First draft of message attributes

akka-http-core/src/main/java/akka/http/javadsl/model/HttpMessage.java

@@ -49,13 +49,13 @@ public interface HttpMessage {
 
     /**
      * Try to find the first header with the given name (case-insensitive) and return
-     * Some(header), otherwise this method returns None.
+     * Optional.of(header), otherwise this method returns an empty Optional.
      */
     Optional<HttpHeader> getHeader(String headerName);
 
     /**
      * Try to find the first header of the given class and return
-     * Some(header), otherwise this method returns None.
+     * Optional.of(header), otherwise this method returns an empty Optional.
      */
     <T extends HttpHeader> Optional<T> getHeader(Class<T> headerClass);
 
@@ -65,6 +65,22 @@ public interface HttpMessage {
      */
     <T extends HttpHeader> Iterable<T> getHeaders(Class<T> headerClass);
 
+    /**
+     * An iterable containing the attributes for this message.
+     */
+    Iterable<Object> getAttributes();
+
+    /**
+     * Try to find the first attribute of the given class and return
+     * Optional.of(attribute), otherwise this method returns an empty Optional
+     */
+    <T> Optional<T> getAttribute(Class<T> attributeClass);
+
+    /**
+     * An iterable containing all attributes of the given class of this message
+     */
+     <T> Iterable<T> getAttributes(Class<T> attributeClass);
+
     /**
      * The entity of this message.
      */

akka-http-core/src/main/mima-filters/10.1.11.backwards.excludes/issue-1500-attributes.excludes

@@ -0,0 +1,12 @@
+# Adding a method to an interface marked DoNotInherit is OK
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.javadsl.model.HttpMessage.getAttributes")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.javadsl.model.HttpMessage.getAttribute")
+
+# Adding a method to a sealed trait is safe
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.scaladsl.model.HttpMessage.attributes")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.scaladsl.model.HttpMessage.withAttributes")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.scaladsl.model.HttpMessage.mapAttributes")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.scaladsl.model.HttpMessage.addAttribute")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.scaladsl.model.HttpMessage.getAttributes")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.scaladsl.model.HttpMessage.getAttribute")
+ProblemFilters.exclude[ReversedMissingMethodProblem]("akka.http.scaladsl.model.HttpMessage.getAttributes")

akka-http-core/src/main/scala/akka/http/scaladsl/model/HttpMessage.scala

@@ -4,8 +4,6 @@
 
 package akka.http.scaladsl.model
 
-import akka.stream.scaladsl.Flow
-import akka.stream.{ FlowShape, Graph }
 import java.io.File
 import java.nio.file.Path
 import java.lang.{ Iterable => JIterable }
@@ -17,9 +15,14 @@ import scala.concurrent.duration.FiniteDuration
 import scala.concurrent.{ ExecutionContext, Future }
 import scala.collection.immutable
 import scala.reflect.{ ClassTag, classTag }
+
 import akka.Done
+import akka.annotation.InternalApi
 import akka.parboiled2.CharUtils
+import akka.stream.FlowShape
+import akka.stream.Graph
 import akka.stream.Materializer
+import akka.stream.scaladsl.Flow
 import akka.util.{ ByteString, HashCode, OptionVal }
 import akka.http.ccompat.{ pre213, since213 }
 import akka.http.impl.util._
@@ -42,6 +45,7 @@ sealed trait HttpMessage extends jm.HttpMessage {
   def isResponse: Boolean
 
   def headers: immutable.Seq[HttpHeader]
+  def attributes: immutable.Seq[AnyRef]
   def entity: ResponseEntity
   def protocol: HttpProtocol
 
@@ -79,6 +83,13 @@ sealed trait HttpMessage extends jm.HttpMessage {
   def withHeaders(firstHeader: HttpHeader, otherHeaders: HttpHeader*): Self =
     withHeaders(firstHeader +: otherHeaders.toList)
 
