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Posted to commits@rya.apache.org by ca...@apache.org on 2018/01/11 14:52:05 UTC

[6/6] incubator-rya git commit: RYA-417 Batch forward-chaining rules engine. Closes #255.

RYA-417 Batch forward-chaining rules engine.  Closes #255.


Project: http://git-wip-us.apache.org/repos/asf/incubator-rya/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-rya/commit/9f611019
Tree: http://git-wip-us.apache.org/repos/asf/incubator-rya/tree/9f611019
Diff: http://git-wip-us.apache.org/repos/asf/incubator-rya/diff/9f611019

Branch: refs/heads/master
Commit: 9f611019fca682148483ae31a1123b8e92b5fda2
Parents: d5ebb73
Author: Jesse Hatfield <je...@parsons.com>
Authored: Fri Dec 22 12:02:33 2017 -0500
Committer: caleb <ca...@parsons.com>
Committed: Thu Jan 11 09:50:38 2018 -0500

----------------------------------------------------------------------
 .../AggregationPipelineQueryNode.java           |   8 +-
 .../mongodb/aggregation/PipelineQueryIT.java    |  32 ++
 .../SparqlToPipelineTransformVisitorTest.java   |  14 +
 .../apache/rya/sail/config/RyaSailFactory.java  |  64 ++--
 extras/pom.xml                                  |   1 +
 extras/rya.forwardchain/pom.xml                 | 119 +++++++
 .../rya/forwardchain/ForwardChainConstants.java |  37 ++
 .../rya/forwardchain/ForwardChainException.java |  54 +++
 .../batch/AbstractForwardChainTool.java         | 148 ++++++++
 .../batch/ForwardChainSpinTool.java             |  77 +++++
 .../rule/AbstractConstructRule.java             |  65 ++++
 .../rule/AbstractInconsistencyRule.java         |  51 +++
 .../forwardchain/rule/AbstractUpdateRule.java   |  34 ++
 .../forwardchain/rule/AntecedentVisitor.java    |  51 +++
 .../rule/ConstructConsequentVisitor.java        | 138 ++++++++
 .../org/apache/rya/forwardchain/rule/Rule.java  |  75 ++++
 .../apache/rya/forwardchain/rule/Ruleset.java   | 166 +++++++++
 .../forwardchain/rule/SpinConstructRule.java    | 344 +++++++++++++++++++
 .../strategy/AbstractForwardChainStrategy.java  |  82 +++++
 .../strategy/AbstractRuleExecutionStrategy.java | 108 ++++++
 .../strategy/MongoPipelineStrategy.java         | 276 +++++++++++++++
 .../strategy/RoundRobinStrategy.java            | 212 ++++++++++++
 .../strategy/SailExecutionStrategy.java         | 223 ++++++++++++
 .../rya/forwardchain/batch/MongoSpinIT.java     | 169 +++++++++
 .../rule/AntecedentVisitorTest.java             | 156 +++++++++
 .../rule/ConstructConsequentVisitorTest.java    | 164 +++++++++
 .../rya/forwardchain/rule/RulesetTest.java      | 137 ++++++++
 .../rule/SpinConstructRuleTest.java             | 213 ++++++++++++
 .../src/test/resources/data.ttl                 |  56 +++
 .../src/test/resources/owlrl.ttl                | 106 ++++++
 .../src/test/resources/query.sparql             |  32 ++
 .../src/test/resources/university.ttl           |  58 ++++
 32 files changed, 3442 insertions(+), 28 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/dao/mongodb.rya/src/main/java/org/apache/rya/mongodb/aggregation/AggregationPipelineQueryNode.java
----------------------------------------------------------------------
diff --git a/dao/mongodb.rya/src/main/java/org/apache/rya/mongodb/aggregation/AggregationPipelineQueryNode.java b/dao/mongodb.rya/src/main/java/org/apache/rya/mongodb/aggregation/AggregationPipelineQueryNode.java
index 7a84f5d..45092e4 100644
--- a/dao/mongodb.rya/src/main/java/org/apache/rya/mongodb/aggregation/AggregationPipelineQueryNode.java
+++ b/dao/mongodb.rya/src/main/java/org/apache/rya/mongodb/aggregation/AggregationPipelineQueryNode.java
@@ -531,7 +531,9 @@ public class AggregationPipelineQueryNode extends ExternalSet {
      * The number of documents produced by the pipeline after this operation
      * will be the number of documents entering this stage (the number of
      * intermediate results) multiplied by the number of
-     * {@link ProjectionElemList}s supplied here.
+     * {@link ProjectionElemList}s supplied here. Empty projections are
+     * unsupported; if one or more projections given binds zero variables, then
+     * the pipeline will be unchanged and the method will return false.
      * @param projections One or more projections, i.e. mappings from the result
      *  at this stage of the query into a set of variables.
      * @return true if the projection(s) were added to the pipeline.
@@ -544,6 +546,10 @@ public class AggregationPipelineQueryNode extends ExternalSet {
         Set<String> bindingNamesUnion = new HashSet<>();
         Set<String> bindingNamesIntersection = null;
         for (ProjectionElemList projection : projections) {
+            if (projection.getElements().isEmpty()) {
+                // Empty projections are unsupported -- fail when seen
+                return false;
+            }
             Document valueDoc = new Document();
             Document hashDoc = new Document();
             Document typeDoc = new Document();

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/PipelineQueryIT.java
----------------------------------------------------------------------
diff --git a/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/PipelineQueryIT.java b/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/PipelineQueryIT.java
index 45855a0..0552ac0 100644
--- a/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/PipelineQueryIT.java
+++ b/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/PipelineQueryIT.java
@@ -49,8 +49,10 @@ import org.openrdf.model.vocabulary.RDFS;
 import org.openrdf.model.vocabulary.XMLSchema;
 import org.openrdf.query.BindingSet;
 import org.openrdf.query.QueryEvaluationException;
+import org.openrdf.query.algebra.Projection;
 import org.openrdf.query.algebra.QueryRoot;
 import org.openrdf.query.algebra.evaluation.QueryBindingSet;
+import org.openrdf.query.impl.EmptyBindingSet;
 import org.openrdf.query.impl.ListBindingSet;
 import org.openrdf.query.parser.sparql.SPARQLParser;
 
@@ -135,6 +137,36 @@ public class PipelineQueryIT extends MongoITBase {
     }
 
     @Test
+    public void testNoVariableSP() throws Exception {
+        // Insert data
+        insert(OWL.THING, RDF.TYPE, OWL.CLASS);
+        insert(FOAF.PERSON, RDF.TYPE, OWL.CLASS, 1);
+        insert(FOAF.PERSON, RDFS.SUBCLASSOF, OWL.THING);
+        insert(VF.createURI("urn:Alice"), RDF.TYPE, FOAF.PERSON);
+        dao.flush();
+        // Define query and expected results
+        final String query = "SELECT * WHERE {\n"
+                + "  owl:Thing a owl:Class .\n"
+                + "}";
+        Multiset<BindingSet> expectedSolutions = HashMultiset.create();
+        expectedSolutions.add(new EmptyBindingSet());
+        // Execute pipeline and verify results
+        QueryRoot queryTree = new QueryRoot(PARSER.parseQuery(query, null).getTupleExpr());
+        SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(getRyaCollection());
+        queryTree.visit(visitor);
+        Assert.assertTrue(queryTree.getArg() instanceof Projection);
+        Projection projection = (Projection) queryTree.getArg();
+        Assert.assertTrue(projection.getArg() instanceof AggregationPipelineQueryNode);
+        AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) projection.getArg();
+        Multiset<BindingSet> solutions = HashMultiset.create();
+        CloseableIteration<BindingSet, QueryEvaluationException> iter = pipelineNode.evaluate(new QueryBindingSet());
