GetCacheVersion.java

/*
 * Copyright 2016 Victor Albertos
 *
 * 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 io.rx_cache2.internal.migration;

import io.reactivex.Observable;
import io.rx_cache2.internal.Persistence;
import javax.inject.Inject;

final class GetCacheVersion extends CacheVersion {

  @Inject public GetCacheVersion(Persistence persistence) {
    super(persistence);
  }

  Observable<Integer> react() {
    Integer currentVersion = persistence.retrieve(KEY_CACHE_VERSION, Integer.class, false, null);
    currentVersion = currentVersion == null ? 0 : currentVersion;
    return Observable.just(currentVersion);
  }
}