Package it.unimi.dsi.fastutil.ints

Class Int2LongLinkedOpenHashMap

java.lang.Object
it.unimi.dsi.fastutil.ints.AbstractInt2LongFunction
it.unimi.dsi.fastutil.ints.AbstractInt2LongMap
it.unimi.dsi.fastutil.ints.AbstractInt2LongSortedMap
it.unimi.dsi.fastutil.ints.Int2LongLinkedOpenHashMap
All Implemented Interfaces:
Function<java.lang.Integer,​java.lang.Long>, Hash, Int2LongFunction, Int2LongMap, Int2LongSortedMap, java.io.Serializable, java.lang.Cloneable, java.util.function.Function<java.lang.Integer,​java.lang.Long>, java.util.function.IntToLongFunction, java.util.Map<java.lang.Integer,​java.lang.Long>, java.util.SortedMap<java.lang.Integer,​java.lang.Long>
public class Int2LongLinkedOpenHashMap
extends AbstractInt2LongSortedMap
implements java.io.Serializable, java.lang.Cloneable, Hash
A type-specific linked hash map with with a fast, small-footprint implementation.

Instances of this class use a hash table to represent a map. The table is filled up to a specified load factor, and then doubled in size to accommodate new entries. If the table is emptied below one fourth of the load factor, it is halved in size; however, the table is never reduced to a size smaller than that at creation time: this approach makes it possible to create maps with a large capacity in which insertions and deletions do not cause immediately rehashing. Moreover, halving is not performed when deleting entries from an iterator, as it would interfere with the iteration process.

Note that clear() does not modify the hash table size. Rather, a family of trimming methods lets you control the size of the table; this is particularly useful if you reuse instances of this class.

Entries returned by the type-specific Int2LongMap.entrySet() method implement the suitable type-specific Pair interface; only values are mutable.

Iterators generated by this map will enumerate pairs in the same order in which they have been added to the map (addition of pairs whose key is already present in the map does not change the iteration order). Note that this order has nothing in common with the natural order of the keys. The order is kept by means of a doubly linked list, represented via an array of longs parallel to the table.

This class implements the interface of a sorted map, so to allow easy access of the iteration order: for instance, you can get the first key in iteration order with firstKey() without having to create an iterator; however, this class partially violates the SortedMap contract because all submap methods throw an exception and comparator() returns always null.

Additional methods, such as getAndMoveToFirst(), make it easy to use instances of this class as a cache (e.g., with LRU policy).

The iterators provided by the views of this class using are type-specific list iterators, and can be started at any element which is a key of the map, or a NoSuchElementException exception will be thrown. If, however, the provided element is not the first or last key in the map, the first access to the list index will require linear time, as in the worst case the entire key set must be scanned in iteration order to retrieve the positional index of the starting key. If you use just the methods of a type-specific BidirectionalIterator, however, all operations will be performed in constant time.

See Also:
Hash, HashCommon, Serialized Form

  • Constructor Details

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(int expected, float f)
      Creates a new hash map.

      The actual table size will be the least power of two greater than expected/f.

      Parameters:
      expected - the expected number of elements in the hash map.
      f - the load factor.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(int expected)
      Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.
      Parameters:
      expected - the expected number of elements in the hash map.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap()
      Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(java.util.Map<? extends java.lang.Integer,​? extends java.lang.Long> m, float f)
      Creates a new hash map copying a given one.
      Parameters:
      m - a Map to be copied into the new hash map.
      f - the load factor.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(java.util.Map<? extends java.lang.Integer,​? extends java.lang.Long> m)
      Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.
      Parameters:
      m - a Map to be copied into the new hash map.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(Int2LongMap m, float f)
      Creates a new hash map copying a given type-specific one.
      Parameters:
      m - a type-specific map to be copied into the new hash map.
      f - the load factor.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(Int2LongMap m)
      Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.
      Parameters:
      m - a type-specific map to be copied into the new hash map.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(int[] k, long[] v, float f)
      Creates a new hash map using the elements of two parallel arrays.
      Parameters:
      k - the array of keys of the new hash map.
      v - the array of corresponding values in the new hash map.
      f - the load factor.
      Throws:
      java.lang.IllegalArgumentException - if k and v have different lengths.

