CaseInsensitiveIntMap (textratypist 0.7.1 API)

java.lang.Object
- com.github.tommyettinger.textra.utils.CaseInsensitiveIntMap

All Implemented Interfaces:

java.lang.Iterable<CaseInsensitiveIntMap.Entry>
```
public class CaseInsensitiveIntMap
extends java.lang.Object
implements java.lang.Iterable<CaseInsensitiveIntMap.Entry>
```
An unordered map where the keys are case-insensitive Strings and the values are unboxed ints. Null keys are not allowed. No allocation is done except when growing the table size.
This class performs fast contains and remove (typically O(1), worst case O(n) but that is rare in practice). Add may be slightly slower, depending on hash collisions. Hashcodes are rehashed to reduce collisions and the need to resize. Load factors greater than 0.91 greatly increase the chances to resize to the next higher POT size.
This implementation uses linear probing with the backward shift algorithm for removal. Hashcodes are rehashed using a form of random hashing; a multiplier changes every time resize(int) gets called, which means if resize() has to be called early due to frequent collisions, the hashes will change when the multiplier does, and that may help alleviate the collisions. Linear probing continues to work even when all hashCodes collide, just more slowly.
This implementation is closely based on ObjectIntMap from libGDX, but also uses ideas from jdkgdxds, such as the randomized hashing (and the case-insensitive matching in general).

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`CaseInsensitiveIntMap.Entries`
`static class`	`CaseInsensitiveIntMap.Entry`
`static class`	`CaseInsensitiveIntMap.Keys`
`static class`	`CaseInsensitiveIntMap.Values`

Field Summary

Fields
Modifier and Type	Field and Description
`protected CaseInsensitiveIntMap.Entries`	`entries1`
`protected CaseInsensitiveIntMap.Entries`	`entries2`
`protected long`	`hashMultiplier` Used by `place(String)` to mix hashCode() results.
`protected CaseInsensitiveIntMap.Keys`	`keys1`
`protected CaseInsensitiveIntMap.Keys`	`keys2`
`protected java.lang.String[]`	`keyTable`
`protected float`	`loadFactor`
`protected int`	`mask` A bitmask used to confine hashcodes to the size of the table.
`protected int`	`shift` Used by `place(String)` to bit shift the upper bits of a `long` into a usable range (>= 0 and <= `mask`).
`int`	`size`
`protected int`	`threshold`
`protected CaseInsensitiveIntMap.Values`	`values1`
`protected CaseInsensitiveIntMap.Values`	`values2`
`protected int[]`	`valueTable`

Constructor Summary

Constructors
Constructor and Description
`CaseInsensitiveIntMap()` Creates a new map with an initial capacity of 51 and a load factor of 0.8.
`CaseInsensitiveIntMap(CaseInsensitiveIntMap map)` Creates a new map identical to the specified map.
`CaseInsensitiveIntMap(int initialCapacity)` Creates a new map with a load factor of 0.8.
`CaseInsensitiveIntMap(int initialCapacity, float loadFactor)` Creates a new map with the specified initial capacity and load factor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clear()`
`void`	`clear(int maximumCapacity)` Clears the map and reduces the size of the backing arrays to be the specified capacity / loadFactor, if they are larger.
`boolean`	`containsKey(java.lang.String key)`
`boolean`	`containsValue(int value)` Returns true if the specified value is in the map.
`void`	`ensureCapacity(int additionalCapacity)` Increases the size of the backing array to accommodate the specified number of additional items / loadFactor.
`CaseInsensitiveIntMap.Entries`	`entries()` Returns an iterator for the entries in the map.
`boolean`	`equals(java.lang.Object obj)`
`java.lang.String`	`findKey(int value)` Returns the key for the specified value, or null if it is not in the map.
`int`	`get(java.lang.String key, int defaultValue)` Returns the value for the specified key, or the default value if the key is not in the map.
`int`	`getAndIncrement(java.lang.String key, int defaultValue, int increment)` Returns the key's current value and increments the stored value.
`int`	`hashCode()`
`boolean`	`isEmpty()` Returns true if the map is empty.
`CaseInsensitiveIntMap.Entries`	`iterator()`
`CaseInsensitiveIntMap.Keys`	`keys()` Returns an iterator for the keys in the map.
`boolean`	`notEmpty()` Returns true if the map has one or more items.
`protected int`	`place(java.lang.String item)` Returns an index >= 0 and <= `mask` for the specified `item`.
`void`	`put(java.lang.String key, int value)`
`int`	`put(java.lang.String key, int value, int defaultValue)` Returns the old value associated with the specified key, or the specified default value.
`void`	`putAll(CaseInsensitiveIntMap map)`
`int`	`remove(java.lang.String key, int defaultValue)` Returns the value for the removed key, or the default value if the key is not in the map.
`void`	`shrink(int maximumCapacity)` Reduces the size of the backing arrays to be the specified capacity / loadFactor, or less.
`static int`	`tableSize(int capacity, float loadFactor)` Used to establish the size of a hash table.
`java.lang.String`	`toString()`
`java.lang.String`	`toString(java.lang.String separator)`
`CaseInsensitiveIntMap.Values`	`values()` Returns an iterator for the values in the map.

