Packages

  • package root
    Definition Classes
    root
  • package com
    Definition Classes
    root
  • package twitter

    Start with com.twitter.finagle.

    Definition Classes
    com
  • package finagle

    Finagle is an extensible RPC system.

    Finagle is an extensible RPC system.

    Services are represented by class com.twitter.finagle.Service. Clients make use of com.twitter.finagle.Service objects while servers implement them.

    Finagle contains a number of protocol implementations; each of these implement Client and/or com.twitter.finagle.Server. For example, Finagle's HTTP implementation, com.twitter.finagle.Http (in package finagle-http), exposes both.

    Thus a simple HTTP server is built like this:

    import com.twitter.finagle.{Http, Service}
    import com.twitter.finagle.http.{Request, Response}
    import com.twitter.util.{Await, Future}
    
    val service = new Service[Request, Response] {
      def apply(req: Request): Future[Response] =
        Future.value(Response())
    }
    val server = Http.server.serve(":8080", service)
    Await.ready(server)

    We first define a service to which requests are dispatched. In this case, the service returns immediately with a HTTP 200 OK response, and with no content.

    This service is then served via the Http protocol on TCP port 8080. Finally we wait for the server to stop serving.

    We can now query our web server:

    % curl -D - localhost:8080
    HTTP/1.1 200 OK

    Building an HTTP client is also simple. (Note that type annotations are added for illustration.)

    import com.twitter.finagle.{Http, Service}
    import com.twitter.finagle.http.{Request, Response}
    import com.twitter.util.{Future, Return, Throw}
    
    val client: Service[Request, Response] = Http.client.newService("localhost:8080")
    val f: Future[Response] = client(Request()).respond {
      case Return(rep) =>
        printf("Got HTTP response %s\n", rep)
      case Throw(exc) =>
        printf("Got error %s\n", exc)
    }

    Http.client.newService("localhost:8080") constructs a new com.twitter.finagle.Service instance connected to localhost TCP port 8080. We then issue a HTTP/1.1 GET request to URI "/". The service returns a com.twitter.util.Future representing the result of the operation. We listen to this future, printing an appropriate message when the response arrives.

    The Finagle homepage contains useful documentation and resources for using Finagle.

    Definition Classes
    twitter
  • package context
    Definition Classes
    finagle
  • BackupRequest
  • Context
  • Contexts
  • Deadline
  • LocalContext
  • MarshalledContext
  • RemoteInfo
  • Retries

trait Context extends AnyRef

A context contains a number of let-delimited bindings. Bindings are indexed by type Key[A] in a typesafe manner. Later bindings shadow earlier ones.

Note that the implementation of context maintains all bindings in a linked list; context lookup requires a linear search.

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Type Members

  1. abstract type Key[A]
  2. case class KeyValuePair[T](key: Key[T], value: T) extends Product with Serializable

    Represents an opaque type that consists of a key-value pair which can be used to set multiple keys in the context.

Abstract Value Members

  1. abstract def get[A](key: Key[A]): Option[A]

    Retrieve the current definition of a key, but only if it is defined in the current request-local context.

  2. abstract def let[R](keys: Iterable[KeyValuePair[_]])(fn: => R): R

    Bind multiple key-value pairs.

    Bind multiple key-value pairs. Keys later in the collection take precedent over keys earlier in the collection.

  3. abstract def let[A, B, R](key1: Key[A], value1: A, key2: Key[B], value2: B)(fn: => R): R

    Bind two keys and values in the scope of fn.

  4. abstract def let[A, R](key: Key[A], value: A)(fn: => R): R

    Bind value to key in the scope of fn.

  5. abstract def letClear[R](keys: Iterable[Key[_]])(fn: => R): R

    Unbind the passed-in keys, in the scope of fn.

  6. abstract def letClear[R](key: Key[_])(fn: => R): R

    Unbind the passed-in key, in the scope of fn.

  7. abstract def letClearAll[R](fn: => R): R

    Clears all bindings in the scope of fn.

    Clears all bindings in the scope of fn.

    For example:

    context.let(Key1, "value1") {
      context.let(Key2, "something else") {
        context.letClearAll {
          // context.contains(Key1) == false
          // context.contains(Key2) == false
        }
        // context(Key1) == "value1"
        // context(Key2) == "something else"
      }
    }

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. def apply[A](key: Key[A]): A

    Retrieve the current definition of a key.

    Retrieve the current definition of a key.

    Annotations
    @throws("If the key does not exist")
    Exceptions thrown

    NoSuchElementException when the key is undefined in the current request-local context.

  5. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  6. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  7. def contains[A](key: Key[A]): Boolean

    Tells whether key is defined in the current request-local context.

  8. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  9. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  10. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
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    Annotations
    @throws(classOf[java.lang.Throwable])
  11. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  12. def getOrElse[A](key: Key[A], orElse: () => A): A

    Retrieve the current definition of a key if it is defined.

    Retrieve the current definition of a key if it is defined. If it is not defined, orElse is evaluated and returned.

  13. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  14. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  15. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  16. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  17. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  18. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  19. def toString(): String
    Definition Classes
    AnyRef → Any
  20. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  21. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  22. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

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