    • Int2LongLinkedOpenHashMap

      public Int2LongLinkedOpenHashMap​(int[] k, long[] v)
      Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.
      Parameters:
      k - the array of keys of the new hash map.
      v - the array of corresponding values in the new hash map.
      Throws:
      java.lang.IllegalArgumentException - if k and v have different lengths.

  • Method Details

    • putAll

      public void putAll​(java.util.Map<? extends java.lang.Integer,​? extends java.lang.Long> m)
      Description copied from class: AbstractInt2LongMap
      Specified by:
      putAll in interface java.util.Map<java.lang.Integer,​java.lang.Long>
      Overrides:
      putAll in class AbstractInt2LongMap

    • put

      public long put​(int k, long v)
      Description copied from interface: Int2LongFunction
      Adds a pair to the map (optional operation).
      Specified by:
      put in interface Int2LongFunction
      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:
      Function.put(Object,Object)

    • addTo

      public long addTo​(int k, long incr)
      Adds an increment to value currently associated with a key.

      Note that this method respects the default return value semantics: when called with a key that does not currently appears in the map, the key will be associated with the default return value plus the given increment.

      Parameters:
      k - the key.
      incr - the increment.
      Returns:
      the old value, or the default return value if no value was present for the given key.

    • remove

      public long remove​(int k)
      Description copied from interface: Int2LongFunction
      Removes the mapping with the given key (optional operation).
      Specified by:
      remove in interface Int2LongFunction
      Parameters:
      k - the key.
      Returns:
      the old value, or the default return value if no value was present for the given key.
      See Also:
      Function.remove(Object)

    • removeFirstLong

      public long removeFirstLong()
      Removes the mapping associated with the first key in iteration order.
      Returns:
      the value previously associated with the first key in iteration order.
      Throws:
      java.util.NoSuchElementException - is this map is empty.

    • removeLastLong

      public long removeLastLong()
      Removes the mapping associated with the last key in iteration order.
      Returns:
      the value previously associated with the last key in iteration order.
      Throws:
      java.util.NoSuchElementException - is this map is empty.

    • getAndMoveToFirst

      public long getAndMoveToFirst​(int k)
      Returns the value to which the given key is mapped; if the key is present, it is moved to the first position of the iteration order.
      Parameters:
      k - the key.
      Returns:
      the corresponding value, or the default return value if no value was present for the given key.

    • getAndMoveToLast

      public long getAndMoveToLast​(int k)
      Returns the value to which the given key is mapped; if the key is present, it is moved to the last position of the iteration order.
      Parameters:
      k - the key.
      Returns:
      the corresponding value, or the default return value if no value was present for the given key.

    • putAndMoveToFirst

      public long putAndMoveToFirst​(int k, long v)
      Adds a pair to the map; if the key is already present, it is moved to the first position of the iteration order.
      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.

    • putAndMoveToLast

      public long putAndMoveToLast​(int k, long v)
      Adds a pair to the map; if the key is already present, it is moved to the last position of the iteration order.
      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.

    • get

      public long get​(int k)
      Description copied from interface: Int2LongFunction
      Returns the value to which the given key is mapped.
      Specified by:
      get in interface Int2LongFunction
      Parameters:
      k - the key.
      Returns:
      the corresponding value, or the default return value if no value was present for the given key.
      See Also:
      Function.get(Object)

    • containsKey

      public boolean containsKey​(int k)
      Description copied from class: AbstractInt2LongMap
      Returns true if this function contains a mapping for the specified key.
      Specified by:
      containsKey in interface Int2LongFunction
      Specified by:
      containsKey in interface Int2LongMap
      Overrides:
      containsKey in class AbstractInt2LongMap
      Parameters:
      k - the key.
      Returns:
      true if this function associates a value to key.
      See Also:
      Map.containsKey(Object)

