Examples with ExtendableIterator com.baidu.hugegraph.iterator.ExtendableIterator used on opensource projects

Example 1 with ExtendableIterator

use of com.baidu.hugegraph.iterator.ExtendableIterator in project incubator-hugegraph by apache.

the class CachedGraphTransaction method queryEdgesFromBackend.

@Override
@Watched(prefix = "graphcache")
protected final Iterator<HugeEdge> queryEdgesFromBackend(Query query) {
    RamTable ramtable = this.params().ramtable();
    if (ramtable != null && ramtable.matched(query)) {
        return ramtable.query(query);
    }
    if (!this.enableCacheEdge() || query.empty() || query.paging() || query.bigCapacity()) {
        // Query all edges or query edges in paging, don't cache it
        return super.queryEdgesFromBackend(query);
    }
    Id cacheKey = new QueryId(query);
    Object value = this.edgesCache.get(cacheKey);
    @SuppressWarnings("unchecked") Collection<HugeEdge> edges = (Collection<HugeEdge>) value;
    if (value != null) {
        for (HugeEdge edge : edges) {
            if (edge.expired()) {
                this.edgesCache.invalidate(cacheKey);
                value = null;
            }
        }
    }
    if (value != null) {
        // Not cached or the cache expired
        return edges.iterator();
    }
    Iterator<HugeEdge> rs = super.queryEdgesFromBackend(query);
    /*
         * Iterator can't be cached, caching list instead
         * there may be super node and too many edges in a query,
         * try fetch a few of the head results and determine whether to cache.
         */
    final int tryMax = 1 + MAX_CACHE_EDGES_PER_QUERY;
    assert tryMax > MAX_CACHE_EDGES_PER_QUERY;
    edges = new ArrayList<>(tryMax);
    for (int i = 0; rs.hasNext() && i < tryMax; i++) {
        edges.add(rs.next());
    }
    if (edges.size() == 0) {
        this.edgesCache.update(cacheKey, Collections.emptyList());
    } else if (edges.size() <= MAX_CACHE_EDGES_PER_QUERY) {
        this.edgesCache.update(cacheKey, edges);
    }
    return new ExtendableIterator<>(edges.iterator(), rs);
}

Example 2 with ExtendableIterator

use of com.baidu.hugegraph.iterator.ExtendableIterator in project incubator-hugegraph by apache.

the class CachedGraphTransaction method queryVerticesByIds.

@Watched(prefix = "graphcache")
private Iterator<HugeVertex> queryVerticesByIds(IdQuery query) {
    if (query.idsSize() == 1) {
        Id vertexId = query.ids().iterator().next();
        HugeVertex vertex = (HugeVertex) this.verticesCache.get(vertexId);
        if (vertex != null) {
            if (!vertex.expired()) {
                return QueryResults.iterator(vertex);
            }
            this.verticesCache.invalidate(vertexId);
        }
        Iterator<HugeVertex> rs = super.queryVerticesFromBackend(query);
        vertex = QueryResults.one(rs);
        if (vertex == null) {
            return QueryResults.emptyIterator();
        }
        if (needCacheVertex(vertex)) {
            this.verticesCache.update(vertex.id(), vertex);
        }
        return QueryResults.iterator(vertex);
    }
    IdQuery newQuery = new IdQuery(HugeType.VERTEX, query);
    List<HugeVertex> vertices = new ArrayList<>();
    for (Id vertexId : query.ids()) {
        HugeVertex vertex = (HugeVertex) this.verticesCache.get(vertexId);
        if (vertex == null) {
            newQuery.query(vertexId);
        } else if (vertex.expired()) {
            newQuery.query(vertexId);
            this.verticesCache.invalidate(vertexId);
        } else {
            vertices.add(vertex);
        }
    }
    // Join results from cache and backend
    ExtendableIterator<HugeVertex> results = new ExtendableIterator<>();
    if (!vertices.isEmpty()) {
        results.extend(vertices.iterator());
    } else {
        // Just use the origin query if find none from the cache
        newQuery = query;
    }
    if (!newQuery.empty()) {
        Iterator<HugeVertex> rs = super.queryVerticesFromBackend(newQuery);
        // Generally there are not too much data with id query
        ListIterator<HugeVertex> listIterator = QueryResults.toList(rs);
        for (HugeVertex vertex : listIterator.list()) {
            // Skip large vertex
            if (needCacheVertex(vertex)) {
                this.verticesCache.update(vertex.id(), vertex);
            }
        }
        results.extend(listIterator);
    }
    return results;
}

Example 3 with ExtendableIterator

use of com.baidu.hugegraph.iterator.ExtendableIterator in project incubator-hugegraph by apache.

the class CassandraTable method query.

protected <R> Iterator<R> query(Query query, Function<Statement, ResultSet> fetcher, BiFunction<Query, ResultSet, Iterator<R>> parser) {
    ExtendableIterator<R> rs = new ExtendableIterator<>();
    if (query.limit() == 0L && !query.noLimit()) {
        LOG.debug("Return empty result(limit=0) for query {}", query);
        return rs;
    }
    List<Select> selects = this.query2Select(this.table(), query);
    try {
        for (Select select : selects) {
            ResultSet results = fetcher.apply(select);
            rs.extend(parser.apply(query, results));
        }
    } catch (DriverException e) {
        LOG.debug("Failed to query [{}], detail statement: {}", query, selects, e);
        throw new BackendException("Failed to query [%s]", e, query);
    }
    LOG.debug("Return {} for query {}", rs, query);
    return rs;
}

Example 4 with ExtendableIterator

use of com.baidu.hugegraph.iterator.ExtendableIterator in project incubator-hugegraph by apache.

the class HugeTraverser method edgesOfVertex.

@Watched
protected Iterator<Edge> edgesOfVertex(Id source, Directions dir, Map<Id, String> labels, long limit) {
    if (labels == null || labels.isEmpty()) {
        return this.edgesOfVertex(source, dir, (Id) null, limit);
    }
    ExtendableIterator<Edge> results = new ExtendableIterator<>();
    for (Id label : labels.keySet()) {
        E.checkNotNull(label, "edge label");
        results.extend(this.edgesOfVertex(source, dir, label, limit));
    }
    if (limit == NO_LIMIT) {
        return results;
    }
    long[] count = new long[1];
    return new LimitIterator<>(results, e -> {
        return count[0]++ >= limit;
    });
}

Example 5 with ExtendableIterator

use of com.baidu.hugegraph.iterator.ExtendableIterator in project hugegraph-common by hugegraph.

the class ReflectionUtil method classes.

public static Iterator<ClassInfo> classes(String... packages) throws IOException {
    ClassPath path = ClassPath.from(ReflectionUtil.class.getClassLoader());
    ExtendableIterator<ClassInfo> results = new ExtendableIterator<>();
    for (String p : packages) {
        results.extend(path.getTopLevelClassesRecursive(p).iterator());
    }
    return results;
}