295533: [query] Use the Limit query instead of custom collectors to short circuit a query https://bugs.eclipse.org/bugs/show_bug.cgi?id=295533

This removes the different short curcuit collectors and replaces them with the limit query.

6 files changed, 10 insertions, 110 deletions

diff --git a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/HasMatchCollector.java b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/HasMatchCollector.java
deleted file mode 100644
index 058e3b3a7..000000000
--- a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/HasMatchCollector.java
+++ /dev/null
@@ -1,30 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2007, 2008 IBM Corporation and others.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors:
- *     IBM Corporation - initial API and implementation
- *******************************************************************************/
-package org.eclipse.equinox.internal.p2.director;
-
-import org.eclipse.equinox.internal.provisional.p2.metadata.query.Collector;
-
-/**
- * A collector that short-circuits on the first match.
- */
-public class HasMatchCollector extends Collector {
-	private boolean hasMatch = false;
-
-	public boolean accept(Object object) {
-		hasMatch = true;
-		return false;
-	}
-
-	public boolean isEmpty() {
-		return !hasMatch;
-	}
-
-}
diff --git a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java
index 1b36f6029..11ab1d001 100644
--- a/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java
+++ b/bundles/org.eclipse.equinox.p2.director/src/org/eclipse/equinox/internal/p2/director/SimplePlanner.java
@@ -10,8 +10,6 @@
  ******************************************************************************/
 package org.eclipse.equinox.internal.p2.director;
 
-import org.eclipse.equinox.p2.metadata.IInstallableUnit;
-
 import java.net.URI;
 import java.util.*;
 import java.util.Map.Entry;
@@ -27,6 +25,7 @@ import org.eclipse.equinox.internal.provisional.p2.metadata.MetadataFactory.Inst
 import org.eclipse.equinox.internal.provisional.p2.metadata.query.*;
 import org.eclipse.equinox.p2.engine.IProvisioningPlan;
 import org.eclipse.equinox.p2.engine.query.IUProfilePropertyQuery;
+import org.eclipse.equinox.p2.metadata.IInstallableUnit;
 import org.eclipse.equinox.p2.metadata.IRequirement;
 import org.eclipse.equinox.p2.metadata.query.IQuery;
 import org.eclipse.equinox.p2.repository.IRepositoryManager;
@@ -373,7 +372,7 @@ public class SimplePlanner implements IPlanner {
 		Collection allMetaRequirements = extractMetaRequirements(newProfile, initialPlan);
 		for (Iterator iterator = allMetaRequirements.iterator(); iterator.hasNext();) {
 			IRequirement requirement = (IRequirement) iterator.next();
-			if (oldProfile.query(requirement.getMatches(), new HasMatchCollector(), null).isEmpty())
+			if (oldProfile.query(new LimitQuery(requirement.getMatches(), 1), new Collector(), null).isEmpty())
 				return allMetaRequirements;
 		}
 		return null;
diff --git a/bundles/org.eclipse.equinox.p2.publisher/src/org/eclipse/equinox/internal/p2/publisher/SingleElementCollector.java b/bundles/org.eclipse.equinox.p2.publisher/src/org/eclipse/equinox/internal/p2/publisher/SingleElementCollector.java
deleted file mode 100644
index 23fb74956..000000000
--- a/bundles/org.eclipse.equinox.p2.publisher/src/org/eclipse/equinox/internal/p2/publisher/SingleElementCollector.java
+++ /dev/null
@@ -1,28 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2009 IBM Corporation and others. All rights reserved. This
- * program and the accompanying materials are made available under the terms of
- * the Eclipse Public License v1.0 which accompanies this distribution, and is
- * available at http://www.eclipse.org/legal/epl-v10.html
- * 
- * Contributors: IBM Corporation - initial API and implementation
- ******************************************************************************/
-package org.eclipse.equinox.internal.p2.publisher;
-
-import org.eclipse.equinox.internal.provisional.p2.metadata.query.Collector;
-
-/**
- * Collect a single element and stop the Query
- */
-public class SingleElementCollector extends Collector {
-
-	public boolean accept(Object object) {
-		super.accept(object);
-		return false;
-	}
-
-	public Object getElement() {
-		if (!isEmpty())
-			return iterator().next();
-		return null;
-	}
-}
diff --git a/bundles/org.eclipse.equinox.p2.publisher/src/org/eclipse/equinox/p2/publisher/AbstractPublisherAction.java b/bundles/org.eclipse.equinox.p2.publisher/src/org/eclipse/equinox/p2/publisher/AbstractPublisherAction.java
index 19f8c0718..5acb37236 100644
--- a/bundles/org.eclipse.equinox.p2.publisher/src/org/eclipse/equinox/p2/publisher/AbstractPublisherAction.java
+++ b/bundles/org.eclipse.equinox.p2.publisher/src/org/eclipse/equinox/p2/publisher/AbstractPublisherAction.java
@@ -19,7 +19,8 @@ import org.eclipse.equinox.internal.p2.core.helpers.LogHelper;
 import org.eclipse.equinox.internal.p2.core.helpers.FileUtils.IPathComputer;
 import org.eclipse.equinox.internal.p2.metadata.IRequiredCapability;
 import org.eclipse.equinox.internal.p2.metadata.LDAPQuery;
-import org.eclipse.equinox.internal.p2.publisher.*;
+import org.eclipse.equinox.internal.p2.publisher.Activator;
+import org.eclipse.equinox.internal.p2.publisher.QuotedTokenizer;
 import org.eclipse.equinox.internal.provisional.p2.core.ProvisionException;
 import org.eclipse.equinox.internal.provisional.p2.metadata.*;
 import org.eclipse.equinox.internal.provisional.p2.metadata.MetadataFactory.InstallableUnitDescription;
@@ -524,13 +525,11 @@ public abstract class AbstractPublisherAction implements IPublisherAction {
 	 */
 	protected IInstallableUnit queryForIU(IPublisherResult publisherResult, String iuId, Version version) {
 		IQuery query = null;
-		Collector collector = null;
+		Collector collector = new Collector();
 		if (version != null && !Version.emptyVersion.equals(version)) {
-			query = new InstallableUnitQuery(iuId, version);
-			collector = new SingleElementCollector();
+			query = new LimitQuery(new InstallableUnitQuery(iuId, version), 1);
 		} else {
 			query = new PipedQuery(new IQuery[] {new InstallableUnitQuery(iuId), new LatestIUVersionQuery()});
-			collector = new Collector();
 		}
 
