it.unimi.dsi.fastutil.shorts

Class Short2LongOpenCustomHashMap

java.lang.Object

it.unimi.dsi.fastutil.shorts.AbstractShort2LongFunction

it.unimi.dsi.fastutil.shorts.AbstractShort2LongMap

it.unimi.dsi.fastutil.shorts.Short2LongOpenCustomHashMap

All Implemented Interfaces:

Function<Short,Long>, Hash, Short2LongFunction, Short2LongMap, Serializable, Cloneable, Map<Short,Long>

public class Short2LongOpenCustomHashMap
extends AbstractShort2LongMap
implements Serializable, Cloneable, Hash

A type-specific hash map with a fast, small-footprint implementation whose hashing strategy is specified at creation time.

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.

See Also:

Hash, HashCommon, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.shorts.AbstractShort2LongMap

AbstractShort2LongMap.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.shorts.Short2LongMap

Short2LongMap.Entry, Short2LongMap.FastEntrySet

Field Summary

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
Short2LongOpenCustomHashMap(int expected, float f, ShortHash.Strategy strategy) Creates a new hash map.
Short2LongOpenCustomHashMap(int expected, ShortHash.Strategy strategy) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.
Short2LongOpenCustomHashMap(Map<? extends Short,? extends Long> m, float f, ShortHash.Strategy strategy) Creates a new hash map copying a given one.
Short2LongOpenCustomHashMap(Map<? extends Short,? extends Long> m, ShortHash.Strategy strategy) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.
Short2LongOpenCustomHashMap(short[] k, long[] v, float f, ShortHash.Strategy strategy) Creates a new hash map using the elements of two parallel arrays.
Short2LongOpenCustomHashMap(short[] k, long[] v, ShortHash.Strategy strategy) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.
Short2LongOpenCustomHashMap(Short2LongMap m, float f, ShortHash.Strategy strategy) Creates a new hash map copying a given type-specific one.
Short2LongOpenCustomHashMap(Short2LongMap m, ShortHash.Strategy strategy) Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.
Short2LongOpenCustomHashMap(ShortHash.Strategy strategy) Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.

Method Summary

Methods

Modifier and Type	Method and Description
long	add(short k, long incr) Deprecated. use addTo() instead; having the same name of a Set method turned out to be a recipe for disaster.
long	addTo(short k, long incr) Adds an increment to value currently associated with a key.
void	clear() Removes all associations from this function (optional operation).
Short2LongOpenCustomHashMap	clone() Returns a deep copy of this map.
boolean	containsKey(short k) Checks whether the given value is contained in AbstractShort2LongMap.keySet().
boolean	containsValue(long v) Checks whether the given value is contained in AbstractShort2LongMap.values().
long	get(short k) Returns the value to which the given key is mapped.
Long	get(Short ok)
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()
ShortSet	keySet() Returns a type-specific-set view of the keys of this map.
long	put(short k, long v) Adds a pair to the map.
Long	put(Short ok, Long ov) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
boolean	rehash() Deprecated. A no-op.
Long	remove(Object ok) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
long	remove(short k) Removes the mapping with the given key.
Short2LongMap.FastEntrySet	short2LongEntrySet() Returns a type-specific set view of the mappings contained in this map.
int	size() Returns the intended number of keys in this function, or -1 if no such number exists.
ShortHash.Strategy	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.
LongCollection	values() Returns a type-specific-set view of the values of this map.

Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShort2LongMap

containsValue, entrySet, equals, putAll, toString

Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShort2LongFunction

containsKey, defaultReturnValue, defaultReturnValue, get

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface it.unimi.dsi.fastutil.shorts.Short2LongFunction

defaultReturnValue, defaultReturnValue

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

containsKey, get

Methods inherited from interface java.util.Map

containsKey, get

Constructor Detail

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(int expected,
                           float f,
                           ShortHash.Strategy strategy)

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.

strategy - the strategy.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(int expected,
                           ShortHash.Strategy strategy)

Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.

