Histogram.java

/*
 * This file is part of Waarp Project (named also Waarp or GG).
 *
 *  Copyright (c) 2019, Waarp SAS, and individual contributors by the @author
 *  tags. See the COPYRIGHT.txt in the distribution for a full listing of
 * individual contributors.
 *
 *  All Waarp Project 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 3 of the License, or (at your
 * option) any later version.
 *
 * Waarp 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
 * Waarp . If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * 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 org.waarp.compress.zstdsafe;

import java.util.Arrays;

class Histogram {
  private Histogram() {
  }

  public static int findLargestCount(final int[] counts, final int maxSymbol) {
    int max = 0;
    for (int i = 0; i <= maxSymbol; i++) {
      if (counts[i] > max) {
        max = counts[i];
      }
    }

    return max;
  }

  public static int findMaxSymbol(final int[] counts, int maxSymbol) {
    while (counts[maxSymbol] == 0) {
      maxSymbol--;
    }
    return maxSymbol;
  }

  public static void count(final byte[] inputBase, final int inputSize,
                           final int[] counts) {
    int input = 0;

    Arrays.fill(counts, 0);

    for (int i = 0; i < inputSize; i++) {
      final int symbol = inputBase[input] & 0xFF;
      input++;
      counts[symbol]++;
    }
  }
}