+        while (iter.hasNext()) {
+            solutions.add(iter.next());
+        }
+        Assert.assertEquals(expectedSolutions, solutions);
+    }
+
+    @Test
     public void testJoinTwoSharedVariables() throws Exception {
         // Insert data
         URI person = VF.createURI("urn:Person");

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/SparqlToPipelineTransformVisitorTest.java
----------------------------------------------------------------------
diff --git a/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/SparqlToPipelineTransformVisitorTest.java b/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/SparqlToPipelineTransformVisitorTest.java
index cc9349b..506b8af 100644
--- a/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/SparqlToPipelineTransformVisitorTest.java
+++ b/dao/mongodb.rya/src/test/java/org/apache/rya/mongodb/aggregation/SparqlToPipelineTransformVisitorTest.java
@@ -29,6 +29,7 @@ import org.mockito.Mockito;
 import org.openrdf.model.URI;
 import org.openrdf.model.ValueFactory;
 import org.openrdf.model.impl.ValueFactoryImpl;
+import org.openrdf.model.vocabulary.OWL;
 import org.openrdf.model.vocabulary.RDF;
 import org.openrdf.query.algebra.Extension;
 import org.openrdf.query.algebra.ExtensionElem;
@@ -153,6 +154,19 @@ public class SparqlToPipelineTransformVisitorTest {
     }
 
     @Test
+    public void testEmptyProjection() throws Exception {
+        StatementPattern isClass = new StatementPattern(constant(UNDERGRAD), constant(RDF.TYPE), constant(OWL.CLASS));
+        QueryRoot queryTree = new QueryRoot(new Projection(isClass, new ProjectionElemList()));
+        SparqlToPipelineTransformVisitor visitor = new SparqlToPipelineTransformVisitor(collection);
+        queryTree.visit(visitor);
+        Assert.assertTrue(queryTree.getArg() instanceof Projection);
+        Projection projectNode = (Projection) queryTree.getArg();
+        Assert.assertTrue(projectNode.getArg() instanceof AggregationPipelineQueryNode);
+        AggregationPipelineQueryNode pipelineNode = (AggregationPipelineQueryNode) projectNode.getArg();
+        Assert.assertEquals(Sets.newHashSet(), pipelineNode.getAssuredBindingNames());
+    }
+
+    @Test
     public void testMultiProjection() throws Exception {
         StatementPattern isUndergrad = new StatementPattern(new Var("x"), constant(RDF.TYPE), constant(UNDERGRAD));
         StatementPattern isCourse = new StatementPattern(new Var("course"), constant(RDF.TYPE), constant(COURSE));

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/indexing/src/main/java/org/apache/rya/sail/config/RyaSailFactory.java
----------------------------------------------------------------------
diff --git a/extras/indexing/src/main/java/org/apache/rya/sail/config/RyaSailFactory.java b/extras/indexing/src/main/java/org/apache/rya/sail/config/RyaSailFactory.java
index b5adee3..56af9b4 100644
--- a/extras/indexing/src/main/java/org/apache/rya/sail/config/RyaSailFactory.java
+++ b/extras/indexing/src/main/java/org/apache/rya/sail/config/RyaSailFactory.java
@@ -88,33 +88,10 @@ public class RyaSailFactory {
             // Get a reference to a Mongo DB configuration object.
             final MongoDBRdfConfiguration mongoConfig = (config instanceof MongoDBRdfConfiguration) ?
                     (MongoDBRdfConfiguration)config : new MongoDBRdfConfiguration(config);
-
-            // Create the MongoClient that will be used by the Sail object's components.
-            final MongoClient client = createMongoClient(mongoConfig);
-
-            // Add the Indexer and Optimizer names to the configuration object that are configured to be used.
-            ConfigUtils.setIndexers(mongoConfig);
-
-            // Populate the configuration using previously stored Rya Details if this instance uses them.
-            try {
-                final MongoRyaInstanceDetailsRepository ryaDetailsRepo = new MongoRyaInstanceDetailsRepository(client, mongoConfig.getRyaInstanceName());
-                RyaDetailsToConfiguration.addRyaDetailsToConfiguration(ryaDetailsRepo.getRyaInstanceDetails(), mongoConfig);
-            } catch (final RyaDetailsRepositoryException e) {
-               LOG.info("Instance does not have a rya details collection, skipping.");
-            }
-
-            // Set the configuration to the stateful configuration that is used to pass the constructed objects around.
-            final StatefulMongoDBRdfConfiguration statefulConfig = new StatefulMongoDBRdfConfiguration(mongoConfig, client);
-            final List<MongoSecondaryIndex> indexers = statefulConfig.getInstances(AccumuloRdfConfiguration.CONF_ADDITIONAL_INDEXERS, MongoSecondaryIndex.class);
-            statefulConfig.setIndexers(indexers);
-            rdfConfig = statefulConfig;
-
-            // Create the DAO that is able to interact with MongoDB.
-            final MongoDBRyaDAO mongoDao = new MongoDBRyaDAO();
-            mongoDao.setConf(statefulConfig);
-            mongoDao.init();
-            dao = mongoDao;
-
+            // Instantiate a Mongo client and Mongo DAO.
+            dao = getMongoDAO(mongoConfig);
+            // Then use the DAO's newly-created stateful conf in place of the original
+            rdfConfig = dao.getConf();
         } else {
             rdfConfig = new AccumuloRdfConfiguration(config);
             user = rdfConfig.get(ConfigUtils.CLOUDBASE_USER);
@@ -237,4 +214,37 @@ public class RyaSailFactory {
             LOG.info("Instance does not have a rya details collection, skipping.");
         }
     }
+
+    /**
+     * Connects to MongoDB and creates a MongoDBRyaDAO.
+     * @param config - user configuration
+     * @return - MongoDBRyaDAO with Indexers configured according to user's specification
+     * @throws RyaDAOException if the DAO can't be initialized
+     */
+    public static MongoDBRyaDAO getMongoDAO(MongoDBRdfConfiguration mongoConfig) throws RyaDAOException {
+            // Create the MongoClient that will be used by the Sail object's components.
+            final MongoClient client = createMongoClient(mongoConfig);
+
+            // Add the Indexer and Optimizer names to the configuration object that are configured to be used.
+            ConfigUtils.setIndexers(mongoConfig);
+
+            // Populate the configuration using previously stored Rya Details if this instance uses them.
+            try {
+                final MongoRyaInstanceDetailsRepository ryaDetailsRepo = new MongoRyaInstanceDetailsRepository(client, mongoConfig.getRyaInstanceName());
+                RyaDetailsToConfiguration.addRyaDetailsToConfiguration(ryaDetailsRepo.getRyaInstanceDetails(), mongoConfig);
+            } catch (final RyaDetailsRepositoryException e) {
+               LOG.info("Instance does not have a rya details collection, skipping.");
+            }
+
+            // Set the configuration to the stateful configuration that is used to pass the constructed objects around.
+            final StatefulMongoDBRdfConfiguration statefulConfig = new StatefulMongoDBRdfConfiguration(mongoConfig, client);
+            final List<MongoSecondaryIndex> indexers = statefulConfig.getInstances(AccumuloRdfConfiguration.CONF_ADDITIONAL_INDEXERS, MongoSecondaryIndex.class);
+            statefulConfig.setIndexers(indexers);
+
+            // Create the DAO that is able to interact with MongoDB.