+  /** Returns a copy of this message with the list of headers set to the given ones. */
+  def withAttributes(attributes: immutable.Seq[AnyRef]): Self
+
+  /** Returns a copy of this message with the list of headers set to the given ones. */
+  def withAttributes(firstAttribute: AnyRef, otherAttributes: AnyRef*): Self =
+    withAttributes(firstAttribute +: otherAttributes.toList)
+
   /**
    * Returns a new message that contains all of the given default headers which didn't already
    * exist (by case-insensitive header name) in this message.
@@ -117,6 +128,9 @@ sealed trait HttpMessage extends jm.HttpMessage {
   /** Returns a copy of this message with the list of headers transformed by the given function */
   def mapHeaders(f: immutable.Seq[HttpHeader] => immutable.Seq[HttpHeader]): Self = withHeaders(f(headers))
 
+  /** Returns a copy of this message with the list of attributes transformed by the given function */
+  def mapAttributes(f: immutable.Seq[AnyRef] => immutable.Seq[AnyRef]): Self = withAttributes(f(headers))
+
   /**
    * The content encoding as specified by the Content-Encoding header. If no Content-Encoding header is present the
    * default value 'identity' is returned.
@@ -140,6 +154,10 @@ sealed trait HttpMessage extends jm.HttpMessage {
   def headers[T <: jm.HttpHeader: ClassTag]: immutable.Seq[T] = headers.collect {
     case h: T => h
   }
+  /** Returns all the attributes of the given type **/
+  def attributes[T: ClassTag]: immutable.Seq[T] = attributes.collect {
+    case a: T => a
+  }
 
   /**
    * Returns true if this message is an:
@@ -149,6 +167,7 @@ sealed trait HttpMessage extends jm.HttpMessage {
   def connectionCloseExpected: Boolean = HttpMessage.connectionCloseExpected(protocol, header[Connection])
 
   def addHeader(header: jm.HttpHeader): Self = mapHeaders(_ :+ header.asInstanceOf[HttpHeader])
+  def addAttribute(attribute: AnyRef): Self = mapAttributes(_ :+ header.asInstanceOf[HttpHeader])
 
   def addCredentials(credentials: jm.headers.HttpCredentials): Self = addHeader(jm.headers.Authorization.create(credentials))
 
@@ -196,6 +215,21 @@ sealed trait HttpMessage extends jm.HttpMessage {
     import JavaMapping.Implicits._
     withHeaders(headers.asScala.toVector.map(_.asScala))
   }
+  /** Java API */
+  def getAttributes: JIterable[AnyRef] = (attributes: immutable.Seq[AnyRef]).asJava
+  /** Java API */
+  def getAttribute[T](attributeClass: Class[T]): Optional[T] = {
+    fastFindAttribute[T](attributeClass) match {
+      case OptionVal.Some(h) => Optional.of(h.asInstanceOf[T])
+      case _                 => Optional.empty()
+    }
+    val attrs = attributes[T](ClassTag[T](attributeClass))
+    if (attrs.isEmpty) Optional.empty()
+    else Optional.of(attrs.head)
+  }
+  def getAttributes[T](attributeClass: Class[T]): JIterable[T] =
+    attributes[T](ClassTag[T](attributeClass)).asJava
+
   /** Java API */
   def toStrict(timeoutMillis: Long, ec: Executor, materializer: Materializer): CompletionStage[Self] = {
     val ex = ExecutionContext.fromExecutor(ec)
@@ -206,6 +240,14 @@ sealed trait HttpMessage extends jm.HttpMessage {
     val ex = ExecutionContext.fromExecutor(ec)
     toStrict(timeoutMillis.millis, maxBytes)(ex, materializer).toJava
   }
+  private def fastFindAttribute[T](clazz: Class[T]): OptionVal[T] = {
+    val it = attributes.iterator
+    while (it.hasNext) it.next() match {
+      case h if clazz.isInstance(h) => return OptionVal.Some[T](h.asInstanceOf[T])
+      case _                        => // continue ...
+    }
+    OptionVal.none[T]
+  }
 }
 
 object HttpMessage {
@@ -265,11 +307,12 @@ object HttpMessage {
  * The immutable model HTTP request model.
  */
 final class HttpRequest(
-  val method:   HttpMethod,
-  val uri:      Uri,
-  val headers:  immutable.Seq[HttpHeader],
-  val entity:   RequestEntity,
-  val protocol: HttpProtocol)
+  val method:     HttpMethod,
+  val uri:        Uri,
+  val headers:    immutable.Seq[HttpHeader],
+  val attributes: immutable.Seq[AnyRef],
+  val entity:     RequestEntity,
+  val protocol:   HttpProtocol)
   extends jm.HttpRequest with HttpMessage {
 
