Object2IntHashMap (Agrona)

java.lang.Object
- org.agrona.collections.Object2IntHashMap<K>

Type Parameters:

K - type of keys stored in the Map

All Implemented Interfaces:

Serializable, Map<K,Integer>
```
public class Object2IntHashMap<K>
extends Object
implements Map<K,Integer>, Serializable
```
Map implementation specialised for int values using open addressing and linear probing for cache efficient access. The implementation is mirror copy of Int2ObjectHashMap and it also relies on missing value concept from Int2IntHashMap

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`class`	`Object2IntHashMap.EntryIterator` Iterator over entries which can provide unboxed access and optionally avoid allocation.
`class`	`Object2IntHashMap.EntrySet` Set of entries which can optionally cache iterators to avoid allocation.
`class`	`Object2IntHashMap.KeyIterator` Iterator over keys.
`class`	`Object2IntHashMap.KeySet` Set of keys that can optionally cache iterators to avoid allocation.
`class`	`Object2IntHashMap.ValueCollection` Collection of values which can optionally cache iterators to avoid allocation.
`class`	`Object2IntHashMap.ValueIterator` Iterator over values providing unboxed access via `Object2IntHashMap.ValueIterator.nextInt()`.

Nested classes/interfaces inherited from interface java.util.Map
Map.Entry<K,V>

Constructor Summary

Constructors
Constructor and Description
`Object2IntHashMap(int missingValue)` Construct a map with default capacity and load factor.
`Object2IntHashMap(int initialCapacity, float loadFactor, int missingValue)` Construct a new map allowing a configuration for initial capacity and load factor.
`Object2IntHashMap(int initialCapacity, float loadFactor, int missingValue, boolean shouldAvoidAllocation)` Construct a new map allowing a configuration for initial capacity and load factor.
`Object2IntHashMap(Object2IntHashMap<K> mapToCopy)` Copy construct a new map from an existing one.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`capacity()` Get the total capacity for the map to which the load factor will be a fraction of.
`void`	`clear()`
`void`	`compact()` Compact the `Map` backing arrays by rehashing with a capacity just larger than current size and giving consideration to the load factor.
`int`	`computeIfAbsent(K key, ToIntFunction<? super K> mappingFunction)` Get a value for a given key, or if it does not exist then default the value via a `IntFunction` and put it in the map.
`boolean`	`containsKey(Object key)` Overloaded version of `Map.containsKey(Object)` that takes a primitive int key.
`boolean`	`containsValue(int value)` Overloaded version to avoid boxing.
`boolean`	`containsValue(Object value)`
`Object2IntHashMap.EntrySet`	`entrySet()`
`boolean`	`equals(Object o)`
`Integer`	`get(Object key)`
`int`	`getValue(K key)` Overloaded version of `Map.get(Object)` that takes a primitive int key.
`int`	`hashCode()`
`boolean`	`isEmpty()`
`Object2IntHashMap.KeySet`	`keySet()`
`float`	`loadFactor()` Get the load factor beyond which the map will increase size.
`int`	`missingValue()` The value to be used as a null marker in the map.
`int`	`put(K key, int value)` Overloaded version of `Map.put(Object, Object)` that takes a primitive int key.
`Integer`	`put(K key, Integer value)`
`void`	`putAll(Map<? extends K,? extends Integer> map)`
`Integer`	`remove(Object key)`
`int`	`removeKey(K key)` Overloaded version of `Map.remove(Object)` that takes a key and returns a primitive int value.
`int`	`replace(K key, int value)` Primitive specialised version of `Map.replace(Object, Object)`
`boolean`	`replace(K key, int oldValue, int newValue)` Primitive specialised version of `Map.replace(Object, Object, Object)`
`int`	`resizeThreshold()` Get the actual threshold which when reached the map will resize.
`int`	`size()`
`String`	`toString()`
`Object2IntHashMap.ValueCollection`	`values()`

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

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

- Constructor Detail
  - Object2IntHashMap
```
public Object2IntHashMap(int missingValue)
```
    Construct a map with default capacity and load factor.
    
    Parameters:
    
    missingValue - value to be used as a null maker in the map
  - Object2IntHashMap
```
public Object2IntHashMap(int initialCapacity,
                         float loadFactor,
                         int missingValue)
```
    Construct a new map allowing a configuration for initial capacity and load factor.
    
    Parameters:
    
    initialCapacity - for the backing array
    
    loadFactor - limit for resizing on puts
    
    missingValue - value to be used as a null marker in the map
  - Object2IntHashMap
```
public Object2IntHashMap(int initialCapacity,
                         float loadFactor,
                         int missingValue,
                         boolean shouldAvoidAllocation)
```
    Construct a new map allowing a configuration for initial capacity and load factor.
    
    Parameters:
    
    initialCapacity - for the backing array
    
    loadFactor - limit for resizing on puts
    
    missingValue - value to be used as a null marker in the map
    
    shouldAvoidAllocation - should allocation be avoided by caching iterators and map entries.
  - Object2IntHashMap
```
public Object2IntHashMap(Object2IntHashMap<K> mapToCopy)
```
    Copy construct a new map from an existing one.
    
