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High Performance Primitive Collections: data structures (maps, sets, lists, stacks, queues) generated for combinations of object and primitive types to conserve JVM memory and speed up execution.

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package com.carrotsearch.hppc;

/*  */
import com.carrotsearch.hppc.cursors.*;
/*  */

import static com.carrotsearch.hppc.Containers.*;
import static com.carrotsearch.hppc.HashContainers.*;

/**
 * An identity hash map of Object to Object.
 */
 @com.carrotsearch.hppc.Generated(
    date = "2021-06-08T13:12:54+0200",
    value = "KTypeVTypeIdentityHashMap.java") 
public class ObjectObjectIdentityHashMap 
  extends ObjectObjectHashMap
{
  /**
   * New instance with sane defaults.
   */
  public ObjectObjectIdentityHashMap() {
    this(DEFAULT_EXPECTED_ELEMENTS);
  }

  /**
   * New instance with sane defaults.
   * @param expectedElements
   *          The expected number of elements guaranteed not to cause buffer
   *          expansion (inclusive).
   */
  public ObjectObjectIdentityHashMap(int expectedElements) {
    this(expectedElements, DEFAULT_LOAD_FACTOR);
  }

  /**
   * New instance with the provided defaults.
   * 
   * @param expectedElements
   *          The expected number of elements guaranteed not to cause a rehash (inclusive).
   * @param loadFactor
   *          The load factor for internal buffers. Insane load factors (zero, full capacity)
   *          are rejected by {@link #verifyLoadFactor(double)}.
   */
  public ObjectObjectIdentityHashMap(int expectedElements, double loadFactor) {
    super(expectedElements, loadFactor);
  }

  /**
   * Create a hash map from all key-value pairs of another container.
   */
  public ObjectObjectIdentityHashMap(ObjectObjectAssociativeContainer container) {
    this(container.size());
    putAll(container);
  }

  @Override
  public int hashKey(KType key) {
    assert !((key) == null); // Handled as a special case (empty slot marker).
    return BitMixer.mixPhi(System.identityHashCode(key));
  }

  @Override
  public boolean equals(Object v1, Object v2) {
    return v1 == v2;
  }

    @SuppressWarnings("unchecked")  
  /*  */
  @Override
  protected boolean equalElements(ObjectObjectHashMap other) {
    if (other.size() != size()) {
      return false;
    }

    for (ObjectObjectCursor c : other) {
      KType key = (KType) c.key;
      if (!containsKey(key) ||
              !equals(c.value, get(key))) {   // Compare values using the same function as keys.
        return false;
      }
    }

    return true;
  }
  /*  */

  /**
   * Creates a hash map from two index-aligned arrays of key-value pairs.
   */
  public static  ObjectObjectIdentityHashMap from(KType[] keys, VType[] values) {
    if (keys.length != values.length) {
      throw new IllegalArgumentException("Arrays of keys and values must have an identical length.");
    }

    ObjectObjectIdentityHashMap map = new ObjectObjectIdentityHashMap<>(keys.length);
    for (int i = 0; i < keys.length; i++) {
      map.put(keys[i], values[i]);
    }

    return map;
  }  
}