   HttpRequest.verifyUri(uri)
@@ -284,6 +327,10 @@ final class HttpRequest(
   override def isRequest = true
   override def isResponse = false
 
+  @deprecated("for backwards compatibility", "10.2.0")
+  def this(method: HttpMethod, uri: Uri, headers: immutable.Seq[HttpHeader], entity: RequestEntity, protocol: HttpProtocol) =
+    this(method, uri, headers, Nil, entity, protocol)
+
   /**
    * Resolve this request's URI according to the logic defined at
    * http://tools.ietf.org/html/rfc7230#section-5.5
@@ -313,6 +360,8 @@ final class HttpRequest(
 
   override def withHeaders(headers: immutable.Seq[HttpHeader]): HttpRequest =
     if (headers eq this.headers) this else copy(headers = headers)
+  override def withAttributes(attributes: immutable.Seq[AnyRef]): HttpRequest =
+    if (attributes eq this.attributes) this else copy(attributes = attributes)
 
   override def withHeadersAndEntity(headers: immutable.Seq[HttpHeader], entity: RequestEntity): HttpRequest = copy(headers = headers, entity = entity)
   override def withEntity(entity: jm.RequestEntity): HttpRequest = copy(entity = entity.asInstanceOf[RequestEntity])
@@ -335,12 +384,20 @@ final class HttpRequest(
 
   /* Manual Case Class things, to easen bin-compat */
 
+  @deprecated("Kept for binary compatibility", "10.2.0")
+  def copy(
+    method:   HttpMethod,
+    uri:      Uri,
+    headers:  immutable.Seq[HttpHeader],
+    entity:   RequestEntity,
+    protocol: HttpProtocol) = new HttpRequest(method, uri, headers, attributes, entity, protocol)
   def copy(
-    method:   HttpMethod                = method,
-    uri:      Uri                       = uri,
-    headers:  immutable.Seq[HttpHeader] = headers,
-    entity:   RequestEntity             = entity,
-    protocol: HttpProtocol              = protocol) = new HttpRequest(method, uri, headers, entity, protocol)
+    method:     HttpMethod                = method,
+    uri:        Uri                       = uri,
+    headers:    immutable.Seq[HttpHeader] = headers,
+    entity:     RequestEntity             = entity,
+    protocol:   HttpProtocol              = protocol,
+    attributes: immutable.Seq[AnyRef]     = attributes) = new HttpRequest(method, uri, headers, attributes, entity, protocol)
 
   override def hashCode(): Int = {
     var result = HashCode.SEED
@@ -439,7 +496,7 @@ object HttpRequest {
     uri:      Uri                       = Uri./,
     headers:  immutable.Seq[HttpHeader] = Nil,
     entity:   RequestEntity             = HttpEntity.Empty,
-    protocol: HttpProtocol              = HttpProtocols.`HTTP/1.1`) = new HttpRequest(method, uri, headers, entity, protocol)
+    protocol: HttpProtocol              = HttpProtocols.`HTTP/1.1`) = new HttpRequest(method, uri, headers, Nil, entity, protocol)
 
   def unapply(any: HttpRequest) = new OptHttpRequest(any)
 }
@@ -448,10 +505,11 @@ object HttpRequest {
  * The immutable HTTP response model.
  */
 final class HttpResponse(
-  val status:   StatusCode,
-  val headers:  immutable.Seq[HttpHeader],
-  val entity:   ResponseEntity,
-  val protocol: HttpProtocol)
+  val status:     StatusCode,
+  val headers:    immutable.Seq[HttpHeader],
+  val attributes: immutable.Seq[AnyRef],
+  val entity:     ResponseEntity,
+  val protocol:   HttpProtocol)
   extends jm.HttpResponse with HttpMessage {
 
   require(entity.isKnownEmpty || status.allowsEntity, "Responses with this status code must have an empty entity")
@@ -465,8 +523,14 @@ final class HttpResponse(
   override def isRequest = false
   override def isResponse = true
 
