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 postgresql
    Definition Classes
    finagle
  • package types
    Definition Classes
    postgresql
  • Json
  • Kind
  • PgDate
  • PgNumeric
  • PgTime
  • PgType
  • ValueReads
  • ValueWrites

trait ValueWrites[T] extends AnyRef

Typeclass for encoding Scala/Java types to Postgres wire values.

Postgres has its own type system, so the mapping of postgres types to scala types is not 1:1. Furthermore, postgres allows creating custom types (i.e.: commonly enums, but any arbitrary type can effectively be created) which also require their own mapping to scala types.

The following built-in types and their corresponding scala / java types are provided * (read this table as "Postgres Type X can be written from Scala / Java Type Y"):

Postgres Type

Scala / Java Type

BIGINT (int8)

Long, Int, Short, Byte

BOOL

Boolean

BYTEA (byte[])

Buf

CHARACTER(n)

String

DATE (date)

java.time.LocalDate

DOUBLE (float8)

Double, Float

INET

Inet (java.net.InetAddress and a subnet)

INTEGER (int, int4)

Int, Short, Byte

JSON

String or Json

JSONB

Json

NUMERIC (decimal)

BigDecimal

REAL (float4)

Float

SMALLINT (int2)

Short and Byte

TEXT

String

TIMESTAMP

java.time.Instant

TIMESTAMP WITH TIME ZONE

java.time.Instant

UUID

java.util.UUID

VARCHAR

String

Note

numeric types don't have the same correspondence for reading and writing.

See also

ValueReads

PgType

Linear Supertypes
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Inherited
  1. ValueWrites
  2. AnyRef
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Visibility
  1. Public
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Abstract Value Members

  1. abstract def accepts(tpe: PgType): Boolean

    Returns true when this implementation is able to encode values of the provided Postgres type.

    Returns true when this implementation is able to encode values of the provided Postgres type. Returns false otherwise.

    tpe

    the Postgres type to check.

    returns

    true if this implementation can encode values for the type, false otherwise.

  2. abstract def writes(tpe: PgType, value: T, charset: Charset): WireValue

    Encode a value to Postgres' wire representation for a particular Postgres type.

    Encode a value to Postgres' wire representation for a particular Postgres type.

    tpe

    the Postgres type to encode the value into.

    value

    the value to encode.

    charset

    when applicable, the character set to use when encoding.

    returns

    the encoded value

    Note

    It is the responsability of the caller to ensure that the Postgres type is accepted by this implementation.

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. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  6. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  7. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  8. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  9. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  10. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  11. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  12. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  14. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  15. def orElse(that: ValueWrites[T]): ValueWrites[T]

    Returns a ValueWrites instance that will use this if it accepts the type, otherwise will delegate to that.

    Returns a ValueWrites instance that will use this if it accepts the type, otherwise will delegate to that.

    that

    the instance to delegate to when this does not accept the provided type.

    returns

    a ValueWrites instance that will use this if it accepts the type, otherwise will delegate to that.

    See also

    ValueWrites.or

  16. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  17. def toString(): String
    Definition Classes
    AnyRef → Any
  18. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  19. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  20. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

Inherited from AnyRef

Inherited from Any

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