    • containsValue

      public boolean containsValue​(long v)
      Description copied from class: AbstractInt2LongMap
      Returns true if this map maps one or more keys to the specified value.
      Specified by:
      containsValue in interface Int2LongMap
      Overrides:
      containsValue in class AbstractInt2LongMap
      See Also:
      Map.containsValue(Object)

    • getOrDefault

      public long getOrDefault​(int k, long defaultValue)
      Returns the value to which the specified key is mapped, or the defaultValue if this map contains no mapping for the key.
      Specified by:
      getOrDefault in interface Int2LongFunction
      Specified by:
      getOrDefault in interface Int2LongMap
      Parameters:
      k - the key.
      defaultValue - the default mapping of the key.
      Returns:
      the value to which the specified key is mapped, or the defaultValue if this map contains no mapping for the key.
      See Also:
      Map.getOrDefault(Object, Object)

    • putIfAbsent

      public long putIfAbsent​(int k, long v)
      If the specified key is not already associated with a value, associates it with the given value and returns the default return value, else returns the current value.
      Specified by:
      putIfAbsent in interface Int2LongMap
      Parameters:
      k - key with which the specified value is to be associated.
      v - value to be associated with the specified key.
      Returns:
      the previous value associated with the specified key, or the default return value if there was no mapping for the key.
      See Also:
      Map.putIfAbsent(Object, Object)

    • remove

      public boolean remove​(int k, long v)
      Removes the entry for the specified key only if it is currently mapped to the specified value.
      Specified by:
      remove in interface Int2LongMap
      Parameters:
      k - key with which the specified value is associated.
      v - value expected to be associated with the specified key.
      Returns:
      true if the value was removed.
      See Also:
      Map.remove(Object, Object)

    • replace

      public boolean replace​(int k, long oldValue, long v)
      Replaces the entry for the specified key only if currently mapped to the specified value.
      Specified by:
      replace in interface Int2LongMap
      Parameters:
      k - key with which the specified value is associated.
      oldValue - value expected to be associated with the specified key.
      v - value to be associated with the specified key.
      Returns:
      true if the value was replaced.
      See Also:
      Map.replace(Object, Object, Object)

    • replace

      public long replace​(int k, long v)
      Replaces the entry for the specified key only if it is currently mapped to some value.
      Specified by:
      replace in interface Int2LongMap
      Parameters:
      k - key with which the specified value is associated.
      v - value to be associated with the specified key.
      Returns:
      the previous value associated with the specified key, or the default return value if there was no mapping for the key.
      See Also:
      Map.replace(Object, Object)

    • computeIfAbsent

      public long computeIfAbsent​(int k, java.util.function.IntToLongFunction mappingFunction)
      If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map.

      Note that contrarily to the default computeIfAbsent(), it is not possible to not add a value for a given key, since the mappingFunction cannot return null. If such a behavior is needed, please use the corresponding nullable version.

      Specified by:
      computeIfAbsent in interface Int2LongMap
      Parameters:
      k - key with which the specified value is to be associated.
      mappingFunction - the function to compute a value.
      Returns:
      the current (existing or computed) value associated with the specified key.
      See Also:
      Map.computeIfAbsent(Object, java.util.function.Function)

    • computeIfAbsent

      public long computeIfAbsent​(int key, Int2LongFunction mappingFunction)
      If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map, unless the key is not present in the given mapping function.

      This version of computeIfAbsent() uses a type-specific version of fastutil's Function. Since Function has a containsKey() method, it is possible to avoid adding a key by having containsKey() return false for that key.

      Specified by:
      computeIfAbsent in interface Int2LongMap
      Parameters:
      key - key with which the specified value is to be associated.
      mappingFunction - the function to compute a value.
      Returns:
      the current (existing or computed) value associated with the specified key.
      See Also:
      Map.computeIfAbsent(Object, java.util.function.Function)

    • computeIfAbsentNullable

      public long computeIfAbsentNullable​(int k, java.util.function.IntFunction<? extends java.lang.Long> mappingFunction)
      If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map unless it is null.

