it.unimi.dsi.fastutil.shorts
Class Short2DoubleOpenHashMap

java.lang.Object
  extended by it.unimi.dsi.fastutil.shorts.AbstractShort2DoubleFunction
      extended by it.unimi.dsi.fastutil.shorts.AbstractShort2DoubleMap
          extended by it.unimi.dsi.fastutil.shorts.Short2DoubleOpenHashMap
All Implemented Interfaces:
Function<Short,Double>, Hash, Short2DoubleFunction, Short2DoubleMap, Serializable, Cloneable, Map<Short,Double>

public class Short2DoubleOpenHashMap
extends AbstractShort2DoubleMap
implements Serializable, 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 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.AbstractShort2DoubleMap
AbstractShort2DoubleMap.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.Short2DoubleMap
Short2DoubleMap.Entry, Short2DoubleMap.FastEntrySet
 
Field Summary
protected  Short2DoubleMap.FastEntrySet entries
          Cached set of entries.
protected  float f
          The acceptable load factor.
protected  short[] key
          The array of keys.
protected  ShortSet 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  boolean[] used
          The array telling whether a position is used.
protected  double[] value
          The array of values.
protected  DoubleCollection values
          Cached collection of values.
 
Fields inherited from class it.unimi.dsi.fastutil.shorts.AbstractShort2DoubleFunction
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
Short2DoubleOpenHashMap()
          Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.
Short2DoubleOpenHashMap(int expected)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor.
Short2DoubleOpenHashMap(int expected, float f)
          Creates a new hash map.
Short2DoubleOpenHashMap(Map<? extends Short,? extends Double> m)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given one.
Short2DoubleOpenHashMap(Map<? extends Short,? extends Double> m, float f)
          Creates a new hash map copying a given one.
Short2DoubleOpenHashMap(short[] k, double[] v)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor using the elements of two parallel arrays.
Short2DoubleOpenHashMap(short[] k, double[] v, float f)
          Creates a new hash map using the elements of two parallel arrays.
Short2DoubleOpenHashMap(Short2DoubleMap m)
          Creates a new hash map with Hash.DEFAULT_LOAD_FACTOR as load factor copying a given type-specific one.
Short2DoubleOpenHashMap(Short2DoubleMap m, float f)
          Creates a new hash map copying a given type-specific one.
 
Method Summary
 double add(short k, double incr)
          Adds an increment to value currently associated with a key.
 void clear()
          Removes all associations from this function (optional operation).
 Short2DoubleOpenHashMap clone()
          Returns a deep copy of this map.
 boolean containsKey(short k)
          Checks whether the given value is contained in AbstractShort2DoubleMap.keySet().
 boolean containsValue(double v)
          Checks whether the given value is contained in AbstractShort2DoubleMap.values().
 double get(short k)
          Returns the value to which the given key is mapped.
 Double 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.
 double put(short k, double v)
          Adds a pair to the map.
 Double put(Short ok, Double 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.
 Double remove(Object ok)
          Delegates to the corresponding type-specific method, taking care of returning null on a missing key.
 double remove(short 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.
 Short2DoubleMap.FastEntrySet short2DoubleEntrySet()
          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.
 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.
 DoubleCollection values()
          Returns a type-specific-set view of the values of this map.
 
Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShort2DoubleMap
containsValue, entrySet, equals, putAll, toString
 
Methods inherited from class it.unimi.dsi.fastutil.shorts.AbstractShort2DoubleFunction
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.shorts.Short2DoubleFunction
defaultReturnValue, defaultReturnValue
 
Methods inherited from interface it.unimi.dsi.fastutil.Function
containsKey, get
 
Methods inherited from interface java.util.Map
containsKey, get
 

Field Detail

serialVersionUID

public static final long serialVersionUID
See Also:
Constant Field Values

key

protected transient short[] key
The array of keys.


value

protected transient double[] 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 Short2DoubleMap.FastEntrySet entries
Cached set of entries.


keys

protected transient volatile ShortSet keys
Cached set of keys.


values

protected transient volatile DoubleCollection values
Cached collection of values.

