org.http4s.Method.scala Maven / Gradle / Ivy

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Core http4s library for servers and clients
There is a newer version: 0.21.0-M1
package org.http4s

import scala.collection.concurrent.TrieMap
import scalaz._

import org.http4s.parser.Rfc2616BasicRules
import org.http4s.util.{Writer, Renderable}

import Method.Semantics

/**
 * An HTTP method.
 *
 * @see [http://tools.ietf.org/html/rfc7231#section-4 RFC7321, Section 4]
 * @see [http://www.iana.org/assignments/http-methods/http-methods.xhtml IANA HTTP Method Registry]
 */
sealed abstract case class Method private (name: String) extends Renderable with Semantics {
  final override def render(writer: Writer): writer.type = writer << name
}

object Method extends MethodInstances {
  sealed trait Semantics {
    def isIdempotent: Boolean
    def isSafe: Boolean
  }

  object Semantics {
    trait Default extends Semantics {
      def isIdempotent = false
      def isSafe = false
    }
    trait Idempotent extends Semantics {
      def isIdempotent = true
      def isSafe = false
    }
    trait Safe extends Semantics {
      def isIdempotent = true
      def isSafe = true
    }
  }

  // Type tags for a method allowing a body or not
  sealed trait PermitsBody
  sealed trait NoBody

  def fromString(s: String): ParseResult[Method] =
    registry.getOrElse(s, Rfc2616BasicRules.token(s).bimap(
      e => ParseFailure("Invalid method", e.details),
      new Method(_) with Semantics.Default
    ))

  import Semantics._

  // Lookups will usually be on fromString, so we store it wrapped in a \/-
  private val registry = TrieMap[String, \/-[Method]]()

  private def register[M <: Method](method: M): method.type = {
    registry(method.name) = \/-(method)
    method
  }

  def registered: Iterable[Method] = registry.readOnlySnapshot().values.map(_.b)
  // TODO: find out the rest of the body permissions. http://www.iana.org/assignments/http-methods/http-methods.xhtml#methods
  val ACL                = register(new Method("ACL")               with Idempotent)
  val `BASELINE-CONTROL` = register(new Method("BASELINE-CONTROL")  with Idempotent)
  val BIND               = register(new Method("BIND")              with Idempotent)
  val CHECKIN            = register(new Method("CHECKIN")           with Idempotent)
  val CHECKOUT           = register(new Method("CHECKOUT")          with Idempotent)
  val CONNECT            = register(new Method("CONNECT")           with Default    with NoBody)
  val COPY               = register(new Method("COPY")              with Idempotent)
  val DELETE             = register(new Method("DELETE")            with Idempotent with NoBody)
  val GET                = register(new Method("GET")               with Safe       with NoBody)
  val HEAD               = register(new Method("HEAD")              with Safe       with NoBody)
  val LABEL              = register(new Method("LABEL")             with Idempotent with PermitsBody)
  val LINK               = register(new Method("LINK")              with Idempotent)
  val LOCK               = register(new Method("LOCK")              with Default)
  val MERGE              = register(new Method("MERGE")             with Idempotent)
  val MKACTIVITY         = register(new Method("MKACTIVITY")        with Idempotent)
  val MKCALENDAR         = register(new Method("MKCALENDAR")        with Idempotent)
  val MKCOL              = register(new Method("MKCOL")             with Idempotent)
  val MKREDIRECTREF      = register(new Method("MKREDIRECTREF")     with Idempotent)
  val MKWORKSPACE        = register(new Method("MKWORKSPACE")       with Idempotent)
  val MOVE               = register(new Method("MOVE")              with Idempotent)
  val OPTIONS            = register(new Method("OPTIONS")           with Safe       with PermitsBody)
  val ORDERPATCH         = register(new Method("ORDERPATCH")        with Idempotent)
  val PATCH              = register(new Method("PATCH")             with Default    with PermitsBody)
  val POST               = register(new Method("POST")              with Default    with PermitsBody)
  val PROPFIND           = register(new Method("PROPFIND")          with Safe)
  val PROPPATCH          = register(new Method("PROPPATCH")         with Idempotent)
  val PUT                = register(new Method("PUT")               with Idempotent with PermitsBody)
  val REBIND             = register(new Method("REBIND")            with Idempotent)
  val REPORT             = register(new Method("REPORT")            with Safe)
  val SEARCH             = register(new Method("SEARCH")            with Safe)
  val TRACE              = register(new Method("TRACE")             with Safe       with PermitsBody)
  val UNBIND             = register(new Method("UNBIND")            with Idempotent)
  val UNCHECKOUT         = register(new Method("UNCHECKOUT")        with Idempotent)
  val UNLINK             = register(new Method("UNLINK")            with Idempotent)
  val UNLOCK             = register(new Method("UNLOCK")            with Idempotent)
  val UPDATE             = register(new Method("UPDATE")            with Idempotent)
  val UPDATEREDIRECTREF  = register(new Method("UPDATEREDIRECTREF") with Idempotent)
  val `VERSION-CONTROL`  = register(new Method("VERSION-CONTROL")   with Idempotent)
}

trait MethodInstances {
  implicit val MethodInstances = new Show[Method] with Equal[Method] {
    override def shows(f: Method): String = f.toString
    override def equal(a1: Method, a2: Method): Boolean = a1 == a2
  }
}