ByteBuf Serialization for kotlinx.serialization

A Kotlin Serialization format for encoding and decoding data into Netty's ByteBuf. This library provides seamless integration with kotlinx.serialization, allowing efficient binary serialization for network communication and other performance-critical applications.

🚀 Features

• Serialize and deserialize objects into ByteBuf
• Supports primitive types, collections, and custom objects
• Extensible API for adding custom serializers (for example, VarInt, UUID)
• Type-safe error handling for invalid ByteBuf types

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📦 Installation (Gradle Kotlin DSL)

Add the dependency to your build.gradle.kts:

repositories {
    maven("https://repo.slne.dev/repository/maven-public/") { name = "slne-maven-public" }
}

dependencies {
    implementation("dev.slne.surf:kotlin-byte-buf-serializer:1.0.0") // ships netty-all by default – you may want to exclude it
}

Enable Kotlin Serialization in your project:

plugins {
    kotlin("plugin.serialization") version "2.1.10"
}

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🔧 Usage

1️⃣ Basic Serialization

@Serializable
data class Player(val name: String, val score: Int)

val player = Player("Alice", 42)
val buf: ByteBuf = Unpooled.buffer()

// Encode to ByteBuf
Buf.encodeToBuf(buf, player)

// Decode from ByteBuf
val decodedPlayer = Buf.decodeFromBuf<Player>(buf)
println(decodedPlayer) // Player(name="Alice", score=42)

2️⃣ Using Byte Arrays

val bytes = Buf.encodeToByteArray(player)
val decodedFromBytes = Buf.decodeFromByteArray<Player>(bytes)

3️⃣ Custom Serializer Example (VarInt)

class MyCustomByteBuf(private val buf: ByteBuf) : ByteBuf() {
    fun writeVarInt(value: Int) {
        // Custom implementation
    }
    
    fun readVarInt(): Int {
        // Custom implementation
    }
    
    // other ByteBuf methods
}

object VarIntSerializer : KBufSerializer<Int, MyCustomByteBuf> {
    override val descriptor = PrimitiveSerialDescriptor("VarInt", PrimitiveKind.INT)
    override val bufClass = MyCustomByteBuf::class

    override fun serialize0(buf: MyCustomByteBuf, value: Int) {
        buf.writeVarInt(value)
    }

    override fun deserialize0(buf: MyCustomByteBuf): Int {
        return buf.readVarInt()
    }
}

Register the custom serializer:

val customModule = SerializersModule {
    contextual(VarIntSerializer)
}

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🛠 Advanced Configuration

Customizing Buf

You can create a custom instance of Buf with a specific SerializersModule:

val bufFormat = Buf(customModule)

Type-Safe Serialization with Error Handling

This library provides explicit type validation for ByteBuf. If an incorrect type is used, a clear error message is thrown.

val wrongBuf: ByteBuf = Unpooled.directBuffer()
val encoder = BufEncoder(wrongBuf, customModule, true)

assertFailsWith<IllegalArgumentException> {
    VarIntSerializer.serialize(encoder, 42)
}

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📝 License

This project is licensed under the GPL-3.0 license.

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👨‍💻 Contributing

Pull requests are welcome! Feel free to open an issue if you find a bug or have a feature request.