org.xacml4j.v30.spi.pip.DefaultPolicyInformationPointCacheProvider.java Source code

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Here is the source code for org.xacml4j.v30.spi.pip.DefaultPolicyInformationPointCacheProvider.java

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package org.xacml4j.v30.spi.pip;

/*
 * #%L
 * Xacml4J Core Engine Implementation
 * %%
 * Copyright (C) 2009 - 2014 Xacml4J.org
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * This program 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 Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/lgpl-3.0.html>.
 * #L%
 */

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

public final class DefaultPolicyInformationPointCacheProvider extends BasePolicyInformationPointCacheProvider {
    private final Cache<ResolverCacheKey, AttributeSet> attributeCache;
    private final Cache<ResolverCacheKey, Content> contentCache;

    /**
     * Default maximum number of items in the attribute cache
     */
    private static final int DEFAULT_MAX_ATTRIBUTE_ITEMS = 2048;

    /**
     * Default maximum number of items in the content cache
     */
    private static final int DEFAULT_MAX_CONTENT_ITEMS = 2048;

    public DefaultPolicyInformationPointCacheProvider() {
        this(DEFAULT_MAX_ATTRIBUTE_ITEMS, DEFAULT_MAX_CONTENT_ITEMS);
    }

    public DefaultPolicyInformationPointCacheProvider(int maxAttrSize, int maxContentSize) {
        this.attributeCache = CacheBuilder.newBuilder().maximumSize(maxAttrSize).build();
        this.contentCache = CacheBuilder.newBuilder().maximumSize(maxContentSize).build();
    }

    @Override
    protected Content doGetContent(ResolverContext context) {
        ResolverCacheKey key = ResolverCacheKey.builder().id(context.getDescriptor()).keys(context.getKeys())
                .build();
        Content v = contentCache.getIfPresent(key);
        if (v != null && isExpired(v, context)) {
            attributeCache.invalidate(key);
        }
        return v;
    }

    @Override
    protected void doPutContent(ResolverContext context, Content content) {
        contentCache.put(ResolverCacheKey.builder().id(context.getDescriptor()).keys(context.getKeys()).build(),
                content);
    }

    @Override
    protected AttributeSet doGetAttributes(ResolverContext context) {
        ResolverCacheKey key = ResolverCacheKey.builder().id(context.getDescriptor()).keys(context.getKeys())
                .build();
        AttributeSet v = attributeCache.getIfPresent(key);
        if (v != null && isExpired(v, context)) {
            attributeCache.invalidate(key);
        }
        return v;
    }

    @Override
    protected void doPutAttributes(ResolverContext context, AttributeSet v) {
        ResolverCacheKey key = ResolverCacheKey.builder().id(context.getDescriptor()).keys(context.getKeys())
                .build();
        attributeCache.put(key, v);
    }

    private boolean isExpired(AttributeSet v, ResolverContext context) {
        return ((context.getTicker().read() - v.getCreatedTime()) / 1000000000L) >= v.getDescriptor()
                .getPreferredCacheTTL();
    }

    private boolean isExpired(Content v, ResolverContext context) {
        return ((context.getTicker().read() - v.getTimestamp()) / 1000000000L) >= v.getDescriptor()
                .getPreferredCacheTTL();
    }
}