Class ShortDoubleHashMap

java.lang.Object
com.carrotsearch.hppc.ShortDoubleHashMap
All Implemented Interfaces:
Preallocable, ShortDoubleAssociativeContainer, ShortDoubleMap, Cloneable, Iterable<ShortDoubleCursor>
Direct Known Subclasses:
ShortDoubleScatterMap

@Generated(date="2024-05-16T08:18:11+0000", value="KTypeVTypeHashMap.java") public class ShortDoubleHashMap extends Object implements ShortDoubleMap, Preallocable, Cloneable
A hash map of short to double, implemented using open addressing with linear probing for collision resolution.

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

See Also:
  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    private final class 
    An iterator implementation for iterator().
    final class 
    A view of the keys inside this hash map.
    private final class 
    An iterator over the set of assigned keys.
    private final class 
    A view over the set of values of this map.
    private final class 
    An iterator over the set of assigned values.
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected int
    The number of stored keys (assigned key slots), excluding the special "empty" key, if any (use size() instead).
    protected boolean
    Special treatment for the "empty slot" key marker.
    protected int
    We perturb hash values with a container-unique seed to avoid problems with nearly-sorted-by-hash values on iterations.
    short[]
    The array holding keys.
    protected double
    The load factor for keys.
    protected int
    Mask for slot scans in keys.
    Per-instance hash order mixing strategy.
    protected int
    Expand (rehash) keys when assigned hits this value.
    double[]
    The array holding values.
  • Constructor Summary

    Constructors
    Constructor
    Description
    New instance with sane defaults.
    ShortDoubleHashMap(int expectedElements)
    New instance with sane defaults.
    ShortDoubleHashMap(int expectedElements, double loadFactor)
    New instance with sane defaults.
    ShortDoubleHashMap(int expectedElements, double loadFactor, HashOrderMixingStrategy orderMixer)
    New instance with the provided defaults.
    Create a hash map from all key-value pairs of another container.
  • Method Summary

    Modifier and Type
    Method
    Description
    double
    addTo(short key, double incrementValue)
    Adds incrementValue to any existing value for the given key or inserts incrementValue if key did not previously exist.
    protected void
    allocateBuffers(int arraySize)
    Allocate new internal buffers.
    protected void
    allocateThenInsertThenRehash(int slot, short pendingKey, double pendingValue)
    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.
    void
    Clear all keys and values in the container.
    boolean
    containsKey(short key)
    Returns true if this container has an association to a value for the given key.
    void
    ensureCapacity(int expectedElements)
    Ensure this container can hold at least the given number of keys (entries) without resizing its buffers.
    protected boolean
    Return true if all keys of some other container exist in this container.
    boolean
    Compares the specified object with this set for equality.
    forEach(T procedure)
    Applies a given procedure to all keys-value pairs in this container.
    from(short[] keys, double[] values)
    Creates a hash map from two index-aligned arrays of key-value pairs.
    double
    get(short key)
    double
    getOrDefault(short key, double defaultValue)
    int
    protected int
    hashKey(short key)
    Returns a hash code for the given key.
    boolean
    indexExists(int index)
    double
    indexGet(int index)
    Returns the value associated with an existing key.
    void
    indexInsert(int index, short key, double value)
    Inserts a key-value pair for a key that is not present in the map.
    int
    indexOf(short key)
    Returns a logical "index" of a given key that can be used to speed up follow-up value setters or getters in certain scenarios (conditional logic).
    double
    indexReplace(int index, double newValue)
    Replaces the value associated with an existing key and returns any previous value stored for that key.
    boolean
    Returns a cursor over the entries (key-value pairs) in this map.
    Returns a specialized view of the keys of this associated container.
    double
    put(short key, double value)
    Place a given key and value in the container.
    int
    Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.
    int
    putAll(Iterable<? extends ShortDoubleCursor> iterable)
    Puts all key/value pairs from a given iterable into this map.
    boolean
    putIfAbsent(short key, double value)
    Trove-inspired API method.
    double
    putOrAdd(short key, double putValue, double incrementValue)
    If key exists, putValue is inserted into the map, otherwise any existing value is incremented by additionValue.
    protected void
    rehash(short[] fromKeys, double[] fromValues)
    Rehash from old buffers to new buffers.
    void
    Removes all elements from the collection and additionally releases any internal buffers.
    double
    remove(short key)
    Remove all values at the given key.
    int
    Removes all keys (and associated values) for which the predicate returns true.
    int
    Removes all keys (and associated values) for which the predicate returns true.
    int
    Removes all keys (and associated values) present in a given container.
    protected void
    shiftConflictingKeys(int gapSlot)
    Shift all the slot-conflicting keys and values allocated to (and including) slot.
    int
    Convert the contents of this map to a human-friendly string.
    Returns a container view of all values present in this container.
    protected double
    verifyLoadFactor(double loadFactor)
    Validate load factor range and return it.
    visualizeKeyDistribution(int characters)
    Visually depict the distribution of keys.

