app.softwork:kotlinx-uuid-ktor-server

Kotlinx-UUID

This is a fork from https://github.com/cy6erGn0m/kotlinx-uuid, released under Apache 2.

The main implementation was thankfully provided by cy6erGn0m!

kotlinx-uuid is a multiplatform (MPP) Kotlin library introducing support for UUID.

The main class UUID is serializable out of the box, so the library depends on kotlinx.serialization. If you don't need serialization, you don't need to apply the plugin.

Supported platforms are:

• JVM (Java 8+, IR only)
• JavaScript (IR backend only)
• Native:
  • iOS ARM64

To support the extensions on iOS, you need

// build.gradle.kts
ios {
  binaries {
    framework {
       // Export transitively.
       transitiveExport = true
    }
  }  
}

Including

This package is uploaded to mavenCentral and to GitHub Packages.

repositories {
    mavenCentral()
    
    // or
    maven {
        url = uri("https://maven.pkg.github.com/hfhbd/*")
        credentials {
            username = project.findProperty("gpr.user") as String? ?: System.getenv("GITHUB_ACTOR")
            password = project.findProperty("gpr.key") as String? ?: System.getenv("GITHUB_TOKEN")
        }
    }
}

dependencies {
    implementation("app.softwork:kotlinx-uuid-core:LATEST")
}

Usage

Creating from a UUID string

val uuid = UUID("1b3e4567-e99b-13d3-a476-446657420000")
val guid = UUID("{1b3e4567-e99b-13d3-a476-446657420000}")

Generating UUID4 using random

// using a default SecureRandom implementation
val uuid = UUID()

// use custom Kotlin Random instance
val uuid = UUID.generateUUID(yourRandom)

Generating UUID5 using hash

kotlin-uud provides the ability to generate uuids by hashing names (Only SHA-1 is supported at the moment).

val appNamespace = UUID("my-app-uuid")
val agentId = UUID.generateUUID(appNamespace, "agentId")

The other alternative is to generate UUID by hashing bytes (similar to java.util.UUID.nameUUIDFromBytes).

val uuid = UUID.generateUUID(bytes)

Note that unlike java.util.UUID, kotlinx's generateUUID doesn't support MD5, so the blind migration from Java to kotlin-uud may lead to changing UUIDs.

Serializing (kotlinx.serialization)

There are two serializers for UUID: the default one and the binary.

The default serializer does always serialize UUIDs as string primitives.

Json.encodeToString(uuid) == "\"1b3e4567-e99b-13d3-a476-446657420000\""

The additional serializer is useful for binary formats. Because they are not human-readable, and it's possible to reduce size.

val bytes = Protobuf.encodeToByteArray(BinarySerializer, uuid)

Using with ktor

Include uuid-ktor-server artifact:

val jvmMain by getting {
    dependencies {
        implementation("app.softwork:kotlinx-uuid-ktor-server:0.0.1")
    }
}

Install converter:

install(DataConversion) {
    uuid()
}

Unfortunately, ktor doesn't provide (KTOR-1309) any way to plug converters automatically, so you need to configure it manually. Also, in some cases, like delegating to call parameters, it will not work and there is no workaround at the moment.

Using with Exposed

Exposed is an ORM framework for Kotlin. It has support for java.util.UUID, but to get kotlin-uuid supported you need to include the corresponding dependency and use DSL functions:

dependencies {
    implementation("app.softwork:kotlinx-uuid-exposed:0.0.1")
}

When declaring a table having UUID as Primary Key:

// SQL DSL
object MyTable : KotlinxUUIDTable() {
    // there is "id" property with the kotlin-uud type
}

// DAO API
class MyTableEntity(id: EntityID<UUID>) : KotlinxUUIDEntity(id) {
    companion object : KotlinxUUIDEntityClass<MyTableEntity>(MyTable)

} 

To declare a regular column, use kotlinxUUID function:

object MyTable : Table() {
    val something = kotlinxUUID("SOME_COLUMN")
}

Unfortunately, there is a function called uuid in the base class, inside of the exposed core, this is why we can't overwrite/override it, so it may lead to confusion. The function uuid only works with java.util.UUID:

object MyTable : Table() {
    val column1 = kotlinxUUID("C1") // kotlinx.uuid.UUID
    val column2 = uuid("C2") // java.util.UUID
}