+            final MongoDBRyaDAO mongoDao = new MongoDBRyaDAO();
+            mongoDao.setConf(statefulConfig);
+            mongoDao.init();
+            return mongoDao;
+    }
 }
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/pom.xml
----------------------------------------------------------------------
diff --git a/extras/pom.xml b/extras/pom.xml
index 62220ca..4ebcb82 100644
--- a/extras/pom.xml
+++ b/extras/pom.xml
@@ -45,6 +45,7 @@ under the License.
         <module>rya.merger</module>
         <module>rya.giraph</module>
         <module>rya.streams</module>
+        <module>rya.forwardchain</module>
     </modules>
 
     <profiles>

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/pom.xml
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/pom.xml b/extras/rya.forwardchain/pom.xml
new file mode 100644
index 0000000..7acabca
--- /dev/null
+++ b/extras/rya.forwardchain/pom.xml
@@ -0,0 +1,119 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+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.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.apache.rya</groupId>
+        <artifactId>rya.extras</artifactId>
+        <version>3.2.12-incubating-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>rya.forwardchain</artifactId>
+    <name>Apache Rya Forward Chaining Inference</name>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.openrdf.sesame</groupId>
+            <artifactId>sesame-runtime</artifactId>
+            </dependency>
+        <dependency>
+            <groupId>org.apache.rya</groupId>
+            <artifactId>rya.api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.rya</groupId>
+            <artifactId>rya.sail</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.rya</groupId>
+            <artifactId>rya.indexing</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.rya</groupId>
+            <artifactId>mongodb.rya</artifactId>
+        </dependency>
+
+        <!-- Testing -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <configuration>
+                    <archive>
+                        <index>true</index>
+                        <manifest>
+                            <addClasspath>true</addClasspath>
+                            <mainClass>org.apache.rya.forwardchain.batch.ForwardChainSpinTool</mainClass>
+                        </manifest>
+                    </archive>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <configuration>
+                    <shadedArtifactAttached>true</shadedArtifactAttached>
+                    <filters>
+                        <filter>
+                            <artifact>*:*</artifact>
+                            <excludes>
+                                <exclude>META-INF/*.SF</exclude>
+                                <exclude>META-INF/*.DSA</exclude>
+                                <exclude>META-INF/*.RSA</exclude>
+                            </excludes>
+                        </filter>
+                    </filters>
+                </configuration>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <shadedArtifactAttached>true</shadedArtifactAttached>
+                            <shadedClassifierName>shaded</shadedClassifierName>
+                            <transformers>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer" />
+                            </transformers>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainConstants.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainConstants.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainConstants.java
new file mode 100644
index 0000000..f1fe8b3
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainConstants.java
@@ -0,0 +1,37 @@
+/*
+ * 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.rya.forwardchain;
+
+import org.apache.rya.api.RdfCloudTripleStoreConstants;
+import org.apache.rya.api.domain.RyaSchema;
+import org.apache.rya.api.domain.RyaURI;
+import org.apache.rya.api.resolver.RdfToRyaConversions;
+import org.openrdf.model.URI;
+import org.openrdf.model.ValueFactory;
+
+public class ForwardChainConstants {
+    private static final ValueFactory VF = RdfCloudTripleStoreConstants.VALUE_FACTORY;
+    private static final String NAMESPACE = RyaSchema.NAMESPACE;
+
+    public static final URI DERIVATION_TIME = VF.createURI(NAMESPACE, "forwardChainIteration");
+    public static final URI DERIVATION_RULE = VF.createURI(NAMESPACE, "forwardChainRule");
+
+    public static final RyaURI RYA_DERIVATION_RULE = RdfToRyaConversions.convertURI(DERIVATION_RULE);
+    public static final RyaURI RYA_DERIVATION_TIME = RdfToRyaConversions.convertURI(DERIVATION_TIME);
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainException.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainException.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainException.java
new file mode 100644
index 0000000..64b05a4
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/ForwardChainException.java
@@ -0,0 +1,54 @@
+/*
+ * 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.rya.forwardchain;
+
+/**
+ * Broad exception representing an error during forward chaining. Useful for
+ * wrapping the diverse kinds of exceptions that may be thrown by
+ * implementations of reasoning logic.
+ */
+public class ForwardChainException extends Exception {
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Constructs a new ForwardChainException with a message and a cause.
+     * @param string Detail message
+     * @param e Underlying cause
+     */
+    public ForwardChainException(String string, Exception e) {
+        super(string , e);
+    }
+
+    /**
+     * Constructs a new ForwardChainException with a message only.
+     * @param string Detail message
+     */
+    public ForwardChainException(String string) {
+        super(string);
+    }
+
+    /**
+     * Constructs a new ForwardChainException with a root cause and no
+     * additional message.
+     * @param e Underlying cause
+     */
+    public ForwardChainException(Exception e) {
+        super(e);
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/AbstractForwardChainTool.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/AbstractForwardChainTool.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/AbstractForwardChainTool.java
new file mode 100644
index 0000000..db08407
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/AbstractForwardChainTool.java
@@ -0,0 +1,148 @@
+/*
+ * 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.rya.forwardchain.batch;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.util.Tool;
+import org.apache.log4j.Logger;
+import org.apache.rya.accumulo.AccumuloRdfConfiguration;
+import org.apache.rya.api.RdfCloudTripleStoreConfiguration;
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.rule.Ruleset;
+import org.apache.rya.forwardchain.strategy.AbstractForwardChainStrategy;
+import org.apache.rya.forwardchain.strategy.AbstractRuleExecutionStrategy;
+import org.apache.rya.forwardchain.strategy.MongoPipelineStrategy;
+import org.apache.rya.forwardchain.strategy.RoundRobinStrategy;
+import org.apache.rya.forwardchain.strategy.SailExecutionStrategy;
+import org.apache.rya.indexing.accumulo.ConfigUtils;
+import org.apache.rya.mongodb.MongoDBRdfConfiguration;
+import com.google.common.base.Preconditions;
+
+/**
+ * Base class for a {@link Tool} that executes forward-chaining rules until
+ * completion (when no more new information can be derived).
+ * <p>
+ * Subclasses must implement {@link #getRuleset()} to yield the specific set of
+ * {@link Rule}s to materialize.
+ * <p>
+ * Subclasses may additionally override {@link #getStrategy()} and/or
+ * {@link #getRuleStrategy()} to provide specific forward chaining execution
+ * logic.
+ */
+public abstract class AbstractForwardChainTool implements Tool {
+    private static final Logger logger = Logger.getLogger(AbstractForwardChainTool.class);
+
+    private RdfCloudTripleStoreConfiguration conf;
+
+    private long numInferences = 0;
+
+    /**
+     * Set the {@link Configuration} for this tool, which will be converted to
+     * an {@link RdfCloudTripleStoreConfiguration}.
+     * @param conf Configuration object that specifies Rya connection details.
+     *  Should not be null.
+     */
+    @Override
+    public void setConf(Configuration conf) {
+        Preconditions.checkNotNull(conf);
+        if (conf.getBoolean(ConfigUtils.USE_MONGO, false)) {
+            this.conf = new MongoDBRdfConfiguration(conf);
+        }
+        else {
+            this.conf = new AccumuloRdfConfiguration(conf);
+        }
+    }
+
+    /**
+     * Get the RdfCloudTripleStoreConfiguration used by this tool.
+     * @return Rya configuration object.
+     */
+    @Override
+    public RdfCloudTripleStoreConfiguration getConf() {
+        return conf;
+    }
+
+    @Override
+    public int run(String[] args) throws Exception {
+        numInferences = getStrategy().executeAll(getRuleset());
+        logger.info("Forward chaining complete; made " + numInferences + " inferences.");
+        return 0;
+    }
+
+    /**
+     * Gets the number of inferences that have been made.
+     * @return zero before forward chaining, or the total number of inferences
+     *  after.