 		NullProgressMonitor progress = new NullProgressMonitor();
diff --git a/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/core/QueryTest.java b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/core/QueryTest.java
index f72ec5569..93c7455c7 100644
--- a/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/core/QueryTest.java
+++ b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/core/QueryTest.java
@@ -64,19 +64,8 @@ public class QueryTest extends TestCase {
 	}
 
 	/**
-	 * A collector that only accepts the first element and then short-circuits.
-	 */
-	static class ShortCircuitCollector extends Collector {
-		@Override
-		public boolean accept(Object object) {
-			super.accept(object);
-			return false;
-		}
-	}
-
-	/**
-	 * Tests a simple perform where all items match.
-	 */
+	* Tests a simple perform where all items match.
+	*/
 	public void testPerformSimple() {
 		List items = Arrays.asList("red", "green", "blue");
 		IQuery query = new AnyStringQuery();
@@ -266,30 +255,6 @@ public class QueryTest extends TestCase {
 		assertTrue("1.9", query2.areHooksExecutedProperly());
 	}
 
-	/**
-	 * Tests a perform where the collector decides to short-circuit the query.
-	 */
-	public void testShortCircuit() {
-		List items = Arrays.asList("red", "green", "blue");
-		IQuery query = new AnyStringQuery();
-		Collector collector = new ShortCircuitCollector();
-		query.perform(items.iterator(), collector);
-		Collection result = collector.toCollection();
-		assertEquals("1.0", 1, result.size());
-		assertTrue("1.1", result.contains("red"));
-	}
-
-	public void testShortCircuitWithLimit() {
-		List items = Arrays.asList("red", "green", "blue");
-		IQuery query = new AnyStringQuery();
-		IQuery limitQuery = new LimitQuery(query, 2);
-		Collector collector = new ShortCircuitCollector();
-		limitQuery.perform(items.iterator(), collector);
-		Collection result = collector.toCollection();
-		assertEquals("1.0", 1, result.size());
-		assertTrue("1.1", result.contains("red")); // The short circuit should trump the limit
-	}
-
 	public void testLimitQuery() {
 		List items = Arrays.asList("red", "green", "blue");
 		IQuery query = new AnyStringQuery();
diff --git a/bundles/org.eclipse.equinox.p2.updatesite/src/org/eclipse/equinox/internal/p2/updatesite/SiteXMLAction.java b/bundles/org.eclipse.equinox.p2.updatesite/src/org/eclipse/equinox/internal/p2/updatesite/SiteXMLAction.java
index 458edd027..3ef1ac2f9 100644
--- a/bundles/org.eclipse.equinox.p2.updatesite/src/org/eclipse/equinox/internal/p2/updatesite/SiteXMLAction.java
+++ b/bundles/org.eclipse.equinox.p2.updatesite/src/org/eclipse/equinox/internal/p2/updatesite/SiteXMLAction.java
@@ -151,13 +151,8 @@ public class SiteXMLAction extends AbstractPublisherAction {
 				query = new PipedQuery(new IQuery[] {qualifierQuery, new LatestIUVersionQuery()});
 				collector = new Collector();
 			} else {
-				query = new InstallableUnitQuery(id, version);
-				collector = new Collector() {
-					public boolean accept(Object object) {
-						super.accept(object);
-						return false; //stop searching once we've found one
-					}
-				};
+				query = new LimitQuery(new InstallableUnitQuery(id, version), 1);
+				collector = new Collector();
 			}
 		}