ObjectCharHashMap (HPPC-RT v0.7.5 API Documentation)

java.lang.Object
- com.carrotsearch.hppcrt.maps.ObjectCharHashMap<KType>

All Implemented Interfaces:

ObjectCharAssociativeContainer<KType>, ObjectCharMap<KType>, java.lang.Cloneable, java.lang.Iterable<ObjectCharCursor<KType>>

Direct Known Subclasses:

ObjectCharIdentityHashMap
```
@Generated(date="2017-07-11T19:16:27+0200",
           value="KTypeVTypeHashMap.java")
public class ObjectCharHashMap<KType>
extends java.lang.Object
implements ObjectCharMap<KType>, java.lang.Cloneable
```
A hash map of Object to char, implemented using open addressing with linear probing for collision resolution.
In addition, the hashing strategy can be changed by overriding (equalKeys(Object, Object) and hashKey(Object)) together, which then replaces the usual (equals(Object) and hashCode()) from the keys themselves. This is useful to define the equivalence of keys when the user has no control over the keys implementation.

The internal buffers of this implementation (keys, values), are always allocated to the nearest size that is a power of two. When the capacity exceeds the given load factor, the buffer size is doubled.

This implementation supports null keys.

Important note. The implementation uses power-of-two tables and linear probing, which may cause poor performance (many collisions) if hash values are not properly distributed.
Robin-Hood hashing algorithm is also used to minimize variance in insertion and search-related operations, for an all-around smother operation at the cost of smaller peak performance:

- Pedro Celis (1986) for the original Robin-Hood hashing paper,

- MoonPolySoft/Cliff Moon for the initial Robin-hood on HPPC implementation,

- Vincent Sonnier for the present implementation using cached hashes.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`class`	`ObjectCharHashMap.EntryIterator` An iterator implementation for `iterator()`.
`class`	`ObjectCharHashMap.KeysCollection` A view of the keys inside this map.
`class`	`ObjectCharHashMap.KeysIterator` An iterator over the set of keys.
`class`	`ObjectCharHashMap.ValuesCollection` A view over the set of values of this map.
`class`	`ObjectCharHashMap.ValuesIterator` An iterator over the set of values.

Field Summary

Fields
Modifier and Type	Field and Description
`boolean`	`allocatedDefaultKey` True if key = 0/null is in the map.
`char`	`allocatedDefaultKeyValue` if allocatedDefaultKey = true, contains the associated V to the key = 0/null
`protected int`	`assigned` Cached number of assigned slots in `keys`.
`protected char`	`defaultValue`
`protected IteratorPool<ObjectCharCursor<KType>,ObjectCharHashMap.EntryIterator>`	`entryIteratorPool` internal pool of EntryIterator
`protected int[]`	`hash_cache` * Caches the hash value = hash(keys[i]) & mask, if keys[i] !
`java.lang.Object[]`	`keys` Hash-indexed array holding all keys.
`protected double`	`loadFactor` The load factor for this map (fraction of allocated slots before the buffers must be rehashed or reallocated).
`char[]`	`values` Hash-indexed array holding all values associated to the keys.

