Lua: Refactor lots of stuff

[lsnes.git] / include / library / lua-base.hpp

#ifndef _library__lua_base__hpp__included__
#define _library__lua_base__hpp__included__

#include <string>
#include <stdexcept>
#include <typeinfo>
#include <typeindex>
#include <map>
#include <unordered_map>
#include <set>
#include <list>
#include <cassert>
#include "string.hpp"
#include "utf8.hpp"
extern "C"
{
#include <lua.h>
}

namespace lua
{
class state;
class function;
class function_group;

/**
 * Lua state object.
 */
class state
{
public:
        //Auxillary type for store-tag.
        template<typename T> struct _store_tag
        {
                T& addr;
                T val;
                _store_tag(T& a, T v) : addr(a), val(v) {}
        };
        //Auxillary type for vararg-tag.
        struct vararg_tag
        {
                std::list<std::string> args;
                vararg_tag(std::list<std::string>& _args) : args(_args) {}
                int pushargs(state& L);
        };

        //Auxillary type for numeric-tag.
        template<typename T> struct _numeric_tag
        {
                T val;
                _numeric_tag(T v) : val(v) {}
        };

        //Auxillary type for fnptr-tag.
        template<typename T> struct _fnptr_tag
        {
                int(*fn)(state& L, T v);
                T val;
                _fnptr_tag(int (*f)(state& L, T v), T v) : fn(f), val(v) {}
        };

        //Auxillary type for fn-tag.
        template<typename T> struct _fn_tag
        {
                T fn;
                _fn_tag(T f) : fn(f) {}
        };

        /**
         * Callback parameter: Don't pass any real parameter, but instead store specified value in specified
         * location.
         *
         * Parameter a: The location to store value to.
         * Parameter v: The value to store.
         * Returns: The parameter structure.
         */
        template<typename T> static struct _store_tag<T> store_tag(T& a, T v) { return _store_tag<T>(a, v); }
        /**
         * Callback parameter: Pass numeric value.
         *
         * Parameter v: The value to pass.
         * Returns: The parameter structure.
         */
        template<typename T> static struct _numeric_tag<T> numeric_tag(T v) { return _numeric_tag<T>(v); }

        /**
         * Callback parameter: Execute function to push more parameters.
         *
         * Parameter f: The function to execute. The return value is number of additional parameters pushed.
         * Parameter v: The value to pass to function.
         * Returns: The parameter structure.
         */
        template<typename T> static struct _fnptr_tag<T> fnptr_tag(int (*f)(state& L, T v), T v)
        {
                return _fnptr_tag<T>(f, v);
        }

        /**
         * Callback parameter: Execute function to push more parameters.
         *
         * Parameter v: The functor to execute. Passed reference to the Lua state. The return value is number of
         *      additional parameters pushed.
         * Returns: The parameter structure.
         */
        template<typename T> static struct _fn_tag<T> fn_tag(T v) { return _fn_tag<T>(v); }

        /**
         * Callback parameter: Pass boolean argument.
         *
         * Parameter v: The boolean value to pass.
         */
        struct boolean_tag { bool val; boolean_tag(bool v) : val(v) {}};

        /**
         * Callback parameter: Pass string argument.
         *
         * Parameter v: The string value to pass.
         */
        struct string_tag { std::string val; string_tag(const std::string& v) : val(v) {}};

        /**
         * Callback parameter: Pass nil argument.
         */
        struct nil_tag { nil_tag() {}};
private:
        template<typename U, typename... T> void _callback(int argc, _store_tag<U> tag, T... args)
        {
                tag.addr = tag.val;
                _callback(argc, args...);
                tag.addr = NULL;
        }

        template<typename... T> void _callback(int argc, vararg_tag tag, T... args)
        {
                int e = tag.pushargs(*this);
                _callback(argc + e, args...);
        }

        template<typename... T> void _callback(int argc, nil_tag tag, T... args)
        {
                pushnil();
                _callback(argc + 1, args...);
        }

        template<typename... T> void _callback(int argc, boolean_tag tag, T... args)
        {
                pushboolean(tag.val);
                _callback(argc + 1, args...);
        }

        template<typename... T> void _callback(int argc, string_tag tag, T... args)
        {
                pushlstring(tag.val.c_str(), tag.val.length());
                _callback(argc + 1, args...);
        }

        template<typename U, typename... T> void _callback(int argc, _numeric_tag<U> tag, T... args)
        {
                pushnumber(tag.val);
                _callback(argc + 1, args...);
        }

        template<typename U, typename... T> void _callback(int argc, _fnptr_tag<U> tag, T... args)
        {
                int extra = tag.fn(*this, tag.val);
                _callback(argc + extra, args...);
        }

        template<typename U, typename... T> void _callback(int argc, _fn_tag<U> tag, T... args)
        {
                int extra = tag.fn(*this);
                _callback(argc + extra, args...);
        }

