http://labs.carrotsearch.com/hppc.html/hppc: High Performance Primitive Collections. Fundamental data structures (maps, sets, lists, stacks, queues) generated for combinations of object and primitive types to conserve JVM memory and speed up execution. (Carrot Search s.c.)
  • Dawid Weiss
  • Stanisław Osiński 
  
package com.carrotsearch.hppc;

import java.util.*;

import com.carrotsearch.hppc.cursors.*;
import com.carrotsearch.hppc.predicates.*;
import com.carrotsearch.hppc.procedures.*;

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


A hash map of int to short, implemented using open
addressing with linear probing for collision resolution.

Note: read about important differences 
between hash and scatter sets.


See Also:
/**
 * A hash map of <code>int</code> to <code>short</code>, implemented using open
 * addressing with linear probing for collision resolution.
 * 
 * <p><strong>Note:</strong> read about <a href="{@docRoot}/overview-summary.html#scattervshash">important differences 
 * between hash and scatter sets</a>.</p>
 * 
 * @see IntShortScatterMap
 * @see <a href="{@docRoot}/overview-summary.html#interfaces">HPPC interfaces diagram</a> 
 */
  
 @com.carrotsearch.hppc.Generated(
    date = "2018-05-21T12:24:06+0200",
    value = "KTypeVTypeHashMap.java") 
public class IntShortHashMap
  implements   
               
             IntShortMap,
             Preallocable,
             Cloneable
{
  
The array holding keys.

/** 
   * The array holding keys.
   */
  public   int []   
         keys;

  
The array holding values. 

/**
   * The array holding values. 
   */
  public   short []   
         values;

  
We perturb hash values with a container-unique
seed to avoid problems with nearly-sorted-by-hash 
values on iterations.

See Also:
  • hashKey
  • http://issues.carrot2.org/browse/HPPC-80
  • http://issues.carrot2.org/browse/HPPC-103
/**
   * We perturb hash values with a container-unique
   * seed to avoid problems with nearly-sorted-by-hash 
   * values on iterations.
   * 
   * @see #hashKey
   * @see "http://issues.carrot2.org/browse/HPPC-80"
   * @see "http://issues.carrot2.org/browse/HPPC-103"
   */
  protected int keyMixer;

  
The number of stored keys (assigned key slots), excluding the special "empty" key, if any (use size() instead). 
See Also:
/**
   * The number of stored keys (assigned key slots), excluding the special 
   * "empty" key, if any (use {@link #size()} instead).
   * 
   * @see #size()
   */
  protected int assigned;

  
Mask for slot scans in keys. 
/**
   * Mask for slot scans in {@link #keys}.
   */
  protected int mask;

  
Expand (rehash) keys when assigned hits this value. 
/**
   * Expand (rehash) {@link #keys} when {@link #assigned} hits this value. 
   */
  protected int resizeAt;

  
Special treatment for the "empty slot" key marker.

/**
   * Special treatment for the "empty slot" key marker.
   */
  protected boolean hasEmptyKey;
  
  
The load factor for keys. 
/**
   * The load factor for {@link #keys}.
   */
  protected double loadFactor;

  
Per-instance hash order mixing strategy.

See Also:
  • keyMixer
/**
   * Per-instance hash order mixing strategy.
   * @see #keyMixer
   */
  protected HashOrderMixingStrategy orderMixer;

  
New instance with sane defaults.

/**
   * New instance with sane defaults.
   */
  public IntShortHashMap() {
    this(DEFAULT_EXPECTED_ELEMENTS);
  }

  
New instance with sane defaults.

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

  
New instance with sane defaults.

Params:
  • expectedElements – 
         The expected number of elements guaranteed not to cause buffer
         expansion (inclusive).
  • loadFactor –  The load factor for internal buffers. Insane load factors (zero, full capacity) are rejected by verifyLoadFactor(double).
/**
   * New instance with sane defaults.
   * 
   * @param expectedElements
   *          The expected number of elements guaranteed not to cause buffer
   *          expansion (inclusive).
   * @param loadFactor
   *          The load factor for internal buffers. Insane load factors (zero, full capacity)
   *          are rejected by {@link #verifyLoadFactor(double)}.
   */
  public IntShortHashMap(int expectedElements, double loadFactor) {
    this(expectedElements, loadFactor, HashOrderMixing.defaultStrategy());
  }

  
New instance with the provided defaults.

