java/src/main/com/google/appengine/api/socket/SocketApiHelper.java

   1 // Copyright 2012 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.api.socket;
   4
   5 import com.google.appengine.api.socket.SocketServicePb.RemoteSocketServiceError;
   6 import com.google.appengine.api.socket.SocketServicePb.RemoteSocketServiceError.ErrorCode;
   7 import com.google.apphosting.api.ApiProxy;
   8 import com.google.io.protocol.ProtocolMessage;
   9
  10 import java.io.Serializable;
  11 import java.net.SocketException;
  12 import java.util.regex.Matcher;
  13 import java.util.regex.Pattern;
  14
  15 /**
  16  */
  17 class SocketApiHelper implements Serializable {
  18   static final String PACKAGE = "remote_socket";
  19
  20   private static final Pattern MESSAGE_PATTERN = Pattern.compile(
  21       "system_error:\\s*(-?\\d+)\\s*,?\\s*error_detail:\\s*\"([^\"]*)\"\\s*");
  22   static void parseErrorDetail(CharSequence string, RemoteSocketServiceError serviceError) {
  23     Matcher matcher = MESSAGE_PATTERN.matcher(string);
  24     if (!matcher.matches()) {
  25       return;
  26     }
  27
  28     serviceError.setErrorDetail(matcher.group(2));
  29     serviceError.setSystemError(Integer.parseInt(matcher.group(1)));
  30   }
  31
  32   /**
  33    * Make an appserver call and optionally return transform certain
  34    * application errors into the passed in serviceError.
  35    * @param <T> The request type.
  36    * @param <V> The response type.
  37    * @param method The service method to call.
  38    * @param request The request proto buffer.
  39    * @param response The response proto buffer.
  40    * @param serviceError The system error proto buffer.  May be null if
  41    *     not the client is not interested.
  42    * @return True if the request was successful, otherwise false only if the
  43    *     error is represented in the serviceError object. Other errors will
  44    *     throw an appropriate exception. If serviceError is null it will
  45    *     always throw on error.
  46    * @throws SocketException
  47    */
  48   <T extends ProtocolMessage<T>, V extends ProtocolMessage<V>> boolean makeSyncCall(
  49       String method, T request, V response,
  50       RemoteSocketServiceError serviceError) throws SocketException {
  51     try {
  52       byte[] responseBytes = apiProxyMakeSyncCall(method, request.toByteArray());
  53       if (responseBytes != null) {
  54         response.mergeFrom(responseBytes);
  55       }
  56       return true;
  57     } catch (ApiProxy.ApplicationException exception) {
  58       if (serviceError != null) {
  59         ErrorCode errorCode =
  60             RemoteSocketServiceError.ErrorCode.valueOf(exception.getApplicationError());
  61         switch (errorCode) {
  62           case SYSTEM_ERROR:
  63           case GAI_ERROR: {
  64             parseErrorDetail(exception.getErrorDetail(), serviceError);
  65             if (serviceError.hasErrorDetail() || serviceError.hasSystemError()) {
  66               return false;
  67             }
  68           }
  69         }
  70       }
  71       throw translateError(exception);
  72     } catch (ApiProxy.ApiDeadlineExceededException e) {
  73       throw new SocketException("Socket operation timed out: " + e.getMessage());
  74     }
  75   }
  76
  77   byte[] apiProxyMakeSyncCall(String method, byte[] request) {
  78     return ApiProxy.makeSyncCall(PACKAGE, method, request);
  79   }
  80
  81   static SocketException translateError(int error, String detail) {
  82     ErrorCode errorCode = RemoteSocketServiceError.ErrorCode.valueOf(error);
  83
  84     switch (errorCode) {
  85       case SYSTEM_ERROR:
  86         return new SocketException("System error: " + detail);
  87       case GAI_ERROR:
  88         return new SocketException("Resolver error: " + detail);
  89       case SSL_ERROR:
  90         return new SocketException("SSL Error: " + detail);
  91       case FAILURE:
  92         return new SocketException("Operation failure: " + detail);
  93       case PERMISSION_DENIED:
  94         return new SocketException("Permission denied: " + detail);
  95       case INVALID_REQUEST:
  96         return new SocketException("Invalid request: " + detail);
  97       case SOCKET_CLOSED:
  98         return new SocketException("Socket is closed: " + detail);
  99       default:
 100         return new SocketException("Unspecified error (" + errorCode + ") : " + detail);
 101     }
 102   }
 103
 104   static SocketException translateError(ApiProxy.ApplicationException exception) {
 105     return translateError(exception.getApplicationError(), exception.getErrorDetail());
 106   }
 107 }