Constructor Summary

Constructors
Constructor and Description
`ObjectCharHashMap()` Default constructor: Creates a hash map with the default capacity of `Containers.DEFAULT_EXPECTED_ELEMENTS`, load factor of `HashContainers.DEFAULT_LOAD_FACTOR`.
`ObjectCharHashMap(int initialCapacity)` Creates a hash map with the given initial capacity, default load factor of `HashContainers.DEFAULT_LOAD_FACTOR`.
`ObjectCharHashMap(int initialCapacity, double loadFactor)` Creates a hash map with the given initial capacity, load factor.
`ObjectCharHashMap(ObjectCharAssociativeContainer<KType> container)` Create a hash map from all key-value pairs of another container.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`char`	`addTo(KType key, char incrementValue)` Adds `incrementValue` to any existing value for the given `key` or inserts `incrementValue` if `key` did not previously exist.
`int`	`capacity()` Return the maximum number of keys this container is guaranteed to hold without reallocating.
`void`	`clear()` Clear all keys and values in the container.
`ObjectCharHashMap<KType>`	`clone()`
`boolean`	`containsKey(KType key)` Returns `true` if this container has an association to a value for the given key.
`protected boolean`	`equalKeys(KType a, KType b)` Override this method together with `hashKey(Object)` to customize the hashing strategy.
`boolean`	`equals(java.lang.Object obj)`
`<T extends ObjectCharPredicate<? super KType>> T`	`forEach(T predicate)` Applies a `predicate` to container elements, as long as the predicate returns `true`.
`<T extends ObjectCharProcedure<? super KType>> T`	`forEach(T procedure)` Applies a given procedure to all keys-value pairs in this container.
`static <KType> ObjectCharHashMap<KType>`	`from(KType[] keys, char[] values)` Creates a hash map from two index-aligned arrays of key-value pairs.
`static <KType> ObjectCharHashMap<KType>`	`from(ObjectCharAssociativeContainer<KType> container)` Create a hash map from another associative container.
`char`	`get(KType key)`
`char`	`getDefaultValue()` Returns the "default value" value used in containers methods returning "default value"
`int`	`hashCode()`
`protected int`	`hashKey(KType key)` Override this method, together with `equalKeys(Object, Object)` to customize the hashing strategy.
`boolean`	`isEmpty()` Note that an empty container may still contain many deleted keys (that occupy buffer space).
`ObjectCharHashMap.EntryIterator`	`iterator()` Returns a cursor over the entries (key-value pairs) in this map.
`ObjectCharHashMap.KeysCollection`	`keys()` Returns a collection view of keys of this container.
`static <KType> ObjectCharHashMap<KType>`	`newInstance()` Create a new hash map without providing the full generic signature (constructor shortcut).
`static <KType> ObjectCharHashMap<KType>`	`newInstance(int initialCapacity, double loadFactor)` Create a new hash map with initial capacity and load factor control.
`char`	`put(KType key, char value)` Place a given key and value in the container.
`int`	`putAll(java.lang.Iterable<? extends ObjectCharCursor<? extends KType>> iterable)` Puts all keys from an iterable cursor to this map, replacing the values of existing keys, if such keys are present.
`int`	`putAll(ObjectCharAssociativeContainer<? extends KType> container)` Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.
`boolean`	`putIfAbsent(KType key, char value)` Trove-inspired API method.
`char`	`putOrAdd(KType key, char putValue, char incrementValue)` If `key` exists, `putValue` is inserted into the map, otherwise any existing value is incremented by `additionValue`.
`char`	`remove(KType key)` Remove the (key, value) pair associated with the given key, and returns the assocaited value.
`int`	`removeAll(ObjectCharPredicate<? super KType> predicate)` Removes all keys (and associated values) for which the predicate on (key, value) pairs returns `true`.
`int`	`removeAll(ObjectContainer<? super KType> other)` Removes all keys (and associated values) present in a given container.
`int`	`removeAll(ObjectPredicate<? super KType> predicate)` Removes all keys (and associated values) for which the predicate on keys returns `true`.
`void`	`setDefaultValue(char defaultValue)` Set the "default value" value to be used in containers methods returning "default value"
`int`	`size()`
`java.lang.String`	`toString()` Convert the contents of this map to a human-friendly string.
`ObjectCharHashMap.ValuesCollection`	`values()` Returns a collection view of all values present in this container.