Params:
  • expectedElements – 
         The expected number of elements guaranteed not to cause a rehash (inclusive).
  • loadFactor –  The load factor for internal buffers. Insane load factors (zero, full capacity) are rejected by verifyLoadFactor(double).
  • orderMixer –  Hash key order mixing strategy. See HashOrderMixing for predefined implementations. Use constant mixers only if you understand the potential consequences.
/**
   * 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)}.
   * @param orderMixer
   *          Hash key order mixing strategy. See {@link HashOrderMixing} for predefined
   *          implementations. Use constant mixers only if you understand the potential
   *          consequences.
   */
  public IntShortHashMap(int expectedElements, double loadFactor, HashOrderMixingStrategy orderMixer) {
    this.orderMixer = orderMixer;
    this.loadFactor = verifyLoadFactor(loadFactor);
    ensureCapacity(expectedElements);
  }

  
Create a hash map from all key-value pairs of another container.

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

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public short put(int key, short value) {
    assert assigned < mask + 1;

    final int mask = this.mask;
    if (((key) == 0)) {
      hasEmptyKey = true;
      short previousValue =  values[mask + 1];
      values[mask + 1] = value;
      return previousValue;
    } else {
      final int[] keys =  this.keys;
      int slot = hashKey(key) & mask;

      int existing;
      while (!((existing = keys[slot]) == 0)) {
        if (((existing) == ( key))) {
          final short previousValue =  values[slot];
          values[slot] = value;
          return previousValue;
        }
        slot = (slot + 1) & mask;
      }

      if (assigned == resizeAt) {
        allocateThenInsertThenRehash(slot, key, value);
      } else {
        keys[slot] = key;
        values[slot] = value;
      }

      assigned++;
      return ((short) 0);
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public int putAll(IntShortAssociativeContainer container) {
    final int count = size();
    for (IntShortCursor c : container) {
      put(c.key, c.value);
    }
    return size() - count;
  }

  
Puts all key/value pairs from a given iterable into this map.

/**
   * Puts all key/value pairs from a given iterable into this map.
   */
  @Override
  public int putAll(Iterable<? extends IntShortCursor> iterable){
    final int count = size();
    for (IntShortCursor c : iterable) {
      put(c.key, c.value);
    }
    return size() - count;
  }

  
Trove-inspired API method. An equivalent
of the following code:

if (!map.containsKey(key)) map.put(value);



Params:
  • key – The key of the value to check.
  • value – The value to put if key does not exist.
Returns:true if key did not exist and value
was placed in the map.
/**
   * <a href="http://trove4j.sourceforge.net">Trove</a>-inspired API method. An equivalent
   * of the following code:
   * <pre>
   * if (!map.containsKey(key)) map.put(value);
   * </pre>
   * 
   * @param key The key of the value to check.
   * @param value The value to put if <code>key</code> does not exist.
   * @return <code>true</code> if <code>key</code> did not exist and <code>value</code>
   * was placed in the map.
   */
  public boolean putIfAbsent(int key, short value) {
    int keyIndex = indexOf(key);
    if (!indexExists(keyIndex)) {
      indexInsert(keyIndex, key, value);
      return true;
    } else {
      return false;
    }
  }

    
  
If key exists, putValue is inserted into the map,
otherwise any existing value is incremented by additionValue.