+     */
+    public long getNumInferences() {
+        return numInferences;
+    }
+
+    /**
+     * Get the high-level {@link AbstractForwardChainStrategy} that governs how
+     * reasoning will proceed. By default, returns a {@link RoundRobinStrategy}
+     * which executes each relevant rule one-by-one, then moves to the next
+     * iteration and repeats, until no rules are still relevant. Subclasses may
+     * override this method to provide alternative strategies.
+     * @return The high-level forward chaining logic.
+     * @throws ForwardChainException if the strategy can't be instantiated.
+     */
+    protected AbstractForwardChainStrategy getStrategy() throws ForwardChainException {
+        return new RoundRobinStrategy(getRuleStrategy());
+    }
+
+    /**
+     * Get the low-level {@link AbstractRuleExecutionStrategy} that governs the
+     * application of rules on an individual basis. This is used by the default
+     * ForwardChainStrategy (RoundRobinStrategy) and may be used by any
+     * high-level strategy that executes rules individually. By default, returns
+     * a {@link MongoPipelineStrategy} if the configuration object specifies a
+     * MongoDB connection with aggregation pipelines enabled, and a
+     * {@link SailExecutionStrategy} otherwise. Subclasses may override this
+     * method to provide alternative strategies.
+     * @return The low-level rule execution logic.
+     * @throws ForwardChainExceptionthe strategy can't be instantiated.
+     */
+    protected AbstractRuleExecutionStrategy getRuleStrategy() throws ForwardChainException {
+        if (ConfigUtils.getUseMongo(conf)) {
+            final MongoDBRdfConfiguration mongoConf;
+            if (conf instanceof MongoDBRdfConfiguration) {
+                mongoConf = (MongoDBRdfConfiguration) conf;
+            }
+            else {
+                mongoConf = new MongoDBRdfConfiguration(conf);
+            }
+            if (mongoConf.getUseAggregationPipeline()) {
+                return new MongoPipelineStrategy(mongoConf);
+            }
+        }
+        return new SailExecutionStrategy(conf);
+    }
+
+    /**
+     * Get the set of rules for this tool to apply. Subclasses should implement
+     * this for their specific domains. The subclass should ensure that the
+     * ruleset returned only contains rules whose types are supported by the
+     * forward chaining strategy. The default strategy supports only CONSTRUCT
+     * rules, so the ruleset should only contain {@link AbstractConstructRule}s.
+     * @return A set of forward-chaining rules.
+     * @throws ForwardChainException if rules couldn't be retrieved.
+     */
+    protected abstract Ruleset getRuleset() throws ForwardChainException;
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/ForwardChainSpinTool.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/ForwardChainSpinTool.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/ForwardChainSpinTool.java
new file mode 100644
index 0000000..c35f37e
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/batch/ForwardChainSpinTool.java
@@ -0,0 +1,77 @@
+/*
+ * 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.rya.forwardchain.batch;
+
+import org.apache.hadoop.util.Tool;
+import org.apache.hadoop.util.ToolRunner;
+import org.apache.rya.api.RdfCloudTripleStoreConfiguration;
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.rule.Ruleset;
+import org.apache.rya.forwardchain.rule.SpinConstructRule;
+
+/**
+ * {@link Tool} to load SPIN Construct rules from a Rya data store, then apply
+ * those rules to the same store using forward-chaining inference
+ * (materialization), adding triples back to Rya until no more information can
+ * be derived.
+ */
+public class ForwardChainSpinTool extends AbstractForwardChainTool {
+    private Ruleset ruleset;
+
+    /**
+     * Constructor that takes in an {@link RdfCloudTripleStoreConfiguration}.
+     * @param conf Configuration object containing Rya connection information.
+     */
+    public ForwardChainSpinTool(RdfCloudTripleStoreConfiguration conf) {
+        setConf(conf);
+    }
+
+    /**
+     * Default constructor that does not take in a configuration object. Rya
+     * connection details should be provided via an
+     * RdfCloudTripleStoreConfiguration, either using
+     * {@link AbstractForwardChainTool#setConf} or a {@link ToolRunner}.
+     */
+    public ForwardChainSpinTool() { }
+
+    /**
+     * Load SPIN Construct rules from Rya.
+     * @return A set of construct query rules.
+     * @throws ForwardChainException if loading rules from Rya fails.
+     */
+    @Override
+    protected Ruleset getRuleset() throws ForwardChainException {
+        if (ruleset == null) {
+            ruleset = SpinConstructRule.loadSpinRules(getConf());
+        }
+        return ruleset;
+    }
+
+    public static void main(String[] args) throws Exception {
+        long start = System.currentTimeMillis();
+        ForwardChainSpinTool tool = new ForwardChainSpinTool();
+        ToolRunner.run(tool, args);
+        long end = System.currentTimeMillis();
+        double seconds = (end - start) / 1000.0;
+        long inferences = tool.getNumInferences();
+        long rules = tool.getRuleset().getRules().size();
+        System.out.println(String.format("ForwardChainSpinTool: %d rules, %d inferences, %.3f seconds",
+                rules, inferences, seconds));
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractConstructRule.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractConstructRule.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractConstructRule.java
new file mode 100644
index 0000000..c4c12c7
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractConstructRule.java
@@ -0,0 +1,65 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import org.apache.rya.api.domain.StatementMetadata;
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.strategy.AbstractRuleExecutionStrategy;
+import org.openrdf.query.algebra.StatementPattern;
+import org.openrdf.query.parser.ParsedGraphQuery;
+
+import com.google.common.base.Preconditions;
+
+/**
+ * A rule that produces new triples, and can be expressed as a graph query
+ * (SPARQL "CONSTRUCT"). Should not modify existing triples.
+ */
+public abstract class AbstractConstructRule implements Rule {
+    /**
+     * Get the query tree corresponding to this construct rule.
+     * @return The query algebra representation of this rule.
+     */
+    public abstract ParsedGraphQuery getQuery();
+
+    @Override
+    public long execute(AbstractRuleExecutionStrategy strategy,
+            StatementMetadata metadata) throws ForwardChainException {
+        Preconditions.checkNotNull(strategy);
+        Preconditions.checkNotNull(metadata);
+        return strategy.executeConstructRule(this, metadata);
+    }
+
+    /**
+     * Whether any of the possible consequents of this rule include anonymous
+     * variables. Care should be taken when executing such rules, so that
+     * repeated application doesn't continually produce new bnodes.
+     * @return true if any subject, predicate, or object variable involved in a
+     *      consequent is flagged as anonymous.
+     */
+    public boolean hasAnonymousConsequent() {
+        for (StatementPattern sp : getConsequentPatterns()) {
+            if (sp.getSubjectVar().isAnonymous()
+                    || sp.getPredicateVar().isAnonymous()
+                    || sp.getObjectVar().isAnonymous()) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractInconsistencyRule.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractInconsistencyRule.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractInconsistencyRule.java
new file mode 100644
index 0000000..451c5e4
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractInconsistencyRule.java
@@ -0,0 +1,51 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+import org.apache.rya.api.domain.StatementMetadata;
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.strategy.AbstractRuleExecutionStrategy;
+import org.openrdf.query.algebra.StatementPattern;
+
+/**
+ * A rule that identifies an inconsistency in the data, but does not add or
+ * modify any triples.
