java/src/main/com/google/appengine/tools/remoteapi/RemoteApiDelegate.java

   1 // Copyright 2010 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.tools.remoteapi;
   4
   5 import com.google.apphosting.api.ApiProxy.Delegate;
   6 import com.google.apphosting.api.ApiProxy.Environment;
   7
   8 /**
   9  * Handles App Engine API calls by making HTTP requests to a remote server.
  10  * The exact mechanism by which the requests are made is an implementation
  11  * detail of subclasses.  Users of this class are expected to call
  12  * {@link #shutdown()} when they are done with an instance.
  13  *
  14  */
  15 abstract class RemoteApiDelegate implements Delegate<Environment> {
  16   private final RemoteRpc remoteRpc;
  17   private final RemoteDatastore remoteDatastore;
  18
  19   /**
  20    * Factory method.
  21    */
  22   public static RemoteApiDelegate newInstance(RemoteRpc remoteRpc, RemoteApiOptions options, Delegate<Environment> containerDelegate) {
  23     return containerDelegate != null ?
  24         new HostedRemoteApiDelegate(remoteRpc, options, containerDelegate) :
  25         new StandaloneRemoteApiDelegate(remoteRpc, options);
  26   }
  27
  28   /**
  29    * Do not call directly, use
  30    * {@link #newInstance(RemoteRpc, RemoteApiOptions, Delegate)} instead.
  31    */
  32   RemoteApiDelegate(RemoteRpc rpc, RemoteApiOptions options) {
  33     this.remoteRpc = rpc;
  34     this.remoteDatastore = new RemoteDatastore(remoteRpc, options);
  35   }
  36
  37   void resetRpcCount() {
  38     remoteRpc.resetRpcCount();
  39   }
  40
  41   int getRpcCount() {
  42     return remoteRpc.getRpcCount();
  43   }
  44
  45   final byte[] makeDefaultSyncCall(
  46       Environment env, String serviceName, String methodName, byte[] request) {
  47     if (serviceName.equals(RemoteDatastore.DATASTORE_SERVICE)) {
  48       return remoteDatastore.handleDatastoreCall(methodName, request);
  49     } else {
  50       return remoteRpc.call(serviceName, methodName, "", request);
  51     }
  52   }
  53
  54   /**
  55    * Perform any necessary clean up and shut down.
  56    */
  57   public abstract void shutdown();
  58 }