org.simantics.r.scl/src/org/simantics/r/scl/RSessionManager.java

   1 package org.simantics.r.scl;\r
   2 \r
   3 import java.util.UUID;\r
   4 import java.util.concurrent.ConcurrentHashMap;\r
   5 \r
   6 import org.rosuda.REngine.Rserve.RConnection;\r
   7 import org.rosuda.REngine.Rserve.RserveException;\r
   8 import org.simantics.scl.runtime.function.Function;\r
   9 \r
  10 public class RSessionManager {\r
  11     static ConcurrentHashMap<String, RSession> CONNECTIONS =\r
  12             new ConcurrentHashMap<String, RSession>(); \r
  13     \r
  14     public static RSession getSession(String id) {\r
  15         // CONNECTIONS is ConcurrentHashMap so no synchronization is needed here\r
  16         return CONNECTIONS.get(id);\r
  17     }\r
  18     \r
  19     public static RSession createSession(RSessionConfiguration configuration) throws RserveException {\r
  20         synchronized(CONNECTIONS) {\r
  21             String id = UUID.randomUUID().toString();\r
  22             return createSession(configuration, id);\r
  23         }\r
  24     }\r
  25     \r
  26     public static Object withConfiguration(RSessionConfiguration configuration, @SuppressWarnings("rawtypes") Function f) throws RserveException {\r
  27         RSession session = createSession(configuration);\r
  28         try {\r
  29             return session.syncExec(f);\r
  30         } catch (InterruptedException e) {\r
  31             throw new RuntimeException(e);\r
  32         } finally {\r
  33             session.close();\r
  34         }\r
  35     }\r
  36     \r
  37     public static RSession getOrCreateSession(RSessionConfiguration configuration, String id) throws RserveException {\r
  38         synchronized(CONNECTIONS) {\r
  39             RSession session = getSession(id);\r
  40             if(session == null)\r
  41                 return createSession(configuration, id);\r
  42             else\r
  43                 return session;\r
  44         }\r
  45     }\r
  46     \r
  47     private static RSession createSession(RSessionConfiguration configuration, String id) throws RserveException {\r
  48         synchronized(CONNECTIONS) {\r
  49             RConnection connection = new RConnection(configuration.host, configuration.port);\r
  50             if(configuration.username != null && !configuration.username.isEmpty())\r
  51                 connection.login(configuration.username, configuration.password);\r
  52             RSession managedConnection = new RSession(connection, id);\r
  53             CONNECTIONS.put(id, managedConnection);\r
  54             return managedConnection;\r
  55         }\r
  56     }\r
  57 }\r