it.unimi.dsi.fastutil.chars
Class Char2ByteLinkedOpenHashMap

java.lang.Object
  it.unimi.dsi.fastutil.chars.AbstractChar2ByteFunction
      it.unimi.dsi.fastutil.chars.AbstractChar2ByteMap
          it.unimi.dsi.fastutil.chars.AbstractChar2ByteSortedMap
              it.unimi.dsi.fastutil.chars.Char2ByteLinkedOpenHashMap

All Implemented Interfaces:

Char2ByteFunction, Char2ByteMap, Char2ByteSortedMap, Function<Character,Byte>, Hash, Serializable, Cloneable, Map<Character,Byte>, SortedMap<Character,Byte>

public class Char2ByteLinkedOpenHashMap
extends AbstractChar2ByteSortedMap
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 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.

The enlargement speed is controlled by the growth factor, a positive number. If the growth factor is p, then the table is enlarged each time roughly by a factor 2^p/16. By default, p is Hash.DEFAULT_GROWTH_FACTOR, which means that the table is doubled at each enlargement, but one can easily set more or less aggressive policies by calling growthFactor(int) (note that the growth factor is not serialized: deserialized tables gets the default growth factor).

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 AbstractChar2ByteSortedMap.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.

The iterators provided by the views of this class using are type-specific list iterators. However, creation of an iterator using a starting point is going to be very expensive, as the chosen starting point must be linearly searched for, unless it is AbstractChar2ByteSortedMap.lastKey(), in which case the iterator is created in constant time.

Note that deletions in a linked table require scanning the list until the element to be removed is found. The only exceptions are the first element, the last element, and deletions performed using an iterator.

See Also:

Hash, HashCommon, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ByteMap

AbstractChar2ByteMap.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.chars.Char2ByteSortedMap

Char2ByteSortedMap.FastSortedEntrySet

Nested classes/interfaces inherited from interface it.unimi.dsi.fastutil.chars.Char2ByteMap

Char2ByteMap.Entry, Char2ByteMap.FastEntrySet

Field Summary

static long

serialVersionUID

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

Char2ByteLinkedOpenHashMap()
Creates a new hash map with Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.

Char2ByteLinkedOpenHashMap(char[] k, byte[] v)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.

Char2ByteLinkedOpenHashMap(char[] k, byte[] v, float f)
Creates a new hash map using the elements of two parallel arrays.

Char2ByteLinkedOpenHashMap(Char2ByteMap m)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.

Char2ByteLinkedOpenHashMap(Char2ByteMap m, float f)
Creates a new hash map copying a given type-specific one.

Char2ByteLinkedOpenHashMap(int n)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.

Char2ByteLinkedOpenHashMap(int n, float f)
Creates a new hash map.

Char2ByteLinkedOpenHashMap(Map<? extends Character,? extends Byte> m)
Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.

Char2ByteLinkedOpenHashMap(Map<? extends Character,? extends Byte> m, float f)
Creates a new hash map copying a given one.

Method Summary

Char2ByteSortedMap.FastSortedEntrySet	char2ByteEntrySet() Returns a type-specific set view of the mappings contained in this map.
void	clear() Removes all associations from this function (optional operation).
Object	clone() Returns a deep copy of this map.
CharComparator	comparator() Returns the comparator associated with this sorted set, or null if it uses its keys' natural ordering.
boolean	containsKey(char k) Checks whether the given value is contained in AbstractChar2ByteMap.keySet().
boolean	containsValue(byte v) Checks whether the given value is contained in AbstractChar2ByteMap.values().
char	firstCharKey() Returns the first key of this map in iteration order.
byte	get(char k) Returns the value to which the given key is mapped.
Byte	get(Character ok)
int	growthFactor() Gets the growth factor.
void	growthFactor(int growthFactor) Sets the growth factor.
int	hashCode() Returns a hash code for this map.
Char2ByteSortedMap	headMap(char to) Returns a view of the portion of this sorted map whose keys are strictly less than toKey.
boolean	isEmpty()
CharSortedSet	keySet() Returns a type-specific-sorted-set view of the keys of this map.
char	lastCharKey() Returns the last key of this map in iteration order.
Byte	put(Character ok, Byte ov) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
byte	put(char k, byte v) Adds a pair to the map.
boolean	rehash() Rehashes this map without changing the table size.
byte	remove(char k) Removes the mapping with the given key.
Byte	remove(Object ok) Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
int	size() Returns the intended number of keys in this function, or -1 if no such number exists.
Char2ByteSortedMap	subMap(char from, char to) Returns a view of the portion of this sorted map whose keys range from fromKey, inclusive, to toKey, exclusive.
Char2ByteSortedMap	tailMap(char 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.
ByteCollection	values() Returns a type-specific collection view of the values contained in this map.