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

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

- Field Detail
  - size
```
public int size
```
  - keyTable
```
protected java.lang.String[] keyTable
```
  - valueTable
```
protected int[] valueTable
```
  - loadFactor
```
protected float loadFactor
```
  - threshold
```
protected int threshold
```
  - shift
```
protected int shift
```
    Used by place(String) to bit shift the upper bits of a long into a usable range (>= 0 and <= mask). The shift can be negative, which is convenient to match the number of bits in mask: if mask is a 7-bit number, a shift of -7 shifts the upper 7 bits into the lowest 7 positions. This class sets the shift > 32 and < 64, which if used with an int will still move the upper bits of an int to the lower bits due to Java's implicit modulus on shifts.
    mask can also be used to mask the low bits of a number, which may be faster for some hashcodes, if place(String) is overridden.
  - mask
```
protected int mask
```
    A bitmask used to confine hashcodes to the size of the table. Must be all 1 bits in its low positions, ie a power of two minus 1. If place(String) is overriden, this can be used instead of shift to isolate usable bits of a hash.
  - hashMultiplier
```
protected long hashMultiplier
```
    Used by place(String) to mix hashCode() results. Changes on every call to resize(int) by default. This only needs to be serialized if the full key and value tables are serialized, or if the iteration order should be the same before and after serialization.
  - entries1
```
protected transient CaseInsensitiveIntMap.Entries entries1
```
  - entries2
```
protected transient CaseInsensitiveIntMap.Entries entries2
```
  - values1
```
protected transient CaseInsensitiveIntMap.Values values1
```
  - values2
```
protected transient CaseInsensitiveIntMap.Values values2
```
  - keys1
```
protected transient CaseInsensitiveIntMap.Keys keys1
```
  - keys2
```
protected transient CaseInsensitiveIntMap.Keys keys2
```
- Constructor Detail
  - CaseInsensitiveIntMap
```
public CaseInsensitiveIntMap()
```
    Creates a new map with an initial capacity of 51 and a load factor of 0.8.
  - CaseInsensitiveIntMap
```
public CaseInsensitiveIntMap(int initialCapacity)
```
    Creates a new map with a load factor of 0.8.
    
    Parameters:
    
    initialCapacity - The backing array size is initialCapacity / loadFactor, increased to the next power of two.
  - CaseInsensitiveIntMap
```
public CaseInsensitiveIntMap(int initialCapacity,
                             float loadFactor)
```
    Creates a new map with the specified initial capacity and load factor. This map will hold initialCapacity items before growing the backing table.
    
    Parameters:
    
    initialCapacity - The backing array size is initialCapacity / loadFactor, increased to the next power of two.
  - CaseInsensitiveIntMap
```
public CaseInsensitiveIntMap(CaseInsensitiveIntMap map)
```
    Creates a new map identical to the specified map.
- Method Detail
  - tableSize
```
public static int tableSize(int capacity,
                            float loadFactor)
```
    Used to establish the size of a hash table. The table size will always be a power of two, and should be the next power of two that is at least equal to capacity / loadFactor.
    
