Package it.unimi.dsi.fastutil.doubles

Class Double2ReferenceArrayMap<V>

java.lang.Object
it.unimi.dsi.fastutil.doubles.AbstractDouble2ReferenceFunction<V>
it.unimi.dsi.fastutil.doubles.AbstractDouble2ReferenceMap<V>
it.unimi.dsi.fastutil.doubles.Double2ReferenceArrayMap<V>
All Implemented Interfaces:
it.unimi.dsi.fastutil.doubles.Double2ReferenceFunction<V>, Double2ReferenceMap<V>, it.unimi.dsi.fastutil.Function<java.lang.Double,​V>, java.io.Serializable, java.lang.Cloneable, java.util.function.DoubleFunction<V>, java.util.function.Function<java.lang.Double,​V>, java.util.Map<java.lang.Double,​V>
public class Double2ReferenceArrayMap<V>
extends AbstractDouble2ReferenceMap<V>
implements java.io.Serializable, java.lang.Cloneable
A simple, brute-force implementation of a map based on two parallel backing arrays.

The main purpose of this implementation is that of wrapping cleanly the brute-force approach to the storage of a very small number of pairs: just put them into two parallel arrays and scan linearly to find an item.

See Also:
Serialized Form

  • Constructor Details

    • Double2ReferenceArrayMap

      public Double2ReferenceArrayMap​(double[] key, java.lang.Object[] value)
      Creates a new empty array map with given key and value backing arrays. The resulting map will have as many entries as the given arrays.

      It is responsibility of the caller that the elements of key are distinct.

      Parameters:
      key - the key array.
      value - the value array (it must have the same length as key).

    • Double2ReferenceArrayMap

      public Double2ReferenceArrayMap()
      Creates a new empty array map.

    • Double2ReferenceArrayMap

      public Double2ReferenceArrayMap​(int capacity)
      Creates a new empty array map of given capacity.
      Parameters:
      capacity - the initial capacity.

    • Double2ReferenceArrayMap

      public Double2ReferenceArrayMap​(Double2ReferenceMap<V> m)
      Creates a new empty array map copying the entries of a given map.
      Parameters:
      m - a map.

    • Double2ReferenceArrayMap

      public Double2ReferenceArrayMap​(java.util.Map<? extends java.lang.Double,​? extends V> m)
      Creates a new empty array map copying the entries of a given map.
      Parameters:
      m - a map.

    • Double2ReferenceArrayMap

      public Double2ReferenceArrayMap​(double[] key, java.lang.Object[] value, int size)
      Creates a new array map with given key and value backing arrays, using the given number of elements.

      It is responsibility of the caller that the first size elements of key are distinct.

      Parameters:
      key - the key array.
      value - the value array (it must have the same length as key).
      size - the number of valid elements in key and value.

  • Method Details

    • double2ReferenceEntrySet

      public Double2ReferenceMap.FastEntrySet<V> double2ReferenceEntrySet()
      Description copied from interface: Double2ReferenceMap
      Returns a type-specific set view of the mappings contained in this map.

      This method is necessary because there is no inheritance along type parameters: it is thus impossible to strengthen Map.entrySet() so that it returns an ObjectSet of type-specific entries (the latter makes it possible to access keys and values with type-specific methods).

      Specified by:
      double2ReferenceEntrySet in interface Double2ReferenceMap<V>
      Returns:
      a type-specific set view of the mappings contained in this map.
      See Also:
      Map.entrySet()

    • get

      public V get​(double k)
      Specified by:
      get in interface it.unimi.dsi.fastutil.doubles.Double2ReferenceFunction<V>

    • size

      public int size()
      Description copied from interface: Double2ReferenceMap
      Returns the number of key/value mappings in this map. If the map contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.
      Specified by:
      size in interface Double2ReferenceMap<V>
      Specified by:
      size in interface it.unimi.dsi.fastutil.Function<java.lang.Double,​V>
      Specified by:
      size in interface java.util.Map<java.lang.Double,​V>
      Returns:
      the number of key-value mappings in this map.
      See Also:
      Size64

    • clear

      public void clear()
      Description copied from interface: Double2ReferenceMap
      Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.
      Specified by:
      clear in interface Double2ReferenceMap<V>
      Specified by:
      clear in interface it.unimi.dsi.fastutil.Function<java.lang.Double,​V>
      Specified by:
      clear in interface java.util.Map<java.lang.Double,​V>

    • containsKey

      public boolean containsKey​(double k)
      Description copied from class: AbstractDouble2ReferenceMap
      Returns true if this function contains a mapping for the specified key.
      Specified by:
      containsKey in interface it.unimi.dsi.fastutil.doubles.Double2ReferenceFunction<V>
      Specified by:
      containsKey in interface Double2ReferenceMap<V>
      Overrides:
      containsKey in class AbstractDouble2ReferenceMap<V>
      Parameters:
      k - the key.
      Returns:
      true if this function associates a value to key.
      See Also:
      Map.containsKey(Object)

    • containsValue

      public boolean containsValue​(java.lang.Object v)
      Description copied from class: AbstractDouble2ReferenceMap
      Specified by:
      containsValue in interface java.util.Map<java.lang.Double,​V>
      Overrides:
      containsValue in class AbstractDouble2ReferenceMap<V>

    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface java.util.Map<java.lang.Double,​V>
      Overrides:
      isEmpty in class AbstractDouble2ReferenceMap<V>

    • put

      public V put​(double k, V v)
      Specified by:
      put in interface it.unimi.dsi.fastutil.doubles.Double2ReferenceFunction<V>

    • remove

      public V remove​(double k)
      Specified by:
      remove in interface it.unimi.dsi.fastutil.doubles.Double2ReferenceFunction<V>

    • keySet

      public it.unimi.dsi.fastutil.doubles.DoubleSet keySet()
      Description copied from class: AbstractDouble2ReferenceMap
      Returns a type-specific-set view of the keys of this map.

      The view is backed by the set returned by Map.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient ad-hoc implementations.

      Specified by:
      keySet in interface Double2ReferenceMap<V>
      Specified by:
      keySet in interface java.util.Map<java.lang.Double,​V>
      Overrides:
      keySet in class AbstractDouble2ReferenceMap<V>
      Returns:
      a set view of the keys of this map; it may be safely cast to a type-specific interface.
      See Also:
      Map.keySet()

    • values

      public ReferenceCollection<V> values()
      Description copied from class: AbstractDouble2ReferenceMap
      Returns a type-specific-set view of the values of this map.

      The view is backed by the set returned by Map.entrySet(). Note that no attempt is made at caching the result of this method, as this would require adding some attributes that lightweight implementations would not need. Subclasses may easily override this policy by calling this method and caching the result, but implementors are encouraged to write more efficient ad-hoc implementations.

      Specified by:
      values in interface Double2ReferenceMap<V>
      Specified by:
      values in interface java.util.Map<java.lang.Double,​V>
      Overrides:
      values in class AbstractDouble2ReferenceMap<V>
      Returns:
      a set view of the values of this map; it may be safely cast to a type-specific interface.
      See Also:
      Map.values()

    • clone

      public Double2ReferenceArrayMap<V> clone()
      Returns a deep copy of this map.

      This method performs a deep copy of this hash map; the data stored in the map, however, is not cloned. Note that this makes a difference only for object keys.

      Returns:
      a deep copy of this map.