Long2ObjectHashMap (Agrona)

java.lang.Object
- org.agrona.collections.Long2ObjectHashMap<V>

Type Parameters:

V - type of values stored in the Map

All Implemented Interfaces:

Map<Long,V>

Direct Known Subclasses:

Long2NullableObjectHashMap
```
public class Long2ObjectHashMap<V>
extends Object
implements Map<Long,V>
```
Map implementation specialised for long keys using open addressing and linear probing for cache efficient access.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`class`	`Long2ObjectHashMap.EntryIterator` Iterator over entries which supports access to unboxed keys via `Long2ObjectHashMap.EntryIterator.getLongKey()`.
`class`	`Long2ObjectHashMap.EntrySet` Set of entries which supports access via an optionally cached iterator to avoid allocation.
`class`	`Long2ObjectHashMap.KeyIterator` Iterator over keys which supports access to unboxed keys via `Long2ObjectHashMap.KeyIterator.nextLong()`.
`class`	`Long2ObjectHashMap.KeySet` Set of keys which supports optionally cached iterators to avoid allocation.
`class`	`Long2ObjectHashMap.ValueCollection` Collection of values which supports optionally cached iterators to avoid allocation.
`class`	`Long2ObjectHashMap.ValueIterator` Iterator over values.

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

Constructor Summary

Constructors
Constructor and Description
`Long2ObjectHashMap()` Constructs map with `MIN_CAPACITY`, `Hashing.DEFAULT_LOAD_FACTOR` and enables caching of iterators.
`Long2ObjectHashMap(int initialCapacity, float loadFactor)` Constructs map with given initial capacity and load factory and enables caching of iterators.
`Long2ObjectHashMap(int initialCapacity, float loadFactor, boolean shouldAvoidAllocation)` Construct a new map allowing a configuration for initial capacity and load factor.
`Long2ObjectHashMap(Long2ObjectHashMap<V> 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.
`V`	`compute(long key, LongObjectToObjectFunction<? super V,? extends V> remappingFunction)` Attempts to compute a mapping for the specified key and its current mapped value (or `null` if there is no current mapping).
`V`	`computeIfAbsent(long key, LongFunction<? extends V> mappingFunction)` Get a value for a given key, or if it does not exist then default the value via a `LongFunction` and put it in the map.
`V`	`computeIfPresent(long key, LongObjectToObjectFunction<? super V,? extends V> remappingFunction)` If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.
`boolean`	`containsKey(long key)` Overloaded version of `Map.containsKey(Object)` that takes a primitive long key.
`boolean`	`containsKey(Object key)`
`boolean`	`containsValue(Object value)`
`Long2ObjectHashMap.EntrySet`	`entrySet()`
`boolean`	`equals(Object o)`
`V`	`get(long key)` Overloaded version of `Map.get(Object)` that takes a primitive long key.
`V`	`get(Object key)`
`protected V`	`getMapped(long key)` Get mapped value without boxing the key.
`int`	`hashCode()`
`boolean`	`isEmpty()`
`Long2ObjectHashMap.KeySet`	`keySet()`
`float`	`loadFactor()` Get the load factor beyond which the map will increase size.
`void`	`longForEach(LongObjConsumer<V> consumer)` Primitive specialised forEach implementation.
`protected Object`	`mapNullValue(Object value)` Longerceptor for masking null values.
`V`	`put(long key, V value)` Overloaded version of `Map.put(Object, Object)` that takes a primitive long key.
`V`	`put(Long key, V value)`
`void`	`putAll(Map<? extends Long,? extends V> map)`
`V`	`remove(long key)` Overloaded version of `Map.remove(Object)` that takes a primitive long key.
`V`	`remove(Object key)`
`V`	`replace(long key, V value)` Primitive specialised version of `Map.replace(Object, Object)`
`boolean`	`replace(long key, V oldValue, V 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()`
`protected V`	`unmapNullValue(Object value)` Longerceptor for unmasking null values.
`Long2ObjectHashMap.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
  - Long2ObjectHashMap
```
public Long2ObjectHashMap()
```
    Constructs map with MIN_CAPACITY, Hashing.DEFAULT_LOAD_FACTOR and enables caching of iterators.
  - Long2ObjectHashMap
```
public Long2ObjectHashMap(int initialCapacity,
                          float loadFactor)
```
    Constructs map with given initial capacity and load factory and enables caching of iterators.
    
