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https://issues.apache.org/jira/browse/TINKERPOP-962?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15135275#comment-15135275
]
ASF GitHub Bot commented on TINKERPOP-962:
------------------------------------------
Github user twilmes commented on a diff in the pull request:
https://github.com/apache/incubator-tinkerpop/pull/210#discussion_r52088164
--- Diff:
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/GraphFilter.java
---
@@ -0,0 +1,193 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.tinkerpop.gremlin.process.computer;
+
+import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
+import
org.apache.tinkerpop.gremlin.process.traversal.step.filter.RangeGlobalStep;
+import org.apache.tinkerpop.gremlin.process.traversal.step.map.VertexStep;
+import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalHelper;
+import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalUtil;
+import org.apache.tinkerpop.gremlin.structure.Direction;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+
+import java.io.Serializable;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+
+/**
+ * GraphFilter is used by {@link GraphComputer} implementations to prune
the source graph data being loaded into the OLAP system.
+ * There are two types of filters: a {@link Vertex} filter and an {@link
Edge} filter.
+ * The vertex filter is a {@link Traversal} that can only check the id,
label, and properties of the vertex.
+ * The edge filter is a {@link Traversal} that starts at the vertex are
emits all legal incident edges.
+ * If no vertex filter is provided, then no vertices are filtered. If no
edge filter is provided, then no edges are filtered.
+ * The use of a GraphFilter can greatly reduce the amount of data
processed by the {@link GraphComputer}.
+ * For instance, for {@code g.V().count()}, there is no reason to load
edges, and thus, the edge filter can be {@code bothE().limit(0)}.
+ *
+ * @author Marko A. Rodriguez (http://markorodriguez.com)
+ */
+public final class GraphFilter implements Cloneable, Serializable {
+
+ public enum Legal {
+ YES, NO, MAYBE;
+
+ public boolean positive() {
+ return this != NO;
+ }
+
+ public boolean negative() {
+ return this == NO;
+ }
+ }
+
+ private Traversal.Admin<Vertex, Vertex> vertexFilter = null;
+ private Traversal.Admin<Vertex, Edge> edgeFilter = null;
+
+ private boolean allowNoEdges = false;
+ private Direction allowedEdgeDirection = Direction.BOTH;
+ private Set<String> allowedEdgeLabels = new HashSet<>();
+ //private boolean allowAllRemainingEdges = false;
+
+ public void setVertexFilter(final Traversal<Vertex, Vertex>
vertexFilter) {
+ if (!TraversalHelper.isLocalVertex(vertexFilter.asAdmin()))
+ throw
GraphComputer.Exceptions.vertexFilterAccessesIncidentEdges(vertexFilter);
+ this.vertexFilter = vertexFilter.asAdmin().clone();
+ }
+
+ public void setEdgeFilter(final Traversal<Vertex, Edge> edgeFilter) {
+ if (!TraversalHelper.isLocalStarGraph(edgeFilter.asAdmin()))
+ throw
GraphComputer.Exceptions.edgeFilterAccessesAdjacentVertices(edgeFilter);
+ this.edgeFilter = edgeFilter.asAdmin().clone();
+ if (this.edgeFilter.getEndStep() instanceof RangeGlobalStep && 0
== ((RangeGlobalStep) this.edgeFilter.getEndStep()).getHighRange())
+ this.allowNoEdges = true;
+ else if (this.edgeFilter.getStartStep() instanceof VertexStep) {
+ this.allowedEdgeLabels.clear();
+ this.allowedEdgeLabels.addAll(Arrays.asList(((VertexStep)
this.edgeFilter.getStartStep()).getEdgeLabels()));
+ this.allowedEdgeDirection = ((VertexStep)
this.edgeFilter.getStartStep()).getDirection();
+ //this.allowAllRemainingEdges = 1 ==
this.edgeFilter.getSteps().size();
+ }
+ }
+
+ /*public void compileFilters() {
--- End diff --
Did you mean to comment this out and remove calls to it? Figure you meant
to but I recognized it from a previous commit.
> Provide "vertex query" selectivity when importing data in OLAP.
> ---------------------------------------------------------------
>
> Key: TINKERPOP-962
> URL: https://issues.apache.org/jira/browse/TINKERPOP-962
> Project: TinkerPop
> Issue Type: Improvement
> Components: process
> Affects Versions: 3.1.0-incubating
> Reporter: Marko A. Rodriguez
> Assignee: Marko A. Rodriguez
> Labels: breaking
> Fix For: 3.2.0-incubating
>
>
> Currently, when you do:
> {code}
> graph.compute().program(PageRankVertexProgram).submit()
> {code}
> We are pulling the entire {{graph}} into the OLAP engine. We should allow the
> user to limit the amount of data pulled via "vertex query"-type filter. For
> instance, we could support the following two new methods on {{GraphComputer}}.
> {code}
> graph.compute().program(PageRankVertexProgram).vertices(hasLabel('person')).edges(out,
> hasLabel('knows','friend').has('weight',gt(0.8)).submit()
> {code}
> The two methods would be defined as:
> {code}
> public interface GraphComputer {
> ...
> GraphComputer vertices(final Traversal<Vertex,Vertex> vertexFilter)
> GraphComputer edges(final Direction direction, final Traversal<Edge,Edge>
> edgeFilter)
> {code}
> If the user does NOT provide a {{vertices()}} (or {{edges()}}) call, then the
> {{Traversal}} is assumed to be {{IdentityTraversal}}. Finally, in terms of
> execution order, first {{vertices()}} is called and if "false" then don't
> call edges. Else, call edges on all the respective incoming and outgoing
> edges. Don't really like {{Direction}} there and perhaps its just:
> {code}
> GraphComputer edges(final Traversal<Vertex,Edge> edgeFilter)
> {code}
> And then all edges that pass through are added to OLAP vertex. You don't want
> {{both}}? Then its {{outE('knows',friend').has('weight',gt(0.8))}}.
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