it.unimi.dsi.fastutil.ints

Class Int2IntLinkedOpenHashMap

java.lang.Object

it.unimi.dsi.fastutil.ints.AbstractInt2IntFunction

it.unimi.dsi.fastutil.ints.AbstractInt2IntMap

it.unimi.dsi.fastutil.ints.AbstractInt2IntSortedMap

it.unimi.dsi.fastutil.ints.Int2IntLinkedOpenHashMap

All Implemented Interfaces:

Function<Integer,Integer>, Hash, Int2IntFunction, Int2IntMap, Int2IntSortedMap, Serializable, Cloneable, Map<Integer,Integer>, SortedMap<Integer,Integer>

public class Int2IntLinkedOpenHashMap
extends AbstractInt2IntSortedMap
implements Serializable, 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 enlarged as needed by doubling its size when new entries are created, but it is never made smaller (even on a clear()). A family of trimming methods lets you control the size of the table; this is particularly useful if you reuse instances of this class.

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 set 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 AbstractInt2IntSortedMap.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 set, 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

Nested Class Summary

Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.ints.AbstractInt2IntSortedMap

AbstractInt2IntSortedMap.KeySetIterator, AbstractInt2IntSortedMap.ValuesCollection, AbstractInt2IntSortedMap.ValuesIterator

Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.ints.AbstractInt2IntMap

AbstractInt2IntMap.BasicEntry

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.Hash

Hash.Strategy<K>

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.ints.Int2IntSortedMap

Int2IntSortedMap.FastSortedEntrySet

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.ints.Int2IntMap

Int2IntMap.Entry, Int2IntMap.FastEntrySet

Field Summary

Fields

Modifier and Type	Field and Description
protected Int2IntSortedMap.FastSortedEntrySet	entries Cached set of entries.
protected float	f The acceptable load factor.
protected int	first The index of the first entry in iteration order.
protected int[]	key The array of keys.
protected IntSortedSet	keys Cached set of keys.
protected int	last The index of the last entry in iteration order.
protected long[]	link For each entry, the next and the previous entry in iteration order, stored as ((prev & 0xFFFFFFFFL) << 32) | (next & 0xFFFFFFFFL).
protected int	mask The mask for wrapping a position counter.
protected int	maxFill Threshold after which we rehash.
protected int	n The current table size.
static long	serialVersionUID
protected int	size Number of entries in the set.
protected boolean[]	used The array telling whether a position is used.
protected int[]	value The array of values.
protected IntCollection	values Cached collection of values.

Fields inherited from class it.unimi.dsi.fastutil.ints.AbstractInt2IntFunction

defRetValue

Fields inherited from interface it.unimi.dsi.fastutil.Hash

DEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR

Constructor Summary

Constructors

Constructor and Description
Int2IntLinkedOpenHashMap() Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.
Int2IntLinkedOpenHashMap(int expected) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.
Int2IntLinkedOpenHashMap(int[] k, int[] v) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.
Int2IntLinkedOpenHashMap(int[] k, int[] v, float f) Creates a new hash map using the elements of two parallel arrays.
Int2IntLinkedOpenHashMap(Int2IntMap m) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.
Int2IntLinkedOpenHashMap(Int2IntMap m, float f) Creates a new hash map copying a given type-specific one.
Int2IntLinkedOpenHashMap(int expected, float f) Creates a new hash map.
Int2IntLinkedOpenHashMap(Map<? extends Integer,? extends Integer> m) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.
Int2IntLinkedOpenHashMap(Map<? extends Integer,? extends Integer> m, float f) Creates a new hash map copying a given one.