      Note that this version of computeIfAbsent() should be used only if you plan to return null in the mapping function.

      Specified by:
      computeIfAbsentNullable in interface Int2LongMap
      Parameters:
      k - key with which the specified value is to be associated.
      mappingFunction - the function to compute a value.
      Returns:
      the current (existing or computed) value associated with the specified key, or the default return value if the computed value is null.
      See Also:
      Map.computeIfAbsent(Object, java.util.function.Function)

    • computeIfPresent

      public long computeIfPresent​(int k, java.util.function.BiFunction<? super java.lang.Integer,​? super java.lang.Long,​? extends java.lang.Long> remappingFunction)
      If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.
      Specified by:
      computeIfPresent in interface Int2LongMap
      Parameters:
      k - key with which the specified value is to be associated.
      remappingFunction - the function to compute a value.
      Returns:
      the new value associated with the specified key, or the default return value if none.
      See Also:
      Map.computeIfPresent(Object, java.util.function.BiFunction)

    • compute

      public long compute​(int k, java.util.function.BiFunction<? super java.lang.Integer,​? super java.lang.Long,​? extends java.lang.Long> remappingFunction)
      Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).

      If the function returns null, the mapping is removed (or remains absent if initially absent). If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.

      Specified by:
      compute in interface Int2LongMap
      Parameters:
      k - key with which the specified value is to be associated.
      remappingFunction - the function to compute a value.
      Returns:
      the new value associated with the specified key, or the default return value if none.
      See Also:
      Map.compute(Object, java.util.function.BiFunction)

    • merge

      public long merge​(int k, long v, java.util.function.BiFunction<? super java.lang.Long,​? super java.lang.Long,​? extends java.lang.Long> remappingFunction)
      If the specified key is not already associated with a value, associates it with the given value. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is null.
      Specified by:
      merge in interface Int2LongMap
      Parameters:
      k - key with which the resulting value is to be associated.
      v - the value to be merged with the existing value associated with the key or, if no existing value is associated with the key, to be associated with the key.
      remappingFunction - the function to recompute a value if present.
      Returns:
      the new value associated with the specified key, or the default return value if no value is associated with the key.
      See Also:
      Map.merge(Object, Object, java.util.function.BiFunction)

    • clear

      public void clear()
      Description copied from interface: Int2LongMap
      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<java.lang.Integer,​java.lang.Long>
      Specified by:
      clear in interface Int2LongMap
      Specified by:
      clear in interface java.util.Map<java.lang.Integer,​java.lang.Long>
      See Also:
      Map.clear()

    • size

      public int size()
      Description copied from interface: Int2LongMap
      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<java.lang.Integer,​java.lang.Long>
      Specified by:
      size in interface Int2LongMap
      Specified by:
      size in interface java.util.Map<java.lang.Integer,​java.lang.Long>
      Returns:
      the number of key-value mappings in this map.
      See Also:
      Size64

    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface java.util.Map<java.lang.Integer,​java.lang.Long>
      Overrides:
      isEmpty in class AbstractInt2LongMap

    • firstIntKey

      public int firstIntKey()
      Returns the first key of this map in iteration order.
      Specified by:
      firstIntKey in interface Int2LongSortedMap
      Returns:
      the first key in iteration order.
      See Also:
      SortedMap.firstKey()

    • lastIntKey

      public int lastIntKey()
      Returns the last key of this map in iteration order.
      Specified by:
      lastIntKey in interface Int2LongSortedMap
      Returns:
      the last key in iteration order.
      See Also:
      SortedMap.lastKey()

    • tailMap

      public Int2LongSortedMap tailMap​(int from)
      Returns a view of the portion of this sorted map whose keys are greater than or equal to fromKey.
      Specified by:
      tailMap in interface Int2LongSortedMap
      See Also:
      SortedMap.tailMap(Object)
      Implementation Specification:
      This implementation just throws an UnsupportedOperationException.

