Int2IntOpenHashMap (common 3.5.1 API)

java.lang.Object
- it.unimi.dsi.fastutil.ints.AbstractInt2IntFunction
- - it.unimi.dsi.fastutil.ints.AbstractInt2IntMap
  - - it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap

All Implemented Interfaces:

Function<java.lang.Integer,java.lang.Integer>, Hash, Int2IntFunction, Int2IntMap, java.io.Serializable, java.lang.Cloneable, java.util.Map<java.lang.Integer,java.lang.Integer>
```
public class Int2IntOpenHashMap
extends AbstractInt2IntMap
implements java.io.Serializable, java.lang.Cloneable, Hash
```
A type-specific hash map 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, 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.

See Also:

Hash, HashCommon, Serialized Form

Nested Class Summary
- 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.Int2IntMap
  Int2IntMap.Entry, Int2IntMap.FastEntrySet

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`containsNullKey` Whether this set contains the key zero.
`protected Int2IntMap.FastEntrySet`	`entries` Cached set of entries.
`protected float`	`f` The acceptable load factor.
`protected int[]`	`key` The array of keys.
`protected IntSet`	`keys` Cached set of keys.
`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.
`protected int`	`size` Number of entries in the set (including the key zero, if present).
`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
`Int2IntOpenHashMap()` Creates a new hash map with initial expected `Hash.DEFAULT_INITIAL_SIZE` entries and `Hash.DEFAULT_LOAD_FACTOR` as load factor.
`Int2IntOpenHashMap(int expected)` Creates a new hash map with `Hash.DEFAULT_LOAD_FACTOR` as load factor.
`Int2IntOpenHashMap(int[] k, int[] v)` Creates a new hash map with `Hash.DEFAULT_LOAD_FACTOR` as load factor using the elements of two parallel arrays.
`Int2IntOpenHashMap(int[] k, int[] v, float f)` Creates a new hash map using the elements of two parallel arrays.
`Int2IntOpenHashMap(Int2IntMap m)` Creates a new hash map with `Hash.DEFAULT_LOAD_FACTOR` as load factor copying a given type-specific one.
`Int2IntOpenHashMap(Int2IntMap m, float f)` Creates a new hash map copying a given type-specific one.
`Int2IntOpenHashMap(int expected, float f)` Creates a new hash map.
`Int2IntOpenHashMap(java.util.Map<? extends java.lang.Integer,? extends java.lang.Integer> m)` Creates a new hash map with `Hash.DEFAULT_LOAD_FACTOR` as load factor copying a given one.
`Int2IntOpenHashMap(java.util.Map<? extends java.lang.Integer,? extends java.lang.Integer> m, float f)` Creates a new hash map copying a given one.

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`int`	`addTo(int k, int incr)` Adds an increment to value currently associated with a key.
`void`	`clear()` Removes all associations from this function (optional operation).
`Int2IntOpenHashMap`	`clone()` Returns a deep copy of this map.
`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`	`get(int k)` Returns the value to which the given key is mapped.
`java.lang.Integer`	`get(java.lang.Integer ok)` Deprecated. Please use the corresponding type-specific method instead.
`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.
`Int2IntMap.FastEntrySet`	`int2IntEntrySet()` Returns a type-specific set view of the mappings contained in this map.
`boolean`	`isEmpty()`
`IntSet`	`keySet()` Returns a type-specific-set view of the keys of this map.
`java.lang.Integer`	`put(java.lang.Integer ok, java.lang.Integer ov)` Deprecated. Please use the corresponding type-specific method instead.
`int`	`put(int k, int v)` Adds a pair to the map.
`void`	`putAll(java.util.Map<? extends java.lang.Integer,? extends java.lang.Integer> m)` Puts all pairs in the given map.
`boolean`	`rehash()` Deprecated. A no-op.
`protected void`	`rehash(int newN)` Rehashes the map.
`int`	`remove(int k)` Removes the mapping with the given key.
`java.lang.Integer`	`remove(java.lang.Object ok)` Deprecated. Please use the corresponding type-specific method instead.
`protected void`	`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.
`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-set view of the values of this map.

Methods inherited from class it.unimi.dsi.fastutil.ints.AbstractInt2IntMap
containsValue, entrySet, equals, 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
compute, computeIfAbsent, computeIfPresent, containsKey, forEach, get, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