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Field Detail
  - defaultValue
```
protected char defaultValue
```
  - keys
```
public java.lang.Object[] keys
```
    Hash-indexed array holding all keys.
    Direct map iteration: iterate {keys[i], values[i]} for i in [0; keys.length[ where keys[i] != 0/null, then also {0/null, allocatedDefaultKeyValue } is in the map if allocatedDefaultKey = true.
  - values
```
public char[] values
```
    Hash-indexed array holding all values associated to the keys. stored in keys.
  - hash_cache
```
protected int[] hash_cache
```
    * Caches the hash value = hash(keys[i]) & mask, if keys[i] != 0/null, for every index i. * @see #assigned
  - allocatedDefaultKey
```
public boolean allocatedDefaultKey
```
    True if key = 0/null is in the map.
  - allocatedDefaultKeyValue
```
public char allocatedDefaultKeyValue
```
    if allocatedDefaultKey = true, contains the associated V to the key = 0/null
  - assigned
```
protected int assigned
```
    Cached number of assigned slots in keys.
  - loadFactor
```
protected final double loadFactor
```
    The load factor for this map (fraction of allocated slots before the buffers must be rehashed or reallocated).
  - entryIteratorPool
```
protected final IteratorPool<ObjectCharCursor<KType>,ObjectCharHashMap.EntryIterator> entryIteratorPool
```
    internal pool of EntryIterator
- Constructor Detail
  - ObjectCharHashMap
```
public ObjectCharHashMap()
```
    Default constructor: Creates a hash map with the default capacity of Containers.DEFAULT_EXPECTED_ELEMENTS, load factor of HashContainers.DEFAULT_LOAD_FACTOR.
    See class notes about hash distribution importance.
  - ObjectCharHashMap
```
public ObjectCharHashMap(int initialCapacity)
```
    Creates a hash map with the given initial capacity, default load factor of HashContainers.DEFAULT_LOAD_FACTOR.
    See class notes about hash distribution importance.
    
    Parameters:
    
    initialCapacity - Initial capacity (greater than zero and automatically rounded to the next power of two).
  - ObjectCharHashMap
```
public ObjectCharHashMap(int initialCapacity,
                         double loadFactor)
```
    Creates a hash map with the given initial capacity, load factor.
    
    Parameters:
    
    loadFactor - The load factor (greater than zero and smaller than 1).
  - ObjectCharHashMap
```
public ObjectCharHashMap(ObjectCharAssociativeContainer<KType> container)
```
    Create a hash map from all key-value pairs of another container.
- Method Detail
  - hashKey
```
protected int hashKey(KType key)
```
    Override this method, together with equalKeys(Object, Object) to customize the hashing strategy. Note that this method is guaranteed to be called with a non-null key argument. By default, this method calls key.hashCode().
    
    Parameters:
    
    key - Object to be hashed.
    
    Returns:
    
    the hashed value of key, following the same semantic as hashCode();
    
    See Also:
    
    hashCode(), equalKeys(Object, Object)
  - equalKeys
```
protected boolean equalKeys(KType a,
                            KType b)
```
    Override this method together with hashKey(Object) to customize the hashing strategy. Note that this method is guaranteed to be called with both non-null arguments. By default, this method calls a.#equals(b).
    
    Parameters:
    
    a - not-null Object to be compared
    
    b - not-null Object to be compared
    
    Returns:
    
    true if a and b are considered equal, following the same semantic as equals(Object).
    
    See Also:
    
    equals(Object), hashKey(Object)
  - put
```
public char put(KType key,
                char value)
```
    Place a given key and value in the container.
    
    Specified by:
    
    put in interface ObjectCharMap<KType>
    
    Returns:
    
    Returns the value previously stored under the given key, if an equal key is already in the map and replaces the existing value only with the argument value. If the given key was not already in the map, the given (key, value) pair is inserted in the map and the default value is returned.
  - putAll
```
public int putAll(ObjectCharAssociativeContainer<? extends KType> container)
```
    Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.
    
    Specified by:
    
    putAll in interface ObjectCharMap<KType>
    
    Returns:
    
    Returns the number of keys added to the map as a result of this call (not previously present in the map). Values of existing keys are overwritten.
  - putAll
```
public int putAll(java.lang.Iterable<? extends ObjectCharCursor<? extends KType>> iterable)
```
    Puts all keys from an iterable cursor to this map, replacing the values of existing keys, if such keys are present.
    
    Specified by:
    
    putAll in interface ObjectCharMap<KType>
    
    Returns:
    
    Returns the number of keys added to the map as a result of this call (not previously present in the map). Values of existing keys are overwritten.
  - putIfAbsent
```
public boolean putIfAbsent(KType key,
                           char value)
```
    Trove-inspired API method. An equivalent of the following code:
```
 if (!map.containsKey(key))
      map.put(key, value);
 
```
    Specified by:
    
    putIfAbsent in interface ObjectCharMap<KType>
    
    Parameters:
    
    key - The key of the value to check.
    
    value - The value to put if key does not exist.
    
