Package com.helger.base.hashcode

Class HashCodeCalculator

java.lang.Object

com.helger.base.hashcode.HashCodeCalculator

@Immutable
public final class HashCodeCalculator
extends Object

This class provides the hash code generation for different data types.

Author:

Philip Helger

Field Summary

Fields

Modifier and Type	Field	Description
static final int	HASHCODE_NULL	The hash code value to be used for null values.
static final int	INITIAL_HASHCODE	Use a prime number as the start.
static final int	MULTIPLIER	Each value is multiplied with this value. 31 because it can easily be optimized to (1 << 5) - 1.

Method Summary

Modifier and Type	Method	Description
static int	append(int nPrevHashCode, boolean x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, boolean[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, boolean[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, byte x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, byte[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, byte[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, char x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, char[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, char[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, double x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, double[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, double[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, float x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, float[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, float[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, int x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, int[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, int[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, long x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, long[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, long[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, short x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, short[] x)	Atomic type hash code generation.
static int	append(int nPrevHashCode, short[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	append(int nPrevHashCode, Object x)	Object hash code generation.
static int	append(int nPrevHashCode, Object[] x)	Array hash code generation.
static int	append(int nPrevHashCode, Object[] x, int nOfs, int nLen)	Atomic type hash code generation.
static int	hashCode(boolean x)
static int	hashCode(boolean[] x, int nOfs, int nLen)
static int	hashCode(byte x)
static int	hashCode(byte[] x, int nOfs, int nLen)
static int	hashCode(char x)
static int	hashCode(char[] x, int nOfs, int nLen)
static long	hashCode(double x)
static int	hashCode(double[] x, int nOfs, int nLen)
static int	hashCode(float x)
static int	hashCode(float[] x, int nOfs, int nLen)
static int	hashCode(int[] x, int nOfs, int nLen)
static int	hashCode(long[] x, int nOfs, int nLen)
static int	hashCode(short x)
static int	hashCode(short[] x, int nOfs, int nLen)
static int	hashCode(Object x)
static int	hashCode(Object[] x, int nOfs, int nLen)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

INITIAL_HASHCODE

public static final int INITIAL_HASHCODE

Use a prime number as the start.

See Also:

• Constant Field Values

MULTIPLIER

public static final int MULTIPLIER

Each value is multiplied with this value. 31 because it can easily be optimized to (1 << 5) - 1.

See Also:

• Constant Field Values

HASHCODE_NULL

public static final int HASHCODE_NULL

The hash code value to be used for null values. Do not use 0 as e.g. BigDecimal ("0") also results in a 0 hash code.

See Also:

• Constant Field Values

Method Details

hashCode

public static int hashCode(boolean x)

hashCode

public static int hashCode(byte x)

hashCode

public static int hashCode(char x)

hashCode

public static long hashCode(double x)

hashCode

public static int hashCode(float x)

hashCode

public static int hashCode(short x)

hashCode

@UsedInGeneratedCode
public static int hashCode(@Nullable
 Object x)

append

public static int append(int nPrevHashCode,
 boolean x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 byte x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 char x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 double x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 float x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 int x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 long x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 short x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 Object x)

Object hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Object to add. May be null.

Returns:

The updated hash code

hashCode

public static int hashCode(@Nonnull
 boolean[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 byte[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 char[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 double[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 float[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 int[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 long[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 short[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

hashCode

public static int hashCode(@Nonnull
 Object[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

append

public static int append(int nPrevHashCode,
 @Nullable
 boolean[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 boolean[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 byte[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 byte[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 char[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 char[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 double[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 double[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 float[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 float[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 int[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 int[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 long[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 long[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 short[] x)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 short[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 Object[] x)

Array hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Object array to add. May be null.

Returns:

The updated hash code

append

public static int append(int nPrevHashCode,
 @Nullable
 Object[] x,
 @Nonnegative
 int nOfs,
 @Nonnegative
 int nLen)

Atomic type hash code generation.

Parameters:

nPrevHashCode - The previous hash code used as the basis for calculation

x - Array to add

nOfs - Offset to start from. Must be ≥ 0.

nLen - Number of array items to use. Must be ≥ 0.

Returns:

The updated hash code