com.google.gerrit.server.cache.h2.DefaultCacheFactory.java Source code

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Here is the source code for com.google.gerrit.server.cache.h2.DefaultCacheFactory.java

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// Copyright (C) 2012 The Android Open Source Project
//
// 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.google.gerrit.server.cache.h2;

import com.google.common.base.Strings;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.cache.Weigher;
import com.google.gerrit.lifecycle.LifecycleModule;
import com.google.gerrit.server.cache.CacheBinding;
import com.google.gerrit.server.cache.ForwardingRemovalListener;
import com.google.gerrit.server.cache.MemoryCacheFactory;
import com.google.gerrit.server.cache.PersistentCacheFactory;
import com.google.gerrit.server.cache.h2.H2CacheImpl.ValueHolder;
import com.google.gerrit.server.config.ConfigUtil;
import com.google.gerrit.server.config.FactoryModule;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.inject.Inject;

import org.eclipse.jgit.lib.Config;

import java.util.concurrent.TimeUnit;

public class DefaultCacheFactory implements MemoryCacheFactory {
    public static class Module extends LifecycleModule {
        @Override
        protected void configure() {
            install(new FactoryModule() {
                @Override
                protected void configure() {
                    factory(ForwardingRemovalListener.Factory.class);
                }
            });

            bind(DefaultCacheFactory.class);
            bind(MemoryCacheFactory.class).to(DefaultCacheFactory.class);
            bind(PersistentCacheFactory.class).to(H2CacheFactory.class);
            listener().to(H2CacheFactory.class);
        }
    }

    private final Config cfg;
    private final ForwardingRemovalListener.Factory forwardingRemovalListenerFactory;

    @Inject
    public DefaultCacheFactory(@GerritServerConfig Config config,
            ForwardingRemovalListener.Factory forwardingRemovalListenerFactory) {
        this.cfg = config;
        this.forwardingRemovalListenerFactory = forwardingRemovalListenerFactory;
    }

    @Override
    public <K, V> Cache<K, V> build(CacheBinding<K, V> def) {
        return create(def, false).build();
    }

    @Override
    public <K, V> LoadingCache<K, V> build(CacheBinding<K, V> def, CacheLoader<K, V> loader) {
        return create(def, false).build(loader);
    }

    @SuppressWarnings("unchecked")
    <K, V> CacheBuilder<K, V> create(CacheBinding<K, V> def, boolean unwrapValueHolder) {
        CacheBuilder<K, V> builder = newCacheBuilder();
        builder.recordStats();
        builder.maximumWeight(cfg.getLong("cache", def.name(), "memoryLimit", def.maximumWeight()));

        builder.removalListener(forwardingRemovalListenerFactory.create(def.name()));

        Weigher<K, V> weigher = def.weigher();
        if (weigher != null && unwrapValueHolder) {
            final Weigher<K, V> impl = weigher;
            weigher = (Weigher<K, V>) new Weigher<K, ValueHolder<V>>() {
                @Override
                public int weigh(K key, ValueHolder<V> value) {
                    return impl.weigh(key, value.value);
                }
            };
        } else if (weigher == null) {
            weigher = unitWeight();
        }
        builder.weigher(weigher);

        Long age = def.expireAfterWrite(TimeUnit.SECONDS);
        if (has(def.name(), "maxAge")) {
            builder.expireAfterWrite(ConfigUtil.getTimeUnit(cfg, "cache", def.name(), "maxAge",
                    age != null ? age : 0, TimeUnit.SECONDS), TimeUnit.SECONDS);
        } else if (age != null) {
            builder.expireAfterWrite(age, TimeUnit.SECONDS);
        }

        return builder;
    }

    private boolean has(String name, String var) {
        return !Strings.isNullOrEmpty(cfg.getString("cache", name, var));
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    private static <K, V> CacheBuilder<K, V> newCacheBuilder() {
        CacheBuilder builder = CacheBuilder.newBuilder();
        return builder;
    }

    private static <K, V> Weigher<K, V> unitWeight() {
        return new Weigher<K, V>() {
            @Override
            public int weigh(K key, V value) {
                return 1;
            }
        };
    }
}