nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/support/CompositeTypeBasedGuardingDynamicLinker.java
changeset 33344 cc4a221f42b7
parent 33025 16b4968f9bb8
parent 33343 23abd10384a5
child 33345 ef8c859f7992
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/support/CompositeTypeBasedGuardingDynamicLinker.java	Wed Jul 05 20:54:58 2017 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,223 +0,0 @@
-/*
- * Copyright (c) 2010, 2013, 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.internal.dynalink.support;
-
-import java.io.Serializable;
-import java.util.Collections;
-import java.util.LinkedList;
-import java.util.List;
-import jdk.internal.dynalink.linker.GuardedInvocation;
-import jdk.internal.dynalink.linker.GuardingDynamicLinker;
-import jdk.internal.dynalink.linker.LinkRequest;
-import jdk.internal.dynalink.linker.LinkerServices;
-import jdk.internal.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, Serializable {
-    private static final long serialVersionUID = 1L;
-
-    // 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
-     */
-    public CompositeTypeBasedGuardingDynamicLinker(final Iterable<? extends TypeBasedGuardingDynamicLinker> linkers) {
-        final List<TypeBasedGuardingDynamicLinker> l = new LinkedList<>();
-        for(final TypeBasedGuardingDynamicLinker linker: linkers) {
-            l.add(linker);
-        }
-        this.classToLinker = new ClassToLinker(l.toArray(new TypeBasedGuardingDynamicLinker[l.size()]));
-    }
-
-    @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
-     */
-    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) {
-            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;
-            }
-        }
-    }
-}