processing/src/main/java/io/druid/query/filter/JavaScriptDimFilter.java

/*
 * Druid - a distributed column store.
 * Copyright (C) 2012, 2013  Metamarkets Group Inc.
 *
 * This program 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 2
 * 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 Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

package io.druid.query.filter;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Charsets;
import com.google.common.base.Preconditions;

import java.nio.ByteBuffer;

public class JavaScriptDimFilter implements DimFilter
{
  private final String dimension;
  private final String function;

  @JsonCreator
  public JavaScriptDimFilter(
      @JsonProperty("dimension") String dimension,
      @JsonProperty("function") String function
  )
  {
    Preconditions.checkArgument(dimension != null, "dimension must not be null");
    Preconditions.checkArgument(function != null, "function must not be null");
    this.dimension = dimension;
    this.function = function;
  }

  @JsonProperty
  public String getDimension()
  {
    return dimension;
  }

  @JsonProperty
  public String getFunction()
  {
    return function;
  }

  @Override
  public byte[] getCacheKey()
  {
    final byte[] dimensionBytes = dimension.getBytes(Charsets.UTF_8);
    final byte[] functionBytes = function.getBytes(Charsets.UTF_8);

    return ByteBuffer.allocate(1 + dimensionBytes.length + functionBytes.length)
        .put(DimFilterCacheHelper.JAVASCRIPT_CACHE_ID)
        .put(dimensionBytes)
        .put(functionBytes)
        .array();
  }
}