+ */
+public abstract class AbstractInconsistencyRule implements Rule {
+
+    @Override
+    public boolean canConclude(StatementPattern sp) {
+        return false;
+    }
+
+    @Override
+    public Collection<StatementPattern> getConsequentPatterns() {
+        return Arrays.asList();
+    }
+
+    @Override
+    public long execute(AbstractRuleExecutionStrategy strategy,
+            StatementMetadata metadata) throws ForwardChainException {
+        return strategy.executeInconsistencyRule(this, metadata);
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractUpdateRule.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractUpdateRule.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractUpdateRule.java
new file mode 100644
index 0000000..d87aeae
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AbstractUpdateRule.java
@@ -0,0 +1,34 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import org.apache.rya.api.domain.StatementMetadata;
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.strategy.AbstractRuleExecutionStrategy;
+
+/**
+ * A rule that modifies existing data.
+ */
+public abstract class AbstractUpdateRule implements Rule {
+    @Override
+    public long execute(AbstractRuleExecutionStrategy strategy,
+            StatementMetadata metadata) throws ForwardChainException {
+        return strategy.executeUpdateRule(this, metadata);
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AntecedentVisitor.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AntecedentVisitor.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AntecedentVisitor.java
new file mode 100644
index 0000000..1f2cbba
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/AntecedentVisitor.java
@@ -0,0 +1,51 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.openrdf.query.algebra.StatementPattern;
+import org.openrdf.query.algebra.helpers.QueryModelVisitorBase;
+
+/**
+ * Query visitor that identifies all triple patterns represented as
+ * {@link StatementPattern}s in a query, which therefore represent triples
+ * that could potentially contribute to a solution. Considers only the statement
+ * patterns themselves, i.e. the leaves of the query tree, and does not consider
+ * other constraints that may restrict the set of triples that may be relevant.
+ * This means relying on this analysis to determine whether a fact can be part
+ * of a solution can yield false positives, but not false negatives.
+ */
+class AntecedentVisitor extends QueryModelVisitorBase<RuntimeException> {
+    private Set<StatementPattern> antecedentStatementPatterns = new HashSet<>();
+
+    /**
+     * Get the StatementPatterns used by this query.
+     * @return A set of patterns that can contribute to query solutions.
+     */
+    public Set<StatementPattern> getAntecedents() {
+        return antecedentStatementPatterns;
+    }
+
+    @Override
+    public void meet(StatementPattern sp) {
+        antecedentStatementPatterns.add(sp.clone());
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/ConstructConsequentVisitor.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/ConstructConsequentVisitor.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/ConstructConsequentVisitor.java
new file mode 100644
index 0000000..e28dbe3
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/ConstructConsequentVisitor.java
@@ -0,0 +1,138 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.openrdf.model.Value;
+import org.openrdf.query.algebra.BNodeGenerator;
+import org.openrdf.query.algebra.Extension;
+import org.openrdf.query.algebra.ExtensionElem;
+import org.openrdf.query.algebra.MultiProjection;
+import org.openrdf.query.algebra.Projection;
+import org.openrdf.query.algebra.ProjectionElem;
+import org.openrdf.query.algebra.ProjectionElemList;
+import org.openrdf.query.algebra.StatementPattern;
+import org.openrdf.query.algebra.ValueConstant;
+import org.openrdf.query.algebra.Var;
+import org.openrdf.query.algebra.helpers.QueryModelVisitorBase;
+
+/**
+ * Query visitor that identifies all triple patterns produced by a "CONSTRUCT"
+ * query. Finds the topmost instance of a {@link Projection} or
+ * {@link MultiProjection}, and expects the variables projected to include
+ * "subject", "predicate", and "object". Each projection is converted to a
+ * {@link StatementPattern}, where any constant values are expected to be
+ * provided by an Extension directly underneath the projection, if applicable.
+ * <p>
+ * Undefined behavior if applied to a query other than a CONSTRUCT query.
+ * <p>
+ * Does not report any constraints on possible consequent triples beyond the
+ * constant values, where appropriate, of each part of the triple. Therefore,
+ * this analysis may produce an overly broad set of possible consequents
+ * compared to some more sophisticated method.
+ */
+public class ConstructConsequentVisitor extends QueryModelVisitorBase<RuntimeException> {
+    private Set<StatementPattern> consequentStatementPatterns = new HashSet<>();
+
+    private static final String SUBJECT_VAR_NAME = "subject";
+    private static final String PREDICATE_VAR_NAME = "predicate";
+    private static final String OBJECT_VAR_NAME = "object";
+
+    /**
+     * Get the possible conclusions of this construct rule.
+     * @return StatementPatterns representing the possible triple patterns that
+     *  can be inferred.
+     */
+    public Set<StatementPattern> getConsequents() {
+        return consequentStatementPatterns;
+    }
+
+    /**
+     * Get the names of any bnodes generated by this construct rule.
+     * @return Variable names corresponding to new entities
+     */
+    public Set<StatementPattern> getBnodes() {
+        return consequentStatementPatterns;
+    }
+
+    @Override
+    public void meet(Projection projection) {
+        if (projection.getArg() instanceof Extension) {
+            recordConsequent(projection.getProjectionElemList(),
+                    ((Extension) projection.getArg()).getElements());
+        }
+        else {
+            recordConsequent(projection.getProjectionElemList(), Arrays.asList());
+        }
+    }
+
+    @Override
+    public void meet(MultiProjection projection) {
+        List<ExtensionElem> bindings;
+        if (projection.getArg() instanceof Extension) {
+            bindings = ((Extension) projection.getArg()).getElements();
+        }
+        else {
+            bindings = Arrays.asList();
+        }
+        for (ProjectionElemList template : projection.getProjections()) {
+            recordConsequent(template, bindings);
+        }
+    }
+
+    private void recordConsequent(ProjectionElemList variables, List<ExtensionElem> extensionElements) {
+        Map<String, Value> bindings = new ConcurrentHashMap<>();
+        Map<String, Value> values = new ConcurrentHashMap<>();
+        Set<String> queryBnodes = new HashSet<>();
+        Set<String> projectedBnodes = new HashSet<>();
+        for (ExtensionElem ee : extensionElements) {
+            if (ee.getExpr() instanceof ValueConstant) {
+                bindings.put(ee.getName(), ((ValueConstant) ee.getExpr()).getValue());
+            }
+            else if (ee.getExpr() instanceof BNodeGenerator) {
+                queryBnodes.add(ee.getName());
+            }
+        }
+        for (ProjectionElem var : variables.getElements()) {
+            String sourceName = var.getSourceName();
+            String targetName = var.getTargetName();
+            Value constValue = bindings.get(sourceName);
+            if (constValue != null) {
+                values.put(targetName, constValue);
+            }
+            else if (queryBnodes.contains(sourceName)) {
+                projectedBnodes.add(targetName);
+            }
+        }
+        Var subjVar = new Var(SUBJECT_VAR_NAME, values.get(SUBJECT_VAR_NAME));
+        Var predVar = new Var(PREDICATE_VAR_NAME, values.get(PREDICATE_VAR_NAME));
+        Var objVar = new Var(OBJECT_VAR_NAME, values.get(OBJECT_VAR_NAME));
+        subjVar.setAnonymous(projectedBnodes.contains(SUBJECT_VAR_NAME));
+        predVar.setAnonymous(projectedBnodes.contains(PREDICATE_VAR_NAME));
+        objVar.setAnonymous(projectedBnodes.contains(OBJECT_VAR_NAME));
+        StatementPattern sp = new StatementPattern(subjVar, predVar, objVar);
+        consequentStatementPatterns.add(sp);
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Rule.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Rule.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Rule.java
new file mode 100644
index 0000000..74004b9
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Rule.java
@@ -0,0 +1,75 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import java.util.Collection;
+
+import org.apache.rya.api.domain.StatementMetadata;
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.strategy.AbstractRuleExecutionStrategy;
+import org.openrdf.query.algebra.StatementPattern;
+
+/**
+ * Represents a forward-chaining inference rule. A rule is triggered by some
+ * combination of triples, and may produce some combination of triples when
+ * applied. Potential triggers (antecedents) and potential results (consequents)
+ * are represented in a general form as {@link StatementPattern}s and can be
+ * used to determine relationships between rules.
