java/src/main/com/google/appengine/api/search/SearchApiHelper.java

   1 // Copyright 2010 Google Inc. All rights reserved.
   2 package com.google.appengine.api.search;
   3
   4 import com.google.appengine.api.utils.FutureWrapper;
   5 import com.google.apphosting.api.ApiProxy;
   6 import com.google.protobuf.GeneratedMessage;
   7 import com.google.protobuf.InvalidProtocolBufferException;
   8
   9 import java.util.concurrent.Future;
  10
  11 /**
  12  * Provides support for translation of calls between userland and appserver
  13  * land.
  14  *
  15  */
  16 class SearchApiHelper {
  17
  18   private static final String PACKAGE = "search";
  19
  20   /**
  21    * Makes an asynchronous call.
  22    *
  23    * @param method the method on the API to call
  24    * @param request the request to forward to the API
  25    * @param responseBuilder the response builder used to fill the response
  26    * @param deadline the deadline of the call. if it is null, the default api deadline will be used
  27    */
  28   <T extends GeneratedMessage.Builder<T>>
  29   Future<T> makeAsyncCall(String method, GeneratedMessage request, final T responseBuilder, Double deadline) {
  30     Future<byte[]> response;
  31     if (deadline == null) {
  32       response = ApiProxy.makeAsyncCall(PACKAGE, method, request.toByteArray());
  33     } else {
  34       ApiProxy.ApiConfig apiConfig = new ApiProxy.ApiConfig();
  35       apiConfig.setDeadlineInSeconds(deadline);
  36       response = ApiProxy.makeAsyncCall(PACKAGE, method, request.toByteArray(), apiConfig);
  37     }
  38     return new FutureWrapper<byte[], T>(response) {
  39       @Override
  40       protected T wrap(byte[] responseBytes) {
  41         if (responseBytes != null) {
  42           try {
  43             responseBuilder.mergeFrom(responseBytes);
  44           } catch (InvalidProtocolBufferException e) {
  45             throw new SearchServiceException(e.toString());
  46           }
  47         }
  48         return responseBuilder;
  49       }
  50
  51       @Override
  52       protected Throwable convertException(Throwable cause) {
  53         return cause;
  54       }
  55     };
  56   }
  57 }