HashMapHelper (dataset 11.1.5 API)

java.lang.Object
- de.gsi.dataset.spi.utils.HashMapHelper

```
public final class HashMapHelper
extends java.lang.Object
```
Common HashMap methods taken from FastUtil implementation

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static int`	`arraySize(int expected, float f)`	Returns the least power of two smaller than or equal to 2³⁰ and larger than or equal to `Math.ceil( expected / f )`.
`static long`	`nextPowerOfTwo(long length)`	Return the least power of two greater than or equal to the specified value.
`static int`	`phiMix(int x)`

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

- Method Detail
  - arraySize
```
public static int arraySize(int expected,
                            float f)
```
    Returns the least power of two smaller than or equal to 2³⁰ and larger than or equal to Math.ceil( expected / f ).
    
    Parameters:
    
    expected - the expected number of elements in a hash table.
    
    f - the load factor.
    
    Returns:
    
    the minimum possible size for a backing array.
    
    Throws:
    
    java.lang.IllegalArgumentException - if the necessary size is larger than 2³⁰.
  - nextPowerOfTwo
```
public static long nextPowerOfTwo(long length)
```
    Return the least power of two greater than or equal to the specified value.
    Note that this function will return 1 when the argument is 0.
    
    Parameters:
    
    length - a long integer smaller than or equal to 2⁶².
    
    Returns:
    
    the least power of two greater than or equal to the specified value.
  - phiMix
```
public static int phiMix(int x)
```