+  @deprecated("for backwards compatibility", "10.2.0")
+  def this(status: StatusCode, headers: immutable.Seq[HttpHeader], entity: ResponseEntity, protocol: HttpProtocol) =
+    this(status, headers, Nil, entity, protocol)
+
   override def withHeaders(headers: immutable.Seq[HttpHeader]): HttpResponse =
     if (headers eq this.headers) this else copy(headers = headers)
+  override def withAttributes(attributes: immutable.Seq[AnyRef]): HttpResponse =
+    if (attributes eq this.attributes) this else copy(attributes = attributes)
 
   override def withProtocol(protocol: akka.http.javadsl.model.HttpProtocol): akka.http.javadsl.model.HttpResponse = withProtocol(protocol.asInstanceOf[HttpProtocol])
   def withProtocol(protocol: HttpProtocol): HttpResponse = copy(protocol = protocol)
@@ -485,11 +549,18 @@ final class HttpResponse(
 
   /* Manual Case Class things, to ease bin-compat */
 
+  @deprecated("Kept for binary compatibility", "10.2.0")
+  def copy(
+    status:   StatusCode,
+    headers:  immutable.Seq[HttpHeader],
+    entity:   ResponseEntity,
+    protocol: HttpProtocol) = new HttpResponse(status, headers, attributes, entity, protocol)
   def copy(
-    status:   StatusCode                = status,
-    headers:  immutable.Seq[HttpHeader] = headers,
-    entity:   ResponseEntity            = entity,
-    protocol: HttpProtocol              = protocol) = new HttpResponse(status, headers, entity, protocol)
+    status:     StatusCode                = status,
+    headers:    immutable.Seq[HttpHeader] = headers,
+    entity:     ResponseEntity            = entity,
+    protocol:   HttpProtocol              = protocol,
+    attributes: immutable.Seq[AnyRef]     = attributes) = new HttpResponse(status, headers, attributes, entity, protocol)
 
   override def equals(obj: scala.Any): Boolean = obj match {
     case HttpResponse(_status, _headers, _entity, _protocol) =>
@@ -526,7 +597,7 @@ object HttpResponse {
     status:   StatusCode                = StatusCodes.OK,
     headers:  immutable.Seq[HttpHeader] = Nil,
     entity:   ResponseEntity            = HttpEntity.Empty,
-    protocol: HttpProtocol              = HttpProtocols.`HTTP/1.1`) = new HttpResponse(status, headers, entity, protocol)
+    protocol: HttpProtocol              = HttpProtocols.`HTTP/1.1`) = new HttpResponse(status, headers, Nil, entity, protocol)
 
   def unapply(any: HttpResponse): OptHttpResponse = new OptHttpResponse(any)
 }

akka-http-core/src/test/scala/akka/http/scaladsl/model/HttpMessageSpec.scala

@@ -71,6 +71,14 @@ class HttpMessageSpec extends WordSpec with Matchers {
       val request = HttpRequest().withHeaders(oneCookieHeader, anotherCookieHeader, hostHeader)
       request.headers[`Set-Cookie`] should ===(Seq(oneCookieHeader, anotherCookieHeader))
     }
+    "retrieve all attributes of a given class when calling attributes[...]" in {
+      val oneStringAttribute: String = "A string attribute!"
+      val anotherStringAttribute: String = "And another"
+      val intAttribute: Integer = 42
+      val request = HttpRequest().withAttributes(oneStringAttribute, anotherStringAttribute, intAttribute)
+      println(request.attributes)
+      request.attributes[String] should ===(Seq(oneStringAttribute, anotherStringAttribute))
+    }
   }
 
 }