Changed client <-> server interface to make less system calls.

1998-06-18  Martin Baulig  <baulig@taurus.uni-trier.de>

	* lib/{command, write, read}.c: Changed client <-> server
	interface to make less system calls.

	* src/daemon/main.c: Changed server side of interface.

	* include/glibtop/command.h (struct _glibtop_response): New
	structure to return data from the server to the client.

lib/Makefile.am

@@ -4,7 +4,7 @@ INCLUDES			= -I$(top_builddir) -I$(top_srcdir) @machine_incs@ \
 				  -I$(top_srcdir)/include -I$(top_srcdir)/intl @GUILE_INCS@ \
 				  -DGTOPLOCALEDIR=\"$(datadir)/locale\" -D_GNU_SOURCE
 
-CFLAGS				= -Wall -W @CFLAGS@ -DGTOP_SERVER=\""@LIBGTOP_SERVER@"\"
+CFLAGS				= -Wall -W @CFLAGS@ -DGTOP_SERVER=\""@LIBGTOP_SERVER@"\" -DDEBUG
 
 lib_LTLIBRARIES			= libgtop.la
 

lib/command.c

@@ -28,27 +28,43 @@
 
 void *
 glibtop_call_l (glibtop *server, unsigned command, size_t send_size, void *send_buf,
-		 size_t recv_size, void *recv_buf)
+		size_t recv_size, void *recv_buf)
 {
-	glibtop_command *cmnd;
+	glibtop_command cmnd;
+	glibtop_response response;
 	void *ptr;
 
 	glibtop_init_r (&server, 0, 0);
 
-	cmnd = glibtop_calloc_r (server, 1, sizeof (glibtop_command));
+	memset (&cmnd, 0, sizeof (glibtop_command));
+
+	memcpy (&cmnd.server, server, sizeof (glibtop));
 	
-	memcpy (&cmnd->server, server, sizeof (glibtop));
+	cmnd.command = command;
+
+	/* If send_size is less than _GLIBTOP_PARAM_SIZE (normally 16 Bytes), we
+	 * send it together with command, so we only need one system call instead
+	 * of two. */
+
+#ifdef DEBUG
+	fprintf (stderr, "COMMAND: send_size = %d; command = %d; sizeof (cmnd) = %d\n",
+		 send_size, command, sizeof (glibtop_command));
+#endif
+
+
+	if (send_size <= _GLIBTOP_PARAM_SIZE)
+		memcpy (cmnd.parameter, send_buf, send_size);
+	else
+		cmnd.size = send_size;
 	
-	cmnd->command = command;
-	cmnd->size = send_size;
-	
-	glibtop_write_l (server, sizeof (glibtop_command), cmnd);
+	glibtop_write_l (server, sizeof (glibtop_command), &cmnd);
 	glibtop_write_l (server, send_size, send_buf);
-	glibtop_read_l  (server, recv_size, recv_buf);
+
+	glibtop_read_l (server, sizeof (glibtop_response), &response);
+
+	/*	glibtop_read_l  (server, recv_size, recv_buf); */
 	
-	ptr = glibtop_read_data_l (server);
+	/* ptr = glibtop_read_data_l (server); */
 	
-	glibtop_free_r (server, cmnd);
-	
-	return ptr;
+	return NULL;
 }

lib/read.c

@@ -26,27 +26,10 @@
 void
 glibtop_read_l (glibtop *server, size_t size, void *buf)
 {
-	size_t	ssize;
 	int ret;
 
 	glibtop_init_r (&server, 0, 0);
 
-#ifdef DEBUG
-	fprintf (stderr, "LIBRARY: reading %d bytes, should be %d.\n", sizeof (size_t), size);
-#endif
-
-	if (server->socket) {
-		ret = recv (server->socket, &ssize, sizeof (size_t), 0);
-	} else {
-		ret = read (server->input [0], &ssize, sizeof (size_t));
-	}
-
-	if (ret < 0)
-		glibtop_error_io_r (server, _("read size"));
-	
-	if (size != ssize)
-		glibtop_error_r (server, _("got %d bytes but requested %d (ret = %d)"), ssize, size, ret);
-
 #ifdef DEBUG
 	fprintf (stderr, "LIBRARY: really reading %d bytes.\n", size);
 #endif

lib/write.c

@@ -30,20 +30,7 @@ glibtop_write_l (glibtop *server, size_t size, void *buf)
 
 	glibtop_init_r (&server, 0, 0);
 
-#ifdef DEBUG
-	fprintf (stderr, "LIBRARY: writing %d bytes = %d.\n", sizeof (size_t), size);
-#endif
-
-	if (server->socket) {
-		ret = send (server->socket, &size, sizeof (size_t), 0);
-	} else {
-		ret = write (server->output [1], &size, sizeof (size_t));
-	}
-
-	if (ret < 0)
-		glibtop_error_io_r (server, _("write size"));
-
-	if (!size) return;
+	if (size == 0) return;
 
 #ifdef DEBUG
 	fprintf (stderr, "LIBRARY: really writing %d bytes.\n", size);