        void _callback(int argc)
        {
                int r = pcall(argc, 0, 0);
                if(r == LUA_ERRRUN) {
                        (stringfmt() << "Error running Lua callback: " << tostring(-1)).throwex();
                        pop(1);
                }
                if(r == LUA_ERRMEM) {
                        (stringfmt() << "Error running Lua callback: Out of memory").throwex();
                        pop(1);
                }
                if(r == LUA_ERRERR) {
                        (stringfmt() << "Error running Lua callback: Double Fault???").throwex();
                        pop(1);
                }
        }
public:
/**
 * Create a new state.
 */
        state() throw(std::bad_alloc);
/**
 * Create a new state with specified master state.
 */
        state(state& _master, lua_State* L);
/**
 * Destroy a state.
 */
        ~state() throw();
/**
 * Get the internal state object.
 *
 * Return value: Internal state.
 */
        lua_State* handle() { return lua_handle; }
/**
 * Get the master state.
 */
        state& get_master() { return master ? master->get_master() : *this; }
/**
 * Set the internal state object.
 */
        void handle(lua_State* l) { lua_handle = l; }
/**
 * Set OOM handler.
 */
        void set_oom_handler(void (*oom)()) { oom_handler = oom ? oom : builtin_oom; }
/**
 * Reset the state.
 */
        void reset() throw(std::runtime_error, std::bad_alloc);
/**
 * Deinit the state.
 */
        void deinit() throw();
/**
 * Get a string argument.
 *
 * Parameter argindex: The stack index.
 * Parameter fname: The name of function to use in error messages.
 * Returns: The string.
 * Throws std::runtime_error: The specified argument is not a string.
 */
        std::string get_string(int argindex, const std::string& fname) throw(std::runtime_error, std::bad_alloc)
        {
                if(lua_isnone(lua_handle, argindex))
                        (stringfmt() << "argument #" << argindex << " to " << fname << " must be string").throwex();
                size_t len;
                const char* f = lua_tolstring(lua_handle, argindex, &len);
                if(!f)
                        (stringfmt() << "argument #" << argindex << " to " << fname << " must be string").throwex();
                return std::string(f, f + len);
        }
/**
 * Get a boolean argument.
 *
 * Parameter argindex: The stack index.
 * Parameter fname: The name of function to use in error messages.
 * Returns: The string.
 * Throws std::runtime_error: The specified argument is not a boolean.
 */
        bool get_bool(int argindex, const std::string& fname) throw(std::runtime_error, std::bad_alloc)
        {
                if(lua_isnone(lua_handle, argindex) || !lua_isboolean(lua_handle, argindex))
                        (stringfmt() << "argument #" << argindex << " to " << fname << " must be boolean").throwex();
                return (lua_toboolean(lua_handle, argindex) != 0);
        }
/**
 * Get a mandatory numeric argument.
 *
 * Parameter argindex: The stack index.
 * Parameter fname: The name of function to use in error messages.
 * Returns: The parsed number.
 * Throws std::runtime_error: Bad type.
 */
        template<typename T>
        T get_numeric_argument(int argindex, const std::string& fname)
        {
                if(lua_isnone(lua_handle, argindex) || !lua_isnumber(lua_handle, argindex))
                        (stringfmt() << "Argument #" << argindex << " to " << fname << " must be numeric").throwex();
                return static_cast<T>(lua_tonumber(lua_handle, argindex));
        }
/**
 * Get a optional numeric argument.
 *
 * Parameter argindex: The stack index.
 * Parameter value: The place to store the value.
 * Parameter fname: The name of function to use in error messages.
 * Throws std::runtime_error: Bad type.
 */
        template<typename T>
        void get_numeric_argument(unsigned argindex, T& value, const std::string& fname)
        {
                if(lua_isnoneornil(lua_handle, argindex))
                        return;
                if(lua_isnone(lua_handle, argindex) || !lua_isnumber(lua_handle, argindex))
                        (stringfmt() << "Argument #" << argindex << " to " << fname << " must be numeric if "
                                "present").throwex();
                value = static_cast<T>(lua_tonumber(lua_handle, argindex));
        }
/**
 * Do a callback.
 *
 * Parameter name: The name of the callback.
 * Parameter args: Arguments to pass to the callback.
 */
        template<typename... T>
        bool callback(const std::string& name, T... args)
        {
                getglobal(name.c_str());
                int t = type(-1);
                if(t != LUA_TFUNCTION) {
                        pop(1);
                        return false;
                }
                _callback(0, args...);
                return true;
        }
/**
 * Do a callback.
 *
 * Parameter cblist: List of environment keys to do callbacks.
 * Parameter args: Arguments to pass to the callback.
 */
        template<typename... T>
        bool callback(const std::list<char>& cblist, T... args)
        {
                bool any = false;
                for(auto& i : cblist) {
                        pushlightuserdata(const_cast<char*>(&i));
                        rawget(LUA_REGISTRYINDEX);
                        int t = type(-1);
                        if(t != LUA_TFUNCTION) {
                                pop(1);
                        } else {
                                _callback(0, args...);
                                any = true;
                        }
                }
                return any;
        }
/**
 * Add a group of functions.
 */
        void add_function_group(function_group& group);
/**
 * Function callback.
 */
        void function_callback(const std::string& name, function* func);
/**
 * Do something just once per VM.
 *
 * Parameter key: The do-once key value.
 * Returns: True if called the first time for given key on given VM, false otherwise.
 */
        bool do_once(void* key);
/**
 * Callback list.
 */
        class callback_list
        {
        public:
                callback_list(state& L, const std::string& name, const std::string& fn_cbname = "");
                ~callback_list();
                void _register(state& L);       //Reads callback from top of lua stack.
                void _unregister(state& L);     //Reads callback from top of lua stack.
                template<typename... T> bool callback(T... args) {
                        bool any = L.callback(callbacks, args...);
                        if(fn_cbname != "" && L.callback(fn_cbname, args...))
                                any = true;
                        return any;
                }
                const std::string& get_name() { return name; }
                void clear() { callbacks.clear(); }
        private:
                callback_list(const callback_list&);
                callback_list& operator=(const callback_list&);
                std::list<char> callbacks;
                state& L;
                std::string name;
                std::string fn_cbname;
        };
/**
 * Enumerate all callbacks.
 */
        std::list<callback_list*> get_callbacks()
        {
                if(master)
                        return master->get_callbacks();
                std::list<callback_list*> r;
                for(auto i : callbacks)
                        r.push_back(i.second);
                return r;
        }
/**
 * Register a callback.
 */
        class callback_proxy
        {
        public:
                callback_proxy(state& _L) : parent(_L) {}
                void do_register(const std::string& name, callback_list& callback)
                {
                        parent.do_register_cb(name, callback);
                }
/**
 * Unregister a callback.
 */
                void do_unregister(const std::string& name)
                {
                        parent.do_unregister_cb(name);
                }
        private:
                state& parent;
        };

