java.lang.Object
- com.carrotsearch.hppc.CharCharWormMap

All Implemented Interfaces:

Accountable, CharCharAssociativeContainer, CharCharMap, Preallocable, java.lang.Cloneable, java.lang.Iterable<CharCharCursor>
```
@Generated(date="2021-06-08T13:12:54+0200",
           value="KTypeVTypeWormMap.java")
public class CharCharWormMap
extends java.lang.Object
implements CharCharMap, Preallocable, java.lang.Cloneable, Accountable
```
A hash map of char to char, implemented using Worm Hashing strategy.
This strategy is appropriate for a medium sized map (less than 2M entries). It takes more time to put entries in the map because it maintains chains of entries having the same hash. Then the lookup speed is fast even if the map is heavy loaded or hashes are clustered. On average it takes slightly less memory than CharCharHashMap: slightly heavier but the load factor is higher (it varies around 80%) so it enlarges later.

See Also:

HPPC interfaces diagram

Nested Class Summary

Nested Classes
Modifier and Type Class Description

class CharCharWormMap.KeysContainer
A view of the keys inside this map.

Field Summary

Fields
Modifier and Type	Field	Description
`protected int`	`iterationSeed`	Seed used to ensure the hash iteration order is different from an iteration to another.
`char[]`	`keys`	The array holding keys.
`byte[]`	`next`	`abs(next[i])=offset` to next chained entry index.
`protected int`	`size`	Map size (number of entries).
`char[]`	`values`	The array holding values.

Constructor Summary

Constructors
Constructor	Description
`CharCharWormMap()`	New instance with sane defaults.
`CharCharWormMap(int expectedElements)`	New instance with the provided defaults.
`CharCharWormMap(CharCharAssociativeContainer container)`	Creates a new instance from all key-value pairs of another container.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`char`	`addTo(char key, char additionValue)`	An equivalent of calling
`protected void`	`allocateBuffers(int capacity)`
`void`	`clear()`	Clear all keys and values in the container.
`CharCharWormMap`	`clone()`	Clones this map.
`boolean`	`containsKey(char key)`	Returns `true` if this container has an association to a value for the given key.
`void`	`ensureCapacity(int expectedElements)`	Ensure this container can hold at least the given number of elements without resizing its buffers.
`boolean`	`equals(java.lang.Object o)`	Compares the specified object with this set for equality.
`<T extends CharCharProcedure> T`	`forEach(T procedure)`	Applies a given procedure to all keys-value pairs in this container.
`static CharCharWormMap`	`from(char[] keys, char[] values)`	Creates a new instance from two index-aligned arrays of key-value pairs.
`char`	`get(char key)`
`char`	`getOrDefault(char key, char defaultValue)`
`int`	`hashCode()`
`protected int`	`hashKey(char key)`
`boolean`	`indexExists(int index)`
`char`	`indexGet(int index)`	Returns the value associated with an existing key.
`void`	`indexInsert(int index, char key, char value)`	Inserts a key-value pair for a key that is not present in the map.
`int`	`indexOf(char key)`	Returns a logical "index" of a given key that can be used to speed up follow-up value setters or getters in certain scenarios (conditional logic).
`char`	`indexRemove(int index)`	Removes a key-value pair at an index previously acquired from `CharCharMap.indexOf(char)`.
`char`	`indexReplace(int index, char newValue)`	Replaces the value associated with an existing key and returns any previous value stored for that key.
`boolean`	`isEmpty()`
`java.util.Iterator<CharCharCursor>`	`iterator()`	Returns a cursor over the entries (key-value pairs) in this map.
`CharCharWormMap.KeysContainer`	`keys()`	Returns a collection of keys of this container.
`protected int`	`nextIterationSeed()`	Provides the next iteration seed used to build the iteration starting slot and offset increment.
`char`	`noValue()`	The value returned when there is no value associated to a key in this map.
`char`	`put(char key, char value)`	Place a given key and value in the container.
`int`	`putAll(CharCharAssociativeContainer container)`	Puts all keys from another container to this map, replacing the values of existing keys, if such keys are present.
`int`	`putAll(java.lang.Iterable<? extends CharCharCursor> iterable)`	Puts all keys from an iterable cursor to this map, replacing the values of existing keys, if such keys are present.
`boolean`	`putIfAbsent(char key, char value)`
`char`	`putOrAdd(char key, char putValue, char incrementValue)`	If `key` exists, `putValue` is inserted into the map, otherwise any existing value is incremented by `additionValue`.
`long`	`ramBytesAllocated()`	Allocated memory estimation
`long`	`ramBytesUsed()`	Bytes that is actually been used
`void`	`release()`	Removes all elements from the collection and additionally releases any internal buffers.
`char`	`remove(char key)`	Remove all values at the given key.
`int`	`removeAll(CharContainer other)`	Removes all keys (and associated values) present in a given container.
`int`	`removeAll(CharCharPredicate predicate)`	Removes all keys (and associated values) for which the predicate returns `true`.
`int`	`removeAll(CharPredicate predicate)`	Removes all keys (and associated values) for which the predicate returns `true`.
`int`	`size()`
`java.lang.String`	`toString()`
`CharCollection`	`values()`	Returns a container view of all values present in this container.
`java.lang.String`	`visualizeKeyDistribution(int characters)`	Visually depict the distribution of keys.

