platform/util/src/com/intellij/util/containers/ObjectCacheBase.java

/*
 * Copyright 2000-2009 JetBrains s.r.o.
 *
 * 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 com.intellij.util.containers;

import java.util.Arrays;

/**
 * @author Eugene Zhuravlev
 *         Date: Nov 28, 2006
 */
class ObjectCacheBase {

  private static final int[] HASHTABLE_SIZES = {
      5, 11, 23, 47, 97, 197, 397, 797, 1597, 3203, 6421, 12853, 25717, 51437, 102877, 205759,
      411527, 823117, 1646237, 3292489, 6584983, 13169977, 26339969, 52679969, 105359939,
      210719881, 421439783, 842879579, 1685759167,
      433, 877, 1759, 3527, 7057, 14143, 28289, 56591, 113189, 226379, 452759, 905551, 1811107,
      3622219, 7244441, 14488931, 28977863, 57955739, 115911563, 231823147, 463646329, 927292699,
      1854585413,
      953, 1907, 3821, 7643, 15287, 30577, 61169, 122347, 244703, 489407, 978821, 1957651, 3915341,
      7830701, 15661423, 31322867, 62645741, 125291483, 250582987, 501165979, 1002331963,
      2004663929,
      1039, 2081, 4177, 8363, 16729, 33461, 66923, 133853, 267713, 535481, 1070981, 2141977, 4283963,
      8567929, 17135863, 34271747, 68543509, 137087021, 274174111, 548348231, 1096696463,
      31, 67, 137, 277, 557, 1117, 2237, 4481, 8963, 17929, 35863, 71741, 143483, 286973, 573953,
      1147921, 2295859, 4591721, 9183457, 18366923, 36733847, 73467739, 146935499, 293871013,
      587742049, 1175484103,
      599, 1201, 2411, 4831, 9677, 19373, 38747, 77509, 155027, 310081, 620171, 1240361, 2480729,
      4961459, 9922933, 19845871, 39691759, 79383533, 158767069, 317534141, 635068283, 1270136683,
      311, 631, 1277, 2557, 5119, 10243, 20507, 41017, 82037, 164089, 328213, 656429, 1312867,
      2625761, 5251529, 10503061, 21006137, 42012281, 84024581, 168049163, 336098327, 672196673,
      1344393353,
      3, 7, 17, 37, 79, 163, 331, 673, 1361, 2729, 5471, 10949, 21911, 43853, 87719, 175447, 350899,
      701819, 1403641, 2807303, 5614657, 11229331, 22458671, 44917381, 89834777, 179669557,
      359339171, 718678369, 1437356741,
      43, 89, 179, 359, 719, 1439, 2879, 5779, 11579, 23159, 46327, 92657, 185323, 370661, 741337,
      1482707, 2965421, 5930887, 11861791, 23723597, 47447201, 94894427, 189788857, 379577741,
      759155483, 1518310967,
      379, 761, 1523, 3049, 6101, 12203, 24407, 48817, 97649, 195311, 390647, 781301, 1562611,
      3125257, 6250537, 12501169, 25002389, 50004791, 100009607, 200019221, 400038451, 800076929,
      1600153859
  };

  static {
    Arrays.sort(HASHTABLE_SIZES);
  }

  protected ObjectCacheBase() {}

  protected static int getAdjustedTableSize(int candidate) {
    int index = Arrays.binarySearch(HASHTABLE_SIZES, candidate);
    if (index >= 0) return candidate;
    return HASHTABLE_SIZES[-index];
  }
}