    Parameters:
    
    capacity - the amount of items the hash table should be able to hold
    
    loadFactor - between 0.0 (exclusive) and 1.0 (inclusive); the fraction of how much of the table can be filled
    
    Returns:
    
    the size of a hash table that can handle the specified capacity with the given loadFactor
  - place
```
protected int place(java.lang.String item)
```
    Returns an index >= 0 and <= mask for the specified item.
  - put
```
public void put(java.lang.String key,
                int value)
```
  - put
```
public int put(java.lang.String key,
               int value,
               int defaultValue)
```
    Returns the old value associated with the specified key, or the specified default value.
  - putAll
```
public void putAll(CaseInsensitiveIntMap map)
```
  - get
```
public int get(java.lang.String key,
               int defaultValue)
```
    Returns the value for the specified key, or the default value if the key is not in the map.
  - getAndIncrement
```
public int getAndIncrement(java.lang.String key,
                           int defaultValue,
                           int increment)
```
    Returns the key's current value and increments the stored value. If the key is not in the map, defaultValue + increment is put into the map and defaultValue is returned.
  - remove
```
public int remove(java.lang.String key,
                  int defaultValue)
```
    Returns the value for the removed key, or the default value if the key is not in the map.
  - notEmpty
```
public boolean notEmpty()
```
    Returns true if the map has one or more items.
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if the map is empty.
  - shrink
```
public void shrink(int maximumCapacity)
```
    Reduces the size of the backing arrays to be the specified capacity / loadFactor, or less. If the capacity is already less, nothing is done. If the map contains more items than the specified capacity, the next highest power of two capacity is used instead.
  - clear
```
public void clear(int maximumCapacity)
```
    Clears the map and reduces the size of the backing arrays to be the specified capacity / loadFactor, if they are larger.
  - clear
```
public void clear()
```
  - containsValue
```
public boolean containsValue(int value)
```
    Returns true if the specified value is in the map. Note this traverses the entire map and compares every value, which may be an expensive operation.
  - containsKey
```
public boolean containsKey(java.lang.String key)
```
  - findKey
```
public java.lang.String findKey(int value)
```
    Returns the key for the specified value, or null if it is not in the map. Note this traverses the entire map and compares every value, which may be an expensive operation.
  - ensureCapacity
```
public void ensureCapacity(int additionalCapacity)
```
    Increases the size of the backing array to accommodate the specified number of additional items / loadFactor. Useful before adding many items to avoid multiple backing array resizes.
  - 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
  - toString
```
public java.lang.String toString(java.lang.String separator)
```
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - iterator
```
public CaseInsensitiveIntMap.Entries iterator()
```
    Specified by:
    
    iterator in interface java.lang.Iterable<CaseInsensitiveIntMap.Entry>
  - entries
```
public CaseInsensitiveIntMap.Entries entries()
```
    Returns an iterator for the entries in the map. Remove is supported. Use the CaseInsensitiveIntMap.Entries constructor for nested or multithreaded iteration.
  - values
```
public CaseInsensitiveIntMap.Values values()
```
    Returns an iterator for the values in the map. Remove is supported.
  - keys
```
public CaseInsensitiveIntMap.Keys keys()
```
    Returns an iterator for the keys in the map. Remove is supported.

Class CaseInsensitiveIntMap

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

size

keyTable

valueTable

loadFactor

threshold

shift

mask

hashMultiplier

entries1

entries2

values1

values2

keys1

keys2

Constructor Detail

CaseInsensitiveIntMap

CaseInsensitiveIntMap

CaseInsensitiveIntMap

CaseInsensitiveIntMap

Method Detail

tableSize

place

put

put

putAll

get

getAndIncrement

remove

notEmpty

isEmpty

shrink

clear

clear

containsValue

containsKey

findKey

ensureCapacity

hashCode

equals

toString

toString

iterator

entries

values

keys