TransferCoding.scala

/*
 * Derived from https://github.com/spray/spray/blob/v1.1-M7/spray-http/src/main/scala/spray/http/HttpEncoding.scala
 *
 * Copyright (C) 2011-2012 spray.io
 * Based on code copyright (C) 2010-2011 by the BlueEyes Web Framework Team (http://github.com/jdegoes/blueeyes)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.http4s

import cats.data.NonEmptyList
import cats.{Order, Show}
import org.http4s.internal.parboiled2.{Parser => PbParser}
import org.http4s.parser.{Http4sParser, Rfc2616BasicRules}
import org.http4s.util._

class TransferCoding private (val coding: String) extends Ordered[TransferCoding] with Renderable {
  override def equals(o: Any) = o match {
    case that: TransferCoding => this.coding.equalsIgnoreCase(that.coding)
    case _ => false
  }

  private[this] var hash = 0
  override def hashCode(): Int = {
    if (hash == 0) {
      hash = hashLower(coding)
    }
    hash
  }

  override def toString = s"TransferCoding($coding)"

  override def compare(other: TransferCoding): Int =
    coding.compareToIgnoreCase(other.coding)

  override def render(writer: Writer): writer.type = writer.append(coding.toString)
}

object TransferCoding {
  private class TransferCodingImpl(coding: String) extends TransferCoding(coding)

  // https://www.iana.org/assignments/http-parameters/http-parameters.xml#transfer-coding
  val chunked: TransferCoding = new TransferCodingImpl("chunked")
  val compress: TransferCoding = new TransferCodingImpl("compress")
  val deflate: TransferCoding = new TransferCodingImpl("deflate")
  val gzip: TransferCoding = new TransferCodingImpl("gzip")
  val identity: TransferCoding = new TransferCodingImpl("identity")

  /**
    * Parse a Transfer Coding
    */
  def parse(s: String): ParseResult[TransferCoding] =
    new Http4sParser[TransferCoding](s, "Invalid Transfer Coding") with TransferCodingParser {
      def main = codingRule
    }.parse

  /**
    * Parse a list of Transfer Coding entries
    */
  def parseList(s: String): ParseResult[NonEmptyList[TransferCoding]] =
    new Http4sParser[NonEmptyList[TransferCoding]](s, "Invalid Transfer Coding")
      with Rfc2616BasicRules
      with TransferCodingParser {
      def main = rule {
        oneOrMore(codingRule).separatedBy(ListSep) ~> { codes: Seq[TransferCoding] =>
          NonEmptyList.of(codes.head, codes.tail: _*)
        }
      }
    }.parse

  private trait TransferCodingParser { self: PbParser =>
    def codingRule = rule {
      "chunked" ~ push(chunked) |
        "compress" ~ push(compress) |
        "deflate" ~ push(deflate) |
        "gzip" ~ push(gzip) |
        "identity" ~ push(identity)
    }
  }

  implicit val http4sOrderForTransferCoding: Order[TransferCoding] =
    Order.fromComparable
  implicit val http4sShowForTransferCoding: Show[TransferCoding] =
    Show.show(_.coding)
  implicit val http4sInstancesForTransferCoding: HttpCodec[TransferCoding] =
    new HttpCodec[TransferCoding] {
      override def parse(s: String): ParseResult[TransferCoding] =
        TransferCoding.parse(s)

      override def render(writer: Writer, coding: TransferCoding): writer.type =
        writer << coding.coding
    }
}