Params:
  • key – 
         The key of the value to adjust.
  • putValue – 
         The value to put if key does not exist.
  • incrementValue – 
         The value to add to the existing value if key exists.
Returns:Returns the current value associated with key (after
        changes).
/**
   * If <code>key</code> exists, <code>putValue</code> is inserted into the map,
   * otherwise any existing value is incremented by <code>additionValue</code>.
   * 
   * @param key
   *          The key of the value to adjust.
   * @param putValue
   *          The value to put if <code>key</code> does not exist.
   * @param incrementValue
   *          The value to add to the existing value if <code>key</code> exists.
   * @return Returns the current value associated with <code>key</code> (after
   *         changes).
   */
  @Override
  public short putOrAdd(int key, short putValue, short incrementValue) {
    assert assigned < mask + 1;

    int keyIndex = indexOf(key);
    if (indexExists(keyIndex)) {
      putValue = ((short) (( values[keyIndex]) + (incrementValue)));
      indexReplace(keyIndex, putValue);
    } else {
      indexInsert(keyIndex, key, putValue);
    }
    return putValue;
  }
    

     
  
Adds incrementValue to any existing value for the given key
or inserts incrementValue if key did not previously exist.

Params:
  • key – The key of the value to adjust.
  • incrementValue – The value to put or add to the existing value if key exists.
Returns:Returns the current value associated with key (after changes).
/**
   * Adds <code>incrementValue</code> to any existing value for the given <code>key</code>
   * or inserts <code>incrementValue</code> if <code>key</code> did not previously exist.
   * 
   * @param key The key of the value to adjust.
   * @param incrementValue The value to put or add to the existing value if <code>key</code> exists.
   * @return Returns the current value associated with <code>key</code> (after changes).
   */
  @Override
  public short addTo(int key, short incrementValue)
  {
    return putOrAdd(key, incrementValue, incrementValue);
  }
    

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public short remove(int key) {
    final int mask = this.mask;
    if (((key) == 0)) {
      hasEmptyKey = false;
      short previousValue =  values[mask + 1];
      values[mask + 1] = ((short) 0);
      return previousValue;
    } else {
      final int[] keys =  this.keys;
      int slot = hashKey(key) & mask;

      int existing;
      while (!((existing = keys[slot]) == 0)) {
        if (((existing) == ( key))) {
          final short previousValue =  values[slot];
          shiftConflictingKeys(slot);
          return previousValue;
        }
        slot = (slot + 1) & mask;
      }

      return ((short) 0);
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public int removeAll(IntContainer other) {
    final int before = size();

    // Try to iterate over the smaller set of values or
    // over the container that isn't implementing 
    // efficient contains() lookup.

    if (other.size() >= size() &&
        other instanceof IntLookupContainer) {
      if (hasEmptyKey) {
        if (other.contains(0)) {
          hasEmptyKey = false;
          values[mask + 1] = ((short) 0);
        }
      }

      final int[] keys =  this.keys;
      for (int slot = 0, max = this.mask; slot <= max;) {
        int existing;
        if (!((existing = keys[slot]) == 0) && other.contains(existing)) {
          // Shift, do not increment slot.
          shiftConflictingKeys(slot);
        } else {
          slot++;
        }
      }
    } else {
      for (IntCursor c : other) {
        this.remove( c.value);
      }
    }

    return before - size();
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public int removeAll(IntShortPredicate predicate) {
    final int before = size();

    final int mask = this.mask;

    if (hasEmptyKey) {
      if (predicate.apply(0,  values[mask + 1])) {
        hasEmptyKey = false;
        values[mask + 1] = ((short) 0);
      }
    }

    final int[] keys =  this.keys;
    final short[] values =  this.values;
    for (int slot = 0; slot <= mask;) {
      int existing;
      if (!((existing = keys[slot]) == 0) && 
          predicate.apply(existing, values[slot])) {
        // Shift, do not increment slot.
        shiftConflictingKeys(slot);
      } else {
        slot++;
      }
    }

    return before - size();    
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public int removeAll(IntPredicate predicate) {
    final int before = size();

    if (hasEmptyKey) {
      if (predicate.apply(0)) {
        hasEmptyKey = false;
        values[mask + 1] = ((short) 0);
      }
    }

