com.github.benmanes.caffeine.guava.CaffeinatedGuavaLoadingCache.java Source code

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Here is the source code for com.github.benmanes.caffeine.guava.CaffeinatedGuavaLoadingCache.java

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/*
 * Copyright 2015 Ben Manes. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the 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.
 */
package com.github.benmanes.caffeine.guava;

import static java.util.Objects.requireNonNull;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutionException;

import javax.annotation.Nonnull;

import com.github.benmanes.caffeine.cache.CacheLoader;
import com.google.common.base.Throwables;
import com.google.common.cache.CacheLoader.InvalidCacheLoadException;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ImmutableMap;
import com.google.common.util.concurrent.ExecutionError;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.UncheckedExecutionException;

/**
 * A Caffeine-backed loading cache through a Guava facade.
 *
 * @author ben.manes@gmail.com (Ben Manes)
 */
@SuppressWarnings("deprecation")
final class CaffeinatedGuavaLoadingCache<K, V> extends CaffeinatedGuavaCache<K, V> implements LoadingCache<K, V> {
    static final ThreadLocal<Boolean> nullBulkLoad = ThreadLocal.withInitial(() -> Boolean.FALSE);
    static final long serialVersionUID = 1L;

    final com.github.benmanes.caffeine.cache.LoadingCache<K, V> cache;

    CaffeinatedGuavaLoadingCache(com.github.benmanes.caffeine.cache.LoadingCache<K, V> cache) {
        super(cache);
        this.cache = cache;
    }

    @Override
    @SuppressWarnings("PMD.PreserveStackTrace")
    public V get(K key) throws ExecutionException {
        requireNonNull(key);
        try {
            return cache.get(key);
        } catch (InvalidCacheLoadException e) {
            throw e;
        } catch (CacheLoaderException e) {
            throw new ExecutionException(e.getCause());
        } catch (RuntimeException e) {
            throw new UncheckedExecutionException(e);
        } catch (Error e) {
            throw new ExecutionError(e);
        }
    }

    @Override
    @SuppressWarnings({ "PMD.PreserveStackTrace", "PMD.AvoidCatchingNPE" })
    public V getUnchecked(K key) {
        try {
            return cache.get(key);
        } catch (NullPointerException | InvalidCacheLoadException e) {
            throw e;
        } catch (CacheLoaderException e) {
            throw new UncheckedExecutionException(e.getCause());
        } catch (Exception e) {
            throw new UncheckedExecutionException(e);
        } catch (Error e) {
            throw new ExecutionError(e);
        }
    }

    @Override
    @SuppressWarnings({ "PMD.PreserveStackTrace", "PMD.AvoidCatchingNPE" })
    public ImmutableMap<K, V> getAll(Iterable<? extends K> keys) throws ExecutionException {
        try {
            Map<K, V> result = cache.getAll(keys);
            if (nullBulkLoad.get()) {
                nullBulkLoad.set(false);
                throw new InvalidCacheLoadException("null key or value");
            }
            for (K key : keys) {
                if (!result.containsKey(key)) {
                    throw new InvalidCacheLoadException("loadAll failed to return a value for " + key);
                }
            }
            return ImmutableMap.copyOf(result);
        } catch (NullPointerException | InvalidCacheLoadException e) {
            throw e;
        } catch (CacheLoaderException e) {
            throw new ExecutionException(e.getCause());
        } catch (Exception e) {
            throw new UncheckedExecutionException(e);
        } catch (Error e) {
            throw new ExecutionError(e);
        }
    }

    @Override
    public V apply(@Nonnull K key) {
        return cache.get(key);
    }

    @Override
    public void refresh(K key) {
        cache.refresh(key);
    }

    static class SingleLoader<K, V> implements CacheLoader<K, V>, Serializable {
        private static final long serialVersionUID = 1L;

        final com.google.common.cache.CacheLoader<K, V> cacheLoader;

        SingleLoader(com.google.common.cache.CacheLoader<K, V> cacheLoader) {
            this.cacheLoader = requireNonNull(cacheLoader);
        }

        @Override
        public V load(K key) {
            try {
                V value = cacheLoader.load(key);
                if (value == null) {
                    throw new InvalidCacheLoadException("null value");
                }
                return value;
            } catch (RuntimeException | Error e) {
                throw e;
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                throw new CacheLoaderException(e);
            } catch (Exception e) {
                throw new CacheLoaderException(e);
            }
        }

        @Override
        public V reload(K key, V oldValue) {
            try {
                V value = Futures.getUnchecked(cacheLoader.reload(key, oldValue));
                if (value == null) {
                    throw new InvalidCacheLoadException("null value");
                }
                return value;
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                throw new CacheLoaderException(e);
            } catch (Exception e) {
                throw Throwables.propagate(e);
            }
        }
    }

    static final class BulkLoader<K, V> extends SingleLoader<K, V> {
        private static final long serialVersionUID = 1L;

        BulkLoader(com.google.common.cache.CacheLoader<K, V> cacheLoader) {
            super(cacheLoader);
        }

        @Override
        public Map<K, V> loadAll(Iterable<? extends K> keys) {
            try {
                Map<K, V> loaded = cacheLoader.loadAll(keys);
                if (loaded == null) {
                    throw new InvalidCacheLoadException("null map");
                }
                Map<K, V> result = new HashMap<>(loaded.size());
                loaded.forEach((key, value) -> {
                    if ((key == null) || (value == null)) {
                        nullBulkLoad.set(true);
                    } else {
                        result.put(key, value);
                    }
                });
                return result;
            } catch (RuntimeException | Error e) {
                throw e;
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                throw new CacheLoaderException(e);
            } catch (Exception e) {
                throw new CacheLoaderException(e);
            }
        }
    }
}