ShapelessVectors.scala

private val allocator: BufferAllocator = new RootAllocator()

private val schema: Schema =
  new Schema(List(
    new Field("id", new FieldType(false, new ArrowType.Int(32, true), null), null),
    new Field("username", new FieldType(false, new ArrowType.Utf8(), null), null),
    new Field("pro", new FieldType(false, new ArrowType.Bool(), null), null)
  ).asJava)

private val vectorSchemaRoot = VectorSchemaRoot.create(schema, allocator)

val ids       = vectorSchemaRoot.getVector("id").asInstanceOf[IntVector]
val usernames = vectorSchemaRoot.getVector("username").asInstanceOf[VarCharVector]
val pros      = vectorSchemaRoot.getVector("pro").asInstanceOf[BitVector]


case class User(
                  id: Int = 0,
                  username: String = "",
                  pro: Boolean = false
                )

case class UserVectors(
                         ids: IntVector,
                         usernames: VarCharVector,
                         pros: BitVector
                       )

private val vectors =
  UserVectors(
    ids,
    usernames,
    pros
  )

private val user =
  User(
    1000,
    "iamsmkr",
    true
  )

// allocate new buffers
AllocateNew[UserVectors].allocateNew(vectors)

// set values to vectors
SetSafe[UserVectors, User].setSafe(vectors, 0, user)

// set value count
SetValueCount[UserVectors].setValueCount(vectors, 1)

// check if values are set against a given row
assert(IsSet[UserVectors].isSet(vectors, 0).forall(_ == 1))

// get values against a row
val encoded = Get[UserVectors, User].invokeGet(vectors, 0)
assert(encoded == user)

// close resources
Close[UserVectors].close(vectors)
vectorSchemaRoot.close()