    Parameters:
    
    mapToCopy - for construction.
- Method Detail
  - missingValue
```
public int missingValue()
```
    The value to be used as a null marker in the map.
    
    Returns:
    
    value to be used as a null marker in the map.
  - loadFactor
```
public float loadFactor()
```
    Get the load factor beyond which the map will increase size.
    
    Returns:
    
    load factor for when the map should increase size.
  - capacity
```
public int capacity()
```
    Get the total capacity for the map to which the load factor will be a fraction of.
    
    Returns:
    
    the total capacity for the map.
  - resizeThreshold
```
public int resizeThreshold()
```
    Get the actual threshold which when reached the map will resize. This is a function of the current capacity and load factor.
    
    Returns:
    
    the threshold when the map will resize.
  - size
```
public int size()
```
    Specified by:
    
    size in interface Map<K,Integer>
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Map<K,Integer>
  - containsKey
```
public boolean containsKey(Object key)
```
    Overloaded version of Map.containsKey(Object) that takes a primitive int key.
    
    Specified by:
    
    containsKey in interface Map<K,Integer>
    
    Parameters:
    
    key - for indexing the Map
    
    Returns:
    
    true if the key is found otherwise false.
  - containsValue
```
public boolean containsValue(Object value)
```
    Specified by:
    
    containsValue in interface Map<K,Integer>
  - containsValue
```
public boolean containsValue(int value)
```
    Overloaded version to avoid boxing.
    
    Parameters:
    
    value - to check.
    
    Returns:
    
    true if the collection contains the value.
  - get
```
public Integer get(Object key)
```
    Specified by:
    
    get in interface Map<K,Integer>
  - getValue
```
public int getValue(K key)
```
    Overloaded version of Map.get(Object) that takes a primitive int key. Due to type erasure have to rename the method
    
    Parameters:
    
    key - for indexing the Map
    
    Returns:
    
    the value if found otherwise missingValue
  - computeIfAbsent
```
public int computeIfAbsent(K key,
                           ToIntFunction<? super K> mappingFunction)
```
    Get a value for a given key, or if it does not exist then default the value via a IntFunction and put it in the map.
    Primitive specialized version of Map.computeIfAbsent(K, java.util.function.Function<? super K, ? extends V>).
    
    Parameters:
    
    key - to search on.
    
    mappingFunction - to provide a value if the get returns missingValue.
    
    Returns:
    
    the value if found otherwise the default.
  - put
```
public Integer put(K key,
                   Integer value)
```
    Specified by:
    
    put in interface Map<K,Integer>
  - put
```
public int put(K key,
               int value)
```
    Overloaded version of Map.put(Object, Object) that takes a primitive int key.
    
    Parameters:
    
    key - for indexing the Map
    
    value - to be inserted in the Map
    
    Returns:
    
    the previous value if found otherwise missingValue
  - remove
```
public Integer remove(Object key)
```
    Specified by:
    
    remove in interface Map<K,Integer>
  - removeKey
```
public int removeKey(K key)
```
    Overloaded version of Map.remove(Object) that takes a key and returns a primitive int value. Due to type erasure have to rename the method
    
    Parameters:
    
    key - for indexing the Map
    
    Returns:
    
    the value if found otherwise missingValue
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Map<K,Integer>
  - compact
```
public void compact()
```
    Compact the Map backing arrays by rehashing with a capacity just larger than current size and giving consideration to the load factor.
  - putAll
```
public void putAll(Map<? extends K,? extends Integer> map)
```
    Specified by:
    
    putAll in interface Map<K,Integer>
  - keySet
```
public Object2IntHashMap.KeySet keySet()
```
    Specified by:
    
    keySet in interface Map<K,Integer>
  - values
```
public Object2IntHashMap.ValueCollection values()
```
    Specified by:
    
    values in interface Map<K,Integer>
  - entrySet
```
public Object2IntHashMap.EntrySet entrySet()
```
    Specified by:
    
    entrySet in interface Map<K,Integer>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - equals
```
public boolean equals(Object o)
```
    Specified by:
    
    equals in interface Map<K,Integer>
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Map<K,Integer>
    
    Overrides:
    
    hashCode in class Object
  - replace
```
public int replace(K key,
                   int value)
```
    Primitive specialised version of Map.replace(Object, Object)
    
    Parameters:
    
    key - key with which the specified value is associated
    
    value - value to be associated with the specified key
    
    Returns:
    
    the previous value associated with the specified key, or null if there was no mapping for the key.
  - replace
```
public boolean replace(K key,
                       int oldValue,
                       int newValue)
```
    Primitive specialised version of Map.replace(Object, Object, Object)
    
    Parameters:
    
    key - key with which the specified value is associated
    
    oldValue - value expected to be associated with the specified key
    
    newValue - value to be associated with the specified key
    
    Returns:
    
    true if the value was replaced

Class Object2IntHashMap<K>

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Map

Constructor Detail

Object2IntHashMap

Object2IntHashMap

Object2IntHashMap

Object2IntHashMap

Method Detail

missingValue

loadFactor

capacity

resizeThreshold

size

isEmpty

containsKey

containsValue

containsValue

get

getValue

computeIfAbsent

put

put

remove

removeKey

clear

compact

putAll

keySet

values

entrySet

toString

equals

hashCode

replace

replace