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
  - keys
```
public char[] keys
```
    The array holding keys.
  - values
```
public char[] values
```
    The array holding values.
  - next
```
public byte[] next
```
    abs(next[i])=offset to next chained entry index.
    next[i]=0 for free bucket.
    
    The offset is always forward, and the array is considered circular, meaning that an entry at the end of the array may point to an entry at the beginning with a positive offset.
    
    The offset is always forward, but the sign of the offset encodes head/tail of chain. next[i] > 0 for the first head-of-chain entry (within [1,WormUtil.maxOffset(int)]), next[i] < 0 for the subsequent tail-of-chain entries (within [-WormUtil.maxOffset(int),-1]. For the last entry in the chain, abs(next[i])=WormUtil.END_OF_CHAIN.
  - size
```
protected int size
```
    Map size (number of entries).
  - iterationSeed
```
protected int iterationSeed
```
    Seed used to ensure the hash iteration order is different from an iteration to another.
- Constructor Detail
  - CharCharWormMap
```
public CharCharWormMap()
```
    New instance with sane defaults.
  - CharCharWormMap
```
public CharCharWormMap(int expectedElements)
```
    New instance with the provided defaults.
    There is no load factor parameter as this map enlarges automatically. In practice the load factor varies around 80% (between 75% and 90%). The load factor is 100% for tiny maps.
    
    Parameters:
    
    expectedElements - The expected number of elements. The capacity of the map is calculated based on it.
  - CharCharWormMap
```
public CharCharWormMap(CharCharAssociativeContainer container)
```
    Creates a new instance from all key-value pairs of another container.
- Method Detail
  - from
```
public static CharCharWormMap from(char[] keys,
                                   char[] values)
```
    Creates a new instance from two index-aligned arrays of key-value pairs.
  - clone
```
public CharCharWormMap clone()
```
    Clones this map. The cloning operation is efficient because it copies directly the internal arrays, without having to put entries in the cloned map. The cloned map has the same entries and the same capacity as this map.
    
    Overrides:
    
    clone in class java.lang.Object
    
    Returns:
    
    A shallow copy of this map.
  - noValue
```
public char noValue()
```
    The value returned when there is no value associated to a key in this map. This method can be extended to change it.
  - size
```
public int size()
```
    Specified by:
    
    size in interface CharCharAssociativeContainer
    
    Returns:
    
    Returns the current size (number of assigned keys) in the container.
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface CharCharAssociativeContainer
    
    Returns:
    
    Return true if this hash map contains no assigned keys.
  - get
```
public char get(char key)
```
    Specified by:
    
    get in interface CharCharMap
    
    Returns:
    
    Returns the value associated with the given key or the default value for the value type, if the key is not associated with any value. For numeric value types, this default value is 0, for object types it is null.
  - getOrDefault
```
public char getOrDefault(char key,
                         char defaultValue)
```
    Specified by:
    
    getOrDefault in interface CharCharMap
    
    Returns:
    
    Returns the value associated with the given key or the provided default value if the key is not associated with any value.
  - put
```
public char put(char key,
                char value)
```
    Place a given key and value in the container.
    
