/** Use high bits of metadata for modification count. */
  static final int MODIFICATION_COUNT_INCREMENT = (1 << HASH_TABLE_BITS_MAX_BITS);

  /** Bitmask that selects the low bits of metadata to get hashTableBits. */
  static final int HASH_TABLE_BITS_MASK = (1 << HASH_TABLE_BITS_MAX_BITS) - 1;

  /** Maximum size of a compact hash-based collection (2^30 - 1 because 0 is UNSET). */

import static java.lang.Character.MAX_SURROGATE;
import static java.lang.Character.MIN_SURROGATE;

import com.google.common.annotations.GwtCompatible;

/**
 * Low-level, high-performance utility methods related to the {@linkplain Charsets#UTF_8 UTF-8}
 * character encoding. UTF-8 is defined in section D92 of <a
 * href="http://www.unicode.org/versions/Unicode6.2.0/ch03.pdf">The Unicode Standard Core

  /** Use high bits of metadata for modification count. */
  static final int MODIFICATION_COUNT_INCREMENT = (1 << HASH_TABLE_BITS_MAX_BITS);

  /** Bitmask that selects the low bits of metadata to get hashTableBits. */
  static final int HASH_TABLE_BITS_MASK = (1 << HASH_TABLE_BITS_MAX_BITS) - 1;

  /** Maximum size of a compact hash-based collection (2^30 - 1 because 0 is UNSET). */

   * of values that will be added, if that knowledge is readily available. It is better to guess a
   * value slightly too high than slightly too low. If the value is not exact, the {@link
   * ImmutableDoubleArray} that is built will very likely occupy more memory than strictly
   * necessary; to trim memory usage, build using {@code builder.build().trimmed()}.
   */

   * and because threads are typically not bound to CPUS forever,
   * may not occur at all. However, despite these limitations,
   * observed contention rates are typically low in these cases.
   *
   * It is possible for a Cell to become unused when threads that
   * once hashed to it terminate, as well as in the case where
   * doubling the table causes no thread to hash to it under

   * and because threads are typically not bound to CPUS forever,
   * may not occur at all. However, despite these limitations,
   * observed contention rates are typically low in these cases.
   *
   * It is possible for a Cell to become unused when threads that
   * once hashed to it terminate, as well as in the case where
   * doubling the table causes no thread to hash to it under

    boolean set(long bitIndex) {
      if (get(bitIndex)) {
        return false;
      }

      int longIndex = (int) (bitIndex >>> LONG_ADDRESSABLE_BITS);
      long mask = 1L << bitIndex; // only cares about low 6 bits of bitIndex

      long oldValue;
      long newValue;
      do {
        oldValue = data.get(longIndex);
        newValue = oldValue | mask;
        if (oldValue == newValue) {

    LoadingCache<?, ?> cache = CacheBuilder.newBuilder().initialCapacity(0).build(identityLoader());
    LocalCache<?, ?> map = CacheTesting.toLocalCache(cache);

    assertThat(map.segments).hasLength(4);
    // 1 is as low as it goes, not 0. it feels dirty to know this/test this.
    assertEquals(1, map.segments[0].table.length());
    assertEquals(1, map.segments[1].table.length());
    assertEquals(1, map.segments[2].table.length());

  /**
   * Contains the logical entries, in the range of [0, size()). The high bits of each int are the
   * part of the smeared hash of the element not covered by the hashtable mask, whereas the low bits
   * are the "next" pointer (pointing to the next entry in the bucket chain), which will always be
   * less than or equal to the hashtable mask.
   *
   * <pre>
   * hash  = aaaaaaaa
   * mask  = 00000fff

   * and because threads are typically not bound to CPUS forever,
   * may not occur at all. However, despite these limitations,
   * observed contention rates are typically low in these cases.
   *
   * It is possible for a Cell to become unused when threads that
   * once hashed to it terminate, as well as in the case where
   * doubling the table causes no thread to hash to it under