    Returns:
    
    true if key did not exist and value was placed in the map.
  - putOrAdd
```
public char putOrAdd(KType key,
                     char putValue,
                     char incrementValue)
```
    If key exists, putValue is inserted into the map, otherwise any existing value is incremented by additionValue.
    
    Specified by:
    
    putOrAdd in interface ObjectCharMap<KType>
    
    Parameters:
    
    key - The key of the value to adjust.
    
    putValue - The value to put if key does not exist.
    
    incrementValue - The value to add to the existing value if key exists.
    
    Returns:
    
    Returns the current value associated with key (after changes).
  - addTo
```
public char addTo(KType key,
                  char incrementValue)
```
    Adds incrementValue to any existing value for the given key or inserts incrementValue if key did not previously exist.
    
    Specified by:
    
    addTo in interface ObjectCharMap<KType>
    
    Parameters:
    
    key - The key of the value to adjust.
    
    incrementValue - The value to put or add to the existing value if key exists.
    
    Returns:
    
    Returns the current value associated with key (after changes).
  - remove
```
public char remove(KType key)
```
    Remove the (key, value) pair associated with the given key, and returns the assocaited value. The default value is returned if the key did not exist in the map.
    
    Specified by:
    
    remove in interface ObjectCharMap<KType>
  - removeAll
```
public int removeAll(ObjectContainer<? super KType> other)
```
    Removes all keys (and associated values) present in a given container.
    
    Specified by:
    
    removeAll in interface ObjectCharAssociativeContainer<KType>
    
    Returns:
    
    Returns the number of elements actually removed as a result of this call.
  - removeAll
```
public int removeAll(ObjectPredicate<? super KType> predicate)
```
    Removes all keys (and associated values) for which the predicate on keys returns true.
    
    Specified by:
    
    removeAll in interface ObjectCharAssociativeContainer<KType>
    
    Returns:
    
    Returns the number of elements actually removed as a result of this call.
  - removeAll
```
public int removeAll(ObjectCharPredicate<? super KType> predicate)
```
    Removes all keys (and associated values) for which the predicate on (key, value) pairs returns true.
    
    Specified by:
    
    removeAll in interface ObjectCharAssociativeContainer<KType>
    
    Returns:
    
    Returns the number of elements actually removed as a result of this call.
  - get
```
public char get(KType key)
```
    Specified by:
    
    get in interface ObjectCharMap<KType>
    
    Returns:
    
    Returns the value associated with the given key, or the default value if the key is not associated with any value.
  - containsKey
```
public boolean containsKey(KType key)
```
    Returns true if this container has an association to a value for the given key.
    
    Specified by:
    
    containsKey in interface ObjectCharAssociativeContainer<KType>
  - clear
```
public void clear()
```
    Clear all keys and values in the container.
    
    Specified by:
    
    clear in interface ObjectCharMap<KType>
  - size
```
public int size()
```
    Specified by:
    
    size in interface ObjectCharAssociativeContainer<KType>
    
    Returns:
    
    Returns the current size (number of assigned keys) in the container.
  - capacity
```
public int capacity()
```
    Return the maximum number of keys this container is guaranteed to hold without reallocating. The time for calculating the container's capacity may take O(n) time.
    
    Specified by:
    
    capacity in interface ObjectCharAssociativeContainer<KType>
  - isEmpty
```
public boolean isEmpty()
```
    Note that an empty container may still contain many deleted keys (that occupy buffer space). Adding even a single element to such a container may cause rehashing.
    
    Specified by:
    
    isEmpty in interface ObjectCharAssociativeContainer<KType>
    
    Returns:
    
    Return true if this hash map contains no assigned keys.
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Overrides:
    
    equals in class java.lang.Object
  - iterator
```
public ObjectCharHashMap.EntryIterator iterator()
```
    Returns a cursor over the entries (key-value pairs) in this map. The iterator is implemented as a cursor and it returns the same cursor instance on every call to Iterator.next(). To read the current key and value use the cursor's public fields. An example is shown below.
```
 for (IntShortCursor c : intShortMap)
 {
     System.out.println("index=" + c.index
       + " key=" + c.key
       + " value=" + c.value);
 }
 
```
    The index field inside the cursor gives the internal index inside the container's implementation. The interpretation of this index depends on to the container.
    Specified by:
    
    iterator in interface ObjectCharAssociativeContainer<KType>
    
    Specified by:
    
    iterator in interface java.lang.Iterable<ObjectCharCursor<KType>>
  - forEach
```
public <T extends ObjectCharProcedure<? super KType>> T forEach(T procedure)
```
    Applies a given procedure to all keys-value pairs in this container. Returns the argument (any subclass of ObjectCharProcedure. This lets the caller to call methods of the argument by chaining the call (even if the argument is an anonymous type) to retrieve computed values, for example.
    
