com.github.mjakubowski84.parquet4s.ValueEncoder.scala Maven / Gradle / Ivy

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package com.github.mjakubowski84.parquet4s

import scala.annotation.implicitNotFound

trait AllValueEncoders extends PrimitiveValueEncoders with TimeValueEncoders with ComplexValueEncoders

/** Contains implicit instances of all [[ValueEncoder]]
  */
object ValueEncoder extends AllValueEncoders

@implicitNotFound(
  "Missing ValueEncoder for value type ${T}. Implement your own encoder in order to serialise your data."
)
trait ValueEncoder[T] {

  /** @param data
    *   source data
    * @param configuration
    *   [ValueCodecConfiguration] used by some codecs
    * @return
    *   encoded Parquet [[Value]]
    */
  def encode(data: T, configuration: ValueCodecConfiguration): Value
}

/** Encoder for non-null type of [[Value]]
  * @tparam T
  *   data type to encode to
  */
trait RequiredValueEncoder[T] extends ValueEncoder[T] {
  override def encode(data: T, configuration: ValueCodecConfiguration): Value =
    Option(data) match {
      case None =>
        throw new IllegalArgumentException("Cannot encode null instance of required type")
      case Some(other) =>
        encodeNonNull(other, configuration)
    }

  protected def encodeNonNull(data: T, configuration: ValueCodecConfiguration): Value
}

/** Encoder for [[Value]] that can be null.
  * @tparam T
  *   data type to encode to
  */
trait OptionalValueEncoder[T] extends ValueEncoder[T] {
  override def encode(data: T, configuration: ValueCodecConfiguration): Value =
    Option(data).fold[Value](NullValue)(nonNullData => encodeNonNull(nonNullData, configuration))

  protected def encodeNonNull(data: T, configuration: ValueCodecConfiguration): Value
}