Constructor Detail

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(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.

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(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.

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap()
Creates a new hash map with initial expected Hash.DEFAULT_INITIAL_SIZE entries and Hash.DEFAULT_LOAD_FACTOR as load factor.


Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(Map<? extends Short,? extends Double> 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.

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(Map<? extends Short,? extends Double> 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.

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(Short2DoubleMap 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.

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(Short2DoubleMap 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.

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(short[] k,
                               double[] 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.

Short2DoubleOpenHashMap

public Short2DoubleOpenHashMap(short[] k,
                               double[] 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 double put(short k,
                  double v)
Description copied from interface: Short2DoubleFunction
Adds a pair to the map.

Specified by:
put in interface Short2DoubleFunction
Overrides:
put in class AbstractShort2DoubleFunction
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 Double put(Short ok,
                  Double ov)
Description copied from class: AbstractShort2DoubleFunction
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,Double>
Specified by:
put in interface Map<Short,Double>
Overrides:
put in class AbstractShort2DoubleFunction
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 double add(short k,
                  double 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 double remove(short k)
Description copied from interface: Short2DoubleFunction
Removes the mapping with the given key.

Specified by:
remove in interface Short2DoubleFunction
Overrides:
remove in class AbstractShort2DoubleFunction
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 Double remove(Object ok)
Description copied from class: AbstractShort2DoubleFunction
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,Double>
Specified by:
remove in interface Map<Short,Double>
Overrides:
remove in class AbstractShort2DoubleFunction
Returns:
the old value, or null if no value was present for the given key.
See Also:
Map.remove(Object)

get

public Double get(Short ok)

get

public double get(short k)
Description copied from interface: Short2DoubleFunction
Returns the value to which the given key is mapped.

Specified by:
get in interface Short2DoubleFunction
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: AbstractShort2DoubleMap
Checks whether the given value is contained in AbstractShort2DoubleMap.keySet().

Specified by:
containsKey in interface Short2DoubleFunction
Overrides:
containsKey in class AbstractShort2DoubleMap
See Also:
Function.containsKey(Object)

containsValue

public boolean containsValue(double v)
Description copied from class: AbstractShort2DoubleMap
Checks whether the given value is contained in AbstractShort2DoubleMap.values().

Specified by:
containsValue in interface Short2DoubleMap
Overrides:
containsValue in class AbstractShort2DoubleMap
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,Double>
Specified by:
clear in interface Map<Short,Double>
Overrides:
clear in class AbstractShort2DoubleFunction
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,Double>
Specified by:
size in interface Map<Short,Double>
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,Double>
Overrides:
isEmpty in class AbstractShort2DoubleMap

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)

short2DoubleEntrySet

public Short2DoubleMap.FastEntrySet short2DoubleEntrySet()
Description copied from interface: Short2DoubleMap
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 Short2DoubleMap.entrySet() so that it returns an ObjectSet of objects of type Short2DoubleMap.Entry (the latter makes it possible to access keys and values with type-specific methods).

Specified by:
short2DoubleEntrySet in interface Short2DoubleMap
Returns:
a type-specific set view of the mappings contained in this map.
See Also:
Short2DoubleMap.entrySet()

keySet

public ShortSet keySet()
Description copied from class: AbstractShort2DoubleMap
Returns a type-specific-set view of the keys of this map.

The view is backed by the set returned by AbstractShort2DoubleMap.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 Short2DoubleMap
Specified by:
keySet in interface Map<Short,Double>
Overrides:
keySet in class AbstractShort2DoubleMap
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 DoubleCollection values()
Description copied from class: AbstractShort2DoubleMap
Returns a type-specific-set view of the values of this map.

The view is backed by the set returned by AbstractShort2DoubleMap.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 Short2DoubleMap
Specified by:
values in interface Map<Short,Double>
Overrides:
values in class AbstractShort2DoubleMap
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)
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 Short2DoubleOpenHashMap 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,Double>
Overrides:
hashCode in class AbstractShort2DoubleMap
Returns:
a hash code for this map.


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