    Specified by:
    
    forEach in interface ObjectCharAssociativeContainer<KType>
  - forEach
```
public <T extends ObjectCharPredicate<? super KType>> T forEach(T predicate)
```
    Applies a predicate to container elements, as long as the predicate returns true. The iteration is interrupted otherwise. Returns the argument (any subclass of ObjectCharPredicate. This lets the caller to call methods of the argument by chaining the call (even if the argument is an anonymous type) to retrieve computed values, for example. The iteration is continued as long as the predicate returns true.
    
    Specified by:
    
    forEach in interface ObjectCharAssociativeContainer<KType>
  - keys
```
public ObjectCharHashMap.KeysCollection keys()
```
    Returns a collection view of keys of this container. The returned collection is a view over the key set and any modifications (if allowed) introduced to the collection will propagate to the associative container immediately.
    
    Specified by:
    
    keys in interface ObjectCharAssociativeContainer<KType>
    
    Returns:
    
    a new KeysCollection view of the keys of this map.
  - values
```
public ObjectCharHashMap.ValuesCollection values()
```
    Returns a collection view of all values present in this container. The returned collection is a view over the value set and any modifications (if allowed) introduced to the collection will propagate to the associative container immediately.
    
    Specified by:
    
    values in interface ObjectCharAssociativeContainer<KType>
    
    Returns:
    
    a new ValuesCollection view of the values of this map.
  - clone
```
public ObjectCharHashMap<KType> clone()
```
    Overrides:
    
    clone in class java.lang.Object
  - toString
```
public java.lang.String toString()
```
    Convert the contents of this map to a human-friendly string.
    
    Overrides:
    
    toString in class java.lang.Object
  - from
```
public static <KType> ObjectCharHashMap<KType> from(KType[] keys,
                                                    char[] values)
```
    Creates a hash map from two index-aligned arrays of key-value pairs. Default load factor is used.
  - from
```
public static <KType> ObjectCharHashMap<KType> from(ObjectCharAssociativeContainer<KType> container)
```
    Create a hash map from another associative container. (constructor shortcut) Default load factor is used.
  - newInstance
```
public static <KType> ObjectCharHashMap<KType> newInstance()
```
    Create a new hash map without providing the full generic signature (constructor shortcut).
  - newInstance
```
public static <KType> ObjectCharHashMap<KType> newInstance(int initialCapacity,
                                                           double loadFactor)
```
    Create a new hash map with initial capacity and load factor control. (constructor shortcut).
  - getDefaultValue
```
public char getDefaultValue()
```
    Returns the "default value" value used in containers methods returning "default value"
    
    Specified by:
    
    getDefaultValue in interface ObjectCharMap<KType>
  - setDefaultValue
```
public void setDefaultValue(char defaultValue)
```
    Set the "default value" value to be used in containers methods returning "default value"
    
    Specified by:
    
    setDefaultValue in interface ObjectCharMap<KType>

Class ObjectCharHashMap<KType>

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Field Detail

defaultValue

keys

values

hash_cache

allocatedDefaultKey

allocatedDefaultKeyValue

assigned

loadFactor

entryIteratorPool

Constructor Detail

ObjectCharHashMap

ObjectCharHashMap

ObjectCharHashMap

ObjectCharHashMap

Method Detail

hashKey

equalKeys

put

putAll

putAll

putIfAbsent

putOrAdd

addTo

remove

removeAll

removeAll

removeAll

get

containsKey

clear

size

capacity

isEmpty

hashCode

equals

iterator

forEach

forEach

keys

values

clone

toString

from

from

newInstance

newInstance

getDefaultValue

setDefaultValue