    Specified by:
    
    put in interface CharCharMap
    
    Returns:
    
    The value previously stored under the given key in the map is returned.
  - putAll
```
public int putAll(CharCharAssociativeContainer 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 CharCharMap
    
    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 CharCharCursor> 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 CharCharMap
    
    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.
  - putOrAdd
```
public char putOrAdd(char 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 CharCharMap
    
    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(char key,
                  char additionValue)
```
    An equivalent of calling
    putOrAdd(key, additionValue, additionValue);
    Specified by:
    
    addTo in interface CharCharMap
    
    Parameters:
    
    key - The key of the value to adjust.
    
    additionValue - The value to put or add to the existing value if key exists.
    
    Returns:
    
    Returns the current value associated with key (after changes).
  - putIfAbsent
```
public boolean putIfAbsent(char key,
                           char value)
```
    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.
  - remove
```
public char remove(char key)
```
    Remove all values at the given key. The default value for the key type is returned if the value does not exist in the map.
    
    Specified by:
    
    remove in interface CharCharMap
  - removeAll
```
public int removeAll(CharContainer other)
```
    Removes all keys (and associated values) present in a given container. An alias to:
    keys().removeAll(container)
    but with no additional overhead.
    Specified by:
    
    removeAll in interface CharCharAssociativeContainer
    
    Returns:
    
    Returns the number of elements actually removed as a result of this call.
  - removeAll
```
public int removeAll(CharPredicate predicate)
```
    Removes all keys (and associated values) for which the predicate returns true.
    
    Specified by:
    
    removeAll in interface CharCharAssociativeContainer
    
    Returns:
    
    Returns the number of elements actually removed as a result of this call.
  - removeAll
```
public int removeAll(CharCharPredicate predicate)
```
    Removes all keys (and associated values) for which the predicate returns true.
    
    Specified by:
    
    removeAll in interface CharCharAssociativeContainer
    
    Returns:
    
    Returns the number of elements actually removed as a result of this call.
  - forEach
```
public <T extends CharCharProcedure> T forEach(T procedure)
```
    Applies a given procedure to all keys-value pairs in this container. Returns the argument (any subclass of CharCharProcedure. 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 CharCharAssociativeContainer
  - forEach
```
public <T extends CharCharPredicate> T forEach(T predicate)
```
    Applies a given predicate to all keys-value pairs in this container. Returns the argument (any subclass of CharCharPredicate. 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 CharCharAssociativeContainer
  - keys
```
public CharCharWormMap.KeysContainer keys()
```
    Returns a collection 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 CharCharAssociativeContainer
  - values
```
public CharCollection values()
```
    Returns a container view of all values present in 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:
    
    values in interface CharCharAssociativeContainer
  - iterator
```
public java.util.Iterator<CharCharCursor> 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 CharCharAssociativeContainer
    
    Specified by:
    
    iterator in interface java.lang.Iterable<CharCharCursor>
  - containsKey
```
public boolean containsKey(char key)
```
    Returns true if this container has an association to a value for the given key.
    
    Specified by:
    
    containsKey in interface CharCharAssociativeContainer
  - clear
```
public void clear()
```
    Clear all keys and values in the container.
    
    Specified by:
    
    clear in interface CharCharMap
    
    See Also:
    
    CharCharMap.release()
  - release
```
public void release()
```
    Removes all elements from the collection and additionally releases any internal buffers. Typically, if the object is to be reused, a simple CharCharMap.clear() should be a better alternative since it'll avoid reallocation.
    
    Specified by:
    
    release in interface CharCharMap
    
    See Also:
    
    CharCharMap.clear()
  - equals
```
public boolean equals(java.lang.Object o)
```
    Compares the specified object with this set for equality. Returns true if and only if the specified object is also a CharCharMap and both objects contains exactly the same key-value pairs.
    
    Specified by:
    
    equals in interface CharCharMap
    
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface CharCharMap
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    A hash code of elements stored in the map. The hash code is defined as a sum of hash codes of keys and values stored within the set). Because sum is commutative, this ensures that different order of elements in a set does not affect the hash code.
  - hashKey
```
protected int hashKey(char key)
```
  - indexOf
```
public int indexOf(char key)
```
    Returns a logical "index" of a given key that can be used to speed up follow-up value setters or getters in certain scenarios (conditional logic). The semantics of "indexes" are not strictly defined. Indexes may (and typically won't be) contiguous. The index is valid only between map modifications (it will not be affected by read-only operations like iteration or value retrievals).
    
    Specified by:
    
    indexOf in interface CharCharMap
    
    Parameters:
    
    key - The key to locate in the map.
    
    Returns:
    
    A non-negative value of the logical "index" of the key in the map or a negative value if the key did not exist.
    