    final int[] keys =  this.keys;
    for (int slot = 0, max = this.mask; slot <= max;) {
      int existing;
      if (!((existing = keys[slot]) == 0) &&
          predicate.apply(existing)) {
        // Shift, do not increment slot.
        shiftConflictingKeys(slot);
      } else {
        slot++;
      }
    }

    return before - size();
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public short get(int key) {
    if (((key) == 0)) {
      return hasEmptyKey ?  values[mask + 1] : ((short) 0);
    } else {
      final int[] keys =  this.keys;
      final int mask = this.mask;
      int slot = hashKey(key) & mask;

      int existing;
      while (!((existing = keys[slot]) == 0)) {
        if (((existing) == ( key))) {
          return  values[slot];
        }
        slot = (slot + 1) & mask;
      }

      return ((short) 0);
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public short getOrDefault(int key, short defaultValue) {
    if (((key) == 0)) {
      return hasEmptyKey ?  values[mask + 1] : defaultValue;
    } else {
      final int[] keys =  this.keys;
      final int mask = this.mask;
      int slot = hashKey(key) & mask;

      int existing;
      while (!((existing = keys[slot]) == 0)) {
        if (((existing) == ( key))) {
          return  values[slot];
        }
        slot = (slot + 1) & mask;
      }

      return defaultValue;
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public boolean containsKey(int key) {
    if (((key) == 0)) {
      return hasEmptyKey;
    } else {
      final int[] keys =  this.keys;
      final int mask = this.mask;
      int slot = hashKey(key) & mask;

      int existing;
      while (!((existing = keys[slot]) == 0)) {
        if (((existing) == ( key))) {
          return true;
        }
        slot = (slot + 1) & mask;
      }    

      return false;
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public int indexOf(int key) {
    final int mask = this.mask;
    if (((key) == 0)) {
      return hasEmptyKey ? mask + 1 : ~(mask + 1);
    } else {
      final int[] keys =  this.keys;
      int slot = hashKey(key) & mask;

      int existing;
      while (!((existing = keys[slot]) == 0)) {
        if (((existing) == ( key))) {
          return slot;
        }
        slot = (slot + 1) & mask;
      }

      return ~slot;
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public boolean indexExists(int index) {
    assert index < 0 || 
           (index >= 0 && index <= mask) ||
           (index == mask + 1 && hasEmptyKey);

    return index >= 0; 
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public short indexGet(int index) {
    assert index >= 0 : "The index must point at an existing key.";
    assert index <= mask ||
           (index == mask + 1 && hasEmptyKey);

    return  values[index];
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public short indexReplace(int index, short newValue) {
    assert index >= 0 : "The index must point at an existing key.";
    assert index <= mask ||
           (index == mask + 1 && hasEmptyKey);

    short previousValue =  values[index];
    values[index] = newValue;
    return previousValue;
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public void indexInsert(int index, int key, short value) {
    assert index < 0 : "The index must not point at an existing key.";

    index = ~index;
    if (((key) == 0)) {
      assert index == mask + 1;
      values[index] = value;
      hasEmptyKey = true;
    } else {
      assert ((keys[index]) == 0);

      if (assigned == resizeAt) {
        allocateThenInsertThenRehash(index, key, value);
      } else {
        keys[index] = key;
        values[index] = value;
      }

      assigned++;
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public void clear() {
    assigned = 0;
    hasEmptyKey = false;

    Arrays.fill(keys, 0);

    /*  */
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public void release() {
    assigned = 0;
    hasEmptyKey = false;

    keys = null;
    values = null;
    ensureCapacity(Containers.DEFAULT_EXPECTED_ELEMENTS);
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public int size() {
    return assigned + (hasEmptyKey ? 1 : 0);
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  public boolean isEmpty() {
    return size() == 0;
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public int hashCode() {
    int h = hasEmptyKey ? 0xDEADBEEF : 0;
    for (IntShortCursor c : this) {
      h += BitMixer.mix(c.key) +
           BitMixer.mix(c.value);
    }
    return h;
  }

  
{@inheritDoc} 

/**
   * {@inheritDoc} 
   */
  @Override
  public boolean equals(Object obj) {
    return obj != null &&
           getClass() == obj.getClass() &&
           equalElements(getClass().cast(obj));
  }

  
Return true if all keys of some other container exist in this container.

