NSProxy / NSConnection – DECODE X NET

前回のRemoteProcedureCallに似たしくみで、Objective-Cにも同様のリモート呼び出しの仕組みがありましたので、テストしてみました。
Objective-Cのダイナミックな特性により、リモートメソッドもローカルとかわらない方法で呼び出せるところが興味深いです。

環境 : GNUStep / Ubuntu 14.04

protocol.h

#include <Foundation/NSConnection.h>

@protocol ServerProtocol 

- (id) sendObject: (id)str;
- (void) getObject: (id *)str;
- (id) sendString: (const char *)str;
@end

#include <Foundation/NSConnection.h>

@protocol ServerProtocol

- (id) sendObject: (id)str;

- (void) getObject: (id *)str;

- (id) sendString: (const char *)str;

@end

nsconnServ.m

#include <Foundation/Foundation.h>
#include "protocol.h"

@interface Server : NSObject <ServerProtocol>
{
}
@end

@implementation Server
- sendString: (const char *)msg
{
  printf("Receive from Client : %s\n", msg);
  fflush(stdout);
  return self;
}

- sendObject: (id)str
{
  printf ("Name : %s\n", GSNameFromSelector(_cmd));
  NSLog(@"%s : %@", GSClassNameFromObject(str), str);
  fflush(stdout);
  return @"OK";
}

- (void) getObject: (id *)str
{
  static NSString *ret = @"Server message";
  printf ("Name : %s\n", GSNameFromSelector(_cmd));
  NSLog(@"%s : %@", GSClassNameFromObject(*str), *str);
  *str = ret;
  printf("Return (%s)\n", [*str cString]);
  fflush(stdout);
}

- connectionBecameInvalid: notification
{
  return self;
}

- (NSConnection*) connection: ancestor didConnect: newConn
{
  printf("-- %s\n", GSNameFromSelector(_cmd));
  [[NSNotificationCenter defaultCenter]
    addObserver: self
    selector: @selector(connectionBecameInvalid:)
    name: NSConnectionDidDieNotification
    object: newConn];
  [newConn setDelegate: self];
  return newConn;
}
@end

int main(int argc, char *argv[])
{
  id srv = [[Server alloc] init];

  NSAutoreleasePool	*arp = [NSAutoreleasePool new];

  id pchk = [NSProtocolChecker protocolCheckerWithTarget: srv
		protocol: @protocol(ServerProtocol)];

  NSPortNameServer *ns = [NSSocketPortNameServer sharedInstance];
  NSPort *port = [NSSocketPort port];
  NSConnection *conn = [NSConnection connectionWithReceivePort: port sendPort: port];
  [conn setRootObject: pchk];

  [conn registerName: @"nsconnServer" withNameServer: ns];

  [[NSNotificationCenter defaultCenter]
    addObserver: srv
    selector: @selector(connectionBecameInvalid:)
    name: NSConnectionDidDieNotification
    object: conn];
  [conn setDelegate: srv];

  printf("Running...\n");

  [[NSRunLoop currentRunLoop] run];
  [arp release];
  return 0;
}

#include <Foundation/Foundation.h>

#include "protocol.h"

@interface Server : NSObject <ServerProtocol>

{

}

@end

@implementation Server

- sendString: (const char *)msg

{

printf("Receive from Client : %s\n", msg);

fflush(stdout);

return self;

}

- sendObject: (id)str

{

printf ("Name : %s\n", GSNameFromSelector(_cmd));

NSLog(@"%s : %@", GSClassNameFromObject(str), str);

fflush(stdout);

return @"OK";

}

- (void) getObject: (id *)str

{

static NSString *ret = @"Server message";

printf ("Name : %s\n", GSNameFromSelector(_cmd));

NSLog(@"%s : %@", GSClassNameFromObject(*str), *str);

*str = ret;

printf("Return (%s)\n", [*str cString]);

fflush(stdout);