Method Summary

Methods

Modifier and Type	Method and Description
int	add(int k, int incr) Adds an increment to value currently associated with a key.
void	clear() Removes all associations from this function (optional operation).
Int2IntLinkedOpenHashMap	clone() Returns a deep copy of this map.
IntComparator	comparator() Returns the comparator associated with this sorted set, or null if it uses its keys' natural ordering.
boolean	containsKey(int k) Checks whether the given value is contained in AbstractInt2IntMap.keySet().
boolean	containsValue(int v) Checks whether the given value is contained in AbstractInt2IntMap.values().
int	firstIntKey() Returns the first key of this map in iteration order.
protected void	fixPointers(int i) Modifies the link vector so that the given entry is removed.
protected void	fixPointers(int s, int d) Modifies the link vector for a shift from s to d.
int	get(int k) Returns the value to which the given key is mapped.
Integer	get(Integer ok)
int	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.
int	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.
int	growthFactor() Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.
void	growthFactor(int growthFactor) Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.
int	hashCode() Returns a hash code for this map.
Int2IntSortedMap	headMap(int to) Returns a view of the portion of this sorted map whose keys are strictly less than toKey.
Int2IntSortedMap.FastSortedEntrySet	int2IntEntrySet() Returns a type-specific sorted-set view of the mappings contained in this map.
boolean	isEmpty()
IntSortedSet	keySet() Returns a type-specific-sorted-set view of the keys of this map.
int	lastIntKey() Returns the last key of this map in iteration order.
Integer	put(Integer ok, Integer ov) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
int	put(int k, int v) Adds a pair to the map.
int	putAndMoveToFirst(int k, int v) Adds a pair to the map; if the key is already present, it is moved to the first position of the iteration order.
int	putAndMoveToLast(int k, int v) Adds a pair to the map; if the key is already present, it is moved to the last position of the iteration order.
boolean	rehash() Deprecated. A no-op.
protected void	rehash(int newN) Resizes the map.
int	remove(int k) Removes the mapping with the given key.
Integer	remove(Object ok) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
int	removeFirstInt() Removes the mapping associated with the first key in iteration order.
int	removeLastInt() Removes the mapping associated with the last key in iteration order.
protected int	shiftKeys(int pos) Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry.
int	size() Returns the intended number of keys in this function, or -1 if no such number exists.
Int2IntSortedMap	subMap(int from, int to) Returns a view of the portion of this sorted map whose keys range from fromKey, inclusive, to toKey, exclusive.
Int2IntSortedMap	tailMap(int from) Returns a view of the portion of this sorted map whose keys are greater than or equal to fromKey.
boolean	trim() Rehashes the map, making the table as small as possible.
boolean	trim(int n) Rehashes this map if the table is too large.
IntCollection	values() Returns a type-specific collection view of the values contained in this map.

Methods inherited from class it.unimi.dsi.fastutil.ints.AbstractInt2IntSortedMap

entrySet, firstKey, headMap, lastKey, subMap, tailMap

Methods inherited from class it.unimi.dsi.fastutil.ints.AbstractInt2IntMap

containsValue, equals, putAll, toString

Methods inherited from class it.unimi.dsi.fastutil.ints.AbstractInt2IntFunction

containsKey, defaultReturnValue, defaultReturnValue, get

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.dsi.fastutil.ints.Int2IntFunction

defaultReturnValue, defaultReturnValue

Methods inherited from interface it.unimi.dsi.fastutil.Function

containsKey, get

Methods inherited from interface java.util.Map

containsKey, containsValue, equals, get, putAll

Field Detail

serialVersionUID

public static final long serialVersionUID

See Also:

Constant Field Values

key

protected transient int[] key

The array of keys.

value

protected transient int[] value

The array of values.

used

protected transient boolean[] used

The array telling whether a position is used.

f

protected final float f

The acceptable load factor.

n

protected transient int n

The current table size.

maxFill

protected transient int maxFill

Threshold after which we rehash. It must be the table size times f.

mask

protected transient int mask

The mask for wrapping a position counter.

size

protected int size

Number of entries in the set.

entries

protected transient volatile Int2IntSortedMap.FastSortedEntrySet entries

Cached set of entries.

keys

protected transient volatile IntSortedSet keys

Cached set of keys.

values

protected transient volatile IntCollection values

Cached collection of values.

first

protected transient int first

The index of the first entry in iteration order. It is valid iff size is nonzero; otherwise, it contains -1.

last

protected transient int last

The index of the last entry in iteration order. It is valid iff size is nonzero; otherwise, it contains -1.

link

protected transient long[] link

For each entry, the next and the previous entry in iteration order, stored as ((prev & 0xFFFFFFFFL) << 32) | (next & 0xFFFFFFFFL). The first entry contains predecessor -1, and the last entry contains successor -1.

Constructor Detail

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(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 set.

f - the load factor.

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(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.

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap()

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

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(Map<? extends Integer,? extends Integer> 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.

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(Map<? extends Integer,? extends Integer> 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.

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(Int2IntMap 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.

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(Int2IntMap 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.

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(int[] k,
                        int[] 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:

IllegalArgumentException - if k and v have different lengths.

Int2IntLinkedOpenHashMap

public Int2IntLinkedOpenHashMap(int[] k,
                        int[] 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:

IllegalArgumentException - if k and v have different lengths.