- Field Detail
  - key
```
protected transient int[] key
```
    The array of keys.
  - value
```
protected transient int[] value
```
    The array of values.
  - mask
```
protected transient int mask
```
    The mask for wrapping a position counter.
  - containsNullKey
```
protected transient boolean containsNullKey
```
    Whether this set contains the key zero.
  - 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.
  - size
```
protected int size
```
    Number of entries in the set (including the key zero, if present).
  - f
```
protected final float f
```
    The acceptable load factor.
  - entries
```
protected transient Int2IntMap.FastEntrySet entries
```
    Cached set of entries.
  - keys
```
protected transient IntSet keys
```
    Cached set of keys.
  - values
```
protected transient IntCollection values
```
    Cached collection of values.
- Constructor Detail
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(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.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(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.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap()
```
    Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(java.util.Map<? extends java.lang.Integer,? extends java.lang.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.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(java.util.Map<? extends java.lang.Integer,? extends java.lang.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.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(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.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(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.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(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:
    
    java.lang.IllegalArgumentException - if k and v have different lengths.
  - Int2IntOpenHashMap
```
public Int2IntOpenHashMap(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:
    
    java.lang.IllegalArgumentException - if k and v have different lengths.
- Method Detail
  - putAll
```
public void putAll(java.util.Map<? extends java.lang.Integer,? extends java.lang.Integer> m)
```
    Puts all pairs in the given map. If the map implements the interface of this map, it uses the faster iterators.
    
    Specified by:
    
    putAll in interface java.util.Map<java.lang.Integer,java.lang.Integer>
    
    Overrides:
    
    putAll in class AbstractInt2IntMap
    
    Parameters:
    
    m - a map.
  - 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
```
@Deprecated
public java.lang.Integer put(java.lang.Integer ok,
                                         java.lang.Integer ov)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    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<java.lang.Integer,java.lang.Integer>
    
    Specified by:
    
    put in interface java.util.Map<java.lang.Integer,java.lang.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)
  - addTo
```
public int addTo(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 void 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.
  - 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
    
    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)
  - remove
```
@Deprecated
public java.lang.Integer remove(java.lang.Object ok)
```
    Deprecated. Please use the corresponding type-specific method instead.
    
    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<java.lang.Integer,java.lang.Integer>
    
    Specified by:
    
    remove in interface java.util.Map<java.lang.Integer,java.lang.Integer>
    
    Overrides:
    
    remove in class AbstractInt2IntFunction
    
    Parameters:
    
    ok - the key.
    
    Returns:
    
    the old value, or null if no value was present for the given key.
    
    See Also:
    
    Map.remove(Object)
  - get
```
@Deprecated
public java.lang.Integer get(java.lang.Integer ok)
```
    Deprecated. Please use the corresponding type-specific method instead.
  - 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<java.lang.Integer,java.lang.Integer>
    
    Specified by:
    
    clear in interface java.util.Map<java.lang.Integer,java.lang.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<java.lang.Integer,java.lang.Integer>
    
    Specified by:
    
    size in interface java.util.Map<java.lang.Integer,java.lang.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 java.util.Map<java.lang.Integer,java.lang.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)
  - int2IntEntrySet
```
public Int2IntMap.FastEntrySet int2IntEntrySet()
```
    Description copied from interface: Int2IntMap
    
    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 Int2IntMap.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:
    
    int2IntEntrySet in interface Int2IntMap
    
    Returns:
    
    a type-specific set view of the mappings contained in this map.
    
    See Also:
    
    Int2IntMap.entrySet()
  - keySet
```
public IntSet keySet()
```
    Description copied from class: AbstractInt2IntMap
    
    Returns a type-specific-set view of the keys of this map.
    The view is backed by the set returned by AbstractInt2IntMap.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 java.util.Map<java.lang.Integer,java.lang.Integer>
    
    Overrides:
    
    keySet in class AbstractInt2IntMap
    
    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 IntCollection values()
```
    Description copied from class: AbstractInt2IntMap
    
    Returns a type-specific-set view of the values of this map.
    The view is backed by the set returned by AbstractInt2IntMap.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 java.util.Map<java.lang.Integer,java.lang.Integer>
    
    Overrides:
    
    values in class AbstractInt2IntMap
    
    Returns:
    
    a set view of the values of this map; it may be safely cast to a type-specific interface.
    
    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)
```
    Rehashes 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 Int2IntOpenHashMap 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 java.lang.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 java.util.Map<java.lang.Integer,java.lang.Integer>
    
    Overrides:
    
    hashCode in class AbstractInt2IntMap
    
    Returns:
    
    a hash code for this map.

Class Int2IntOpenHashMap

Nested Class Summary

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

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

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

Field Summary

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

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

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

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

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

Methods inherited from interface java.util.Map

Field Detail

key

value

mask

containsNullKey

n

maxFill

size

f

entries

keys

values

Constructor Detail

Int2IntOpenHashMap

Int2IntOpenHashMap

Int2IntOpenHashMap

Int2IntOpenHashMap

Int2IntOpenHashMap

Int2IntOpenHashMap

Int2IntOpenHashMap

Int2IntOpenHashMap

Int2IntOpenHashMap

Method Detail

putAll

put

put

addTo

shiftKeys

remove

remove

get

get

containsKey

containsValue

clear

size

isEmpty

growthFactor

growthFactor

int2IntEntrySet

keySet

values

rehash

trim

trim

rehash

clone

hashCode