From dfd7f99eecefc19effd97034048641de9d6b7e94 Mon Sep 17 00:00:00 2001
From: Josh Blum <josh@joshknows.com>
Date: Tue, 9 Feb 2010 15:45:24 -0800
Subject: work on link and proxy args
---
lib/wax.cpp | 76 ++++++++++++++++++++++++++++++++++++++-----------------------
1 file changed, 47 insertions(+), 29 deletions(-)
diff --git a/lib/wax.cpp b/lib/wax.cpp
index a75acdc7f..ce9705b1e 100644
--- a/lib/wax.cpp
+++ b/lib/wax.cpp
@@ -16,23 +16,8 @@
//
#include <usrp_uhd/wax.hpp>
-#include <stdexcept>
-#include <boost/bind.hpp>
#include <boost/format.hpp>
-#include <boost/function.hpp>
-
-/*!
- * The proxy args for internal use within this cpp file:
- *
- * It contains bound functions for setting/getting a property.
- * Only the methods in this file may create or parse proxy args.
- * Class methods have special handling for the case when the
- * wax obj contains an instance of the proxy args.
- */
-struct proxy_args_t{
- boost::function<void(wax::obj &)> get;
- boost::function<void(const wax::obj &)> set;
-};
+#include <stdexcept>
/*!
* The link args for internal use within this cpp file:
@@ -41,9 +26,45 @@ struct proxy_args_t{
* Only the methods in this file may create or parse link args.
* The get_link method is the creator of a link args object.
* The [] operator will resolve the link and make the [] call.
+ *
+ * TODO: register the link args with the wax obj that it links to.
+ * That way, if the obj destructs, the link can be invalidated.
+ * The operator() will throw, rather than dereferencing bad memory.
*/
-struct link_args_t{
- wax::obj *obj_ptr;
+class link_args_t{
+public:
+ link_args_t(const wax::obj *obj_ptr) : _obj_ptr(obj_ptr){
+ /* NOP */
+ }
+ wax::obj & operator()(void){
+ return *const_cast<wax::obj *>(_obj_ptr);
+ }
+private:
+ const wax::obj *_obj_ptr;
+};
+
+/*!
+ * The proxy args for internal use within this cpp file:
+ *
+ * It contains a link and a key for setting/getting a property.
+ * Only the methods in this file may create or parse proxy args.
+ * Class methods have special handling for the case when the
+ * wax obj contains an instance of the proxy args.
+ */
+class proxy_args_t{
+public:
+ proxy_args_t(const wax::obj *obj_ptr, const wax::obj &key) : _key(key){
+ _obj_link = obj_ptr->get_link();
+ }
+ wax::obj & operator()(void){
+ return wax::cast<link_args_t>(_obj_link)();
+ }
+ const wax::obj & key(void){
+ return _key;
+ }
+private:
+ wax::obj _obj_link;
+ const wax::obj _key;
};
/***********************************************************************
@@ -69,22 +90,20 @@ wax::obj wax::obj::operator[](const obj &key){
obj val = resolve();
//check if its a special link and call
if (val.type() == typeid(link_args_t)){
- return (*cast<link_args_t>(val).obj_ptr)[key];
+ return cast<link_args_t>(val)()[key];
}
//unknown obj
throw std::runtime_error("cannot use [] on non wax::obj link");
}
else{
- proxy_args_t proxy_args;
- proxy_args.get = boost::bind(&obj::get, this, key, _1);
- proxy_args.set = boost::bind(&obj::set, this, key, _1);
- return wax::obj(proxy_args);
+ return proxy_args_t(this, key);
}
}
wax::obj & wax::obj::operator=(const obj &val){
if (_contents.type() == typeid(proxy_args_t)){
- boost::any_cast<proxy_args_t>(_contents).set(val);
+ proxy_args_t proxy_args = boost::any_cast<proxy_args_t>(_contents);
+ proxy_args().set(proxy_args.key(), val);
}
else{
_contents = val._contents;
@@ -96,13 +115,11 @@ wax::obj & wax::obj::operator=(const obj &val){
* Public Methods
**********************************************************************/
wax::obj wax::obj::get_link(void) const{
- link_args_t link_args;
- link_args.obj_ptr = const_cast<obj*>(this);
- return link_args;
+ return link_args_t(this);
}
const std::type_info & wax::obj::type(void) const{
- return _contents.type();
+ return resolve().type();
}
/***********************************************************************
@@ -111,7 +128,8 @@ const std::type_info & wax::obj::type(void) const{
boost::any wax::obj::resolve(void) const{
if (_contents.type() == typeid(proxy_args_t)){
obj val;
- boost::any_cast<proxy_args_t>(_contents).get(val);
+ proxy_args_t proxy_args = boost::any_cast<proxy_args_t>(_contents);
+ proxy_args().get(proxy_args.key(), val);
return val.resolve();
}
else{
--
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