--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.dynalink/share/classes/jdk/dynalink/linker/support/CompositeTypeBasedGuardingDynamicLinker.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,237 @@
+/*
+ * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file, and Oracle licenses the original version of this file under the BSD
+ * license:
+ */
+/*
+ Copyright 2009-2013 Attila Szegedi
+
+ Licensed under both the Apache License, Version 2.0 (the "Apache License")
+ and the BSD License (the "BSD License"), with licensee being free to
+ choose either of the two at their discretion.
+
+ You may not use this file except in compliance with either the Apache
+ License or the BSD License.
+
+ If you choose to use this file in compliance with the Apache License, the
+ following notice applies to you:
+
+ You may obtain a copy of the Apache 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.
+
+ If you choose to use this file in compliance with the BSD License, the
+ following notice applies to you:
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are
+ met:
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+ * Neither the name of the copyright holder nor the names of
+ contributors may be used to endorse or promote products derived from
+ this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
+ BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+package jdk.dynalink.linker.support;
+
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Objects;
+import jdk.dynalink.linker.GuardedInvocation;
+import jdk.dynalink.linker.GuardingDynamicLinker;
+import jdk.dynalink.linker.LinkRequest;
+import jdk.dynalink.linker.LinkerServices;
+import jdk.dynalink.linker.TypeBasedGuardingDynamicLinker;
+
+/**
+ * A composite type-based guarding dynamic linker. When a receiver of a not yet
+ * seen class is encountered, all linkers are queried sequentially on their
+ * {@link TypeBasedGuardingDynamicLinker#canLinkType(Class)} method. The linkers
+ * returning true are then bound to the class, and next time a receiver of same
+ * type is encountered, the linking is delegated to those linkers only, speeding
+ * up dispatch.
+ */
+public class CompositeTypeBasedGuardingDynamicLinker implements TypeBasedGuardingDynamicLinker {
+ // Using a separate static class instance so there's no strong reference from the class value back to the composite
+ // linker.
+ private static class ClassToLinker extends ClassValue<List<TypeBasedGuardingDynamicLinker>> {
+ private static final List<TypeBasedGuardingDynamicLinker> NO_LINKER = Collections.emptyList();
+ private final TypeBasedGuardingDynamicLinker[] linkers;
+ private final List<TypeBasedGuardingDynamicLinker>[] singletonLinkers;
+
+ @SuppressWarnings({"unchecked", "rawtypes"})
+ ClassToLinker(final TypeBasedGuardingDynamicLinker[] linkers) {
+ this.linkers = linkers;
+ singletonLinkers = new List[linkers.length];
+ for(int i = 0; i < linkers.length; ++i) {
+ singletonLinkers[i] = Collections.singletonList(linkers[i]);
+ }
+ }
+
+ @SuppressWarnings("fallthrough")
+ @Override
+ protected List<TypeBasedGuardingDynamicLinker> computeValue(final Class<?> clazz) {
+ List<TypeBasedGuardingDynamicLinker> list = NO_LINKER;
+ for(int i = 0; i < linkers.length; ++i) {
+ final TypeBasedGuardingDynamicLinker linker = linkers[i];
+ if(linker.canLinkType(clazz)) {
+ switch(list.size()) {
+ case 0: {
+ list = singletonLinkers[i];
+ break;
+ }
+ case 1: {
+ list = new LinkedList<>(list);
+ }
+ default: {
+ list.add(linker);
+ }
+ }
+ }
+ }
+ return list;
+ }
+ }
+
+ private final ClassValue<List<TypeBasedGuardingDynamicLinker>> classToLinker;
+
+ /**
+ * Creates a new composite type-based linker.
+ *
+ * @param linkers the component linkers
+ * @throws NullPointerException if {@code linkers} or any of its elements
+ * are null.
+ */
+ public CompositeTypeBasedGuardingDynamicLinker(final Iterable<? extends TypeBasedGuardingDynamicLinker> linkers) {
+ final List<TypeBasedGuardingDynamicLinker> l = new LinkedList<>();
+ for(final TypeBasedGuardingDynamicLinker linker: linkers) {
+ l.add(Objects.requireNonNull(linker));
+ }
+ this.classToLinker = new ClassToLinker(l.toArray(new TypeBasedGuardingDynamicLinker[0]));
+ }
+
+ /**
+ * Returns true if at least one of the composite linkers returns true from
+ * {@link TypeBasedGuardingDynamicLinker#canLinkType(Class)} for the type.
+ * @param type the type to link
+ * @return true true if at least one of the composite linkers returns true
+ * from {@link TypeBasedGuardingDynamicLinker#canLinkType(Class)}, false
+ * otherwise.
+ */
+ @Override
+ public boolean canLinkType(final Class<?> type) {
+ return !classToLinker.get(type).isEmpty();
+ }
+
+ @Override
+ public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest, final LinkerServices linkerServices)
+ throws Exception {
+ final Object obj = linkRequest.getReceiver();
+ if(obj == null) {
+ return null;
+ }
+ for(final TypeBasedGuardingDynamicLinker linker: classToLinker.get(obj.getClass())) {
+ final GuardedInvocation invocation = linker.getGuardedInvocation(linkRequest, linkerServices);
+ if(invocation != null) {
+ return invocation;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Optimizes a list of type-based linkers. If a group of adjacent linkers in
+ * the list all implement {@link TypeBasedGuardingDynamicLinker}, they will
+ * be replaced with a single instance of
+ * {@link CompositeTypeBasedGuardingDynamicLinker} that contains them.
+ *
+ * @param linkers the list of linkers to optimize
+ * @return the optimized list
+ * @throws NullPointerException if {@code linkers} or any of its elements
+ * are null.
+ */
+ public static List<GuardingDynamicLinker> optimize(final Iterable<? extends GuardingDynamicLinker> linkers) {
+ final List<GuardingDynamicLinker> llinkers = new LinkedList<>();
+ final List<TypeBasedGuardingDynamicLinker> tblinkers = new LinkedList<>();
+ for(final GuardingDynamicLinker linker: linkers) {
+ Objects.requireNonNull(linker);
+ if(linker instanceof TypeBasedGuardingDynamicLinker) {
+ tblinkers.add((TypeBasedGuardingDynamicLinker)linker);
+ } else {
+ addTypeBased(llinkers, tblinkers);
+ llinkers.add(linker);
+ }
+ }
+ addTypeBased(llinkers, tblinkers);
+ return llinkers;
+ }
+
+ private static void addTypeBased(final List<GuardingDynamicLinker> llinkers,
+ final List<TypeBasedGuardingDynamicLinker> tblinkers) {
+ switch(tblinkers.size()) {
+ case 0: {
+ break;
+ }
+ case 1: {
+ llinkers.addAll(tblinkers);
+ tblinkers.clear();
+ break;
+ }
+ default: {
+ llinkers.add(new CompositeTypeBasedGuardingDynamicLinker(tblinkers));
+ tblinkers.clear();
+ break;
+ }
+ }
+ }
+}