+ */
+public interface Rule {
+    /**
+     * Whether this rule, if applied, could produce triples of a given form.
+     * @param sp A statement pattern describing a possible inferred triple;
+     *  assumed not null.
+     * @return true if a consequent of this rule could match the pattern.
+     */
+    abstract public boolean canConclude(StatementPattern sp);
+
+    /**
+     * All {@link StatementPattern}s that can, in some combination, trigger this
+     * rule. Should be a complete set, such that if no statements matching any
+     * of the patterns exist, the rule cannot derive any new information.
+     * @return Any number of statement patterns.
+     */
+    abstract public Collection<StatementPattern> getAntecedentPatterns();
+
+    /**
+     * {@link StatementPattern}s completely describing the possible conclusions
+     * of this rule. Any derived statement should match one of these patterns.
+     * @return Any number of statement patterns.
+     */
+    abstract public Collection<StatementPattern> getConsequentPatterns();
+
+    /**
+     * Given an {@link AbstractRuleExecutionStrategy}, executes this rule.
+     * Associates any new or modified triples with the specified statement
+     * metadata.
+     * @param strategy A strategy capable of applying individual rules; should
+     *  not be null.
+     * @param metadata StatementMetadata to add to any results. Can be used to
+     *  record the circumstances of the derivation. Should not be null; use
+     *  {@link StatementMetadata#EMPTY_METADATA} to add none. Implementing
+     *  classes may add additional metadata specific to the rule.
+     * @return The number of new inferences made during rule execution.
+     * @throws ForwardChainException if an error was encountered during
+     *  rule application.
+     */
+    abstract public long execute(AbstractRuleExecutionStrategy strategy,
+            StatementMetadata metadata) throws ForwardChainException;
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Ruleset.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Ruleset.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Ruleset.java
new file mode 100644
index 0000000..965d2d3
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/Ruleset.java
@@ -0,0 +1,166 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.log4j.Logger;
+import org.openrdf.query.algebra.StatementPattern;
+
+import com.google.common.base.Preconditions;
+
+/**
+ * Represents a set of forward-chaining {@link Rule}s and their relationships.
+ */
+public class Ruleset {
+    private final Set<Rule> rules;
+    private final Map<Rule, Set<Rule>> successors;
+    private final Map<Rule, Set<Rule>> predecessors;
+
+    private final Logger logger = Logger.getLogger(this.getClass());
+
+    /**
+     * Constructor. Takes in a set of rules and determines their dependencies.
+     * @param rules The complete set of rules to process; should not be null.
+     */
+    public Ruleset(Collection<Rule> rules) {
+        Preconditions.checkNotNull(rules);
+        this.rules = new HashSet<>();
+        for (Rule rule : rules) {
+            if (rule != null) {
+                this.rules.add(rule);
+            }
+        }
+        successors = new ConcurrentHashMap<>();
+        predecessors = new ConcurrentHashMap<>();
+        // Build the dependency graph of all the rules, in both directions
+        for (Rule rule : rules) {
+            successors.put(rule, new HashSet<>());
+            predecessors.put(rule, new HashSet<>());
+        }
+        for (Rule rule1 : rules) {
+            for (Rule rule2 : rules) {
+                if (canTrigger(rule1, rule2)) {
+                    logger.trace("\t" + rule1.toString() + " can trigger " + rule2.toString());
+                    successors.get(rule1).add(rule2);
+                    predecessors.get(rule2).add(rule1);
+                }
+            }
+        }
+    }
+
+    /**
+     * Get the rules associated with this ruleset.
+     * @return The complete set of rules.
+     */
+    public Set<Rule> getRules() {
+        return rules;
+    }
+
+    /**
+     * Given a rule, return the set of all rules that it may trigger. That is,
+     * if the rule were to produce inferences, those inferences might directly
+     * cause other rules to apply in turn.
+     * @param precedingRule The potentially triggering rule; not null.
+     * @return All rules that could be triggered by the given rule.
+     */
+    public Collection<Rule> getSuccessorsOf(Rule precedingRule) {
+        Preconditions.checkNotNull(precedingRule);
+        return successors.get(precedingRule);
+    }
+
+    /**
+     * Given a rule, return the set of all rules that could trigger it. That is,
+     * if any one of those rules were applied, their potential conclusions could
+     * directly cause the specified rule to apply in turn.
+     * @param dependentRule The potentially triggered rule; not null.
+     * @return All rules that could trigger the given rule.
+     */
+    public Collection<Rule> getPredecessorsOf(Rule dependentRule) {
+        Preconditions.checkNotNull(dependentRule);
+        return predecessors.get(dependentRule);
+    }
+
+    /**
+     * Given a pair of rules, determine whether a path exists from the first to
+     * the second. That is, whether the first rule precedes the second rule
+     * either directly or transitively. If either rule is null, no path exists.
+     * @param r1 The start of the path
+     * @param r2 The end of the path
+     * @return whether a forward path exists.
+     */
+    public boolean pathExists(Rule r1, Rule r2) {
+        if (r1 == null || r2 == null) {
+            return false;
+        }
+        Set<Rule> forwardFrontier = new HashSet<>();
+        Set<Rule> backwardFrontier = new HashSet<>();
+        Set<Rule> visitedForward = new HashSet<>();
+        Set<Rule> visitedBackward = new HashSet<>();
+        forwardFrontier.addAll(getSuccessorsOf(r1));
+        backwardFrontier.add(r2);
+        while (!forwardFrontier.isEmpty() && !backwardFrontier.isEmpty()) {
+            Set<Rule> currentGoals = new HashSet<>(backwardFrontier);
+            for (Rule goal : currentGoals) {
+                if (forwardFrontier.contains(goal)) {
+                    return true;
+                }
+                else {
+                    visitedBackward.add(goal);
+                    backwardFrontier.addAll(getPredecessorsOf(goal));
+                }
+            }
+            backwardFrontier.removeAll(visitedBackward);
+            Set<Rule> currentSources = new HashSet<>(forwardFrontier);
+            for (Rule source : currentSources) {
+                if (backwardFrontier.contains(source)) {
+                    return true;
+                }
+                else {
+                    visitedForward.add(source);
+                    forwardFrontier.addAll(getSuccessorsOf(source));
+                }
+            }
+            forwardFrontier.removeAll(visitedForward);
+        }
+        return false;
+    }
+
+    /**
+     * Whether the first rule can, in any circumstance, directly trigger the second.
+     * @param rule1 The first rule, which may produce some inferences
+     * @param rule2 The second rule, which may use the first rule's conclusions
+     * @return True if the first rule's conclusions could be used by the second.
