[ issue #40 ] Better state machine management on DeepPagingIterator

spaziocodice · Mar 17, 2015 · 500ae52 · 500ae52
1 parent dc0284f
commit 500ae52
Show file tree

Hide file tree

Showing 3 changed files with 20 additions and 22 deletions.
diff --git a/solrdf/src/main/java/org/gazzax/labs/solrdf/search/component/PagedResultSet.java b/solrdf/src/main/java/org/gazzax/labs/solrdf/search/component/PagedResultSet.java
@@ -50,12 +50,8 @@ public boolean hasNext() {
 		}
 
 		@Override
-		public QuerySolution next() {
-			while (getRowNumber() < offset && resultSet.hasNext()) {
-				resultSet.nextBinding();
-			}
-
-			if (resultSet.getRowNumber() >= offset && getRowNumber() < (offset + size) && resultSet.hasNext()){
+		public QuerySolution next() {			
+			if (resultSet.getRowNumber() >= offset && getRowNumber() < (offset + size)){
 				final QuerySolution solution = resultSet.nextSolution();
 				rows.add(solution);
 				return solution;
@@ -191,6 +187,18 @@ public int size() {
 				// This is because we need to trigger a request to Solr in order to collect DocSet (e.g. for faceting) 
 				resultSet.next();
 				currentState = new CachedResultSet();
+			} else {
+				if (offset > 0) {
+					while (resultSet.hasNext() && resultSet.getRowNumber() < offset) {
+						resultSet.nextBinding();
+					}				
+
+					// Sanity check: if offset is greater than the available 
+					// rows then the resulting ResultSet must be empty
+					if (!resultSet.hasNext()) {
+						currentState = new CachedResultSet();					
+					}
+				}
 			}
 		}		
 	}

diff --git a/solrdf/src/test/java/org/gazzax/labs/solrdf/integration/LearningSparql_ITCase.java b/solrdf/src/test/java/org/gazzax/labs/solrdf/integration/LearningSparql_ITCase.java
@@ -28,8 +28,6 @@
 import java.util.Arrays;
 import java.util.List;
 
-import org.apache.jena.riot.RDFLanguages;
-import org.apache.jena.riot.resultset.ResultSetLang;
 import org.apache.solr.client.solrj.SolrServer;
 import org.apache.solr.client.solrj.SolrServerException;
 import org.apache.solr.client.solrj.impl.HttpSolrServer;
@@ -75,12 +73,6 @@ public class LearningSparql_ITCase {
 	static SolrServer solr;
 	static final List<MisteryGuest> DATA = new ArrayList<MisteryGuest>();
 
-	public static void main(String[] args) {
-		ResultSetLang.init();
-		System.out.println(RDFLanguages.contentTypeToLang("application/sparql-results+json"));
-		System.out.println(RDFLanguages.contentTypeToLang("application/sparql-results+xml"));
-	}
-
 	/**
 	 * Fills the data and queries map.
 	 */

diff --git a/solrdf/src/test/java/org/gazzax/labs/solrdf/search/component/PagedResultSetTestCase.java b/solrdf/src/test/java/org/gazzax/labs/solrdf/search/component/PagedResultSetTestCase.java
@@ -60,17 +60,15 @@ public void sizeGreaterThanEffectiveSize() {
 	public void outOfAvailableRange() {
 		final ResultSetRewindable cut = new PagedResultSet(executeQuery(), 10, (int)(model.size() + 1));
 
-		try {
-			while (cut.hasNext()) {
-				cut.next();
-			}
-			fail();
-		} catch (IllegalStateException expected) {
-			// Nothing, this is the expected behaviour
-		}		
+		while (cut.hasNext()) {
+			cut.next();
+		}
 
 		assertEquals(0, cut.size());
+
 		cut.reset();
+
+		assertEquals(0, cut.size());
 	}
 
 	/**