New type. (glibtop_backend_module): New private type.

2000-01-12  Martin Baulig  <martin@home-of-linux.org>

	* include/glibtop/backend.h (glibtop_backend_entry): New type.
	(glibtop_backend_module): New private type.

	* lib/backend.c (glibtop_register_backend): This now takes a
	`glibtop_backend_entry' argument, not a `glibtop_backend_info' one.
	(glibtop_backend_by_id): Return a `glibtop_backend_entry' type,
	not a `glibtop_backend_info' one.
	(glibtop_backend_by_name): Likewise.

	* lib/init-backends.c: If we have libxml, read all `.backend' files
	in $(LIBGTOP_BACKEND_DIR), XML parse them and register them via
	`glibtop_backend_register'. This builds a list of all currently
	supported backends without actually loading them into memory.

	* lib/open-backend.c (glibtop_open_backend_l): GModule load the
	backend if it's not already in memory.

lib/init-backends.c

@@ -33,6 +33,18 @@ extern glibtop_backend_info glibtop_backend_server;
 extern glibtop_backend_info glibtop_backend_sysdeps;
 extern glibtop_backend_info glibtop_backend_common;
 
+#if HAVE_LIBXML
+
+#define LIBGTOP_XML_NAMESPACE	"http://www.home-of-linux.org/libgtop/1.1"
+
+#include <gnome-xml/parser.h>
+
+#include <dirent.h>
+
+static void _glibtop_init_gmodule_backends (const char *);
+
+#endif /* HAVE_LIBXML */
+
 void
 glibtop_init_backends (void)
 {
@@ -42,7 +54,147 @@ glibtop_init_backends (void)
 	return;
     backends_initialized = 1;
 
-    glibtop_register_backend (&glibtop_backend_server);
-    glibtop_register_backend (&glibtop_backend_sysdeps);
-    glibtop_register_backend (&glibtop_backend_common);
+#if HAVE_LIBXML
+    _glibtop_init_gmodule_backends (LIBGTOP_BACKEND_DIR);
+#endif
 }
+
+#if HAVE_LIBXML
+
+static gchar *
+_get_library_filename (xmlDocPtr doc, xmlNodePtr cur, const char *directory)
+{
+    char *filename = xmlNodeListGetString (doc, cur->childs, 1);
+    gchar *retval;
+
+    if (!filename)
+	return NULL;
+
+    /* already absolute */
+    if (filename [0] == '/')
+	retval = g_strdup (filename);
+    else
+	retval = g_strdup_printf ("%s/%s", directory, filename);
+
+    return retval;
+}
+
+static glibtop_backend_entry *
+_parseBackend (xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur, const char *dir)
+{
+    glibtop_backend_entry *ret = NULL;
+
+    /*
+     * allocate the struct
+     */
+    ret = g_new0 (glibtop_backend_entry, 1);
+
+    /* We don't care what the top level element name is */
+    cur = cur->childs;
+    while (cur != NULL) {
+        if ((!strcmp (cur->name, "Name")) && (cur->ns == ns))
+            ret->name = xmlNodeListGetString
+		(doc, cur->childs, 1);
+
+        if ((!strcmp (cur->name, "Location")) && (cur->ns == ns)) {
+	    xmlNodePtr sub = cur->childs;
+
+	    while (sub != NULL) {
+		if ((!strcmp (sub->name, "LibtoolName")) && (sub->ns == ns))
+		    ret->libtool_name = _get_library_filename (doc, sub, dir);
+		if ((!strcmp (sub->name, "ShlibName")) && (sub->ns == ns))
+		    ret->shlib_name = _get_library_filename (doc, sub, dir);
+
+		sub = sub->next;
+	    }
+	}
+
+        cur = cur->next;
+    }
+
+    return ret;
+}
+
+static void
+_glibtop_init_gmodule_backends (const char *directory)
+{
+    DIR *dir;
+    struct dirent *entry;
+
+    dir = opendir (directory);
+    if (!dir) return;
+
+    while ((entry = readdir (dir)) != NULL) {
+	size_t len = strlen (entry->d_name);
+	gchar *filename;
+	xmlDocPtr doc;
+	xmlNsPtr ns;
+	xmlNodePtr cur;
+
+	if (len < 8)
+	    continue;
+
+	if (strcmp (entry->d_name+len-8, ".backend"))
+	    continue;
+
+	filename = g_strdup_printf ("%s/%s", directory, entry->d_name);
+
+	doc = xmlParseFile (filename);
+
+	if (!doc) {
+	    g_warning ("Cannot parse %s", filename);
+	    g_free (filename);
+	    continue;
+	}
+
+	/* Make sure the document is of the right kind */
+
+	cur = xmlDocGetRootElement (doc);
+	if (!cur) {
+	    xmlFreeDoc (doc);
+	    g_free (filename);
+	    continue;
+	}
+
+	ns = xmlSearchNsByHref (doc, cur, LIBGTOP_XML_NAMESPACE);
+	if (!ns) {
+	    g_warning ("File %s of wrong type; LibGTop Namespace not found",
+		       filename);
+	    g_free (filename);
+	    xmlFreeDoc (doc);
+	    continue;
+	}
+
+	if (strcmp (cur->name, "Backends")) {
+	    g_warning ("File %s of the wrong type, root node != 'Backends'",
+		       filename);
+	    g_free (filename);
+	    xmlFreeDoc (doc);
+	    continue;
+	}
+
+	cur = cur->childs;
+	while (cur != NULL) {
+	    glibtop_backend_entry *backend;
+
+	    if ((!strcmp(cur->name, "Backend")) && (cur->ns == ns)) {
+		backend = _parseBackend (doc, ns, cur, directory);
+		if (!backend) {
+		    g_warning ("File %s of wrong type; cannot parse",
+			       filename);
+		    continue;
+		}
+
+		glibtop_register_backend (backend);
+	    }
+	    cur = cur->next;
+	}
+
+	g_free (filename);
+	xmlFreeDoc (doc);
+    }
+
+    closedir (dir);
+}
+
+#endif /* HAVE_LIBXML */