+     */
+    private boolean canTrigger(Rule rule1, Rule rule2) {
+        if (rule1 == null || rule2 == null) {
+            return false;
+        }
+        for (StatementPattern antecedent : rule2.getAntecedentPatterns()) {
+            if (rule1.canConclude(antecedent)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/SpinConstructRule.java
----------------------------------------------------------------------
diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/SpinConstructRule.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/SpinConstructRule.java
new file mode 100644
index 0000000..44e15e6
--- /dev/null
+++ b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/rule/SpinConstructRule.java
@@ -0,0 +1,344 @@
+/*
+ * 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.rya.forwardchain.rule;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.log4j.Logger;
+import org.apache.rya.api.RdfCloudTripleStoreConfiguration;
+import org.apache.rya.api.domain.StatementMetadata;
+import org.apache.rya.api.resolver.RdfToRyaConversions;
+import org.apache.rya.forwardchain.ForwardChainConstants;
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.strategy.AbstractRuleExecutionStrategy;
+import org.apache.rya.sail.config.RyaSailFactory;
+import org.openrdf.model.Literal;
+import org.openrdf.model.Resource;
+import org.openrdf.model.Value;
+import org.openrdf.model.vocabulary.OWL;
+import org.openrdf.model.vocabulary.RDF;
+import org.openrdf.model.vocabulary.RDFS;
+import org.openrdf.model.vocabulary.SP;
+import org.openrdf.model.vocabulary.SPIN;
+import org.openrdf.query.BindingSet;
+import org.openrdf.query.MalformedQueryException;
+import org.openrdf.query.QueryEvaluationException;
+import org.openrdf.query.QueryLanguage;
+import org.openrdf.query.TupleQuery;
+import org.openrdf.query.TupleQueryResultHandlerBase;
+import org.openrdf.query.TupleQueryResultHandlerException;
+import org.openrdf.query.algebra.Extension;
+import org.openrdf.query.algebra.Join;
+import org.openrdf.query.algebra.QueryModelNode;
+import org.openrdf.query.algebra.SingletonSet;
+import org.openrdf.query.algebra.StatementPattern;
+import org.openrdf.query.algebra.TupleExpr;
+import org.openrdf.query.algebra.UnaryTupleOperator;
+import org.openrdf.query.algebra.ValueExpr;
+import org.openrdf.query.algebra.Var;
+import org.openrdf.query.algebra.helpers.QueryModelVisitorBase;
+import org.openrdf.query.parser.ParsedGraphQuery;
+import org.openrdf.query.parser.ParsedQuery;
+import org.openrdf.query.parser.sparql.SPARQLParser;
+import org.openrdf.repository.RepositoryException;
+import org.openrdf.repository.sail.SailRepository;
+import org.openrdf.repository.sail.SailRepositoryConnection;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Sets;
+
+/**
+ * Represents a SPIN Construct rule extracted from the data store, providing
+ * access to its associated query tree and providing methods to apply the rule.
+ */
+public class SpinConstructRule extends AbstractConstructRule {
+    private static Logger logger = Logger.getLogger(SpinConstructRule.class);
+
+    private final Resource ruleId;
+    private final ParsedGraphQuery graphQuery;
+    private Set<StatementPattern> antecedentStatementPatterns = null;
+    private Set<StatementPattern> consequentStatementPatterns = null;
+
+    /**
+     * Instantiate a SPIN construct rule given its associated type, URI or bnode
+     * identifier, and construct query tree. Modifies the query tree to
+     * incorporate the fact that ?this must belong to the associated type, and
+     * traverses the modified tree to find antecedent and consequent triple
+     * patterns.
+     * @param type This rule applies to objects of this type. Should not be
+     *  null. If the type is owl:Thing or rdfs:Resource, it will be applied to
+     *  any objects. Otherwise, a statement pattern will be added that
+     *  effectively binds ?this to members of the type. Therefore, passing
+     *  owl:Thing or rdfs:Resource yields the intended behavior of
+     *  sp:thisUnbound.
+     * @param ruleId The Resource representing this rule in the RDF data;
+     *  should not be null.
+     * @param graphQuery The query tree corresponding to the "construct" text;
+     *  should not be null.
+     */
+    public SpinConstructRule(Resource type, Resource ruleId,
+            ParsedGraphQuery graphQuery) {
+        Preconditions.checkNotNull(type);
+        Preconditions.checkNotNull(ruleId);
+        Preconditions.checkNotNull(graphQuery);
+        this.ruleId = ruleId;
+        this.graphQuery = graphQuery;
+        // Add the type requirement: ?this must belong to the type
+        graphQuery.getTupleExpr().visit(new TypeRequirementVisitor("this", type));
+        // Find all statement patterns that could trigger this rule
+        AntecedentVisitor aVisitor = new AntecedentVisitor();
+        graphQuery.getTupleExpr().visit(aVisitor);
+        antecedentStatementPatterns = aVisitor.getAntecedents();
+        // Construct statement patterns for all possible conclusions of this rule
+        ConstructConsequentVisitor cVisitor = new ConstructConsequentVisitor();
+        graphQuery.getTupleExpr().visit(cVisitor);
+        consequentStatementPatterns = cVisitor.getConsequents();
+    }
+
+    /**
+     * Get the URI or bnode associated with this rule in the data.
+     * @return The rule's identifier.
+     */
+    public Resource getId() {
+        return ruleId;
+    }
+
+    @Override
+    public String toString() {
+        return "SpinConstructRule{" + ruleId.stringValue() + "}";
+    }
+
+    @Override
+    public ParsedGraphQuery getQuery() {
+        return graphQuery;
+    }
+
+    @Override
+    public boolean canConclude(StatementPattern sp) {
+        Preconditions.checkNotNull(sp);
+        Value s1 = getVarValue(sp.getSubjectVar());
+        Value p1 = getVarValue(sp.getPredicateVar());
+        Value o1 = getVarValue(sp.getObjectVar());
+        Value c1 = getVarValue(sp.getContextVar());
+        for (StatementPattern consequent : consequentStatementPatterns) {
+            Value s2 = getVarValue(consequent.getSubjectVar());
+            Value p2 = getVarValue(consequent.getPredicateVar());
+            Value o2 = getVarValue(consequent.getObjectVar());
+            Value c2 = getVarValue(consequent.getContextVar());
+            if ((s1 == null || s2 == null || s1.equals(s2))
+                    && (p1 == null || p2 == null || p1.equals(p2))
+                    && (o1 == null || o2 == null || o1.equals(o2))
+                    && (c1 == null || c2 == null || c1.equals(c2))) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public Collection<StatementPattern> getAntecedentPatterns() {
+        return antecedentStatementPatterns;
+    }
+
+    @Override
+    public Collection<StatementPattern> getConsequentPatterns() {
+        return consequentStatementPatterns;
+    }
+
+    @Override
+    public long execute(AbstractRuleExecutionStrategy strategy,
+            StatementMetadata metadata) throws ForwardChainException {
+        metadata.addMetadata(ForwardChainConstants.RYA_DERIVATION_RULE,
+                RdfToRyaConversions.convertResource(ruleId));
+        return super.execute(strategy, metadata);
+    }
+
+    private static Value getVarValue(Var var) {
+        return var == null ? null : var.getValue();
+    }
+
+    private static class TypeRequirementVisitor extends QueryModelVisitorBase<RuntimeException> {
+        private static final Var RDF_TYPE_VAR = new Var("-const-" + RDF.TYPE.stringValue(), RDF.TYPE);
+        private static final Set<Resource> BASE_TYPES = Sets.newHashSet(RDFS.RESOURCE, OWL.THING);
+        static {
+            RDF_TYPE_VAR.setConstant(true);
+        }
+
+        private final String varName;
+        private final StatementPattern typeRequirement;
+        public TypeRequirementVisitor(String varName, Resource requiredType) {
+            final Var typeVar = new Var("-const-" + requiredType.stringValue(), requiredType);
+            typeVar.setConstant(true);
+            this.varName = varName;
+            if (BASE_TYPES.contains(requiredType)) {
+                this.typeRequirement = null;
+            }
+            else {
+                this.typeRequirement = new StatementPattern(new Var(varName), RDF_TYPE_VAR, typeVar);
+            }
+        }
+        @Override
+        public void meet(SingletonSet node) {
+            if (typeRequirement != null) {
+                node.replaceWith(typeRequirement);
+            }
+        }
+        @Override
+        public void meet(Extension node) {
+            Set<String> argBindings = node.getArg().getBindingNames();
+            if (typeRequirement != null) {
+                node.getElements().removeIf(elem -> {
+                    if (varName.equals(elem.getName())) {
+                        ValueExpr expr = elem.getExpr();
+                        if (expr == null) {
+                            return true;
+                        }
+                        else if (expr instanceof Var) {
+                            String fromName = ((Var) expr).getName();
+                            if (getVarValue((Var) expr) == null && !argBindings.contains(fromName)) {
+                                return true;
+                            }
+                        }
+                    }
+                    return false;
+                });
+                meetUnaryTupleOperator(node);
+            }
+        }
+        @Override
+        public void meetNode(QueryModelNode node) {
+            if (typeRequirement != null) {
+                if (node instanceof TupleExpr && ((TupleExpr) node).getBindingNames().contains(varName)) {
+                    final Join withType = new Join((TupleExpr) node.clone(), typeRequirement);
+                    node.replaceWith(withType);
+                }
+                else {
+                    node.visitChildren(this);
+                }
+            }
+        }
+        @Override
+        public void meetUnaryTupleOperator(UnaryTupleOperator node) {
+            if (typeRequirement != null) {
+                if (node.getArg().getBindingNames().contains(varName)) {
+                    node.visitChildren(this);
+                }
+                else {
+                    meetNode(node);
+                }
+            }
+        }
+    }
+
+    /**
+     * Load a set of SPIN rules from a data store.
