Added new scripting interface and Lua engine.

3 files changed, 296 insertions, 0 deletions

diff --git a/src/scripting/lua.cpp b/src/scripting/lua.cpp
new file mode 100644
index 00000000..b22d2879
--- /dev/null
+++ b/src/scripting/lua.cpp
@@ -0,0 +1,145 @@
+/*
+ *  The Mana World Server
+ *  Copyright 2007 The Mana World Development Team
+ *
+ *  This file is part of The Mana World.
+ *
+ *  The Mana World 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 2 of the License, or
+ *  any later version.
+ *
+ *  The Mana World 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 The Mana World; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  $Id$
+ */
+
+#include <cassert>
+
+extern "C" {
+#include <lualib.h>
+#include <lauxlib.h>
+}
+
+#include "resourcemanager.h"
+#include "scripting/script.hpp"
+#include "utils/logger.h"
+
+/**
+ * Implementation of the Script class for Lua.
+ */
+class LuaScript: public Script
+{
+    public:
+
+        LuaScript(lua_State *);
+
+        ~LuaScript();
+
+        void prepare(std::string const &);
+
+        void push(int);
+
+        void push(Character *);
+
+        int execute();
+
+    private:
+
+        lua_State *mState;
+        int nbArgs;
+};
+
+LuaScript::LuaScript(lua_State *s):
+    mState(s),
+    nbArgs(-1)
+{
+    luaL_openlibs(mState);
+    // A Lua state is like a function, so "execute" it in order to initialize it.
+    int res = lua_pcall(mState, 0, 0, 0);
+    if (res)
+    {
+        LOG_ERROR("Failure while initializing Lua script: "
+                  << lua_tostring(mState, 0));
+    }
+}
+
+LuaScript::~LuaScript()
+{
+    lua_close(mState);
+}
+
+void LuaScript::prepare(std::string const &name)
+{
+    assert(nbArgs == -1);
+    lua_getglobal(mState, name.c_str());
+    nbArgs = 0;
+}
+
+void LuaScript::push(int v)
+{
+    assert(nbArgs >= 0);
+    lua_pushinteger(mState, v);
+    ++nbArgs;
+}
+
+void LuaScript::push(Character *v)
+{
+}
+
+int LuaScript::execute()
+{
+    assert(nbArgs >= 0);
+    int res = lua_pcall(mState, nbArgs, 1, 0);
+    nbArgs = -1;
+    if (res || !lua_isnumber(mState, 0))
+    {
+        LOG_ERROR("Failure while calling Lua function: "
+                  << lua_tostring(mState, 0));
+        return 0;
+    }
+    res = lua_tointeger(mState, 0);
+    lua_pop(mState, 1);
+    return res;
+}
+
+static Script *loadScript(std::string const &filename)
+{
+    // Load the file through resource manager.
+    ResourceManager *resman = ResourceManager::getInstance();
+    int fileSize;
+    char *buffer = (char *)resman->loadFile(filename, fileSize);
+    if (!buffer) return NULL;
+
+    lua_State *s = luaL_newstate();
+    int res = luaL_loadstring(s, buffer);
+    free(buffer);
+
+    switch(res)
+    {
+        case 0:
+            LOG_INFO("Successfully loaded script " << filename);
+            return new LuaScript(s);
+        case LUA_ERRSYNTAX:
+            LOG_ERROR("Syntax error while loading script " << filename);
+    }
+
+    lua_close(s);
+    return NULL;
+}
+
+struct LuaRegister
+{
+    LuaRegister() { Script::registerEngine("lua", loadScript); }
+};
+
+static LuaRegister dummy;
+
+
diff --git a/src/scripting/script.cpp b/src/scripting/script.cpp
new file mode 100644
index 00000000..4d917273
--- /dev/null
+++ b/src/scripting/script.cpp
@@ -0,0 +1,67 @@
+/*
+ *  The Mana World Server
+ *  Copyright 2007 The Mana World Development Team
+ *
+ *  This file is part of The Mana World.
+ *
+ *  The Mana World 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 2 of the License, or
+ *  any later version.
+ *
+ *  The Mana World 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 The Mana World; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  $Id$
+ */
+
+#include <map>
+
+#include "utils/logger.h"
+#include "scripting/script.hpp"
+
+typedef std::map< std::string, Script::Factory > Engines;
+
+static Engines *engines = NULL;
+
+void Script::registerEngine(std::string const &name, Factory f)
+{
+    if (!engines)
+    {
+        /* The "engines" variable is a pointer instead of an object, because
+           this file may not have been initialized at the time this function
+           is called. So we take care of the initialization by hand, in order
+           to ensure we will not segfault at startup. */
+        engines = new Engines;
+    }
+    (*engines)[name] = f;
+}
+
+Script *Script::create(std::string const &engine, std::string const &file)
+{
+    Engines::const_iterator i = engines->find(engine);
+    if (i == engines->end())
+    {
+        LOG_ERROR("No scripting engine named " << engine);
+        return NULL;
+    }
+    Script *s = i->second(file);
+    if (!s)
+    {
+        LOG_ERROR("Failure while loading script " << file);
+    }
+    return s;
+}
+
+void Script::update()
+{
+    prepare("update");
+    execute();
+}
+
diff --git a/src/scripting/script.hpp b/src/scripting/script.hpp
new file mode 100644
index 00000000..c167dda6
--- /dev/null
+++ b/src/scripting/script.hpp
@@ -0,0 +1,84 @@
+/*
+ *  The Mana World Server
+ *  Copyright 2007 The Mana World Development Team
+ *
+ *  This file is part of The Mana World.
+ *
+ *  The Mana World 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 2 of the License, or
+ *  any later version.
+ *
+ *  The Mana World 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 The Mana World; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  $Id$
+ */
+
+#ifndef _TMWSERV_SCRIPTING_SCRIPT_HPP
+#define _TMWSERV_SCRIPTING_SCRIPT_HPP
+
+#include <string>
+
+class Character;
+
+/**
+ * Abstract interface for calling functions written in an external language.
+ */
+class Script
+{
+    public:
+
+        typedef Script *(*Factory)(std::string const &);
+
+        /**
+         * Registers a new scripting engine.
+         */
+        static void registerEngine(std::string const &, Factory);
+
+        /**
+         * Creates a new script.
+         */
+        static Script *create(std::string const &engine, std::string const &file);
+
+        virtual ~Script() {}
+
+        /**
+         * Called every tick for the script to manage its data.
+         * Calls the "update" function of the script by default.
+         */
+        virtual void update();
+
+        /**
+         * Prepares a call to the given function.
+         * Only one function can be prepared at once.
+         */
+        virtual void prepare(std::string const &name) = 0;
+
+        /**
+         * Pushes an integer argument for the function being prepared.
+         */
+        virtual void push(int) = 0;
+
+        /**
+         * Pushes a pointer to Character for the function being prepared.
+         * It usually is the character doing the action. The interface can
+         * pass the pointer as an opaque value to the scripting engine, if
+         * needed.
+         */
+        virtual void push(Character *) = 0;
+
+        /**
+         * Executes the function being prepared.
+         * @return the value returned by the script.
+         */
+        virtual int execute() = 0;
+};
+
+#endif