/**
   * Return true if all keys of some other container exist in this container.
   */
  protected boolean equalElements(IntShortHashMap other) {
    if (other.size() != size()) {
      return false;
    }

    for (IntShortCursor c : other) {
      int key =  c.key;
      if (!containsKey(key) ||
          !((get(key)) == (c.value))) {
        return false;
      }
    }

    return true;
  }

  
Ensure this container can hold at least the
given number of keys (entries) without resizing its buffers.

Params:
  • expectedElements – The total number of keys, inclusive.
/**
   * Ensure this container can hold at least the
   * given number of keys (entries) without resizing its buffers.
   * 
   * @param expectedElements The total number of keys, inclusive.
   */
  @Override
  public void ensureCapacity(int expectedElements) {
    if (expectedElements > resizeAt || keys == null) {
      final int[] prevKeys =  this.keys;
      final short[] prevValues =  this.values;
      allocateBuffers(minBufferSize(expectedElements, loadFactor));
      if (prevKeys != null && !isEmpty()) {
        rehash(prevKeys, prevValues);
      }
    }
  }

  
An iterator implementation for IntShortHashMap.iterator. 
/**
   * An iterator implementation for {@link #iterator}.
   */
  private final class EntryIterator extends AbstractIterator<IntShortCursor> {
    private final IntShortCursor cursor;
    private final int max = mask + 1;
    private int slot = -1;

    public EntryIterator() {
      cursor = new IntShortCursor();
    }

    @Override
    protected IntShortCursor fetch() {
      if (slot < max) {
        int existing;
        for (slot++; slot < max; slot++) {
          if (!((existing =  keys[slot]) == 0)) {
            cursor.index = slot;
            cursor.key = existing;
            cursor.value =  values[slot];
            return cursor;
          }
        }
      }

      if (slot == max && hasEmptyKey) {
        cursor.index = slot;
        cursor.key = 0;
        cursor.value =  values[max];
        slot++;
        return cursor;
      }

      return done();
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public Iterator<IntShortCursor> iterator() {
      return new EntryIterator();
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public <T extends IntShortProcedure> T forEach(T procedure) {
    final int[] keys =  this.keys;
    final short[] values =  this.values;

    if (hasEmptyKey) {
      procedure.apply(0,  values[mask + 1]);
    }

    for (int slot = 0, max = this.mask; slot <= max; slot++) {
      if (!((keys[slot]) == 0)) {
        procedure.apply(keys[slot], values[slot]);
      }
    }

    return procedure;
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public <T extends IntShortPredicate> T forEach(T predicate) {
    final int[] keys =  this.keys;
    final short[] values =  this.values;

    if (hasEmptyKey) {
      if (!predicate.apply(0,  values[mask + 1])) {
        return predicate;
      }
    }

    for (int slot = 0, max = this.mask; slot <= max; slot++) {
      if (!((keys[slot]) == 0)) {
        if (!predicate.apply(keys[slot], values[slot])) {
          break;
        }
      }
    }

    return predicate;
  }

  
Returns a specialized view of the keys of this associated container. The view additionally implements ObjectLookupContainer. 
/**
   * Returns a specialized view of the keys of this associated container. The
   * view additionally implements {@link ObjectLookupContainer}.
   */
  public KeysContainer keys() {
    return new KeysContainer();
  }

  
A view of the keys inside this hash map.

