Class Long2LongArrayMap

All Implemented Interfaces:
Function<Long,Long>, Long2LongFunction, Long2LongMap, Serializable, Cloneable, Function<Long,Long>, LongUnaryOperator, Map<Long,Long>

public class Long2LongArrayMap extends AbstractLong2LongMap implements Serializable, 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:
  • Constructor Details

    • Long2LongArrayMap

      public Long2LongArrayMap(long[] 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).
    • Long2LongArrayMap

      public Long2LongArrayMap()
      Creates a new empty array map.
    • Long2LongArrayMap

      public Long2LongArrayMap(int capacity)
      Creates a new empty array map of given capacity.
      Parameters:
      capacity - the initial capacity.
    • Long2LongArrayMap

      public Long2LongArrayMap(Long2LongMap m)
      Creates a new empty array map copying the entries of a given map.
      Parameters:
      m - a map.
    • Long2LongArrayMap

      public Long2LongArrayMap(Map<? extends Long,? extends Long> m)
      Creates a new empty array map copying the entries of a given map.
      Parameters:
      m - a map.
    • Long2LongArrayMap

      public Long2LongArrayMap(long[] 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 Details

    • long2LongEntrySet

      public Long2LongMap.FastEntrySet long2LongEntrySet()
      Description copied from interface: Long2LongMap
      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:
      long2LongEntrySet in interface Long2LongMap
      Returns:
      a type-specific set view of the mappings contained in this map.
      See Also:
    • get

      public long get(long k)
      Description copied from interface: Long2LongFunction
      Returns the value to which the given key is mapped.
      Specified by:
      get in interface Long2LongFunction
      Parameters:
      k - the key.
      Returns:
      the corresponding value, or the default return value if no value was present for the given key.
      See Also:
    • size

      public int size()
      Description copied from interface: Long2LongMap
      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<Long,Long>
      Specified by:
      size in interface Long2LongMap
      Specified by:
      size in interface Map<Long,Long>
      Returns:
      the number of key-value mappings in this map.
      See Also:
    • clear

      public void clear()
      Description copied from interface: Long2LongMap
      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<Long,Long>
      Specified by:
      clear in interface Long2LongMap
      Specified by:
      clear in interface Map<Long,Long>
      See Also:
    • containsKey

      public boolean containsKey(long k)
      Description copied from class: AbstractLong2LongMap
      Returns true if this function contains a mapping for the specified key.
      Specified by:
      containsKey in interface Long2LongFunction
      Specified by:
      containsKey in interface Long2LongMap
      Overrides:
      containsKey in class AbstractLong2LongMap
      Parameters:
      k - the key.
      Returns:
      true if this function associates a value to key.
      See Also:
    • containsValue

      public boolean containsValue(long v)
      Description copied from class: AbstractLong2LongMap
      Returns true if this map maps one or more keys to the specified value.
      Specified by:
      containsValue in interface Long2LongMap
      Overrides:
      containsValue in class AbstractLong2LongMap
      See Also:
    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface Map<Long,Long>
      Overrides:
      isEmpty in class AbstractLong2LongMap
    • put

      public long put(long k, long v)
      Description copied from interface: Long2LongFunction
      Adds a pair to the map (optional operation).
      Specified by:
      put in interface Long2LongFunction
      Parameters:
      k - the key.
      v - the value.
      Returns:
      the old value, or the default return value if no value was present for the given key.
      See Also:
    • remove

      public long remove(long k)
      Description copied from interface: Long2LongFunction
      Removes the mapping with the given key (optional operation).
      Specified by:
      remove in interface Long2LongFunction
      Parameters:
      k - the key.
      Returns:
      the old value, or the default return value if no value was present for the given key.
      See Also:
    • keySet

      public LongSet keySet()
      Description copied from class: AbstractLong2LongMap
      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 Long2LongMap
      Specified by:
      keySet in interface Map<Long,Long>
      Overrides:
      keySet in class AbstractLong2LongMap
      Returns:
      a set view of the keys of this map; it may be safely cast to a type-specific interface.
      See Also:
    • values

      public LongCollection values()
      Description copied from class: AbstractLong2LongMap
      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 Long2LongMap
      Specified by:
      values in interface Map<Long,Long>
      Overrides:
      values in class AbstractLong2LongMap
      Returns:
      a set view of the values of this map; it may be safely cast to a type-specific interface.
      See Also:
    • clone

      public Long2LongArrayMap 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.