org.apache.datasketches.tuple.strings.ArrayOfStringsSketch Maven / Gradle / Ivy

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Core sketch algorithms used alone and by other Java repositories in the DataSketches library.

There is a newer version: 7.0.0

/*
 * 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.datasketches.tuple.strings;

import static org.apache.datasketches.tuple.strings.ArrayOfStringsSummary.stringArrHash;

import org.apache.datasketches.ResizeFactor;
import org.apache.datasketches.memory.Memory;
import org.apache.datasketches.tuple.UpdatableSketch;

/**
 * @author Lee Rhodes
 */
public class ArrayOfStringsSketch extends UpdatableSketch {

  /**
   * Constructs new sketch with default K = 4096 (lgK = 12), default ResizeFactor=X8,
   * and default p = 1.0.
   */
  public ArrayOfStringsSketch() {
    this(12);
  }

  /**
   * Constructs new sketch with default ResizeFactor=X8, default p = 1.0 and given lgK.
   * @param lgK Log_base2 of Nominal Entries.
   * See Nominal Entries
   */
  public ArrayOfStringsSketch(final int lgK) {
    this(lgK, ResizeFactor.X8, 1.0F);
  }

  /**
   * Constructs new sketch with given ResizeFactor, p and lgK.
   * @param lgK Log_base2 of Nominal Entries.
   * See Nominal Entries
   * @param rf ResizeFactor
   * See Resize Factor
   * @param p sampling probability
   * See Sampling Probability
   */
  public ArrayOfStringsSketch(final int lgK, final ResizeFactor rf, final float p) {
    super(1 << lgK, rf.lg(), p, new ArrayOfStringsSummaryFactory());
  }

  /**
   * Constructs this sketch from a Memory image, which must be from an ArrayOfStringsSketch, and
   * usually with data.
   * @param mem the given Memory
   */
  public ArrayOfStringsSketch(final Memory mem) {
    super(mem, new ArrayOfStringsSummaryDeserializer(), new ArrayOfStringsSummaryFactory());
  }

  /**
   * Updates the sketch with String arrays for both key and value.
   * @param strArrKey the given String array key
   * @param strArr the given String array value
   */
  public void update(final String[] strArrKey, final String[] strArr) {
    super.update(stringArrHash(strArrKey), strArr);
  }

}