Method Detail

put

public int put(int k,
      int v)

Description copied from interface: Int2IntFunction

Adds a pair to the map.

Specified by:

put in interface Int2IntFunction

Overrides:

put in class AbstractInt2IntFunction

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)

put

public Integer put(Integer ok,
          Integer ov)

Description copied from class: AbstractInt2IntFunction

Delegates to the corresponding type-specific method, taking care of returning null on a missing key.

This method must check whether the provided key is in the map using containsKey(). Thus, it probes the map twice. Implementors of subclasses should override it with a more efficient method.

Specified by:

put in interface Function<Integer,Integer>

Specified by:

put in interface Map<Integer,Integer>

Overrides:

put in class AbstractInt2IntFunction

Parameters:

ok - the key.

ov - the value.

Returns:

the old value, or null if no value was present for the given key.

See Also:

Map.put(Object,Object)

add

public int add(int k,
      int 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.

shiftKeys

protected final int shiftKeys(int pos)

Shifts left entries with the specified hash code, starting at the specified position, and empties the resulting free entry.

Parameters:

pos - a starting position.

Returns:

the position cleared by the shifting process.

remove

public int remove(int k)

Description copied from interface: Int2IntFunction

Removes the mapping with the given key.

Specified by:

remove in interface Int2IntFunction

Overrides:

remove in class AbstractInt2IntFunction

Returns:

the old value, or the default return value if no value was present for the given key.

See Also:

Function.remove(Object)

remove

public Integer remove(Object ok)

Description copied from class: AbstractInt2IntFunction

Delegates to the corresponding type-specific method, taking care of returning null on a missing key.

This method must check whether the provided key is in the map using containsKey(). Thus, it probes the map twice. Implementors of subclasses should override it with a more efficient method.

Specified by:

remove in interface Function<Integer,Integer>

Specified by:

remove in interface Map<Integer,Integer>

Overrides:

remove in class AbstractInt2IntFunction

Returns:

the old value, or null if no value was present for the given key.

See Also:

Map.remove(Object)

removeFirstInt

public int removeFirstInt()

Removes the mapping associated with the first key in iteration order.

Returns:

the value previously associated with the first key in iteration order.

Throws:

NoSuchElementException - is this map is empty.

removeLastInt

public int removeLastInt()

Removes the mapping associated with the last key in iteration order.

Returns:

the value previously associated with the last key in iteration order.

Throws:

NoSuchElementException - is this map is empty.

getAndMoveToFirst

public int 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 int 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 int putAndMoveToFirst(int k,
                    int 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 int putAndMoveToLast(int k,
                   int 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 Integer get(Integer ok)

get

public int get(int k)

Description copied from interface: Int2IntFunction

Returns the value to which the given key is mapped.

Specified by:

get in interface Int2IntFunction

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: AbstractInt2IntMap

Checks whether the given value is contained in AbstractInt2IntMap.keySet().

Specified by:

containsKey in interface Int2IntFunction

Overrides:

containsKey in class AbstractInt2IntMap

See Also:

Function.containsKey(Object)

containsValue

public boolean containsValue(int v)

Description copied from class: AbstractInt2IntMap

Checks whether the given value is contained in AbstractInt2IntMap.values().

Specified by:

containsValue in interface Int2IntMap

Overrides:

containsValue in class AbstractInt2IntMap

See Also:

Map.containsValue(Object)

clear

public void clear()

Description copied from interface: Function

Removes all associations from this function (optional operation).

Specified by:

clear in interface Function<Integer,Integer>

Specified by:

clear in interface Map<Integer,Integer>

Overrides:

clear in class AbstractInt2IntFunction

See Also:

Map.clear()

size

public int size()

Description copied from interface: Function

Returns the intended number of keys in this function, or -1 if no such number exists.

Most function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible.

Specified by:

size in interface Function<Integer,Integer>

Specified by:

size in interface Map<Integer,Integer>

Returns:

the intended number of keys in this function, or -1 if that number is not available.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<Integer,Integer>

Overrides:

isEmpty in class AbstractInt2IntMap

growthFactor

@Deprecated
public void growthFactor(int growthFactor)

Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.

A no-op for backward compatibility.

Parameters:

growthFactor - unused.

growthFactor

@Deprecated
public int growthFactor()

Deprecated. Since fastutil 6.1.0, hash tables are doubled when they are too full.

Gets the growth factor (2).

Returns:

the growth factor of this set, which is fixed (2).