    See Also:
    
    CharCharMap.indexExists(int), CharCharMap.indexGet(int), CharCharMap.indexInsert(int, char, char), CharCharMap.indexReplace(int, char)
  - indexExists
```
public boolean indexExists(int index)
```
    Specified by:
    
    indexExists in interface CharCharMap
    
    Parameters:
    
    index - The index of a given key, as returned from CharCharMap.indexOf(char).
    
    Returns:
    
    Returns true if the index corresponds to an existing key or false otherwise. This is equivalent to checking whether the index is a positive value (existing keys) or a negative value (non-existing keys).
    
    See Also:
    
    CharCharMap.indexOf(char)
  - indexGet
```
public char indexGet(int index)
```
    Returns the value associated with an existing key.
    
    Specified by:
    
    indexGet in interface CharCharMap
    
    Parameters:
    
    index - The index of an existing key.
    
    Returns:
    
    Returns the value currently associated with the key.
    
    See Also:
    
    CharCharMap.indexOf(char)
  - indexReplace
```
public char indexReplace(int index,
                         char newValue)
```
    Replaces the value associated with an existing key and returns any previous value stored for that key.
    
    Specified by:
    
    indexReplace in interface CharCharMap
    
    Parameters:
    
    index - The index of an existing key.
    
    Returns:
    
    Returns the previous value associated with the key.
    
    See Also:
    
    CharCharMap.indexOf(char)
  - indexInsert
```
public void indexInsert(int index,
                        char key,
                        char value)
```
    Inserts a key-value pair for a key that is not present in the map. This method may help in avoiding double recalculation of the key's hash.
    
    Specified by:
    
    indexInsert in interface CharCharMap
    
    Parameters:
    
    index - The index of a previously non-existing key, as returned from CharCharMap.indexOf(char).
    
    See Also:
    
    CharCharMap.indexOf(char)
  - indexRemove
```
public char indexRemove(int index)
```
    Removes a key-value pair at an index previously acquired from CharCharMap.indexOf(char).
    
    Specified by:
    
    indexRemove in interface CharCharMap
    
    Parameters:
    
    index - The index of the key to remove, as returned from CharCharMap.indexOf(char).
    
    Returns:
    
    Returns the previous value associated with the key.
    
    See Also:
    
    CharCharMap.indexOf(char)
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - ensureCapacity
```
public void ensureCapacity(int expectedElements)
```
    Ensure this container can hold at least the given number of elements without resizing its buffers.
    
    Specified by:
    
    ensureCapacity in interface Preallocable
    
    Parameters:
    
    expectedElements - The total number of elements, inclusive.
  - visualizeKeyDistribution
```
public java.lang.String visualizeKeyDistribution(int characters)
```
    Visually depict the distribution of keys.
    
    Specified by:
    
    visualizeKeyDistribution in interface CharCharMap
    
    Parameters:
    
    characters - The number of characters to "squeeze" the entire buffer into.
    
    Returns:
    
    Returns a sequence of characters where '.' depicts an empty fragment of the internal buffer and 'X' depicts full or nearly full capacity within the buffer's range and anything between 1 and 9 is between.
  - ramBytesAllocated
```
public long ramBytesAllocated()
```
    Allocated memory estimation
    
    Specified by:
    
    ramBytesAllocated in interface Accountable
    
    Returns:
    
    Ram allocated in bytes
  - ramBytesUsed
```
public long ramBytesUsed()
```
    Bytes that is actually been used
    
    Specified by:
    
    ramBytesUsed in interface Accountable
    
    Returns:
    
    Ram used in bytes
  - allocateBuffers
```
protected void allocateBuffers(int capacity)
```
  - nextIterationSeed
```
protected int nextIterationSeed()
```
    Provides the next iteration seed used to build the iteration starting slot and offset increment. This method does not need to be synchronized, what matters is that each thread gets a sequence of varying seeds.

Class CharCharWormMap

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

keys

values

next

size

iterationSeed

Constructor Detail

CharCharWormMap

CharCharWormMap

CharCharWormMap

Method Detail

from

clone

noValue

size

isEmpty

get

getOrDefault

put

putAll

putAll

putOrAdd

addTo

putIfAbsent

remove

removeAll

removeAll

removeAll

forEach

forEach

keys

values

iterator

containsKey

clear

release

equals

hashCode

hashKey

indexOf

indexExists

indexGet

indexReplace

indexInsert

indexRemove

toString

ensureCapacity

visualizeKeyDistribution

ramBytesAllocated

ramBytesUsed

allocateBuffers

nextIterationSeed