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ByteSortedMap

entrySet, firstKey, headMap, lastKey, subMap, tailMap

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ByteMap

containsValue, equals, putAll, toString

Methods inherited from class it.unimi.dsi.fastutil.chars.AbstractChar2ByteFunction

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.chars.Char2ByteFunction

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

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

Constructor Detail

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(int n,
                                  float f)

Creates a new hash map. The actual table size is the least available prime greater than n/f.

Parameters:

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

f - the load factor.

See Also:

Hash.PRIMES

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(int n)

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

Parameters:

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

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap()

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

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(Map<? extends Character,? extends Byte> 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.

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(Map<? extends Character,? extends Byte> 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.

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(Char2ByteMap 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.

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(Char2ByteMap 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.

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(char[] k,
                                  byte[] 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.

Char2ByteLinkedOpenHashMap

public Char2ByteLinkedOpenHashMap(char[] k,
                                  byte[] 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

growthFactor

public void growthFactor(int growthFactor)

Sets the growth factor. Subsequent enlargements will increase the table size roughly by a multiplicative factor of 2^p/16.

Parameters:

growthFactor - the new growth factor; it must be positive.

growthFactor

public int growthFactor()

Gets the growth factor.

Returns:

the growth factor of this set.

See Also:

growthFactor(int)

put

public byte put(char k,
                byte v)

Description copied from interface: Char2ByteFunction

Adds a pair to the map.

Specified by:

put in interface Char2ByteFunction

Overrides:

put in class AbstractChar2ByteFunction

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 Byte put(Character ok,
                Byte ov)

Description copied from class: AbstractChar2ByteFunction

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<Character,Byte>

Specified by:

put in interface Map<Character,Byte>

Overrides:

put in class AbstractChar2ByteFunction

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)

containsValue

public boolean containsValue(byte v)

Description copied from class: AbstractChar2ByteMap

Checks whether the given value is contained in AbstractChar2ByteMap.values().

Specified by:

containsValue in interface Char2ByteMap

Overrides:

containsValue in class AbstractChar2ByteMap

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<Character,Byte>

Specified by:

clear in interface Map<Character,Byte>

Overrides:

clear in class AbstractChar2ByteFunction

See Also:

Map.clear()

firstCharKey

public char firstCharKey()

Returns the first key of this map in iteration order.

Specified by:

firstCharKey in interface Char2ByteSortedMap

Returns:

the first key in iteration order.

See Also:

SortedMap.firstKey()

lastCharKey

public char lastCharKey()

Returns the last key of this map in iteration order.

Specified by:

lastCharKey in interface Char2ByteSortedMap

Returns:

the last key in iteration order.

See Also:

SortedMap.lastKey()

comparator

public CharComparator comparator()

Description copied from interface: Char2ByteSortedMap

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 Char2ByteSortedMap

Specified by:

comparator in interface SortedMap<Character,Byte>

See Also:

SortedMap.comparator()

tailMap

public Char2ByteSortedMap tailMap(char from)

Description copied from interface: Char2ByteSortedMap

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

Specified by:

tailMap in interface Char2ByteSortedMap

See Also:

SortedMap.tailMap(Object)

headMap

public Char2ByteSortedMap headMap(char to)

Description copied from interface: Char2ByteSortedMap

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

Specified by:

headMap in interface Char2ByteSortedMap

See Also:

SortedMap.headMap(Object)

subMap

public Char2ByteSortedMap subMap(char from,
                                 char to)

Description copied from interface: Char2ByteSortedMap

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

Specified by:

subMap in interface Char2ByteSortedMap

See Also:

SortedMap.subMap(Object,Object)

containsKey

public boolean containsKey(char k)

Description copied from class: AbstractChar2ByteMap

Checks whether the given value is contained in AbstractChar2ByteMap.keySet().

