Index optimization in Expression.

2 files changed, 44 insertions, 6 deletions

diff --git a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/ExpressionMatchQuery.java b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/ExpressionMatchQuery.java
index 8a6f6271c..1b0284165 100644
--- a/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/ExpressionMatchQuery.java
+++ b/bundles/org.eclipse.equinox.p2.metadata/src/org/eclipse/equinox/p2/query/ExpressionMatchQuery.java
@@ -10,11 +10,9 @@
  *******************************************************************************/
 package org.eclipse.equinox.p2.query;
 
-import java.util.HashSet;
-import java.util.Iterator;
+import java.util.*;
 import org.eclipse.equinox.internal.p2.metadata.expression.Expression;
 import org.eclipse.equinox.internal.p2.metadata.expression.ExpressionFactory;
-import org.eclipse.equinox.p2.metadata.IArtifactKey;
 import org.eclipse.equinox.p2.metadata.expression.*;
 import org.eclipse.equinox.p2.metadata.index.*;
 
@@ -25,12 +23,14 @@ import org.eclipse.equinox.p2.metadata.index.*;
 public class ExpressionMatchQuery<T> implements IMatchQuery<T>, IQueryWithIndex<T> {
 	private final IMatchExpression<T> expression;
 	private final Class<? extends T> matchingClass;
-	private IEvaluationContext context;
+	private final IEvaluationContext context;
+	private final List<String> indexedMembers;
 
 	public ExpressionMatchQuery(Class<? extends T> matchingClass, IExpression expression, Object... parameters) {
 		this.matchingClass = matchingClass;
 		this.expression = ExpressionUtil.getFactory().<T> matchExpression(expression, parameters);
 		this.context = this.expression.createContext();
+		this.indexedMembers = Expression.getIndexCandidateMembers(matchingClass, ExpressionFactory.THIS, (Expression) expression);
 	}
 
 	public ExpressionMatchQuery(Class<? extends T> matchingClass, String expression, Object... parameters) {
@@ -47,8 +47,9 @@ public class ExpressionMatchQuery<T> implements IMatchQuery<T>, IQueryWithIndex<
 
 	public IQueryResult<T> perform(IIndexProvider<T> indexProvider) {
 		Iterator<T> iterator = null;
-		for (String member : Expression.getIndexCandidateMembers(IArtifactKey.class, ExpressionFactory.THIS, (Expression) expression)) {
-			IIndex<T> index = indexProvider.getIndex(member);
+		int top = indexedMembers.size();
+		for (int idx = 0; idx < top; ++idx) {
+			IIndex<T> index = indexProvider.getIndex(indexedMembers.get(idx));
 			if (index != null) {
 				iterator = index.getCandidates(context, ExpressionFactory.THIS, expression);
 				if (iterator != null)
diff --git a/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/ql/PerformanceTest.java b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/ql/PerformanceTest.java
index b71322fa4..00493e767 100644
--- a/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/ql/PerformanceTest.java
+++ b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/ql/PerformanceTest.java
@@ -17,12 +17,49 @@ import org.eclipse.equinox.internal.p2.director.QueryableArray;
 import org.eclipse.equinox.internal.p2.director.Slicer;
 import org.eclipse.equinox.internal.p2.metadata.InstallableUnit;
 import org.eclipse.equinox.p2.metadata.*;
+import org.eclipse.equinox.p2.metadata.expression.SimplePattern;
 import org.eclipse.equinox.p2.query.*;
 import org.eclipse.equinox.p2.repository.metadata.IMetadataRepository;
 import org.eclipse.equinox.p2.repository.metadata.IMetadataRepositoryManager;
 import org.eclipse.equinox.p2.tests.AbstractProvisioningTest;
 
 public class PerformanceTest extends AbstractProvisioningTest {
+	public void testMatchQueryVersusExpressionPerformance() throws Exception {
+
+		IMetadataRepository repo = getMDR("/testData/galileoM7");
+
+		IQuery<IInstallableUnit> expressionQuery = QueryUtil.createMatchQuery("id ~= /org.eclipse.*.feature.group/");
+		final SimplePattern pattern = SimplePattern.compile("org.eclipse.*.feature.group");
+		IQuery<IInstallableUnit> matchQuery = new MatchQuery<IInstallableUnit>() {
+			@Override
+			public boolean isMatch(IInstallableUnit candidate) {
+				return pattern.isMatch(candidate.getId());
+			}
+		};
+		IQueryResult<IInstallableUnit> result;
+		long tradQueryMS = 0;
+		long exprQueryMS = 0;
+
+		for (int i = 0; i < 5; ++i) {
+			long start = System.currentTimeMillis();
+			for (int idx = 0; idx < 80; ++idx) {
+				result = repo.query(expressionQuery, new NullProgressMonitor());
+				assertEquals(queryResultSize(result), 482);
+			}
+			tradQueryMS += (System.currentTimeMillis() - start);
+
+			start = System.currentTimeMillis();
+			for (int idx = 0; idx < 80; ++idx) {
+				result = repo.query(matchQuery, new NullProgressMonitor());
+				assertEquals(queryResultSize(result), 482);
+			}
+			exprQueryMS += (System.currentTimeMillis() - start);
+		}
+		System.out.println("ExpressionQuery took: " + tradQueryMS + " milliseconds");
+		System.out.println("MatchQuery took: " + exprQueryMS + " milliseconds");
+		System.out.println();
+	}
+
 	public void testCapabilityQueryPerformance() throws Exception {
 
 		IMetadataRepository repo = getMDR("/testData/galileoM7");