}

- connectionBecameInvalid: notification

{

return self;

}

- (NSConnection*) connection: ancestor didConnect: newConn

{

printf("-- %s\n", GSNameFromSelector(_cmd));

[[NSNotificationCenter defaultCenter]

addObserver: self

selector: @selector(connectionBecameInvalid:)

name: NSConnectionDidDieNotification

object: newConn];

[newConn setDelegate: self];

return newConn;

}

@end

int main(int argc, char *argv[])

{

id srv = [[Server alloc] init];

NSAutoreleasePool *arp = [NSAutoreleasePool new];

id pchk = [NSProtocolChecker protocolCheckerWithTarget: srv

protocol: @protocol(ServerProtocol)];

NSPortNameServer *ns = [NSSocketPortNameServer sharedInstance];

NSPort *port = [NSSocketPort port];

NSConnection *conn = [NSConnection connectionWithReceivePort: port sendPort: port];

[conn setRootObject: pchk];

[conn registerName: @"nsconnServer" withNameServer: ns];

[[NSNotificationCenter defaultCenter]

addObserver: srv

selector: @selector(connectionBecameInvalid:)

name: NSConnectionDidDieNotification

object: conn];

[conn setDelegate: srv];

printf("Running...\n");

[[NSRunLoop currentRunLoop] run];

[arp release];

return 0;

}

nsconnClie.m

#include <Foundation/Foundation.h>
#include "protocol.h"

int main (int argc, char *argv[])
{
  NSAutoreleasePool *arp = [NSAutoreleasePool new];
  NSPortNameServer *ns = [NSSocketPortNameServer sharedInstance];

  id  proxy = [NSConnection rootProxyForConnectionWithRegisteredName:
		@"nsconnServer" host: @"" usingNameServer: ns];

  Protocol *ps = @protocol(ServerProtocol);
  [proxy setProtocolForProxy: ps];

  [proxy sendString: "Client String"];

  NSString *msg = @"Client message";
  printf("Send (%s)\n", [msg cString]);

  id obj = [proxy sendObject: msg];

  printf("Res : %s\n", [[obj description] cString]);
  
  [proxy getObject: &obj];
  printf("Ref : %s\n",  [[obj description] cString]);

  [arp release];
  return 0;
}

#include <Foundation/Foundation.h>

#include "protocol.h"

int main (int argc, char *argv[])

{

NSAutoreleasePool *arp = [NSAutoreleasePool new];

NSPortNameServer *ns = [NSSocketPortNameServer sharedInstance];

id proxy = [NSConnection rootProxyForConnectionWithRegisteredName:

@"nsconnServer" host: @"" usingNameServer: ns];

Protocol *ps = @protocol(ServerProtocol);

[proxy setProtocolForProxy: ps];

[proxy sendString: "Client String"];

NSString *msg = @"Client message";

printf("Send (%s)\n", [msg cString]);

id obj = [proxy sendObject: msg];

printf("Res : %s\n", [[obj description] cString]);

[proxy getObject: &obj];

printf("Ref : %s\n", [[obj description] cString]);

[arp release];

return 0;

}

コマンド

apt-get install gnustep
apt-get install gnustep-devel
gcc gnustep-config --objc-flags nsconnServ.m -lobjc -lgnustep-base -o nsconnServ
gcc gnustep-config --objc-flags nsconnClie.m -lobjc -lgnustep-base -o nsconnClie

実行結果

文字列、オブジェクトの送信・受信をしています。

パケットキャプチャ

gdomapサービスが、サーバとクライアントの通信を仲介します。これはUbuntuでgnustepをインストールすると自動的にたちあがります。
nsconnServが立ち上がると、gdomapサービスにアクセスし、nsconnClieからのリクエストまちになります。ポート番号は指定していないので、nsconnClieが起動時gdomapサービスにアクセスしたときに、通知されると思われます。

参考:https://github.com/timburks/gnustep-base