Specified by:

containsKey in interface Char2ByteFunction

Overrides:

containsKey in class AbstractChar2ByteMap

See Also:

Function.containsKey(Object)

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<Character,Byte>

Specified by:

size in interface Map<Character,Byte>

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<Character,Byte>

Overrides:

isEmpty in class AbstractChar2ByteMap

get

public byte get(char k)

Description copied from interface: Char2ByteFunction

Returns the value to which the given key is mapped.

Specified by:

get in interface Char2ByteFunction

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)

remove

public byte remove(char k)

Description copied from interface: Char2ByteFunction

Removes the mapping with the given key.

Specified by:

remove in interface Char2ByteFunction

Overrides:

remove in class AbstractChar2ByteFunction

Returns:

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

See Also:

Function.remove(Object)

get

public Byte get(Character ok)

remove

public Byte remove(Object ok)

Description copied from class: AbstractChar2ByteFunction

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<Character,Byte>

Specified by:

remove in interface Map<Character,Byte>

Overrides:

remove in class AbstractChar2ByteFunction

Returns:

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

See Also:

Map.remove(Object)

char2ByteEntrySet

public Char2ByteSortedMap.FastSortedEntrySet char2ByteEntrySet()

Description copied from interface: Char2ByteMap

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 Char2ByteMap.entrySet() so that it returns an ObjectSet of objects of type Char2ByteMap.Entry (the latter makes it possible to access keys and values with type-specific methods).

Specified by:

char2ByteEntrySet in interface Char2ByteMap

Specified by:

char2ByteEntrySet in interface Char2ByteSortedMap

Returns:

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

See Also:

Char2ByteMap.entrySet()

keySet

public CharSortedSet keySet()

Description copied from class: AbstractChar2ByteSortedMap

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

The view is backed by the sorted set returned by AbstractChar2ByteSortedMap.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 Char2ByteMap

Specified by:

keySet in interface Char2ByteSortedMap

Specified by:

keySet in interface Map<Character,Byte>

Overrides:

keySet in class AbstractChar2ByteSortedMap

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 ByteCollection values()

Description copied from class: AbstractChar2ByteSortedMap

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

The view is backed by the sorted set returned by AbstractChar2ByteSortedMap.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 Char2ByteMap

Specified by:

values in interface Char2ByteSortedMap

Specified by:

values in interface Map<Character,Byte>

Overrides:

values in class AbstractChar2ByteSortedMap

Returns:

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

See Also:

Map.values()

rehash

public boolean rehash()

Rehashes this map without changing the table size.

This method should be called when the map underwent numerous deletions and insertions. In this case, free entries become rare, and unsuccessful searches require probing all entries. For reasonable load factors this method is linear in the number of entries. You will need as much additional free memory as that occupied by the table.

If you need to reduce the table siza to fit exactly this map, you must use trim().

Returns:

true if there was enough memory to rehash the map, false otherwise.

See Also:

trim()

trim

public boolean trim()

Rehashes the map, making the table as small as possible.

This method rehashes to the smallest size satisfying the load factor. It can be used when the map will not be changed anymore, so to optimize access speed (by collecting deleted entries) and size.

If the table size is already the minimum possible, this method does nothing. If you want to guarantee rehashing, use rehash().

Returns:

true if there was enough memory to trim the map.

See Also:

trim(int), rehash()

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()

clone

public Object 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<Character,Byte>

Overrides:

hashCode in class AbstractChar2ByteMap

Returns:

a hash code for this map.