/**
   * A view of the keys inside this hash map.
   */
  public final class KeysContainer extends AbstractIntCollection 
                                   implements IntLookupContainer {
    private final IntShortHashMap owner = IntShortHashMap.this;

    @Override
    public boolean contains(int e) {
      return owner.containsKey(e);
    }

    @Override
    public <T extends IntProcedure> T forEach(final T procedure) {
      owner.forEach(new IntShortProcedure() {
        @Override
        public void apply(int key, short value) {
          procedure.apply(key);
        }
      });

      return procedure;
    }

    @Override
    public <T extends IntPredicate> T forEach(final T predicate) {
      owner.forEach(new IntShortPredicate() {
        @Override
        public boolean apply(int key, short value) {
          return predicate.apply(key);
        }
      });

      return predicate;
    }

    @Override
    public boolean isEmpty() {
      return owner.isEmpty();
    }

    @Override
    public Iterator<IntCursor> iterator() {
      return new KeysIterator();
    }

    @Override
    public int size() {
      return owner.size();
    }

    @Override
    public void clear() {
      owner.clear();
    }
    
    @Override
    public void release() {
      owner.release();
    }

    @Override
    public int removeAll(IntPredicate predicate) {
      return owner.removeAll(predicate);
    }

    @Override
    public int removeAll(final int e) {
      final boolean hasKey = owner.containsKey(e);
      if (hasKey) {
        owner.remove(e);
        return 1;
      } else {
        return 0;
      }
    }
  };

  
An iterator over the set of assigned keys.

/**
   * An iterator over the set of assigned keys.
   */
  private final class KeysIterator extends AbstractIterator<IntCursor> {
    private final IntCursor cursor;
    private final int max = mask + 1;
    private int slot = -1;

    public KeysIterator() {
      cursor = new IntCursor();
    }

    @Override
    protected IntCursor fetch() {
      if (slot < max) {
        int existing;
        for (slot++; slot < max; slot++) {
          if (!((existing =  keys[slot]) == 0)) {
            cursor.index = slot;
            cursor.value = existing;
            return cursor;
          }
        }
      }

      if (slot == max && hasEmptyKey) {
        cursor.index = slot;
        cursor.value = 0;
        slot++;
        return cursor;
      }

      return done();
    }
  }

  
Returns:Returns a container with all values stored in this map.
/**
   * @return Returns a container with all values stored in this map.
   */
  @Override
  public ShortCollection values() {
    return new ValuesContainer();
  }

  
A view over the set of values of this map.

/**
   * A view over the set of values of this map.
   */
  private final class ValuesContainer extends AbstractShortCollection {
    private final IntShortHashMap owner = IntShortHashMap.this;

    @Override
    public int size() {
      return owner.size();
    }

    @Override
    public boolean isEmpty() {
      return owner.isEmpty();
    }

    @Override
    public boolean contains(short value) {
      for (IntShortCursor c : owner) {
        if (((c.value) == (value))) {
          return true;
        }
      }
      return false;
    }

    @Override
    public <T extends ShortProcedure> T forEach(T procedure) {
      for (IntShortCursor c : owner) {
        procedure.apply(c.value);
      }
      return procedure;
    }

    @Override
    public <T extends ShortPredicate> T forEach(T predicate) {
      for (IntShortCursor c : owner) {
        if (!predicate.apply(c.value)) {
          break;
        }
      }
      return predicate;
    }

    @Override
    public Iterator<ShortCursor> iterator() {
      return new ValuesIterator();
    }

    @Override
    public int removeAll(final short e) {
      return owner.removeAll(new IntShortPredicate() {
        @Override
        public boolean apply(int key, short value) {
          return ((value) == (e));
        }
      });
    }

    @Override
    public int removeAll(final ShortPredicate predicate) {
      return owner.removeAll(new IntShortPredicate() {
        @Override
        public boolean apply(int key, short value) {
          return predicate.apply(value);
        }
      });
    }

    @Override
    public void clear() {
      owner.clear();
    }
    
    @Override
    public void release() {
      owner.release();
    }
  }
  
  
An iterator over the set of assigned values.