    • headMap

      public Int2LongSortedMap headMap​(int to)
      Returns a view of the portion of this sorted map whose keys are strictly less than toKey.
      Specified by:
      headMap in interface Int2LongSortedMap
      See Also:
      SortedMap.headMap(Object)
      Implementation Specification:
      This implementation just throws an UnsupportedOperationException.

    • subMap

      public Int2LongSortedMap subMap​(int from, int to)
      Returns a view of the portion of this sorted map whose keys range from fromKey, inclusive, to toKey, exclusive.
      Specified by:
      subMap in interface Int2LongSortedMap
      See Also:
      SortedMap.subMap(Object,Object)
      Implementation Specification:
      This implementation just throws an UnsupportedOperationException.

    • comparator

      public IntComparator comparator()
      Returns the comparator associated with this sorted set, or null if it uses its keys' natural ordering.
      Specified by:
      comparator in interface Int2LongSortedMap
      Specified by:
      comparator in interface java.util.SortedMap<java.lang.Integer,​java.lang.Long>
      See Also:
      SortedMap.comparator()
      Implementation Specification:
      This implementation just returns null.

    • int2LongEntrySet

      public Int2LongSortedMap.FastSortedEntrySet int2LongEntrySet()
      Description copied from interface: Int2LongSortedMap
      Returns a type-specific sorted-set view of the mappings contained in this map.
      Specified by:
      int2LongEntrySet in interface Int2LongMap
      Specified by:
      int2LongEntrySet in interface Int2LongSortedMap
      Returns:
      a type-specific sorted-set view of the mappings contained in this map.
      See Also:
      Int2LongSortedMap.entrySet()

    • keySet

      public IntSortedSet keySet()
      Description copied from class: AbstractInt2LongSortedMap
      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.

      The view is backed by the sorted 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 Int2LongMap
      Specified by:
      keySet in interface Int2LongSortedMap
      Specified by:
      keySet in interface java.util.Map<java.lang.Integer,​java.lang.Long>
      Specified by:
      keySet in interface java.util.SortedMap<java.lang.Integer,​java.lang.Long>
      Overrides:
      keySet in class AbstractInt2LongSortedMap
      Returns:
      a sorted 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: AbstractInt2LongSortedMap
      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.

      The view is backed by the sorted 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 Int2LongMap
      Specified by:
      values in interface Int2LongSortedMap
      Specified by:
      values in interface java.util.Map<java.lang.Integer,​java.lang.Long>
      Specified by:
      values in interface java.util.SortedMap<java.lang.Integer,​java.lang.Long>
      Overrides:
      values in class AbstractInt2LongSortedMap
      Returns:
      a type-specific collection view of the values contained in this map.
      See Also:
      Map.values()

    • trim

      public boolean trim()
      Rehashes the map, making the table as small as possible.

      This method rehashes the table to the smallest size satisfying the load factor. It can be used when the set will not be changed anymore, so to optimize access speed and size.

      If the table size is already the minimum possible, this method does nothing.

      Returns:
      true if there was enough memory to trim the map.
      See Also:
      trim(int)

    • trim

      public boolean trim​(int n)
      Rehashes this map if the table is too large.

      Let N be the smallest table size that can hold max(n,size()) entries, still satisfying the load factor. If the current table size is smaller than or equal to N, this method does nothing. Otherwise, it rehashes this map in a table of size N.

      This method is useful when reusing maps. Clearing a map leaves the table size untouched. If you are reusing a map many times, you can call this method with a typical size to avoid keeping around a very large table just because of a few large transient maps.

      Parameters:
      n - the threshold for the trimming.
      Returns:
      true if there was enough memory to trim the map.
      See Also:
      trim()

    • clone

      public Int2LongLinkedOpenHashMap 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.

    • hashCode

      public int hashCode()
      Returns a hash code for this map. This method overrides the generic method provided by the superclass. Since equals() is not overriden, it is important that the value returned by this method is the same value as the one returned by the overriden method.
      Specified by:
      hashCode in interface java.util.Map<java.lang.Integer,​java.lang.Long>
      Overrides:
      hashCode in class AbstractInt2LongMap
      Returns:
      a hash code for this map.