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The modules contains the core implementation code of Fluo.

There is a newer version: 1.0.0-beta-2

/*
 * Copyright 2014 Fluo authors (see AUTHORS)
 *
 * 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.fluo.core.impl;

import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.Weigher;
import io.fluo.api.data.Bytes;
import io.fluo.api.data.Column;
import io.fluo.core.util.ByteUtil;
import org.apache.accumulo.core.security.ColumnVisibility;

/**
 * PArsing Column visibilities can be expensive. This class provides a cache of parsed visibility objects.
 */

public class VisibilityCache {

  public static final ColumnVisibility EMPTY_VIS = new ColumnVisibility();

  private static class VisWeigher implements Weigher {
    @Override
    public int weigh(Bytes key, ColumnVisibility vis) {
      return key.length() + vis.getExpression().length + 32;
    }
  }

  private final Cache visCache;

  VisibilityCache() {
    visCache = CacheBuilder.newBuilder().expireAfterAccess(TxInfoCache.CACHE_TIMEOUT_MIN, TimeUnit.MINUTES).maximumWeight(10000000).weigher(new VisWeigher())
        .concurrencyLevel(10).build();
  }

  public ColumnVisibility getCV(Column col) {
    return getCV(col.getVisibility());
  }

  public ColumnVisibility getCV(final Bytes colvis) {
    if (colvis.length() == 0)
      return EMPTY_VIS;

    try {
      return visCache.get(colvis, new Callable() {
        @Override
        public ColumnVisibility call() throws Exception {
          return new ColumnVisibility(ByteUtil.toText(colvis));
        }
      });
    } catch (ExecutionException e) {
      throw new RuntimeException(e);
    }
  }

  public void validate(Column col) {
    getCV(col.getVisibility());
  }

  public void validate(Set columns) {
    for (Column column : columns) {
      validate(column);
    }

  }

}