processing/src/main/java/org/apache/druid/query/filter/RegexDimFilter.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.druid.query.filter;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.RangeSet;
import org.apache.druid.java.util.common.StringUtils;
import org.apache.druid.query.extraction.ExtractionFn;
import org.apache.druid.segment.filter.RegexFilter;

import javax.annotation.Nullable;
import java.nio.ByteBuffer;
import java.util.Objects;
import java.util.Set;
import java.util.regex.Pattern;

/**
 */
public class RegexDimFilter implements DimFilter
{
  private final String dimension;
  private final String pattern;
  @Nullable
  private final ExtractionFn extractionFn;
  @Nullable
  private final FilterTuning filterTuning;

  private final Pattern compiledPattern;

  @JsonCreator
  public RegexDimFilter(
      @JsonProperty("dimension") String dimension,
      @JsonProperty("pattern") String pattern,
      @JsonProperty("extractionFn") @Nullable ExtractionFn extractionFn,
      @JsonProperty("filterTuning") @Nullable FilterTuning filterTuning
  )
  {
    Preconditions.checkArgument(dimension != null, "dimension must not be null");
    Preconditions.checkArgument(pattern != null, "pattern must not be null");
    this.dimension = dimension;
    this.pattern = pattern;
    this.extractionFn = extractionFn;
    this.compiledPattern = Pattern.compile(pattern);
    this.filterTuning = filterTuning;
  }

  @VisibleForTesting
  public RegexDimFilter(String dimension, String pattern, @Nullable ExtractionFn extractionFn)
  {
    this(dimension, pattern, extractionFn, null);
  }

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

  @JsonProperty
  public String getPattern()
  {
    return pattern;
  }

  @Nullable
  @JsonProperty
  public ExtractionFn getExtractionFn()
  {
    return extractionFn;
  }

  @Nullable
  @JsonInclude(JsonInclude.Include.NON_NULL)
  @JsonProperty
  public FilterTuning getFilterTuning()
  {
    return filterTuning;
  }

  @Override
  public byte[] getCacheKey()
  {
    final byte[] dimensionBytes = StringUtils.toUtf8(dimension);
    final byte[] patternBytes = StringUtils.toUtf8(pattern);
    byte[] extractionFnBytes = extractionFn == null ? new byte[0] : extractionFn.getCacheKey();

    return ByteBuffer.allocate(3 + dimensionBytes.length + patternBytes.length + extractionFnBytes.length)
                     .put(DimFilterUtils.REGEX_CACHE_ID)
                     .put(dimensionBytes)
                     .put(DimFilterUtils.STRING_SEPARATOR)
                     .put(patternBytes)
                     .put(DimFilterUtils.STRING_SEPARATOR)
                     .put(extractionFnBytes)
                     .array();
  }

  @Override
  public DimFilter optimize()
  {
    return this;
  }

  @Override
  public Filter toFilter()
  {
    return new RegexFilter(dimension, compiledPattern, extractionFn, filterTuning);
  }

  @Override
  public RangeSet<String> getDimensionRangeSet(String dimension)
  {
    return null;
  }

  @Override
  public Set<String> getRequiredColumns()
  {
    return ImmutableSet.of(dimension);
  }

  @Override
  public String toString()
  {
    return "RegexDimFilter{" +
           "dimension='" + dimension + '\'' +
           ", pattern='" + pattern + '\'' +
           ", extractionFn='" + extractionFn + '\'' +
           ", filterTuning=" + filterTuning +
           '}';
  }

  @Override
  public boolean equals(Object o)
  {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    RegexDimFilter that = (RegexDimFilter) o;
    return dimension.equals(that.dimension) &&
           pattern.equals(that.pattern) &&
           Objects.equals(extractionFn, that.extractionFn) &&
           Objects.equals(filterTuning, that.filterTuning);
  }

  @Override
  public int hashCode()
  {
    return Objects.hash(dimension, pattern, extractionFn, filterTuning);
  }
}