    Methods inherited from class java.lang.Object

    finalize, getClass, notify, notifyAll, wait, wait, wait

    Methods inherited from interface java.lang.Iterable

    forEach, spliterator
  • Field Details

    • keys

      public short[] keys
      The array holding keys.
    • values

      public double[] values
      The array holding values.
    • keyMixer

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

      protected int assigned
      The number of stored keys (assigned key slots), excluding the special "empty" key, if any (use size() instead).
      See Also:
    • mask

      protected int mask
      Mask for slot scans in keys.
    • resizeAt

      protected int resizeAt
      Expand (rehash) keys when assigned hits this value.
    • hasEmptyKey

      protected boolean hasEmptyKey
      Special treatment for the "empty slot" key marker.
    • loadFactor

      protected double loadFactor
      The load factor for keys.
    • orderMixer

      protected HashOrderMixingStrategy orderMixer
      Per-instance hash order mixing strategy.
      See Also:
  • Constructor Details

    • ShortDoubleHashMap

      public ShortDoubleHashMap()
      New instance with sane defaults.
    • ShortDoubleHashMap

      public ShortDoubleHashMap(int expectedElements)
      New instance with sane defaults.
      Parameters:
      expectedElements - The expected number of elements guaranteed not to cause buffer expansion (inclusive).
    • ShortDoubleHashMap

      public ShortDoubleHashMap(int expectedElements, double loadFactor)
      New instance with sane defaults.
      Parameters:
      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).
    • ShortDoubleHashMap

      public ShortDoubleHashMap(int expectedElements, double loadFactor, HashOrderMixingStrategy orderMixer)
      New instance with the provided defaults.
      Parameters:
      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.
    • ShortDoubleHashMap

      public ShortDoubleHashMap(ShortDoubleAssociativeContainer container)
      Create a hash map from all key-value pairs of another container.
  • Method Details

    • put

      public double put(short key, double value)
      Place a given key and value in the container.
      Specified by:
      put in interface ShortDoubleMap
      Returns:
      The value previously stored under the given key in the map is returned.
    • putAll

      public int putAll(ShortDoubleAssociativeContainer container)
      Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.
      Specified by:
      putAll in interface ShortDoubleMap
      Returns:
      Returns the number of keys added to the map as a result of this call (not previously present in the map). Values of existing keys are overwritten.
    • putAll

      public int putAll(Iterable<? extends ShortDoubleCursor> iterable)
      Puts all key/value pairs from a given iterable into this map.
      Specified by:
      putAll in interface ShortDoubleMap
      Returns:
      Returns the number of keys added to the map as a result of this call (not previously present in the map). Values of existing keys are overwritten.
    • putIfAbsent

      public boolean putIfAbsent(short key, double value)
      Trove-inspired API method. An equivalent of the following code:
       if (!map.containsKey(key)) map.put(value);
       
      Parameters:
      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.
    • putOrAdd

      public double putOrAdd(short key, double putValue, double incrementValue)
      If key exists, putValue is inserted into the map, otherwise any existing value is incremented by additionValue.
      Specified by:
      putOrAdd in interface ShortDoubleMap
      Parameters:
      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).
    • addTo

      public double addTo(short key, double incrementValue)
      Adds incrementValue to any existing value for the given key or inserts incrementValue if key did not previously exist.
      Specified by:
      addTo in interface ShortDoubleMap
      Parameters:
      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).
    • remove

      public double remove(short key)
      Remove all values at the given key. The default value for the key type is returned if the value does not exist in the map.
      Specified by:
      remove in interface ShortDoubleMap
    • removeAll

      public int removeAll(ShortContainer other)
      Removes all keys (and associated values) present in a given container. An alias to:
       keys().removeAll(container)
       
      but with no additional overhead.
      Specified by:
      removeAll in interface ShortDoubleAssociativeContainer
      Returns:
      Returns the number of elements actually removed as a result of this call.
    • removeAll