/**
   * An iterator over the set of assigned values.
   */
  private final class ValuesIterator extends AbstractIterator<ShortCursor> {
    private final ShortCursor cursor;
    private final int max = mask + 1;
    private int slot = -1;

    public ValuesIterator() {
      cursor = new ShortCursor();
    }

    @Override
    protected ShortCursor fetch() {
      if (slot < max) {
        for (slot++; slot < max; slot++) {
          if (!(( keys[slot]) == 0)) {
            cursor.index = slot;
            cursor.value =  values[slot];
            return cursor;
          }
        }
      }

      if (slot == max && hasEmptyKey) {
        cursor.index = slot;
        cursor.value =  values[max];
        slot++;
        return cursor;
      }

      return done();
    }
  }

  
{@inheritDoc}

/**
   * {@inheritDoc}
   */
  @Override
  public IntShortHashMap clone() {
    try {
      /*  */
      IntShortHashMap cloned = (IntShortHashMap) super.clone();
      cloned.keys = keys.clone();
      cloned.values = values.clone();
      cloned.hasEmptyKey = cloned.hasEmptyKey;
      cloned.orderMixer = orderMixer.clone();
      return cloned;
    } catch (CloneNotSupportedException e) {
      throw new RuntimeException(e);
    }
  }

  
Convert the contents of this map to a human-friendly string.

/**
   * Convert the contents of this map to a human-friendly string.
   */
  @Override
  public String toString() {
    final StringBuilder buffer = new StringBuilder();
    buffer.append("[");

    boolean first = true;
    for (IntShortCursor cursor : this) {
      if (!first) {
        buffer.append(", ");
      }
      buffer.append(cursor.key);
      buffer.append("=>");
      buffer.append(cursor.value);
      first = false;
    }
    buffer.append("]");
    return buffer.toString();
  }

  @Override
  public String visualizeKeyDistribution(int characters) {
    return IntBufferVisualizer.visualizeKeyDistribution(keys, mask, characters);
  }

  
Creates a hash map from two index-aligned arrays of key-value pairs.

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

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

    return map;
  }
    
  
Returns a hash code for the given key.

The default implementation mixes the hash of the key with keyMixer to differentiate hash order of keys between hash containers. Helps alleviate problems resulting from linear conflict resolution in open addressing.


The output from this function should evenly distribute keys across the
entire integer range.


/**
   * Returns a hash code for the given key.
   * 
   * <p>The default implementation mixes the hash of the key with {@link #keyMixer}
   * to differentiate hash order of keys between hash containers. Helps
   * alleviate problems resulting from linear conflict resolution in open
   * addressing.</p>
   * 
   * <p>The output from this function should evenly distribute keys across the
   * entire integer range.</p>
   */
    protected  
  int hashKey(int key) {
    assert !((key) == 0); // Handled as a special case (empty slot marker).
    return BitMixer.mix(key, this.keyMixer);
  }

  
Validate load factor range and return it. Override and suppress if you need
insane load factors.

/**
   * Validate load factor range and return it. Override and suppress if you need
   * insane load factors.
   */
  protected double verifyLoadFactor(double loadFactor) {
    checkLoadFactor(loadFactor, MIN_LOAD_FACTOR, MAX_LOAD_FACTOR);
    return loadFactor;
  }

  
Rehash from old buffers to new buffers. 

/**
   * Rehash from old buffers to new buffers. 
   */
  protected void rehash(int[] fromKeys, short[] fromValues) {
    assert fromKeys.length == fromValues.length &&
           HashContainers.checkPowerOfTwo(fromKeys.length - 1);
    
    // Rehash all stored key/value pairs into the new buffers.
    final int[] keys =  this.keys;
    final short[] values =  this.values;
    final int mask = this.mask;
    int existing;

    // Copy the zero element's slot, then rehash everything else.
    int from = fromKeys.length - 1;
    keys[keys.length - 1] = fromKeys[from];
    values[values.length - 1] = fromValues[from];
    while (--from >= 0) {
      if (!((existing = fromKeys[from]) == 0)) {
        int slot = hashKey(existing) & mask;
        while (!((keys[slot]) == 0)) {
          slot = (slot + 1) & mask;
        }
        keys[slot] = existing;
        values[slot] = fromValues[from];
      }
    }
  }

  
Allocate new internal buffers. This method attempts to allocate
and assign internal buffers atomically (either allocations succeed or not).

