tech.beshu.ror.acl.definitions.groupsproviders.CachedGroupsProviderServiceClient.java Source code

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Here is the source code for tech.beshu.ror.acl.definitions.groupsproviders.CachedGroupsProviderServiceClient.java

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/*
 *    This file is part of ReadonlyREST.
 *
 *    ReadonlyREST is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    ReadonlyREST 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 for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with ReadonlyREST.  If not, see http://www.gnu.org/licenses/
 */
package tech.beshu.ror.acl.definitions.groupsproviders;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import tech.beshu.ror.commons.domain.LoggedUser;
import tech.beshu.ror.settings.rules.CacheSettings;

import java.time.Duration;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;

public class CachedGroupsProviderServiceClient implements GroupsProviderServiceClient {

    private final GroupsProviderServiceClient underlying;
    private final Cache<String, Set<String>> cache;

    private CachedGroupsProviderServiceClient(GroupsProviderServiceClient underlying, Duration ttl) {
        this.underlying = underlying;
        this.cache = CacheBuilder.newBuilder().expireAfterWrite(ttl.toMillis(), TimeUnit.MILLISECONDS).build();
    }

    public static GroupsProviderServiceClient wrapInCacheIfCacheIsEnabled(CacheSettings settings,
            GroupsProviderServiceClient client) {
        return settings.getCacheTtl().isZero() ? client
                : new CachedGroupsProviderServiceClient(client, settings.getCacheTtl());
    }

    @Override
    public CompletableFuture<Set<String>> fetchGroupsFor(LoggedUser user) {
        Set<String> cachedUserGroups = cache.getIfPresent(user.getId());
        if (cachedUserGroups == null) {
            return underlying.fetchGroupsFor(user).thenApply(groups -> {
                cache.put(user.getId(), groups);
                return groups;
            });
        }
        return CompletableFuture.completedFuture(cachedUserGroups);
    }
}