See Also:

growthFactor(int)

fixPointers

protected void fixPointers(int i)

Modifies the link vector so that the given entry is removed.

If the given entry is the first or the last one, this method will complete in constant time; otherwise, it will have to search for the given entry.

Parameters:

i - the index of an entry.

fixPointers

protected void fixPointers(int s,
               int d)

Modifies the link vector for a shift from s to d.

If the given entry is the first or the last one, this method will complete in constant time; otherwise, it will have to search for the given entry.

Parameters:

s - the source position.

d - the destination position.

firstIntKey

public int firstIntKey()

Returns the first key of this map in iteration order.

Specified by:

firstIntKey in interface Int2IntSortedMap

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 Int2IntSortedMap

Returns:

the last key in iteration order.

See Also:

SortedMap.lastKey()

comparator

public IntComparator comparator()

Description copied from interface: Int2IntSortedMap

Returns the comparator associated with this sorted set, or null if it uses its keys' natural ordering.

Note that this specification strengthens the one given in SortedMap.comparator().

Specified by:

comparator in interface Int2IntSortedMap

Specified by:

comparator in interface SortedMap<Integer,Integer>

See Also:

SortedMap.comparator()

tailMap

public Int2IntSortedMap tailMap(int from)

Description copied from interface: Int2IntSortedMap

Returns a view of the portion of this sorted map whose keys are greater than or equal to fromKey.

Specified by:

tailMap in interface Int2IntSortedMap

See Also:

SortedMap.tailMap(Object)

headMap

public Int2IntSortedMap headMap(int to)

Description copied from interface: Int2IntSortedMap

Returns a view of the portion of this sorted map whose keys are strictly less than toKey.

Specified by:

headMap in interface Int2IntSortedMap

See Also:

SortedMap.headMap(Object)

subMap

public Int2IntSortedMap subMap(int from,
                      int to)

Description copied from interface: Int2IntSortedMap

Returns a view of the portion of this sorted map whose keys range from fromKey, inclusive, to toKey, exclusive.

Specified by:

subMap in interface Int2IntSortedMap

See Also:

SortedMap.subMap(Object,Object)

int2IntEntrySet

public Int2IntSortedMap.FastSortedEntrySet int2IntEntrySet()

Description copied from interface: Int2IntSortedMap

Returns a type-specific sorted-set view of the mappings contained in this map. Note that this specification strengthens the one given in the corresponding type-specific unsorted map.

Specified by:

int2IntEntrySet in interface Int2IntMap

Specified by:

int2IntEntrySet in interface Int2IntSortedMap

Returns:

a type-specific sorted-set view of the mappings contained in this map.

See Also:

Int2IntSortedMap.entrySet()

keySet

public IntSortedSet keySet()

Description copied from class: AbstractInt2IntSortedMap

Returns a type-specific-sorted-set view of the keys of this map.

The view is backed by the sorted set returned by AbstractInt2IntSortedMap.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 Int2IntMap

Specified by:

keySet in interface Int2IntSortedMap

Specified by:

keySet in interface Map<Integer,Integer>

Specified by:

keySet in interface SortedMap<Integer,Integer>

Overrides:

keySet in class AbstractInt2IntSortedMap

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 IntCollection values()

Description copied from class: AbstractInt2IntSortedMap

Returns a type-specific collection view of the values contained in this map.

The view is backed by the sorted set returned by AbstractInt2IntSortedMap.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 Int2IntMap

Specified by:

values in interface Int2IntSortedMap

Specified by:

values in interface Map<Integer,Integer>

Specified by:

values in interface SortedMap<Integer,Integer>

Overrides:

values in class AbstractInt2IntSortedMap

Returns:

a type-specific collection view of the values contained in this map.

See Also:

Map.values()

rehash

@Deprecated
public boolean rehash()

Deprecated. A no-op.

A no-op for backward compatibility. The kind of tables implemented by this class never need rehashing.

If you need to reduce the table size to fit exactly this set, use trim().

Returns:

true.

See Also:

trim()

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()

rehash

protected void rehash(int newN)

Resizes the map.

This method implements the basic rehashing strategy, and may be overriden by subclasses implementing different rehashing strategies (e.g., disk-based rehashing). However, you should not override this method unless you understand the internal workings of this class.

Parameters:

newN - the new size

clone

public Int2IntLinkedOpenHashMap 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.

Overrides:

clone in class Object

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 Map<Integer,Integer>

Overrides:

hashCode in class AbstractInt2IntMap

Returns:

a hash code for this map.