 -> {
        Stream<Answer> answerStream = l2.stream();
        answerStream = answerStream.filter(ans -> {
            for (Var v : joinVars) {
                if (!ans.get(v).equals(a1.get(v))) {
                    return false;
                }
            }
            return true;
        });
        return answerStream.map(a -> a.merge(a1));
    });
}

Example 9 with LazyAnswerIterator

use of ai.grakn.graql.internal.reasoner.iterator.LazyAnswerIterator in project grakn by graknlabs.

the class QueryAnswerStream method joinWithInverse.

/**
 * lazy stream join with fast lookup from inverse answer map
 * @param stream left stream operand
 * @param stream2 right stream operand
 * @param stream2InverseMap inverse map of right operand from cache
 * @param joinVars intersection on variables of two streams
 * @return joined stream
 */
static Stream<Answer> joinWithInverse(Stream<Answer> stream, Stream<Answer> stream2, Map<Pair<Var, Concept>, Set<Answer>> stream2InverseMap, ImmutableSet<Var> joinVars) {
    if (joinVars.isEmpty()) {
        LazyAnswerIterator l2 = new LazyAnswerIterator(stream2);
        return stream.flatMap(a1 -> l2.stream().map(a -> a.merge(a1)));
    }
    return stream.flatMap(a1 -> {
        Iterator<Var> vit = joinVars.iterator();
        Set<Answer> matchAnswers = findMatchingAnswers(a1, stream2InverseMap, vit.next());
        while (vit.hasNext()) {
            matchAnswers = Sets.intersection(matchAnswers, findMatchingAnswers(a1, stream2InverseMap, vit.next()));
        }
        return matchAnswers.stream().map(a -> a.merge(a1));
    });
}