Bytonio

Bytonio (said Byte on IO) is a library and a KSP processor intended to ease the serialization and deserialization of Kotlin objects into ByteArray, to be used in protocols that use binary data. The goal is to be purely compatible with Kotlin Multiplatform, without using any platform specific library.

How to use

Add KSP processor to your Kotlin module

Those examples are for a Kotlin Multiplatform module.

Add the KSP plugin:

plugins {
    id("com.google.devtools.ksp")
}

Add the core library as a dependency:

    sourceSets {
        commonMain {
            dependencies {
                api("net.cacheux.bytonio:bytonio-core:<version>")
                ...
            }
        }
        ...
    }

Add the KSP processor for platforms you want to have their own code generated:

dependencies {
    add("kspCommonMainMetadata", "net.cacheux.bytonio:bytonio-processor:<version>")
    add("kspJvm", "net.cacheux.bytonio:bytonio-processor:<version>")
    add("kspAndroid", "net.cacheux.bytonio:bytonio-processor:<version>")
}

For a JVM or Android library, you can add both dependencies like this:

dependencies {
    api("net.cacheux.bytonio:bytonio-core:<version>")
    ksp("net.cacheux.bytonio:bytonio-processor:<version>")
}

Processor options

• bytonio.packageName : Change the package where the processor generate code (default is bytonio)
• bytonio.dataSizeFormat : Change the default format used to store size of arrays and objects. Allowed values are int, short and byte. Default is int.
• bytonio.byteOrder : Change the byte order for int and short serialization. Allowed values are littleEndian and bigEndian. Default is bigEndian.

Example:

ksp {
    arg("bytonio.packageName", "net.cacheux.generated")
    arg("bytonio.dataSizeFormat", "short")
    arg("bytonio.byteOrder", "littleEndian")
}

Use annotations in the code

Classes annotated with @DataObject will have a serializer and a deserializer class created, as well as extension methods getBinarySize() and toByteArray(), if these are not already existing for the class.

These classes must have a constructor with one or more arguments with type supported by the processor : Int, Short, Byte, ByteArray, or another data type which have the @DataObject annotation.

You can have ignored arguments of any type, annotated with @IgnoreEncoding, but they must have a default value that will be used during deserialization.

Numeric arguments can be encoded using a different type than the one used in the class, by using annotations @EncodeAsByte, @EncodeAsShort and @EncodeAsInt.

Custom serializers and deserializers

A class annotated with @DataObject can also have custom serializers and deserializers that will be used instead of the one generated. This is also a way to have different types for constructor arguments. Use @Serializer and @Deserializer annotations to specify them.