+     * @param conf Contains the connection information. Not null.
+     * @return A map of rule identifiers to rule objects.
+     * @throws ForwardChainException if connecting, querying for rules, or
+     *  parsing rules fails.
+     */
+    public static Ruleset loadSpinRules(RdfCloudTripleStoreConfiguration conf)
+            throws ForwardChainException {
+        Preconditions.checkNotNull(conf);
+        Map<Resource, Rule> rules = new ConcurrentHashMap<>();
+        // Connect to Rya
+        SailRepository repository = null;
+        SailRepositoryConnection conn = null;
+        try {
+            repository = new SailRepository(RyaSailFactory.getInstance(conf));
+        } catch (Exception e) {
+            throw new ForwardChainException("Couldn't initialize SAIL from configuration", e);
+        }
+        // Load and parse the individual SPIN rules from the data store
+        String ruleQueryString = "SELECT ?type ?rule ?text WHERE {\n"
+                + "  ?type <" + SPIN.RULE_PROPERTY.stringValue() + "> ?rule .\n"
+                + "  {\n"
+                + "    ?rule a <" + SP.CONSTRUCT_CLASS.stringValue() + "> .\n"
+                + "    ?rule <" + SP.TEXT_PROPERTY.stringValue() + "> ?text .\n"
+                + "  } UNION {\n"
+                + "    ?rule a ?template .\n"
+                + "    ?template <" + SPIN.BODY_PROPERTY + ">? ?body .\n"
+                + "    ?body a <" + SP.CONSTRUCT_CLASS.stringValue() + "> .\n"
+                + "    ?body <" + SP.TEXT_PROPERTY.stringValue() + "> ?text .\n"
+                + "  }\n"
+                + "}";
+        SPARQLParser parser = new SPARQLParser();
+        try {
+            conn = repository.getConnection();
+            TupleQuery ruleQuery = conn.prepareTupleQuery(QueryLanguage.SPARQL, ruleQueryString);
+            ruleQuery.evaluate(new TupleQueryResultHandlerBase() {
+                @Override
+                public void handleSolution(BindingSet bs) throws TupleQueryResultHandlerException {
+                // For each rule identifier found, instantiate a SpinRule
+                    Value requiredType = bs.getValue("type");
+                    Value ruleIdentifier = bs.getValue("rule");
+                    Value ruleText = bs.getValue("text");
+                    if (requiredType instanceof Resource
+                            && ruleIdentifier instanceof Resource
+                            && ruleText instanceof Literal) {
+                        ParsedQuery parsedRule;
+                        try {
+                            parsedRule = parser.parseQuery(ruleText.stringValue(), null);
+                            if (parsedRule instanceof ParsedGraphQuery) {
+                                SpinConstructRule rule = new SpinConstructRule(
+                                        (Resource) requiredType,
+                                        (Resource) ruleIdentifier,
+                                        (ParsedGraphQuery) parsedRule);
+                                if (rule.hasAnonymousConsequent()) {
+                                    logger.error("Skipping unsupported rule " + ruleIdentifier
+                                            + " -- consequent refers to bnode, which is not"
+                                            + " currently supported (creating new bnodes at each"
+                                            + " application could lead to infinite recursion).");
+                                }
+                                else {
+                                    rules.put((Resource) ruleIdentifier, rule);
+                                }
+                            }
+                        } catch (Exception e) {
+                            throw new TupleQueryResultHandlerException(e);
+                        }
+                    }
+                }
+            });
+        } catch (TupleQueryResultHandlerException | QueryEvaluationException
+                | MalformedQueryException | RepositoryException e) {
+            throw new ForwardChainException("Couldn't retrieve SPIN rules", e);
+        }
+        finally {
+            if (conn != null) {
+                try {
+                    conn.close();
+                } catch (RepositoryException e) {
+                    logger.warn("Error closing repository connection", e);
+                }
+            }
+            if (repository.isInitialized()) {
+                try {
+                    repository.shutDown();
+                } catch (RepositoryException e) {
+                    logger.warn("Error shutting down repository", e);
+                }
+            }
+        }
+        return new Ruleset(rules.values());
+    }
+}

http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/9f611019/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/strategy/AbstractForwardChainStrategy.java
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diff --git a/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/strategy/AbstractForwardChainStrategy.java b/extras/rya.forwardchain/src/main/java/org/apache/rya/forwardchain/strategy/AbstractForwardChainStrategy.java
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+/*
+ * 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.rya.forwardchain.strategy;
+
+import org.apache.rya.forwardchain.ForwardChainException;
+import org.apache.rya.forwardchain.rule.Ruleset;
+
+/**
+ * Base class for high-level strategies which define how to conduct
+ * forward-chaining reasoning (materialization).
+ */
+public abstract class AbstractForwardChainStrategy {
+    /**
+     * A running count of new inferences so far.
+     */
+    protected long totalInferences;
+
+    /**
+     * Initializes reasoning with respect to a given ruleset.
+     * @param ruleset The complete set of rules to materialize. Should not be
+     *  null.
+     * @throws ForwardChainException if initialization fails.
+     */
+    abstract public void initialize(Ruleset ruleset) throws ForwardChainException;
+
+    /**
+     * Whether forward chaining is both initialized and yet to finish.
+     * @return true if a ruleset has been provided and some rules may still
+     *  yield new information.
+     */
+    abstract protected boolean isActive();
+
+    /**
+     * Execute the next step of reasoning, such as a single rule if the strategy
+     * proceeds one rule at a time.
+     * @return The number of inferences made during this step.
+     * @throws ForwardChainException if any error is encountered during rule
+     *  application.
+     */
+    abstract protected long executeNext() throws ForwardChainException;
+
+    /**
+     * Execute an entire ruleset until no new rules can be derived. Initializes
+     * strategy and proceeds until completion.
+     * @param rules The complete set of rules; not null.
+     * @return The number of total inferences made.
+     * @throws ForwardChainException if any error is encountered during
+     *  initialization or application.
+     */
+    public long executeAll(Ruleset rules) throws ForwardChainException {
+        initialize(rules);
+        totalInferences = 0;
+        while (isActive()) {
+            totalInferences += executeNext();
+        }
+        return totalInferences;
+    }
+
+    /**
+     * Get the running total of inferences made so far.
+     * @return The number of inferences made since initialization.
+     */
+    public long getNumInferences() {
+        return totalInferences;
+    }
+}