[ issue #14 ] SPARQL Integration suite works on SOLR too!

jena-nosql-binding/jena-nosql-binding-solr/pom.xml

@@ -15,7 +15,6 @@
 			<groupId>org.apache.solr</groupId>
 			<artifactId>solr-solrj</artifactId>
 			<version>${solr.version}</version>
-			<scope>provided</scope>
 		</dependency>
 	</dependencies>
 </project>

jena-nosql-binding/jena-nosql-binding-solr/src/main/java/org/gazzax/labs/jena/nosql/solr/Field.java

@@ -1,6 +1,7 @@
 package org.gazzax.labs.jena.nosql.solr;
 
 public interface Field {
+	String ID = "id";
 	String S = "s";
 	String P = "p";
 	String O = "o";

jena-nosql-binding/jena-nosql-binding-solr/src/main/java/org/gazzax/labs/jena/nosql/solr/NoOpDictionary.java

@@ -0,0 +1,137 @@
+package org.gazzax.labs.jena.nosql.solr;
+
+import java.util.Iterator;
+
+import org.gazzax.labs.jena.nosql.fwk.StorageLayerException;
+import org.gazzax.labs.jena.nosql.fwk.dictionary.TopLevelDictionary;
+import org.gazzax.labs.jena.nosql.fwk.factory.StorageLayerFactory;
+
+import com.hp.hpl.jena.graph.Node;
+import com.hp.hpl.jena.graph.Triple;
+import com.hp.hpl.jena.sparql.core.Quad;
+
+/**
+ * A NullObject dictionary that, as the name suggests, does nothing.
+ * 
+ * @author Andrea Gazzarini
+ * @since 1.0
+ */
+class NoOpDictionary implements TopLevelDictionary {
+
+	@Override
+	public void close() {
+		// Nothing to be done here...
+	}
+
+	@Override
+	public byte[] getID(Node node, boolean p) throws StorageLayerException {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public Node getValue(byte[] id, boolean p) throws StorageLayerException {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public void removeValue(Node value, boolean p) throws StorageLayerException {
+		// Nothing to be done here...
+	}
+
+	@Override
+	public String getName() {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public void initialise(final StorageLayerFactory factory) {
+		// Nothing to be done here...
+	}
+
+	@Override
+	public byte[][] asIdentifiers(final Node s, final Node p, final Node o) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public byte[][] asIdentifiers(final Node s, final Node p, final Node o, final Node c) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public Triple asTriple(final byte[] s, final byte[] p, final byte[] o) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public Quad asQuad(final byte[] s, final byte[] p, final byte[] o, final byte[] c) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public boolean isBNode(final byte[] id) {
+		// Nothing to be done here...
+		return false;
+	}
+
+	@Override
+	public boolean isLiteral(final byte[] id) {
+		// Nothing to be done here...
+		return false;
+	}
+
+	@Override
+	public boolean isResource(final byte[] id) {
+		// Nothing to be done here...
+		return false;
+	}
+
+	@Override
+	public Iterator<byte[][]> asTripleIdentifiersIterator(final Iterator<Triple> triples) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public Iterator<byte[][]> asQuadIdentifiersIterator(final Iterator<Quad> quads) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public Iterator<Triple> asTripleIterator(final Iterator<byte[][]> identifiers) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public Iterator<Quad> asQuadIterator(final Iterator<byte[][]> quads) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public byte[] compose(final byte[] id1, final byte[] id2) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public byte[] compose(final byte[] id1, final byte[] id2, final byte[] id3) {
+		// Nothing to be done here...
+		return null;
+	}
+
+	@Override
+	public byte[][] decompose(final byte[] compositeId) {
+		// Nothing to be done here...
+		return null;
+	}
+}

jena-nosql-binding/jena-nosql-binding-solr/src/main/java/org/gazzax/labs/jena/nosql/solr/SolrStorageLayerFactory.java

@@ -25,6 +25,7 @@
  * @since 1.0
  */
 public class SolrStorageLayerFactory extends StorageLayerFactory {
+	private final TopLevelDictionary dictionary = new NoOpDictionary();
 	private SolrServer solr;
 
 	@Override
@@ -65,7 +66,7 @@ public TripleIndexDAO<Triple, TripleMatch> getTripleIndexDAO() {
 
 	@Override
 	public TopLevelDictionary getDictionary() {
-		throw new UnsupportedOperationException();
+		return dictionary;
 	}
 
 	@Override

jena-nosql-binding/jena-nosql-binding-solr/src/main/java/org/gazzax/labs/jena/nosql/solr/dao/SolrDeepPagingIterator.java

