lib-hashx

lib-hashx

Hashing utilities for computing deterministic hash values from various input types.

Overview

Provides a simple, fluent API for computing hashes with two implementations:

• Sha256Hasher: SHA-256 based hasher for cryptographic-quality hashing
• Sip24Hasher: SipHash 2-4 based hasher for fast, high-quality non-cryptographic hashing

Installation

Add this dependency to your build.gradle:

dependencies {
    implementation 'io.seqera:lib-hashx:1.0.0'
}

Usage

import io.seqera.lib.hash.Hasher;
import io.seqera.lib.hash.Sha256Hasher;
import io.seqera.lib.hash.Sip24Hasher;

// SHA-256 based hashing
Hasher hasher = new Sha256Hasher();
long hash = hasher
    .putString("hello")
    .putInt(42)
    .putBoolean(true)
    .toLong();

// SipHash 2-4 based hashing (faster, non-cryptographic)
Hasher sipHasher = new Sip24Hasher();
long fastHash = sipHasher
    .putString("key")
    .putSeparator()
    .putString("value")
    .toLong();

Using separators

Separators help prevent hash collisions when concatenating fields:

// Without separator: "ab" + "cd" could collide with "abc" + "d"
// With separator: fields are properly delimited
long hash = new Sha256Hasher()
    .putString("ab")
    .putSeparator()
    .putString("cd")
    .toLong();

API

Hasher Interface

Method	Description
Hasher putString(String value)	Add a string to the hash (null-safe, treated as no-op)
Hasher putBoolean(boolean value)	Add a boolean to the hash
Hasher putInt(int value)	Add an integer to the hash
Hasher putSeparator()	Add a delimiter to prevent field collisions
long toLong()	Compute and return the final hash value

Implementations

Implementation	Use Case
Sha256Hasher	When cryptographic properties are needed
Sip24Hasher	When speed is preferred over cryptographic strength

Testing

./gradlew :lib-hashx:test