ArrayHashMap (Lucene 4.3.0 API)

java.lang.Object
- org.apache.lucene.facet.collections.ArrayHashMap<K,V>

All Implemented Interfaces:

Iterable<V>
```
public class ArrayHashMap<K,V>
extends Object
implements Iterable<V>
```
An Array-based hashtable which maps, similar to Java's HashMap, only performance tests showed it performs better.
The hashtable is constructed with a given capacity, or 16 as a default. In case there's not enough room for new pairs, the hashtable grows. Capacity is adjusted to a power of 2, and there are 2 * capacity entries for the hash. The pre allocated arrays (for keys, values) are at length of capacity + 1, where index 0 is used as 'Ground' or 'NULL'.
The arrays are allocated ahead of hash operations, and form an 'empty space' list, to which the <key,value> pair is allocated.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary

Constructors
Constructor and Description

ArrayHashMap()
Constructs a map with default capacity.

ArrayHashMap(int capacity)
Constructs a map with given capacity.

Constructors
Constructor and Description
`ArrayHashMap()` Constructs a map with default capacity.
`ArrayHashMap(int capacity)` Constructs a map with given capacity.

Method Summary

Methods
Modifier and Type	Method and Description
`protected int`	`calcBaseHashIndex(K key)` Calculating the baseHash index using the internal internal `hashFactor`.
`void`	`clear()` Empties the map.
`boolean`	`containsKey(K key)` Returns true iff the key exists in the map.
`boolean`	`containsValue(Object o)` Returns true iff the object exists in the map.
`boolean`	`equals(Object o)`
`protected int`	`find(K key)` Returns the index of the given key, or zero if the key wasn't found.
`V`	`get(K key)` Returns the object mapped with the given key, or null if the key wasn't found.
`protected void`	`grow()` Allocates a new map of double the capacity, and fast-insert the old key-value pairs.
`int`	`hashCode()`
`boolean`	`isEmpty()` Returns true iff the map is empty.
`Iterator<V>`	`iterator()` Returns an iterator on the mapped objects.
`Iterator<K>`	`keyIterator()` Returns an iterator on the map keys.
`V`	`put(K key, V e)` Inserts the <key,value> pair into the map.
`V`	`remove(K key)` Removes a <key,value> pair from the map and returns the mapped value, or null if the none existed.
`int`	`size()` Returns number of pairs currently in the map.
`Object[]`	`toArray()` Translates the mapped pairs' values into an array of Objects
`V[]`	`toArray(V[] a)` Translates the mapped pairs' values into an array of V
`String`	`toString()`

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

- Constructor Detail
  - ArrayHashMap
```
public ArrayHashMap()
```
    Constructs a map with default capacity.
  - ArrayHashMap
```
public ArrayHashMap(int capacity)
```
    Constructs a map with given capacity. Capacity is adjusted to a native power of 2, with minimum of 16.
    
    Parameters:
    capacity - minimum capacity for the map.
- Method Detail
  - calcBaseHashIndex
```
protected int calcBaseHashIndex(K key)
```
    Calculating the baseHash index using the internal internal hashFactor.
  - clear
```
public void clear()
```
    Empties the map. Generates the "Empty" space list for later allocation.
  - containsKey
```
public boolean containsKey(K key)
```
    Returns true iff the key exists in the map.
  - containsValue
```
public boolean containsValue(Object o)
```
    Returns true iff the object exists in the map.
  - find
```
protected int find(K key)
```
    Returns the index of the given key, or zero if the key wasn't found.
  - get
```
public V get(K key)
```
    Returns the object mapped with the given key, or null if the key wasn't found.
  - grow
```
protected void grow()
```
    Allocates a new map of double the capacity, and fast-insert the old key-value pairs.
  - isEmpty
```
public boolean isEmpty()
```
    Returns true iff the map is empty.
  - iterator
```
public Iterator<V> iterator()
```
    Returns an iterator on the mapped objects.
    
    Specified by:
    
    iterator in interface Iterable<V>
  - keyIterator
```
public Iterator<K> keyIterator()
```
    Returns an iterator on the map keys.
  - put
```
public V put(K key,
    V e)
```
    Inserts the <key,value> pair into the map. If the key already exists, this method updates the mapped value to the given one, returning the old mapped value.
    
    Returns:
    the old mapped value, or null if the key didn't exist.
  - remove
```
public V remove(K key)
```
    Removes a <key,value> pair from the map and returns the mapped value, or null if the none existed.
    
    Parameters:
    key - used to find the value to remove
    
    Returns:
    the removed value or null if none existed.
  - size
```
public int size()
```
    Returns number of pairs currently in the map.
  - toArray
```
public Object[] toArray()
```
    Translates the mapped pairs' values into an array of Objects
    
    Returns:
    an object array of all the values currently in the map.
  - toArray
```
public V[] toArray(V[] a)
```
    Translates the mapped pairs' values into an array of V
    
    Parameters:
    a - the array into which the elements of the list are to be stored, if it is big enough; otherwise, use as much space as it can.
    
    Returns:
    an array containing the elements of the list
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object

Class ArrayHashMap<K,V>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ArrayHashMap

ArrayHashMap

Method Detail

calcBaseHashIndex

clear

containsKey

containsValue

find

get

grow

isEmpty

iterator

keyIterator

put

remove

size

toArray

toArray

toString

hashCode

equals