ceph/src/jaegertracing/thrift/lib/delphi/src/Thrift.Protocol.Multiplex.pas

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  15  * KIND, either express or implied. See the License for the
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  17  * under the License.
  18  *)
  19
  20 unit Thrift.Protocol.Multiplex;
  21
  22 interface
  23
  24 uses Thrift.Protocol;
  25
  26 { TMultiplexedProtocol is a protocol-independent concrete decorator
  27   that allows a Thrift client to communicate with a multiplexing Thrift server,
  28   by prepending the service name to the function name during function calls.
  29
  30   NOTE: THIS IS NOT USED BY SERVERS.
  31   On the server, use TMultiplexedProcessor to handle requests from a multiplexing client.
  32
  33   This example uses a single socket transport to invoke two services:
  34
  35       TSocket transport = new TSocket("localhost", 9090);
  36       transport.open();
  37
  38       TBinaryProtocol protocol = new TBinaryProtocol(transport);
  39
  40       TMultiplexedProtocol mp = new TMultiplexedProtocol(protocol, "Calculator");
  41       Calculator.Client service = new Calculator.Client(mp);
  42
  43       TMultiplexedProtocol mp2 = new TMultiplexedProtocol(protocol, "WeatherReport");
  44       WeatherReport.Client service2 = new WeatherReport.Client(mp2);
  45
  46       System.out.println(service.add(2,2));
  47       System.out.println(service2.getTemperature());
  48
  49 }
  50
  51 type
  52   TMultiplexedProtocol = class( TProtocolDecorator)
  53   public const
  54     {  Used to delimit the service name from the function name }
  55     SEPARATOR = ':';
  56
  57   private
  58      FServiceName : String;
  59
  60   public
  61     { Wrap the specified protocol, allowing it to be used to communicate with a multiplexing server.
  62       The serviceName is required as it is prepended to the message header so that the multiplexing
  63       server can broker the function call to the proper service.
  64
  65       Args:
  66         protocol ....... Your communication protocol of choice, e.g. TBinaryProtocol.
  67         serviceName .... The service name of the service communicating via this protocol.
  68     }
  69     constructor Create( const aProtocol : IProtocol; const aServiceName : string);
  70
  71     { Prepends the service name to the function name, separated by SEPARATOR.
  72       Args: The original message.
  73     }
  74     procedure WriteMessageBegin( const msg: TThriftMessage); override;
  75   end;
  76
  77
  78 implementation
  79
  80
  81 constructor TMultiplexedProtocol.Create(const aProtocol: IProtocol; const aServiceName: string);
  82 begin
  83   ASSERT( aServiceName <> '');
  84   inherited Create(aProtocol);
  85   FServiceName := aServiceName;
  86 end;
  87
  88
  89 procedure TMultiplexedProtocol.WriteMessageBegin( const msg: TThriftMessage);
  90 // Prepends the service name to the function name, separated by TMultiplexedProtocol.SEPARATOR.
  91 var newMsg : TThriftMessage;
  92 begin
  93   case msg.Type_ of
  94     TMessageType.Call,
  95     TMessageType.Oneway : begin
  96       Init( newMsg, FServiceName + SEPARATOR + msg.Name, msg.Type_, msg.SeqID);
  97       inherited WriteMessageBegin( newMsg);
  98     end;
  99
 100   else
 101     inherited WriteMessageBegin( msg);
 102   end;
 103 end;
 104
 105
 106 end.
 107