import org.jspecify.annotations.Nullable;

/**
 * Helper classes and static methods for implementing compact hash-based collections.
 *
 * @author Jon Noack
 */
@GwtIncompatible
final class CompactHashing {
  private CompactHashing() {}

  /** Indicates blank table entries. */
  static final byte UNSET = 0;

  /** Number of bits used to store the numbers of hash table bits (max 30). */

import org.jspecify.annotations.Nullable;

/**
 * Helper classes and static methods for implementing compact hash-based collections.
 *
 * @author Jon Noack
 */
@GwtIncompatible
final class CompactHashing {
  private CompactHashing() {}

  /** Indicates blank table entries. */
  static final byte UNSET = 0;

  /** Number of bits used to store the numbers of hash table bits (max 30). */

        int hash = CompactHashing.getHashPrefix(oldEntry, oldMask) | oldTableIndex;

        int newTableIndex = hash & newMask;
        int newNext = CompactHashing.tableGet(newTable, newTableIndex);
        CompactHashing.tableSet(newTable, newTableIndex, oldNext);
        entries[entryIndex] = CompactHashing.maskCombine(hash, newNext, newMask);

        oldNext = CompactHashing.getNext(oldEntry, oldMask);
      }

        int hash = CompactHashing.getHashPrefix(oldEntry, oldMask) | oldTableIndex;

        int newTableIndex = hash & newMask;
        int newNext = CompactHashing.tableGet(newTable, newTableIndex);
        CompactHashing.tableSet(newTable, newTableIndex, oldNext);
        entries[entryIndex] = CompactHashing.maskCombine(hash, newNext, newMask);

        oldNext = CompactHashing.getNext(oldEntry, oldMask);
      }

    metadata =
        CompactHashing.maskCombine(metadata, hashTableBits, CompactHashing.HASH_TABLE_BITS_MASK);
  }

  /** Gets the hash table mask using the stored number of hash table bits. */
  private int hashTableMask() {
    return (1 << (metadata & CompactHashing.HASH_TABLE_BITS_MASK)) - 1;
  }

  void incrementModCount() {
    metadata += CompactHashing.MODIFICATION_COUNT_INCREMENT;
  }

    assertThat(set.elements).isNull();

    set.add(1);
    assertThat(set.needsAllocArrays()).isFalse();
    assertThat(set.elements).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {
    for (int i = 0; i <= CompactHashing.DEFAULT_SIZE; i++) {
      CompactHashSet<Integer> set = CompactHashSet.createWithExpectedSize(i);
      assertThat(set.needsAllocArrays()).isTrue();

    assertThat(set.elements).isNull();

    set.add(1);
    assertThat(set.needsAllocArrays()).isFalse();
    assertThat(set.elements).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {
    for (int i = 0; i <= CompactHashing.DEFAULT_SIZE; i++) {
      CompactHashSet<Integer> set = CompactHashSet.createWithExpectedSize(i);
      assertThat(set.needsAllocArrays()).isTrue();

    metadata =
        CompactHashing.maskCombine(metadata, hashTableBits, CompactHashing.HASH_TABLE_BITS_MASK);
  }

  /** Gets the hash table mask using the stored number of hash table bits. */
  private int hashTableMask() {
    return (1 << (metadata & CompactHashing.HASH_TABLE_BITS_MASK)) - 1;
  }

  void incrementModCount() {
    metadata += CompactHashing.MODIFICATION_COUNT_INCREMENT;
  }

    assertThat(map.entries).hasLength(CompactHashing.DEFAULT_SIZE);
    assertThat(map.keys).hasLength(CompactHashing.DEFAULT_SIZE);
    assertThat(map.values).hasLength(CompactHashing.DEFAULT_SIZE);
    assertThat(map.links).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {
    for (int i = 0; i <= CompactHashing.DEFAULT_SIZE; i++) {

    assertThat(map.needsAllocArrays()).isFalse();
    assertThat(map.entries).hasLength(CompactHashing.DEFAULT_SIZE);
    assertThat(map.keys).hasLength(CompactHashing.DEFAULT_SIZE);
    assertThat(map.values).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  public void testAllocArraysExpectedSize() {
    for (int i = 0; i <= CompactHashing.DEFAULT_SIZE; i++) {