Kotlin Multiplatform Library for xxHash with support for Android, JVM, iOS, JS, and Wasm.

The core library is in :lib. This repository also includes demo apps for Android, iOS, and Web, plus a shared Compose UI module.

• Algorithms: XXH32, XXH64, XXH3_64bits, XXH3_128bits
• Targets: Android, JVM, iOS Arm64, iOS Simulator Arm64, JS, WasmJS
• Android uses JNI + the original C implementation
• iOS uses the same original C source implementation as Android, exposed through Kotlin/Native cinterop
• JS and WasmJS currently use a pure Kotlin implementation maintained in webMain

• Android: JNI wrapper over lib_android_native/src/main/cpp/xxhash.c
• iOS: same implementation strategy as Android, using the original xxhash C sources through Kotlin/Native cinterop
• JVM: JVM-side implementation backed by org.lz4:lz4-java and net.openhft:zero-allocation-hashing
• Web: pure Kotlin implementation in lib/src/webMain/kotlin/io/github/limuyang2/xxhash/lib

The public API is consistent, but the JVM and Web implementations are not exactly the same.

dependencies {
    implementation("io.github.limuyang2:xxhash:<latest-version>")
}

Maven Central:

• io.github.limuyang2:xxhash
• io.github.limuyang2:xxhash-android
• io.github.limuyang2:xxhash-jvm
• io.github.limuyang2:xxhash-js
• io.github.limuyang2:xxhash-wasm-js

The root xxhash artifact is the normal entry point for KMP projects.

import io.github.limuyang2.xxhash.lib.xxh32
import io.github.limuyang2.xxhash.lib.xxh64
import io.github.limuyang2.xxhash.lib.xxh3As64
import io.github.limuyang2.xxhash.lib.xxh3As128

val text = "Hello, World!"

val h32 = text.xxh32()
val h64 = text.xxh64()
val h3_64 = text.xxh3As64()
val h3_128 = text.xxh3As128() // longArrayOf(low64, high64)

val bytes = text.encodeToByteArray()
val slice = bytes.xxh32(offset = 7, length = 6)
val seeded = bytes.xxh64(seed = 42)

All values are exposed as signed Kotlin Long. Treat them as unsigned when formatting or comparing against canonical xxHash hex output.

Android demo:

./gradlew :androidApp:installDebug

iOS demo:

./gradlew :commonApp:embedAndSignAppleFrameworkForXcode

Web demo:

./gradlew :webApp:jsBrowserDevelopmentWebpack
./gradlew :webApp:wasmJsBrowserDevelopmentWebpack

commonApp contains the shared Compose UI used by Android, iOS, and Web.

Library compile checks:

./gradlew :lib:compileKotlinJs
./gradlew :lib:compileKotlinWasmJs
./gradlew :lib:compileTestKotlinJs

Selected tests:

./gradlew :lib:jvmTest
./gradlew :lib:iosSimulatorArm64Test
./gradlew :lib:jsNodeTest
./gradlew :lib:wasmJsNodeTest

Some web tasks depend on the local Gradle/Node toolchain and your environment setup.

Useful paths:

• lib/src/commonMain/kotlin/io/github/limuyang2/xxhash/lib
• lib/src/webMain/kotlin/io/github/limuyang2/xxhash/lib
• lib/src/iosMain/kotlin/io/github/limuyang2/xxhash/lib
• lib/src/androidMain/kotlin/io/github/limuyang2/xxhash/lib
• lib_android_native/src/main/cpp

MIT License

This repository includes xxHash source code. xxHash itself is distributed under the BSD 2-Clause License.