      public int removeAll(ShortDoublePredicate predicate)
      Removes all keys (and associated values) for which the predicate returns true.
      Specified by:
      removeAll in interface ShortDoubleAssociativeContainer
      Returns:
      Returns the number of elements actually removed as a result of this call.
    • removeAll

      public int removeAll(ShortPredicate predicate)
      Removes all keys (and associated values) for which the predicate returns true.
      Specified by:
      removeAll in interface ShortDoubleAssociativeContainer
      Returns:
      Returns the number of elements actually removed as a result of this call.
    • get

      public double get(short key)
      Specified by:
      get in interface ShortDoubleMap
      Returns:
      Returns the value associated with the given key or the default value for the key type, if the key is not associated with any value. Important note: For primitive type values, the value returned for a non-existing key may not be the default value of the primitive type (it may be any value previously assigned to that slot).
    • getOrDefault

      public double getOrDefault(short key, double defaultValue)
      Specified by:
      getOrDefault in interface ShortDoubleMap
      Returns:
      Returns the value associated with the given key or the provided default value if the key is not associated with any value.
    • containsKey

      public boolean containsKey(short key)
      Returns true if this container has an association to a value for the given key.
      Specified by:
      containsKey in interface ShortDoubleAssociativeContainer
    • indexOf

      public int indexOf(short key)
      Returns a logical "index" of a given key that can be used to speed up follow-up value setters or getters in certain scenarios (conditional logic). The semantics of "indexes" are not strictly defined. Indexes may (and typically won't be) contiguous. The index is valid only between map modifications (it will not be affected by read-only operations like iteration or value retrievals).
      Specified by:
      indexOf in interface ShortDoubleMap
      Parameters:
      key - The key to locate in the map.
      Returns:
      A non-negative value of the logical "index" of the key in the map or a negative value if the key did not exist.
      See Also:
    • indexExists

      public boolean indexExists(int index)
      Specified by:
      indexExists in interface ShortDoubleMap
      Parameters:
      index - The index of a given key, as returned from ShortDoubleMap.indexOf(short).
      Returns:
      Returns true if the index corresponds to an existing key or false otherwise. This is equivalent to checking whether the index is a positive value (existing keys) or a negative value (non-existing keys).
      See Also:
    • indexGet

      public double indexGet(int index)
      Returns the value associated with an existing key.
      Specified by:
      indexGet in interface ShortDoubleMap
      Parameters:
      index - The index of an existing key.
      Returns:
      Returns the value currently associated with the key.
      See Also:
    • indexReplace

      public double indexReplace(int index, double newValue)
      Replaces the value associated with an existing key and returns any previous value stored for that key.
      Specified by:
      indexReplace in interface ShortDoubleMap
      Parameters:
      index - The index of an existing key.
      Returns:
      Returns the previous value associated with the key.
      See Also:
    • indexInsert

      public void indexInsert(int index, short key, double value)
      Inserts a key-value pair for a key that is not present in the map. This method may help in avoiding double recalculation of the key's hash.
      Specified by:
      indexInsert in interface ShortDoubleMap
      Parameters:
      index - The index of a previously non-existing key, as returned from ShortDoubleMap.indexOf(short).
      See Also:
    • clear

      public void clear()
      Clear all keys and values in the container.
      Specified by:
      clear in interface ShortDoubleMap
      See Also:
    • release

      public void release()
      Removes all elements from the collection and additionally releases any internal buffers. Typically, if the object is to be reused, a simple ShortDoubleMap.clear() should be a better alternative since it'll avoid reallocation.
      Specified by:
      release in interface ShortDoubleMap
      See Also:
    • size

      public int size()
      Specified by:
      size in interface ShortDoubleAssociativeContainer
      Returns:
      Returns the current size (number of assigned keys) in the container.
    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface ShortDoubleAssociativeContainer
      Returns:
      Return true if this hash map contains no assigned keys.
    • hashCode

      public int hashCode()
      Specified by:
      hashCode in interface ShortDoubleMap
      Overrides:
      hashCode in class Object
      Returns:
      A hash code of elements stored in the map. The hash code is defined as a sum of hash codes of keys and values stored within the set). Because sum is commutative, this ensures that different order of elements in a set does not affect the hash code.
    • equals

