17.4. Performing Remote Queries via the Hot Rod C# Client

Procedure 17.3. Enable Remote Querying on the Hot Rod C# Client

1. Obtain a connection to the remote JBoss Data Grid server, passing the Protobuf marshaller into the configuration:

   using System;
   using System.Collections.Generic;
   using System.Linq;
   using System.Text;
   using System.Threading.Tasks;
   using Infinispan.HotRod;
   using Infinispan.HotRod.Config;
   using Google.Protobuf;
   using Org.Infinispan.Protostream;
   using Org.Infinispan.Query.Remote.Client;
   using QueryExampleBankAccount;
   using System.IO;
   
   namespace Query
   {
       /// <summary>
       /// This sample code shows how to perform Infinispan queries using the C# client
       /// </summary>
       class Query
       {
           static void Main(string[] args)
           {
               // Cache manager setup
               RemoteCacheManager remoteManager;
               const string ERRORS_KEY_SUFFIX = ".errors";
               const string PROTOBUF_METADATA_CACHE_NAME = "___protobuf_metadata";
               ConfigurationBuilder conf = new ConfigurationBuilder();
               conf.AddServer().Host("127.0.0.1").Port(11222).ConnectionTimeout(90000).SocketTimeout(6000);
               conf.Marshaller(new BasicTypesProtoStreamMarshaller());
               remoteManager = new RemoteCacheManager(conf.Build(), true);
               IRemoteCache<String, String> metadataCache = remoteManager.GetCache<String, String>(PROTOBUF_METADATA_CACHE_NAME);
               IRemoteCache<int, User> testCache = remoteManager.GetCache<int, User>("namedCache");

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2. Install any protobuf entities model:

               // This example continues the previous codeblock
               // Installing the entities model into the Infinispan __protobuf_metadata cache    
               metadataCache.Put("sample_bank_account/bank.proto", File.ReadAllText("resources/proto2/bank.proto"));
               if (metadataCache.ContainsKey(ERRORS_KEY_SUFFIX))
               {
                   Console.WriteLine("fail: error in registering .proto model");
                   Environment.Exit(-1);
               }

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3. This step adds data to the cache for the purposes of this demonstration, and may be ignored when simply querying a remote cache:

               // This example continues the previous codeblock
               // The application cache must contain entities only 
               testCache.Clear();
               // Fill the application cache
               User user1 = new User();
               user1.Id = 4;
               user1.Name = "Jerry";
               user1.Surname = "Mouse";
               User ret = testCache.Put(4, user1);

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4. Query the remote cache:

               // This example continues the previous codeblock
               // Run a query
               QueryRequest qr = new QueryRequest();
               qr.JpqlString = "from sample_bank_account.User";
               QueryResponse result = testCache.Query(qr);
               List<User> listOfUsers = new List<User>();
               unwrapResults(result, listOfUsers);
   
           }

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5. To process the results convert the protobuf matter into C# objects. The following method demonstrates this conversion:

           // Convert Protobuf matter into C# objects
           private static bool unwrapResults<T>(QueryResponse resp, List<T> res) where T : IMessage<T>
           {
               if (resp.ProjectionSize > 0)
               {  // Query has select
                   return false;
               }
               for (int i = 0; i < resp.NumResults; i++)
               {
                   WrappedMessage wm = resp.Results.ElementAt(i);
   
                   if (wm.WrappedBytes != null)
                   {
                       WrappedMessage wmr = WrappedMessage.Parser.ParseFrom(wm.WrappedBytes);
                       if (wmr.WrappedMessageBytes != null)
                       {
                           System.Reflection.PropertyInfo pi = typeof(T).GetProperty("Parser");
   
                           MessageParser<T> p = (MessageParser<T>)pi.GetValue(null);
                           T u = p.ParseFrom(wmr.WrappedMessageBytes);
                           res.Add(u);
                       }
                   }
               }
               return true;
           }
       }
   }

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