export functions for accessing data sources to lua

this adds some code to main() which tests these features and then exits, so it's normal that
conky doesn't work anymore.

src/CMakeLists.txt

@@ -38,7 +38,7 @@ set(conky_sources colours.cc combine.cc common.cc conky.cc core.cc
 	diskio.cc entropy.cc exec.cc fs.cc mail.cc mixer.cc net_stat.cc template.cc
 	mboxscan.cc read_tcp.cc scroll.cc specials.cc tailhead.cc
 	temphelper.cc text_object.cc timeinfo.cc top.cc algebra.cc prioqueue.c proc.cc
-	user.cc luamm.cc data-source.cc)
+	user.cc luamm.cc data-source.cc lua-config.cc)
 
 # add timed thread library
 add_library(timed-thread timed-thread.cc)

src/conky.cc

@@ -94,6 +94,9 @@
 #include "timeinfo.h"
 #include "top.h"
 
+#include <iostream>
+#include "lua-config.hh"
+
 /* check for OS and include appropriate headers */
 #if defined(__linux__)
 #include "linux.h"
@@ -3945,6 +3948,9 @@ static const char *getopt_string = "vVqdDt:u:i:hc:p:"
 #endif
 	;
 
+int printme(lua::state *, const char *str)
+{ fprintf(stderr, str); return 0;}
+
 static const struct option longopts[] = {
 	{ "help", 0, NULL, 'h' },
 	{ "version", 0, NULL, 'V' },
@@ -4302,6 +4308,53 @@ int main(int argc, char **argv)
 		}
 	}
 
+	//////////// XXX ////////////////////////////////
+	lua::state l;	
+	try {
+		conky::export_symbols(l);
+		l.loadstring(
+				"print(conky.asnumber(conky.variables.asdf{}));\n"
+				"print(conky.astext(conky.variables.asdf{}));\n"
+				"print(conky.asnumber(conky.variables.zxcv{}));\n"
+				);
+		l.call(0, 0);
+	}
+	catch(std::exception &e) {
+		std::cerr << "caught exception: " << e.what() << std::endl;
+	}
+
+#if 0
+    try {
+        lua::stack_sentry s(l);
+		l.pushvalue(lua::GLOBALSINDEX); ++s;
+        l.pushnil();                     ++s;
+        while(l.next(-2)) {
+            lua::stack_sentry s2(l, 1);
+            if(l.isnumber(-2))
+                std::cout << l.tonumber(-2);
+			else if(l.isstring(-2))
+				std::cout << '"' << l.tostring(-2) << '"';
+            else
+                std::cout << l.type_name(l.type(-2));
+            std::cout << " -> ";
+
+            if(l.isnumber(-1))
+                std::cout << l.tonumber(-1);
+			else if(l.isstring(-1))
+				std::cout << '"' << l.tostring(-1) << '"';
+            else
+                std::cout << l.type_name(l.type(-1));
+            std::cout << std::endl;
+        }
+    }
+    catch(std::exception &e) {
+        std::cerr << "caught exception: " << e.what() << std::endl;
+    }
+#endif
+	free(current_config);
+	return 0;
+	//////////// XXX ////////////////////////////////
+
 #ifdef BUILD_WEATHER_XOAP
 	/* Load xoap keys, if existing */
 	load_xoap_keys();

src/lua-config.cc

@@ -0,0 +1,100 @@
+/* -*- mode: c++; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: t -*-
+ * vim: ts=4 sw=4 noet ai cindent syntax=cpp
+ *
+ * Conky, a system monitor, based on torsmo
+ *
+ * Please see COPYING for details
+ *
+ * Copyright (C) 2010 Pavel Labath et al.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <config.h>
+
+#include "lua-config.hh"
+
+#include "data-source.hh"
+
+namespace conky {
+	namespace {
+		const char data_source_metatable[] = "conky::data_source_metatable";
+
+		data_source_base& get_data_source(lua::state *l)
+		{
+			if(l->gettop() != 1)
+				throw std::runtime_error("Wrong number of parameters");
+
+			l->rawgetfield(lua::REGISTRYINDEX, data_source_metatable);
+			if(not l->getmetatable(-2) or not l->rawequal(-1, -2))
+				throw std::runtime_error("Invalid parameter");
+
+			return **static_cast<std::shared_ptr<data_source_base> *>(l->touserdata(1));
+		}
+
+		int data_source_asnumber(lua::state *l)
+		{
+			double x = get_data_source(l).get_number();
+			l->pushnumber(x);
+			return 1;
+		}
+
+		int data_source_astext(lua::state *l)
+		{
+			std::string x = get_data_source(l).get_text();
+			l->pushstring(x.c_str());
+			return 1;
+		}
+
+		int create_data_source(lua::state *l, const data_sources_t::value_type &v)
+		{
+			l->createuserdata<std::shared_ptr<data_source_base>>(v.second(*l, v.first));
+			l->rawgetfield(lua::REGISTRYINDEX, data_source_metatable);
+			l->setmetatable(-2);
+			return 1;
+		}
+	}
+
+	void export_symbols(lua::state &l)
+	{
+		lua::stack_sentry s(l);
+		l.checkstack(3);
+
+		l.newmetatable(data_source_metatable); ++s; {
+			l.pushboolean(false); ++s;
+			l.rawsetfield(-2, "__metatable"); --s;
+
+			l.pushdestructor<std::shared_ptr<data_source_base>>(); ++s;
+			l.rawsetfield(-2, "__gc"); --s;
+		} l.pop(); --s;
+
+		l.newtable(); ++s; {
+			l.newtable(); ++s; {
+				const data_sources_t &ds = get_data_sources();
+				for(auto i = ds.begin(); i != ds.end(); ++i) {
+					l.pushfunction(std::bind(create_data_source, 
+										std::placeholders::_1, std::cref(*i)
+								)); ++s;
+					l.rawsetfield(-2, i->first.c_str()); --s;
+				}
+			} l.rawsetfield(-2, "variables"); --s;
+
+			l.pushfunction(data_source_asnumber); ++s;
+			l.rawsetfield(-2, "asnumber"); --s;
+
+			l.pushfunction(data_source_astext); ++s;
+			l.rawsetfield(-2, "astext"); --s;
+		} l.setglobal("conky"); --s;
+	}
+}

src/lua-config.hh

@@ -0,0 +1,33 @@
+/* -*- mode: c++; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: t -*-
+ * vim: ts=4 sw=4 noet ai cindent syntax=cpp
+ *
+ * Conky, a system monitor, based on torsmo
+ *
+ * Please see COPYING for details
+ *
+ * Copyright (C) 2010 Pavel Labath et al.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef LUA_CONFIG_HH
+#define LUA_CONFIG_HH
+
+#include "luamm.hh"
+
+namespace conky {
+	void export_symbols(lua::state &l);
+}
+
+#endif /* LUA_CONFIG_HH */