Class Object2LongArrayMap<K>

  • All Implemented Interfaces:
    Function<K,​java.lang.Long>, Object2LongFunction<K>, Object2LongMap<K>, java.io.Serializable, java.lang.Cloneable, java.util.function.Function<K,​java.lang.Long>, java.util.function.ToLongFunction<K>, java.util.Map<K,​java.lang.Long>

    public class Object2LongArrayMap<K>
    extends AbstractObject2LongMap<K>
    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 Detail

      • Object2LongArrayMap

        public Object2LongArrayMap​(java.lang.Object[] key,
                                   long[] 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).
      • Object2LongArrayMap

        public Object2LongArrayMap()
        Creates a new empty array map.
      • Object2LongArrayMap

        public Object2LongArrayMap​(int capacity)
        Creates a new empty array map of given capacity.
        Parameters:
        capacity - the initial capacity.
      • Object2LongArrayMap

        public Object2LongArrayMap​(Object2LongMap<K> m)
        Creates a new empty array map copying the entries of a given map.
        Parameters:
        m - a map.
      • Object2LongArrayMap

        public Object2LongArrayMap​(java.util.Map<? extends K,​? extends java.lang.Long> m)
        Creates a new empty array map copying the entries of a given map.
        Parameters:
        m - a map.
      • Object2LongArrayMap

        public Object2LongArrayMap​(java.lang.Object[] key,
                                   long[] 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 Detail

      • object2LongEntrySet

        public Object2LongMap.FastEntrySet<K> object2LongEntrySet()
        Description copied from interface: Object2LongMap
        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:
        object2LongEntrySet in interface Object2LongMap<K>
        Returns:
        a type-specific set view of the mappings contained in this map.
        See Also:
        Map.entrySet()
      • size

        public int size()
        Description copied from interface: Object2LongMap
        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 Function<K,​java.lang.Long>
        Specified by:
        size in interface java.util.Map<K,​java.lang.Long>
        Specified by:
        size in interface Object2LongMap<K>
        Returns:
        the number of key-value mappings in this map.
        See Also:
        Size64
      • clear

        public void clear()
        Description copied from interface: Object2LongMap
        Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.
        Specified by:
        clear in interface Function<K,​java.lang.Long>
        Specified by:
        clear in interface java.util.Map<K,​java.lang.Long>
        Specified by:
        clear in interface Object2LongMap<K>
        See Also:
        Map.clear()
      • containsKey

        public boolean containsKey​(java.lang.Object k)
        Description copied from interface: Object2LongMap
        Returns true if this function contains a mapping for the specified key.
        Specified by:
        containsKey in interface Function<K,​java.lang.Long>
        Specified by:
        containsKey in interface java.util.Map<K,​java.lang.Long>
        Specified by:
        containsKey in interface Object2LongMap<K>
        Overrides:
        containsKey in class AbstractObject2LongMap<K>
        Parameters:
        k - the key.
        Returns:
        true if this function associates a value to key.
        See Also:
        Map.containsKey(Object)
      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface java.util.Map<K,​java.lang.Long>
        Overrides:
        isEmpty in class AbstractObject2LongMap<K>
      • keySet

        public ObjectSet<K> keySet()
        Description copied from class: AbstractObject2LongMap
        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 java.util.Map<K,​java.lang.Long>
        Specified by:
        keySet in interface Object2LongMap<K>
        Overrides:
        keySet in class AbstractObject2LongMap<K>
        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 LongCollection values()
        Description copied from class: AbstractObject2LongMap
        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 java.util.Map<K,​java.lang.Long>
        Specified by:
        values in interface Object2LongMap<K>
        Overrides:
        values in class AbstractObject2LongMap<K>
        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 Object2LongArrayMap<K> 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.