    Parameters:
    
    initialCapacity - for the backing array
    
    loadFactor - limit for resizing on puts
  - Long2ObjectHashMap
```
public Long2ObjectHashMap(int initialCapacity,
                          float loadFactor,
                          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
    
    shouldAvoidAllocation - should allocation be avoided by caching iterators and map entries.
  - Long2ObjectHashMap
```
public Long2ObjectHashMap(Long2ObjectHashMap<V> mapToCopy)
```
    Copy construct a new map from an existing one.
    
    Parameters:
    
    mapToCopy - for construction.
- Method Detail
  - 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<Long,V>
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Map<Long,V>
  - longForEach
```
public void longForEach(LongObjConsumer<V> consumer)
```
    Primitive specialised forEach implementation.
    NB: Renamed from forEach to avoid overloading on parameter types of lambda expression, which doesn't play well with type inference in lambda expressions.
    
    Parameters:
    
    consumer - a callback called for each key/value pair in the map.
  - containsKey
```
public boolean containsKey(Object key)
```
    Specified by:
    
    containsKey in interface Map<Long,V>
  - containsKey
```
public boolean containsKey(long key)
```
    Overloaded version of Map.containsKey(Object) that takes a primitive long key.
    
    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<Long,V>
  - get
```
public V get(Object key)
```
    Specified by:
    
    get in interface Map<Long,V>
  - get
```
public V get(long key)
```
    Overloaded version of Map.get(Object) that takes a primitive long key.
    
    Parameters:
    
    key - for indexing the Map.
    
    Returns:
    
    the value if found otherwise null.
  - getMapped
```
protected V getMapped(long key)
```
    Get mapped value without boxing the key.
    
    Parameters:
    
    key - to get value by.
    
    Returns:
    
    mapped value or null.
  - computeIfAbsent
```
public V computeIfAbsent(long key,
                         LongFunction<? extends V> mappingFunction)
```
    Get a value for a given key, or if it does not exist then default the value via a LongFunction 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 null.
    
    Returns:
    
    the value if found otherwise the default.
  - computeIfPresent
```
public V computeIfPresent(long key,
                          LongObjectToObjectFunction<? super V,? extends V> remappingFunction)
```
    If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value.
    If the function returns null, the mapping is removed.
    Primitive specialized version of Map.computeIfPresent(K, java.util.function.BiFunction<? super K, ? super V, ? extends V>).
    
    Parameters:
    
    key - to search on.
    
    remappingFunction - to provide a value if the get returns missingValue.
    
    Returns:
    
    the new value associated with the specified key, or null if none.
  - compute
```
public V compute(long key,
                 LongObjectToObjectFunction<? super V,? extends V> remappingFunction)
```
    Attempts to compute a mapping for the specified key and its current mapped value (or null if there is no current mapping).
    If the function returns null, the mapping is removed (or remains absent if initially absent).
    Primitive specialized version of Map.compute(K, java.util.function.BiFunction<? super K, ? super V, ? extends V>).
    
    Parameters:
    
    key - to search on.
    
    remappingFunction - to provide a value if the get returns missingValue.
    
    Returns:
    
    the new value associated with the specified key, or null if none.
  - put
```
public V put(Long key,
             V value)
```
    Specified by:
    
    put in interface Map<Long,V>
  - put
```
public V put(long key,
             V value)
```
    Overloaded version of Map.put(Object, Object) that takes a primitive long key.
    
    Parameters:
    
    key - for indexing the Map.
    
    value - to be inserted in the Map.
    
    Returns:
    
    the previous value if found otherwise null.
  - remove
```
public V remove(Object key)
```
    Specified by:
    
    remove in interface Map<Long,V>
  - remove
```
public V remove(long key)
```
    Overloaded version of Map.remove(Object) that takes a primitive long key.
    
    Parameters:
    
    key - for indexing the Map.
    
    Returns:
    
    the value if found otherwise null.
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Map<Long,V>
  - 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 Long,? extends V> map)
```
    Specified by:
    
    putAll in interface Map<Long,V>
  - keySet
```
public Long2ObjectHashMap.KeySet keySet()
```
    Specified by:
    
    keySet in interface Map<Long,V>
  - values
```
public Long2ObjectHashMap.ValueCollection values()
```
    Specified by:
    
    values in interface Map<Long,V>
  - entrySet
```
public Long2ObjectHashMap.EntrySet entrySet()
```
    Specified by:
    
    entrySet in interface Map<Long,V>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - equals
```
public boolean equals(Object o)
```
    Specified by:
    
    equals in interface Map<Long,V>
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Map<Long,V>
    
    Overrides:
    
    hashCode in class Object
  - mapNullValue
```
protected Object mapNullValue(Object value)
```
    Longerceptor for masking null values.
    
    Parameters:
    
    value - value to mask.
    
    Returns:
    
    masked value.
  - unmapNullValue
```
protected V unmapNullValue(Object value)
```
    Longerceptor for unmasking null values.
    
    Parameters:
    
    value - value to unmask.
    
    Returns:
    
    unmasked value.
  - replace
```
public V replace(long key,
                 V 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(long key,
                       V oldValue,
                       V 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 Long2ObjectHashMap<V>

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

Long2ObjectHashMap

Long2ObjectHashMap

Long2ObjectHashMap

Long2ObjectHashMap

Method Detail

loadFactor

capacity

resizeThreshold

size

isEmpty

longForEach

containsKey

containsKey

containsValue

get

get

getMapped

computeIfAbsent

computeIfPresent

compute

put

put

remove

remove

clear

compact

putAll

keySet

values

entrySet

toString

equals

hashCode

mapNullValue

unmapNullValue

replace

replace