/
SessionVar.scala
71 lines (57 loc) · 2.51 KB
/
SessionVar.scala
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package sbt
import Def.ScopedKey
import Types.Id
import Keys.sessionVars
import sbinary.{Format, Operations}
object SessionVar
{
val DefaultDataID = "data"
// these are required because of inference+manifest limitations
final case class Key[T](key: ScopedKey[Task[T]])
final case class Map(map: IMap[Key, Id]) {
def get[T](k: ScopedKey[Task[T]]): Option[T] = map get Key(k)
def put[T](k: ScopedKey[Task[T]], v: T): Map = Map(map put (Key(k), v))
}
def emptyMap = Map(IMap.empty)
def persistAndSet[T](key: ScopedKey[Task[T]], state: State, value: T)(implicit f: sbinary.Format[T]): State =
{
persist(key, state, value)(f)
set(key, state, value)
}
def persist[T](key: ScopedKey[Task[T]], state: State, value: T)(implicit f: sbinary.Format[T]): Unit =
Project.structure(state).streams(state).use(key)( s =>
Operations.write(s.binary(DefaultDataID), value)(f)
)
def clear(s: State): State = s.put(sessionVars, SessionVar.emptyMap)
def get[T](key: ScopedKey[Task[T]], state: State): Option[T] = orEmpty(state get sessionVars) get key
def set[T](key: ScopedKey[Task[T]], state: State, value: T): State = state.update(sessionVars)(om => orEmpty(om) put (key, value))
def orEmpty(opt: Option[Map]) = opt getOrElse emptyMap
def transform[S](task: Task[S], f: (State, S) => State): Task[S] =
{
val g = (s: S, map: AttributeMap) => map.put(Keys.transformState, (state: State) => f(state, s))
task.copy(info = task.info.postTransform(g))
}
def resolveContext[T](key: ScopedKey[Task[T]], context: Scope, state: State): ScopedKey[Task[T]] =
{
val subScope = Scope.replaceThis(context)(key.scope)
val scope = Project.structure(state).data.definingScope(subScope, key.key) getOrElse subScope
ScopedKey(scope, key.key)
}
def read[T](key: ScopedKey[Task[T]], state: State)(implicit f: Format[T]): Option[T] =
Project.structure(state).streams(state).use(key) { s =>
try { Some(Operations.read(s.readBinary(key, DefaultDataID))) }
catch { case e: Exception => None }
}
def load[T](key: ScopedKey[Task[T]], state: State)(implicit f: Format[T]): Option[T] =
get(key, state) orElse read(key, state)(f)
def loadAndSet[T](key: ScopedKey[Task[T]], state: State, setIfUnset: Boolean = true)(implicit f: Format[T]): (State, Option[T]) =
get(key, state) match {
case s: Some[T] => (state, s)
case None => read(key, state)(f) match {
case s @ Some(t) =>
val newState = if(setIfUnset && get(key, state).isDefined) state else set(key, state, t)
(newState, s)
case None => (state, None)
}
}
}