001    /*
002     * Copyright 2010-2015 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.kotlin.utils;
018    
019    import org.jetbrains.annotations.NotNull;
020    import org.jetbrains.annotations.Nullable;
021    
022    public class WrappedValues {
023        private static final Object NULL_VALUE = new Object() {
024            @Override
025            public String toString() {
026                return "NULL_VALUE";
027            }
028        };
029        public static volatile boolean throwWrappedProcessCanceledException = false;
030    
031        private final static class ThrowableWrapper {
032            private final Throwable throwable;
033    
034            private ThrowableWrapper(@NotNull Throwable throwable) {
035                this.throwable = throwable;
036            }
037    
038            @NotNull
039            public Throwable getThrowable() {
040                return throwable;
041            }
042    
043            @Override
044            public String toString() {
045                return throwable.toString();
046            }
047        }
048    
049        private WrappedValues() {
050        }
051    
052        @Nullable
053        @SuppressWarnings("unchecked")
054        public static <V> V unescapeNull(@NotNull Object value) {
055            if (value == NULL_VALUE) return null;
056            return (V) value;
057        }
058    
059        @NotNull
060        public static <V> Object escapeNull(@Nullable V value) {
061            if (value == null) return NULL_VALUE;
062            return value;
063        }
064    
065        @NotNull
066        public static Object escapeThrowable(@NotNull Throwable throwable) {
067            return new ThrowableWrapper(throwable);
068        }
069    
070        @Nullable
071        public static <V> V unescapeExceptionOrNull(@NotNull Object value) {
072            return unescapeNull(unescapeThrowable(value));
073        }
074    
075        @Nullable
076        @SuppressWarnings("unchecked")
077        public static <V> V unescapeThrowable(@Nullable Object value) {
078            if (value instanceof ThrowableWrapper) {
079                Throwable originThrowable = ((ThrowableWrapper) value).getThrowable();
080    
081                if (throwWrappedProcessCanceledException &&
082                        originThrowable.getClass().getName().equals("com.intellij.openapi.progress.ProcessCanceledException")) {
083                    throw new WrappedProcessCanceledException(originThrowable);
084                }
085    
086                throw ExceptionUtilsKt.rethrow(originThrowable);
087            }
088    
089            return (V) value;
090        }
091    
092        public static class WrappedProcessCanceledException extends RuntimeException {
093            public WrappedProcessCanceledException(Throwable cause) {
094                super("Rethrow stored exception", cause);
095            }
096        }
097    }