cloud.opencode.base.hash.HashCodes

public final class HashCodes extends Object

Zero-allocation hash code combining utility 零分配哈希码组合工具

Provides high-quality hash code combining using MurmurHash3's fmix32 mixing function. Unlike Objects.hash(), this utility avoids varargs array allocation and produces better distribution through proper mixing at each step.

使用MurmurHash3的fmix32混合函数提供高质量的哈希码组合。与 Objects.hash() 不同，此工具避免了可变参数数组分配，并通过每一步的正确混合产生更好的分布。

Features | 主要功能:

Zero-allocation fixed-arity combine methods (2-8 params) - 零分配固定参数组合方法(2-8个参数)
Chainable Combiner builder for dynamic combining - 可链式调用的Combiner构建器用于动态组合
MurmurHash3 fmix32 mixing for excellent avalanche - MurmurHash3 fmix32混合实现优秀的雪崩效应
Order-sensitive: combine(a,b) != combine(b,a) - 顺序敏感: combine(a,b) != combine(b,a)

Usage Examples | 使用示例:

// Fixed-arity combining (zero allocation)
// 固定参数组合（零分配）
int hash = HashCodes.combine(name.hashCode(), age);
int hash3 = HashCodes.combine(a.hashCode(), b.hashCode(), c.hashCode());

// Chainable builder for dynamic combining
// 可链式调用的构建器用于动态组合
int hash = HashCodes.start()
    .add(name.hashCode())
    .add(age)
    .add(active)
    .add(address)
    .result();

Security | 安全性:

Thread-safe: Yes (stateless utility methods) - 线程安全: 是（无状态工具方法）
Combiner instances are NOT thread-safe - Combiner实例非线程安全

Performance | 性能特性:

Time complexity: O(n) where n = number of values - O(n), n为值的数量
Space complexity: O(1) - zero heap allocation for combine() - O(1) - combine()零堆分配

Since:

JDK 25, opencode-base-hash V1.0.3

Author:

Leon Soo www.LeonSoo.com

See Also:

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

static final class

HashCodes.Combiner

Chainable hash code combiner 可链式调用的哈希码组合器
Method Summary

Modifier and Type

Method

Description

static int

combine(int a, int b)

Combines two hash codes into one 将两个哈希码组合为一个

static int

combine(int a, int b, int c)

Combines three hash codes into one 将三个哈希码组合为一个

static int

combine(int a, int b, int c, int d)

Combines four hash codes into one 将四个哈希码组合为一个

static int

combine(int a, int b, int c, int d, int e)

Combines five hash codes into one 将五个哈希码组合为一个

static int

combine(int a, int b, int c, int d, int e, int f)

Combines six hash codes into one 将六个哈希码组合为一个

static int

combine(int a, int b, int c, int d, int e, int f, int g)

Combines seven hash codes into one 将七个哈希码组合为一个

static int

combine(int a, int b, int c, int d, int e, int f, int g, int h)

Combines eight hash codes into one 将八个哈希码组合为一个

static HashCodes.Combiner

start()

Creates a new Combiner with the default seed 使用默认种子创建新的Combiner

static HashCodes.Combiner

start(int initial)

Creates a new Combiner with an initial value mixed into the seed 使用混入种子的初始值创建新的Combiner

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

Method Details
- combine
  
  public static int combine(int a, int b)
  
  Combines two hash codes into one 将两个哈希码组合为一个
  
  Parameters:
  
  a - first hash code | 第一个哈希码
  
  b - second hash code | 第二个哈希码
  
  Returns:
  
  combined hash code | 组合后的哈希码
- combine
  
  public static int combine(int a, int b, int c)
  
  Combines three hash codes into one 将三个哈希码组合为一个
  
  Parameters:
  
  a - first hash code | 第一个哈希码
  
  b - second hash code | 第二个哈希码
  
  c - third hash code | 第三个哈希码
  
  Returns:
  
  combined hash code | 组合后的哈希码
- combine
  
  public static int combine(int a, int b, int c, int d)
  
  Combines four hash codes into one 将四个哈希码组合为一个
  
  Parameters:
  
  a - first hash code | 第一个哈希码
  
  b - second hash code | 第二个哈希码
  
  c - third hash code | 第三个哈希码
  
  d - fourth hash code | 第四个哈希码
  
  Returns:
  
  combined hash code | 组合后的哈希码
- combine
  
  public static int combine(int a, int b, int c, int d, int e)
  
  Combines five hash codes into one 将五个哈希码组合为一个
  
  Parameters:
  
  a - first hash code | 第一个哈希码
  
  b - second hash code | 第二个哈希码
  
  c - third hash code | 第三个哈希码
  
  d - fourth hash code | 第四个哈希码
  
  e - fifth hash code | 第五个哈希码
  
  Returns:
  
  combined hash code | 组合后的哈希码
- combine
  
  public static int combine(int a, int b, int c, int d, int e, int f)
  
  Combines six hash codes into one 将六个哈希码组合为一个
  
  Parameters:
  
  a - first hash code | 第一个哈希码
  
  b - second hash code | 第二个哈希码
  
  c - third hash code | 第三个哈希码
  
  d - fourth hash code | 第四个哈希码
  
  e - fifth hash code | 第五个哈希码
  
  f - sixth hash code | 第六个哈希码
  
  Returns:
  
  combined hash code | 组合后的哈希码
- combine
  
  public static int combine(int a, int b, int c, int d, int e, int f, int g)
  
  Combines seven hash codes into one 将七个哈希码组合为一个
  
  Parameters:
  
  a - first hash code | 第一个哈希码
  
  b - second hash code | 第二个哈希码
  
  c - third hash code | 第三个哈希码
  
  d - fourth hash code | 第四个哈希码
  
  e - fifth hash code | 第五个哈希码
  
  f - sixth hash code | 第六个哈希码
  
  g - seventh hash code | 第七个哈希码
  
  Returns:
  
  combined hash code | 组合后的哈希码
- combine
  
  public static int combine(int a, int b, int c, int d, int e, int f, int g, int h)
  
  Combines eight hash codes into one 将八个哈希码组合为一个
  
  Parameters:
  
  a - first hash code | 第一个哈希码
  
  b - second hash code | 第二个哈希码
  
  c - third hash code | 第三个哈希码
  
  d - fourth hash code | 第四个哈希码
  
  e - fifth hash code | 第五个哈希码
  
  f - sixth hash code | 第六个哈希码
  
  g - seventh hash code | 第七个哈希码
  
  h - eighth hash code | 第八个哈希码
  
  Returns:
  
  combined hash code | 组合后的哈希码
- start
  
  public static HashCodes.Combiner start()
  
  Creates a new Combiner with the default seed 使用默认种子创建新的Combiner
  
  Returns:
  
  a new Combiner instance | 新的Combiner实例
- start
  
  public static HashCodes.Combiner start(int initial)
  
  Creates a new Combiner with an initial value mixed into the seed 使用混入种子的初始值创建新的Combiner
  
  Parameters:
  
  initial - initial hash value | 初始哈希值
  
  Returns:
  
  a new Combiner instance | 新的Combiner实例

Class HashCodes

Nested Class Summary

Method Summary

Methods inherited from class Object

Method Details

combine

combine

combine

combine

combine

combine

combine

start

start