public class Object2ShortOpenCustomHashMap<K> extends AbstractObject2ShortMap<K> implements Serializable, Cloneable, Hash
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.
Warning: The implementation of this class has significantly
changed in fastutil 6.1.0. Please read the
comments about this issue in the section “Faster Hash Tables” of the overview.
Hash,
HashCommon,
Serialized FormAbstractObject2ShortMap.BasicEntry<K>Hash.Strategy<K>Object2ShortMap.Entry<K>, Object2ShortMap.FastEntrySet<K>| Modifier and Type | Field and Description |
|---|---|
protected Object2ShortMap.FastEntrySet<K> |
entries
Cached set of entries.
|
protected float |
f
The acceptable load factor.
|
protected K[] |
key
The array of keys.
|
protected ObjectSet<K> |
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.
|
static long |
serialVersionUID |
protected int |
size
Number of entries in the set.
|
protected Hash.Strategy<K> |
strategy
The hash strategy of this custom map.
|
protected boolean[] |
used
The array telling whether a position is used.
|
protected short[] |
value
The array of values.
|
protected ShortCollection |
values
Cached collection of values.
|
defRetValueDEFAULT_GROWTH_FACTOR, DEFAULT_INITIAL_SIZE, DEFAULT_LOAD_FACTOR, FAST_LOAD_FACTOR, FREE, OCCUPIED, PRIMES, REMOVED, VERY_FAST_LOAD_FACTOR| Constructor and Description |
|---|
Object2ShortOpenCustomHashMap(Hash.Strategy<K> strategy)
Creates a new hash map with initial expected
Hash.DEFAULT_INITIAL_SIZE entries
and Hash.DEFAULT_LOAD_FACTOR as load factor. |
Object2ShortOpenCustomHashMap(int expected,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map.
|
Object2ShortOpenCustomHashMap(int expected,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor. |
Object2ShortOpenCustomHashMap(K[] k,
short[] v,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map using the elements of two parallel arrays.
|
Object2ShortOpenCustomHashMap(K[] k,
short[] v,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays. |
Object2ShortOpenCustomHashMap(Map<? extends K,? extends Short> m,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map copying a given one.
|
Object2ShortOpenCustomHashMap(Map<? extends K,? extends Short> m,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one. |
Object2ShortOpenCustomHashMap(Object2ShortMap<K> m,
float f,
Hash.Strategy<K> strategy)
Creates a new hash map copying a given type-specific one.
|
Object2ShortOpenCustomHashMap(Object2ShortMap<K> m,
Hash.Strategy<K> strategy)
Creates a new hash map with
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one. |
| Modifier and Type | Method and Description |
|---|---|
short |
add(K k,
short incr)
Adds an increment to value currently associated with a key.
|
void |
clear()
Removes all associations from this function (optional operation).
|
Object2ShortOpenCustomHashMap<K> |
clone()
Returns a deep copy of this map.
|
boolean |
containsKey(Object k)
Checks whether the given value is contained in
AbstractObject2ShortMap.keySet(). |
boolean |
containsValue(short v)
Checks whether the given value is contained in
AbstractObject2ShortMap.values(). |
short |
getShort(Object k)
Returns the value to which the given key is mapped.
|
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.
|
boolean |
isEmpty() |
ObjectSet<K> |
keySet()
Returns a type-specific-set view of the keys of this map.
|
Object2ShortMap.FastEntrySet<K> |
object2ShortEntrySet()
Returns a type-specific set view of the mappings contained in this map.
|
short |
put(K k,
short v)
Adds a pair to the map.
|
Short |
put(K ok,
Short ov)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
boolean |
rehash()
Deprecated.
A no-op.
|
protected void |
rehash(int newN)
Resizes the map.
|
Short |
remove(Object ok)
Delegates to the corresponding type-specific method, taking care of returning
null on a missing key. |
short |
removeShort(Object k)
Removes the mapping with the given key.
|
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.
|
Hash.Strategy<K> |
strategy()
Returns the hashing strategy.
|
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.
|
ShortCollection |
values()
Returns a type-specific-set view of the values of this map.
|
containsValue, entrySet, equals, putAll, toStringdefaultReturnValue, defaultReturnValue, getfinalize, getClass, notify, notifyAll, wait, wait, waitdefaultReturnValue, defaultReturnValuepublic static final long serialVersionUID
protected transient K[] key
protected transient short[] value
protected transient boolean[] used
protected final float f
protected transient int n
protected transient int maxFill
f.protected transient int mask
protected int size
protected transient volatile Object2ShortMap.FastEntrySet<K> entries
protected transient volatile ShortCollection values
protected Hash.Strategy<K> strategy
public Object2ShortOpenCustomHashMap(int expected,
float f,
Hash.Strategy<K> strategy)
The actual table size will be the least power of two greater than expected/f.
