src/Pure/System/session.scala

+/*
+ * Isabelle session, potentially with running prover
+ *
+ * @author Makarius
+ */
+
+package isabelle
+
+
+import scala.actors.TIMEOUT
+import scala.actors.Actor._
+
+
+object Session
+{
+  /* events */
+
+  case object Global_Settings
+
+
+  /* managed entities */
+
+  type Entity_ID = String
+
+  trait Entity
+  {
+    val id: Entity_ID
+    def consume(session: Session, message: XML.Tree): Unit
+  }
+}
+
+
+class Session(system: Isabelle_System)
+{
+  /* pervasive event buses */
+
+  val global_settings = new Event_Bus[Session.Global_Settings.type]
+  val raw_results = new Event_Bus[Isabelle_Process.Result]
+  val results = new Event_Bus[Command]
+
+  val command_change = new Event_Bus[Command]
+
+
+  /* unique ids */
+
+  private var id_count: BigInt = 0
+  def create_id(): Session.Entity_ID = synchronized { id_count += 1; "j" + id_count }
+
+
+
+  /** main actor **/
+
+  @volatile private var syntax = new Outer_Syntax(system.symbols)
+  def current_syntax: Outer_Syntax = syntax
+
+  @volatile private var entities = Map[Session.Entity_ID, Session.Entity]()
+  def lookup_entity(id: Session.Entity_ID): Option[Session.Entity] = entities.get(id)
+  def lookup_command(id: Session.Entity_ID): Option[Command] =
+    lookup_entity(id) match {
+      case Some(cmd: Command) => Some(cmd)
+      case _ => None
+    }
+
+  private case class Start(timeout: Int, args: List[String])
+  private case object Stop
+  private case class Begin_Document(path: String)
+
+  private val session_actor = actor {
+
+    var prover: Isabelle_Process with Isar_Document = null
+
+    def register(entity: Session.Entity) { entities += (entity.id -> entity) }
+
+    var documents = Map[Isar_Document.Document_ID, Document]()
+    def register_document(doc: Document) { documents += (doc.id -> doc) }
+
+
+    /* document changes */
+
+    def handle_change(change: Change)
+    {
+      require(change.parent.isDefined)
+
+      val (changes, doc) = change.result.join
+      val id_changes = changes map {
+        case (c1, c2) =>
+          (c1.map(_.id).getOrElse(""),
+           c2 match {
+              case None => None
+              case Some(command) =>
+                if (!lookup_command(command.id).isDefined) {
+                  register(command)
+                  prover.define_command(command.id, system.symbols.encode(command.source))
+                }
+                Some(command.id)
+            })
+      }
+      register_document(doc)
+      prover.edit_document(change.parent.get.id, doc.id, id_changes)
+    }
+
+
+    /* prover results */
+
+    def bad_result(result: Isabelle_Process.Result)
+    {
+      System.err.println("Ignoring prover result: " + result)
+    }
+
+    def handle_result(result: Isabelle_Process.Result)
+    {
+      raw_results.event(result)
+
+      val target_id: Option[Session.Entity_ID] = Position.get_id(result.props)
+      val target: Option[Session.Entity] =
+        target_id match {
+          case None => None
+          case Some(id) => lookup_entity(id)
+        }
+      if (target.isDefined) target.get.consume(this, result.message)
+      else if (result.kind == Isabelle_Process.Kind.STATUS) {
+        // global status message
+        result.body match {
+
+          // document state assigment
+          case List(XML.Elem(Markup.ASSIGN, _, edits)) if target_id.isDefined =>
+            documents.get(target_id.get) match {
+              case Some(doc) =>
+                val states =
+                  for {
+                    XML.Elem(Markup.EDIT, (Markup.ID, cmd_id) :: (Markup.STATE, state_id) :: _, _)
+                      <- edits
+                    cmd <- lookup_command(cmd_id)
+                  } yield {
+                    val st = cmd.assign_state(state_id)
+                    register(st)
+                    (cmd, st)
+                  }
+                doc.assign_states(states)
+              case None => bad_result(result)
+            }
+
+          // command and keyword declarations
+          case List(XML.Elem(Markup.COMMAND_DECL, (Markup.NAME, name) :: (Markup.KIND, kind) :: _, _)) =>
+            syntax += (name, kind)
+          case List(XML.Elem(Markup.KEYWORD_DECL, (Markup.NAME, name) :: _, _)) =>
+            syntax += name
+
+          case _ => if (!result.is_ready) bad_result(result)
+        }
+      }
+      else if (result.kind == Isabelle_Process.Kind.EXIT)
+        prover = null
+      else if (result.kind != Isabelle_Process.Kind.STDIN && !result.is_raw)
+        bad_result(result)
+    }
+
+
+    /* prover startup */
+
+    def startup_error(): String =
+    {
+      val buf = new StringBuilder
+      while (
+        receiveWithin(0) {
+          case result: Isabelle_Process.Result =>
+            if (result.is_raw) {
+              for (text <- XML.content(result.message))
+                buf.append(text)
+            }
+            true
+          case TIMEOUT => false
+        }) {}
+      buf.toString
+    }
+
+    def prover_startup(timeout: Int): Option[String] =
+    {
+      receiveWithin(timeout) {
+        case result: Isabelle_Process.Result
+          if result.kind == Isabelle_Process.Kind.INIT =>
+          while (receive {
+            case result: Isabelle_Process.Result =>
+              handle_result(result); !result.is_ready
+            }) {}
+          None
+
+        case result: Isabelle_Process.Result
+          if result.kind == Isabelle_Process.Kind.EXIT =>
+          Some(startup_error())
+
+        case TIMEOUT =>  // FIXME clarify
+          prover.kill; Some(startup_error())
+      }
+    }
+
+
+    /* main loop */
+
+    val xml_cache = new XML.Cache(131071)
+
+    loop {
+      react {
+        case Start(timeout, args) =>
+          if (prover == null) {
+            prover = new Isabelle_Process(system, self, args:_*) with Isar_Document
+            val origin = sender
+            val opt_err = prover_startup(timeout)
+            if (opt_err.isDefined) prover = null
+            origin ! opt_err
+          }
+          else reply(None)
+
+        case Stop =>  // FIXME clarify; synchronous
+          if (prover != null) {
+            prover.kill
+            prover = null
+          }
+
+        case Begin_Document(path: String) if prover != null =>
+          val id = create_id()
+          val doc = Document.empty(id)
+          register_document(doc)
+          prover.begin_document(id, path)
+          reply(doc)
+
+        case change: Change if prover != null =>
+          handle_change(change)
+
+        case result: Isabelle_Process.Result =>
+          handle_result(result.cache(xml_cache))
+
+        case bad if prover != null =>
+          System.err.println("session_actor: ignoring bad message " + bad)
+      }
+    }
+  }
+
+
+  /* main methods */
+
+  def start(timeout: Int, args: List[String]): Option[String] =
+    (session_actor !? Start(timeout, args)).asInstanceOf[Option[String]]
+
+  def stop() { session_actor ! Stop }
+  def input(change: Change) { session_actor ! change }
+
+  def begin_document(path: String): Document =
+    (session_actor !? Begin_Document(path)).asInstanceOf[Document]
+}