      public boolean equals(Object obj)
      Compares the specified object with this set for equality. Returns true if and only if the specified object is also a ShortDoubleMap and both objects contains exactly the same key-value pairs.
      Specified by:
      equals in interface ShortDoubleMap
      Overrides:
      equals in class Object
    • equalElements

      protected boolean equalElements(ShortDoubleHashMap other)
      Return true if all keys of some other container exist in this container.
    • ensureCapacity

      public void ensureCapacity(int expectedElements)
      Ensure this container can hold at least the given number of keys (entries) without resizing its buffers.
      Specified by:
      ensureCapacity in interface Preallocable
      Parameters:
      expectedElements - The total number of keys, inclusive.
    • iterator

      public Iterator<ShortDoubleCursor> iterator()
      Returns a cursor over the entries (key-value pairs) in this map. The iterator is implemented as a cursor and it returns the same cursor instance on every call to Iterator.next(). To read the current key and value use the cursor's public fields. An example is shown below.
       for (IntShortCursor c : intShortMap) {
         System.out.println("index=" + c.index + " key=" + c.key + " value=" + c.value);
       }

      The index field inside the cursor gives the internal index inside the container's implementation. The interpretation of this index depends on to the container.

      Specified by:
      iterator in interface Iterable<ShortDoubleCursor>
      Specified by:
      iterator in interface ShortDoubleAssociativeContainer
    • forEach

      public <T extends ShortDoubleProcedure> T forEach(T procedure)
      Applies a given procedure to all keys-value pairs in this container. Returns the argument (any subclass of ShortDoubleProcedure. This lets the caller to call methods of the argument by chaining the call (even if the argument is an anonymous type) to retrieve computed values, for example.
      Specified by:
      forEach in interface ShortDoubleAssociativeContainer
    • forEach

      public <T extends ShortDoublePredicate> T forEach(T predicate)
      Applies a given predicate to all keys-value pairs in this container. Returns the argument (any subclass of ShortDoublePredicate. This lets the caller to call methods of the argument by chaining the call (even if the argument is an anonymous type) to retrieve computed values, for example. The iteration is continued as long as the predicate returns true.
      Specified by:
      forEach in interface ShortDoubleAssociativeContainer
    • keys

      Returns a specialized view of the keys of this associated container. The view additionally implements ObjectLookupContainer.
      Specified by:
      keys in interface ShortDoubleAssociativeContainer
    • values

      public DoubleCollection values()
      Description copied from interface: ShortDoubleAssociativeContainer
      Returns a container view of all values present in this container. The returned collection is a view over the key set and any modifications (if allowed) introduced to the collection will propagate to the associative container immediately.
      Specified by:
      values in interface ShortDoubleAssociativeContainer
      Returns:
      Returns a container with all values stored in this map.
    • clone

      public ShortDoubleHashMap clone()
      Overrides:
      clone in class Object
    • toString

      public String toString()
      Convert the contents of this map to a human-friendly string.
      Overrides:
      toString in class Object
    • visualizeKeyDistribution

      public String visualizeKeyDistribution(int characters)
      Description copied from interface: ShortDoubleMap
      Visually depict the distribution of keys.
      Specified by:
      visualizeKeyDistribution in interface ShortDoubleMap
      Parameters:
      characters - The number of characters to "squeeze" the entire buffer into.
      Returns:
      Returns a sequence of characters where '.' depicts an empty fragment of the internal buffer and 'X' depicts full or nearly full capacity within the buffer's range and anything between 1 and 9 is between.
    • from

      public static ShortDoubleHashMap from(short[] keys, double[] values)
      Creates a hash map from two index-aligned arrays of key-value pairs.
    • hashKey

      protected int hashKey(short key)
      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.

    • verifyLoadFactor

      protected double verifyLoadFactor(double loadFactor)
      Validate load factor range and return it. Override and suppress if you need insane load factors.
    • rehash

      protected void rehash(short[] fromKeys, double[] fromValues)
      Rehash from old buffers to new buffers.
    • allocateBuffers

      protected void allocateBuffers(int arraySize)
      Allocate new internal buffers. This method attempts to allocate and assign internal buffers atomically (either allocations succeed or not).
    • allocateThenInsertThenRehash

      protected void allocateThenInsertThenRehash(int slot, short pendingKey, double pendingValue)
      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.
    • shiftConflictingKeys

      protected void shiftConflictingKeys(int gapSlot)
      Shift all the slot-conflicting keys and values allocated to (and including) slot.