expected - the expected number of elements in the hash set.f - the load factor.strategy - the strategy.public Object2ShortOpenCustomHashMap(int expected,
Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR as load factor.expected - the expected number of elements in the hash map.strategy - the strategy.public Object2ShortOpenCustomHashMap(Hash.Strategy<K> strategy)
Hash.DEFAULT_INITIAL_SIZE entries
and Hash.DEFAULT_LOAD_FACTOR as load factor.strategy - the strategy.public Object2ShortOpenCustomHashMap(Map<? extends K,? extends Short> m, float f, Hash.Strategy<K> strategy)
m - a Map to be copied into the new hash map.f - the load factor.strategy - the strategy.public Object2ShortOpenCustomHashMap(Map<? extends K,? extends Short> m, Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.m - a Map to be copied into the new hash map.strategy - the strategy.public Object2ShortOpenCustomHashMap(Object2ShortMap<K> m, float f, Hash.Strategy<K> strategy)
m - a type-specific map to be copied into the new hash map.f - the load factor.strategy - the strategy.public Object2ShortOpenCustomHashMap(Object2ShortMap<K> m, Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.m - a type-specific map to be copied into the new hash map.strategy - the strategy.public Object2ShortOpenCustomHashMap(K[] k, short[] v, float f, Hash.Strategy<K> strategy)
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.strategy - the strategy.IllegalArgumentException - if k and v have different lengths.public Object2ShortOpenCustomHashMap(K[] k, short[] v, Hash.Strategy<K> strategy)
Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.k - the array of keys of the new hash map.v - the array of corresponding values in the new hash map.strategy - the strategy.IllegalArgumentException - if k and v have different lengths.public Hash.Strategy<K> strategy()
public short put(K k, short v)
Object2ShortFunctionput in interface Object2ShortFunction<K>put in class AbstractObject2ShortFunction<K>k - the key.v - the value.Function.put(Object,Object)public Short put(K ok, Short ov)
AbstractObject2ShortFunctionnull 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.
public short add(K k, short incr)
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.
k - the key.incr - the increment.protected final int shiftKeys(int pos)
pos - a starting position.public short removeShort(Object k)
Object2ShortFunctionremoveShort in interface Object2ShortFunction<K>removeShort in class AbstractObject2ShortFunction<K>Function.remove(Object)public Short remove(Object ok)
AbstractObject2ShortFunctionnull 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.
public short getShort(Object k)
Object2ShortFunctiongetShort in interface Object2ShortFunction<K>k - the key.Function.get(Object)public boolean containsKey(Object k)
AbstractObject2ShortMapAbstractObject2ShortMap.keySet().containsKey in interface Function<K,Short>containsKey in interface Map<K,Short>containsKey in class AbstractObject2ShortMap<K>k - the key.key.Map.containsKey(Object)public boolean containsValue(short v)
AbstractObject2ShortMapAbstractObject2ShortMap.values().containsValue in interface Object2ShortMap<K>containsValue in class AbstractObject2ShortMap<K>Map.containsValue(Object)public void clear()
Functionpublic int size()
FunctionMost function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible.
public boolean isEmpty()
@Deprecated public void growthFactor(int growthFactor)
fastutil 6.1.0, hash tables are doubled when they are too full.growthFactor - unused.@Deprecated public int growthFactor()
fastutil 6.1.0, hash tables are doubled when they are too full.growthFactor(int)public Object2ShortMap.FastEntrySet<K> object2ShortEntrySet()
Object2ShortMapThis method is necessary because there is no inheritance along
type parameters: it is thus impossible to strengthen Object2ShortMap.entrySet()
so that it returns an ObjectSet
of objects of type Map.Entry (the latter makes it possible to
access keys and values with type-specific methods).
object2ShortEntrySet in interface Object2ShortMap<K>Object2ShortMap.entrySet()public ObjectSet<K> keySet()
AbstractObject2ShortMapThe view is backed by the set returned by AbstractObject2ShortMap.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.
keySet in interface Object2ShortMap<K>keySet in interface Map<K,Short>keySet in class AbstractObject2ShortMap<K>Map.keySet()public ShortCollection values()
AbstractObject2ShortMapThe view is backed by the set returned by AbstractObject2ShortMap.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.
values in interface Object2ShortMap<K>values in interface Map<K,Short>values in class AbstractObject2ShortMap<K>Map.values()@Deprecated public boolean rehash()
If you need to reduce the table size to fit exactly
this set, use trim().
trim()public boolean trim()
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.
trim(int)public boolean trim(int n)
Let N be the smallest table size that can hold
max(n, 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.
size())
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.
n - the threshold for the trimming.trim()protected void rehash(int newN)
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.
newN - the new sizepublic Object2ShortOpenCustomHashMap<K> clone()
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.
public int hashCode()
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.Copyright © 2013. All Rights Reserved.