Rebuild the C++ interface to use RAII.

Simplifies the code and invalidates Berlios ug #17778: crash in libgpsmm.

4 files changed, 51 insertions, 34 deletions

diff --git a/libgpsmm.cpp b/libgpsmm.cpp
index 9e3d050b..f7d2354b 100644
--- a/libgpsmm.cpp
+++ b/libgpsmm.cpp
@@ -11,16 +11,7 @@
 #include "libgpsmm.h"
 
 
-gpsmm::gpsmm() : to_user(0)
-{
-}
-
-struct gps_data_t* gpsmm::open(void) 
-{
-	return open("localhost",DEFAULT_GPSD_PORT);
-}
-
-struct gps_data_t* gpsmm::open(const char *host, const char *port) 
+struct gps_data_t* gpsmm::gps_inner_open(const char *host, const char *port) 
 {
 	const bool err = (gps_open(host, port, gps_data()) != 0);
 	if ( err ) {
@@ -65,11 +56,6 @@ struct gps_data_t* gpsmm::read(void)
 	}
 }
 
-int gpsmm::close(void)
-{
-	return gps_close(gps_data());
-}
-
 bool gpsmm::waiting(void)
 {
 	return gps_waiting(gps_data());
diff --git a/libgpsmm.h b/libgpsmm.h
index e3f99497..3c77a403 100644
--- a/libgpsmm.h
+++ b/libgpsmm.h
@@ -18,10 +18,16 @@ class gpsmm {
 class LIBQGPSMMSHARED_EXPORT gpsmm {
 #endif
 	public:
-		gpsmm();
+		gpsmm(const char *host, const char *port) : to_user(0) {
+			gps_inner_open(host, port);
+		}
+#ifdef __UNUSED__
+		gpsmm(void) : to_user(0) 
+		{
+		        gps_inner_open("localhost", DEFAULT_GPSD_PORT);
+		}
+#endif
 		virtual ~gpsmm();
-		struct gps_data_t* open(const char *host,const char *port); //opens the connection with gpsd, MUST call this before any other method
-		struct gps_data_t* open(void); //open() with default values
 		struct gps_data_t* send(const char *request); //put a command to gpsd and return the updated struct
 		struct gps_data_t* stream(int); //set watcher and policy flags
 		struct gps_data_t* read(void); //block until gpsd returns new data, then return the updated struct
@@ -32,6 +38,8 @@ class LIBQGPSMMSHARED_EXPORT gpsmm {
 	private:
 		struct gps_data_t *to_user;	//we return the user a copy of the internal structure. This way she can modify it without
 						//integrity loss for the entire class
+		struct gps_data_t* gps_inner_open(const char *host,
+						  const char *port);
 		struct gps_data_t _gps_data;
 		struct gps_data_t * gps_data() { return &_gps_data; }
 		struct gps_data_t* backup(void) { *to_user=*gps_data(); return to_user;}; //return the backup copy
diff --git a/test_gpsmm.cpp b/test_gpsmm.cpp
index 2343d262..2731655e 100644
--- a/test_gpsmm.cpp
+++ b/test_gpsmm.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005 Alfredo Pironti
+ * Copyright (C) 2010 Eric S. Raymond.
  *
  * This software is distributed under a BSD-style license. See the
  * file "COPYING" in the top-level directory of the distribution for details.
@@ -96,14 +96,7 @@ static void libgps_dump_state(struct gps_data_t *collect)
 
 int main(void) 
 {
-    gpsmm gps_rec;
-    struct gps_data_t *resp;
-
-    resp = gps_rec.open();
-    if (resp==NULL) {
-	    cout << "Error opening gpsd\n";
-	    return (1);
-    }
+    gpsmm gps_rec("localhost", DEFAULT_GPSD_PORT);
 
     gps_rec.stream(WATCH_ENABLE|WATCH_JSON);
 
diff --git a/www/protocol-transition.txt b/www/protocol-transition.txt
index 927a7f05..bbe920ce 100644
--- a/www/protocol-transition.txt
+++ b/www/protocol-transition.txt
@@ -403,17 +403,47 @@ of the gpsdata structure. Two new DOPs, xdop and ydop, are available;
 these express dilution of precision in longitude and latitude,
 respectively.
 
-The raw_hook member is gone.
+There is a gps_waiting() method analogous to the waiting() method in
+the Python class -- a non-blocking way to check if input is waiting
+from the daemon.
 
-The 2.91 API includes a gps_waiting() method analogous to the 
-waiting() method in the Python class -- a non-blocking way to check
-if input is waiting from the daemon.
+The raw_hook member is gone.
 
 == C++  client library changes ==
 
-The C++ client library continues to be a trivial class wrpapper around
-the C.  About all you need to know is that the query() method is gone
-and there is a new stream() method that calls gps_stream().
+In API version 5, the C++ library defines a single object using RAII.
+There are no explicit open() and close() methods; instead, you initialize
+the object handing it a host and server, and the connection is shut down
+when the object is deleted or goes out of scope.
+
+The following code skeleton implements a C++ client:
+
+----------------------------------------------------------------------
+
+int main(void) 
+{
+    gpsmm gps_rec("localhost", DEFAULT_GPSD_PORT);
+
+    gps_rec.stream(WATCH_ENABLE|WATCH_JSON);
+
+    for (;;) {
+	struct gps_data_t* newdata;
+
+	if (!gps_rec.waiting())
+	  continue;
+
+	if ((newdata = gps_rec.read()) == NULL) {
+	    cerr << "Read error.\n";
+	    return 1;
+	} else {
+	    PROCESS(newdata);
+	}
+    }
+    return 0;
+}
+
+----------------------------------------------------------------------
+
 
 == Python client library changes ==