@@ -0,0 +1,136 @@
+package org.gazzax.labs.jena.nosql.solr.dao;
+
+import java.util.Iterator;
+
+import org.apache.solr.client.solrj.SolrQuery;
+import org.apache.solr.client.solrj.SolrServer;
+import org.apache.solr.client.solrj.response.QueryResponse;
+import org.apache.solr.common.SolrDocument;
+import org.apache.solr.common.SolrDocumentList;
+import org.apache.solr.common.params.CursorMarkParams;
+import org.gazzax.labs.jena.nosql.fwk.util.NTriples;
+import org.gazzax.labs.jena.nosql.solr.Field;
+
+import com.google.common.collect.UnmodifiableIterator;
+import com.hp.hpl.jena.graph.Triple;
+
+/**
+ * An iterator over SOLR results that uses the built-in Deep Paging strategy.
+ * Internally it uses other iterators to represents each iteration state. 
+ * 
+ * @see http://solr.pl/en/2014/03/10/solr-4-7-efficient-deep-paging
+ * @see http://heliosearch.org/solr/paging-and-deep-paging
+ * @see <a href="http://en.wikipedia.org/wiki/Finite-state_machine">http://en.wikipedia.org/wiki/Finite-state_machine</a>
+ * @author Andrea Gazzarini
+ * @since 1.0
+ */
+public class SolrDeepPagingIterator extends UnmodifiableIterator<Triple> {
+
+	private final SolrServer solr;
+	private final SolrQuery query;
+	private SolrDocumentList page;
+
+	private String nextCursorMark;
+	private String sentCursorMark;
+
+	/**
+	 * Iteration state: we need to (re)execute a query. 
+	 * This could be needed the very first time we start iteration and each time the current result
+	 * page has been consumed.
+	 */
+	private final Iterator<Triple> executeQuery = new UnmodifiableIterator<Triple>() {
+		@Override
+		public boolean hasNext() {
+			try {
+				final QueryResponse response = solr.query(query);
+				nextCursorMark = response.getNextCursorMark();
+				page = response.getResults();
+				return page.getNumFound() > 0;
+			} catch (final Exception exception) {
+				throw new RuntimeException(exception);
+			}
+		}
+
+		@Override
+		public Triple next() {
+			currentState = iterateOverCurrentPage;
+			return currentState.next();
+		}
+	};
+
+	/**
+	 * Iteration state: query has been executed and now it's time to iterate over results. 
+	 */
+	private final Iterator<Triple> iterateOverCurrentPage = new UnmodifiableIterator<Triple>() {
+		Iterator<SolrDocument> iterator;
+
+		@Override
+		public boolean hasNext() {
+			if (iterator().hasNext()) {
+				return true;
+			} else {
+				currentState = checkForIterationCompleteness;
+				return currentState.hasNext();
+			}
+		}
+
+		@Override
+		public Triple next() {
+			final SolrDocument document = iterator().next();
+			return Triple.create(
+					NTriples.asURIorBlankNode((String) document.getFieldValue(Field.S)), 
+					NTriples.asURI((String) document.getFieldValue(Field.P)),
+					NTriples.asNode((String) document.getFieldValue(Field.O)));
+		}
+
+		Iterator<SolrDocument> iterator() {
+			if (iterator == null) {
+				iterator = page.iterator();	
+			}
+			return iterator;
+
+		}
+	};
+
+	/**
+	 * Iteration state: once a page has been consumed we need to determine if another query should be issued or not. 
+	 */
+	private final Iterator<Triple> checkForIterationCompleteness = new UnmodifiableIterator<Triple>() {
+		@Override
+		public boolean hasNext() {
+			return !(page.size() < query.getRows() || sentCursorMark.equals(nextCursorMark));
+		}
+
+		@Override
+		public Triple next() {
+			query.set(CursorMarkParams.CURSOR_MARK_PARAM, nextCursorMark);
+			currentState = executeQuery;
+			return currentState.next();
+		}
+	};
+
+	private Iterator<Triple> currentState = executeQuery;
+
+	/**
+	 * Builds a new iterator with the given data.
+	 * 
+	 * @param solr the SOLR facade.
+	 * @param query the query that will be submitted.
+	 */
+	public SolrDeepPagingIterator(final SolrServer solr, final SolrQuery query) {
+		this.solr = solr;
+		this.query = query;
+		this.sentCursorMark = CursorMarkParams.CURSOR_MARK_START;
+		this.query.set(CursorMarkParams.CURSOR_MARK_PARAM, CursorMarkParams.CURSOR_MARK_START);
+	}
+
+	@Override
+	public boolean hasNext() {
+		return currentState.hasNext();
+	}
+
+	@Override
+	public Triple next() {
+		return currentState.next();
+	}
+}