/**
   * Allocate new internal buffers. This method attempts to allocate
   * and assign internal buffers atomically (either allocations succeed or not).
   */
  protected void allocateBuffers(int arraySize) {
    assert Integer.bitCount(arraySize) == 1;

    // Compute new hash mixer candidate before expanding.
    final int newKeyMixer = this.orderMixer.newKeyMixer(arraySize);

    // Ensure no change is done if we hit an OOM.
    int[] prevKeys =  this.keys;
    short[] prevValues =  this.values;
    try {
      int emptyElementSlot = 1;
      this.keys = (new int [arraySize + emptyElementSlot]);
      this.values = (new short [arraySize + emptyElementSlot]);
    } catch (OutOfMemoryError e) {
      this.keys = prevKeys;
      this.values = prevValues;
      throw new BufferAllocationException(
          "Not enough memory to allocate buffers for rehashing: %,d -> %,d", 
          e,
          this.mask + 1, 
          arraySize);
    }

    this.resizeAt = expandAtCount(arraySize, loadFactor);
    this.keyMixer = newKeyMixer;
    this.mask = arraySize - 1;
  }

  
This method is invoked when there is a new key/ value pair to be inserted into
the buffers but there is not enough empty slots to do so.
New buffers are allocated. If this succeeds, we know we can proceed
with rehashing so we assign the pending element to the previous buffer
(possibly violating the invariant of having at least one empty slot)
and rehash all keys, substituting new buffers at the end.  

/**
   * This method is invoked when there is a new key/ value pair to be inserted into
   * the buffers but there is not enough empty slots to do so.
   * 
   * New buffers are allocated. If this succeeds, we know we can proceed
   * with rehashing so we assign the pending element to the previous buffer
   * (possibly violating the invariant of having at least one empty slot)
   * and rehash all keys, substituting new buffers at the end.  
   */
  protected void allocateThenInsertThenRehash(int slot, int pendingKey, short pendingValue) {
    assert assigned == resizeAt
           && (( keys[slot]) == 0)
           && !((pendingKey) == 0);

    // Try to allocate new buffers first. If we OOM, we leave in a consistent state.
    final int[] prevKeys =  this.keys;
    final short[] prevValues =  this.values;
    allocateBuffers(nextBufferSize(mask + 1, size(), loadFactor));
    assert this.keys.length > prevKeys.length;

    // We have succeeded at allocating new data so insert the pending key/value at
    // the free slot in the old arrays before rehashing.
    prevKeys[slot] = pendingKey;
    prevValues[slot] = pendingValue;

    // Rehash old keys, including the pending key.
    rehash(prevKeys, prevValues);
  }
  
  
Shift all the slot-conflicting keys and values allocated to 
(and including) slot.

/**
   * Shift all the slot-conflicting keys and values allocated to 
   * (and including) <code>slot</code>.
   */
  protected void shiftConflictingKeys(int gapSlot) {
    final int[] keys =  this.keys;
    final short[] values =  this.values;
    final int mask = this.mask;

    // Perform shifts of conflicting keys to fill in the gap.
    int distance = 0;
    while (true) {
      final int slot = (gapSlot + (++distance)) & mask;
      final int existing = keys[slot];
      if (((existing) == 0)) {
        break;
      }

      final int idealSlot = hashKey(existing);
      final int shift = (slot - idealSlot) & mask;
      if (shift >= distance) {
        // Entry at this position was originally at or before the gap slot.
        // Move the conflict-shifted entry to the gap's position and repeat the procedure
        // for any entries to the right of the current position, treating it
        // as the new gap.
        keys[gapSlot] = existing;
        values[gapSlot] = values[slot]; 
        gapSlot = slot;
        distance = 0;
      }
    }

    // Mark the last found gap slot without a conflict as empty.
    keys[gapSlot] = 0;
    values[gapSlot] = ((short) 0);
    assigned--;
  }

        
}