Parameters:

expected - the expected number of elements in the hash map.

strategy - the strategy.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(ShortHash.Strategy strategy)

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

Parameters:

strategy - the strategy.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(Map<? extends Short,? extends Long> m,
                           float f,
                           ShortHash.Strategy strategy)

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.

strategy - the strategy.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(Map<? extends Short,? extends Long> m,
                           ShortHash.Strategy strategy)

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.

strategy - the strategy.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(Short2LongMap m,
                           float f,
                           ShortHash.Strategy strategy)

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.

strategy - the strategy.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(Short2LongMap m,
                           ShortHash.Strategy strategy)

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.

strategy - the strategy.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(short[] k,
                           long[] v,
                           float f,
                           ShortHash.Strategy strategy)

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.

strategy - the strategy.

Throws:

IllegalArgumentException - if k and v have different lengths.

Short2LongOpenCustomHashMap

public Short2LongOpenCustomHashMap(short[] k,
                           long[] v,
                           ShortHash.Strategy strategy)

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.

strategy - the strategy.

Throws:

IllegalArgumentException - if k and v have different lengths.

Method Detail

strategy

public ShortHash.Strategy strategy()

Returns the hashing strategy.

Returns:

the hashing strategy of this custom hash map.

put

public long put(short k,
       long v)

Description copied from interface: Short2LongFunction

Adds a pair to the map.

Specified by:

put in interface Short2LongFunction

Overrides:

put in class AbstractShort2LongFunction

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 Long put(Short ok,
       Long ov)

Description copied from class: AbstractShort2LongFunction

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<Short,Long>

Specified by:

put in interface Map<Short,Long>

Overrides:

put in class AbstractShort2LongFunction

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

@Deprecated
public long add(short k,
                  long incr)

Deprecated. use addTo() instead; having the same name of a Set method turned out to be a recipe for disaster.

Adds an increment to value currently associated with a key.

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.

addTo

public long addTo(short 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(short k)

Description copied from interface: Short2LongFunction

Removes the mapping with the given key.

Specified by:

remove in interface Short2LongFunction

Overrides:

remove in class AbstractShort2LongFunction

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 Long remove(Object ok)

Description copied from class: AbstractShort2LongFunction

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<Short,Long>

Specified by:

remove in interface Map<Short,Long>

Overrides:

remove in class AbstractShort2LongFunction

Returns:

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

See Also:

Map.remove(Object)

get

public Long get(Short ok)

get

public long get(short k)

Description copied from interface: Short2LongFunction

Returns the value to which the given key is mapped.

Specified by:

get in interface Short2LongFunction

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(short k)

Description copied from class: AbstractShort2LongMap

Checks whether the given value is contained in AbstractShort2LongMap.keySet().

Specified by:

containsKey in interface Short2LongFunction

Overrides:

containsKey in class AbstractShort2LongMap

See Also:

Function.containsKey(Object)

containsValue

public boolean containsValue(long v)

Description copied from class: AbstractShort2LongMap

Checks whether the given value is contained in AbstractShort2LongMap.values().

Specified by:

containsValue in interface Short2LongMap

Overrides:

containsValue in class AbstractShort2LongMap

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<Short,Long>

Specified by:

clear in interface Map<Short,Long>

Overrides:

clear in class AbstractShort2LongFunction

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<Short,Long>

Specified by:

size in interface Map<Short,Long>

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<Short,Long>

Overrides:

isEmpty in class AbstractShort2LongMap

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)

short2LongEntrySet

public Short2LongMap.FastEntrySet short2LongEntrySet()

Description copied from interface: Short2LongMap

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 Short2LongMap.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).

Specified by:

short2LongEntrySet in interface Short2LongMap

Returns:

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

See Also:

Short2LongMap.entrySet()

keySet

public ShortSet keySet()

Description copied from class: AbstractShort2LongMap

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

The view is backed by the set returned by AbstractShort2LongMap.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 Short2LongMap

Specified by:

keySet in interface Map<Short,Long>

Overrides:

keySet in class AbstractShort2LongMap

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 LongCollection values()

Description copied from class: AbstractShort2LongMap

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

The view is backed by the set returned by AbstractShort2LongMap.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 Short2LongMap

Specified by:

values in interface Map<Short,Long>

Overrides:

values in class AbstractShort2LongMap

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()

clone

public Short2LongOpenCustomHashMap 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<Short,Long>

Overrides:

hashCode in class AbstractShort2LongMap

Returns:

a hash code for this map.