        void do_register_cb(const std::string& name, callback_list& callback)
        {
                callbacks[name] = &callback;
        }

        void do_unregister_cb(const std::string& name)
        {
                callbacks.erase(name);
        }

        //All kinds of Lua API functions.
        void pop(int n) { lua_pop(lua_handle, n); }
        void* newuserdata(size_t size) { return lua_newuserdata(lua_handle, size); }
        int setmetatable(int index) { return lua_setmetatable(lua_handle, index); }
        int type(int index) { return lua_type(lua_handle, index); }
        int getmetatable(int index) { return lua_getmetatable(lua_handle, index); }
        int rawequal(int index1, int index2) { return lua_rawequal(lua_handle, index1, index2); }
        void* touserdata(int index) { return lua_touserdata(lua_handle, index); }
        const void* topointer(int index) { return lua_topointer(lua_handle, index); }
        int gettop() { return lua_gettop(lua_handle); }
        void pushvalue(int index) { lua_pushvalue(lua_handle, index); }
        void pushlightuserdata(void* p) { lua_pushlightuserdata(lua_handle, p); }
        void rawset(int index) { lua_rawset(lua_handle, index); }
        void pushnil() { lua_pushnil(lua_handle); }
        void pushstring(const char* s) { lua_pushstring(lua_handle, s); }
        void rawget(int index) { lua_rawget(lua_handle, index); }
        int isnil(int index) { return lua_isnil(lua_handle, index); }
        void newtable() { lua_newtable(lua_handle); }
        void pushcclosure(lua_CFunction fn, int n) { lua_pushcclosure(lua_handle, fn, n); }
        void pushcfunction(lua_CFunction fn) { lua_pushcfunction(lua_handle, fn); }
        void setfield(int index, const char* k) { lua_setfield(lua_handle, index, k); }
        void getfield(int index, const char* k) { lua_getfield(lua_handle, index, k); }
        void getglobal(const char* name) { lua_getglobal(lua_handle, name); }
        void setglobal(const char* name) { lua_setglobal(lua_handle, name); }
        void insert(int index) { lua_insert(lua_handle, index); }
        void settable(int index) { lua_settable(lua_handle, index); }
        int isnone(int index) { return lua_isnone(lua_handle, index); }
        void pushnumber(lua_Number n) { return lua_pushnumber(lua_handle, n); }
        int isnumber(int index) { return lua_isnumber(lua_handle, index); }
        int isboolean(int index) { return lua_isboolean(lua_handle, index); }
        int toboolean(int index) { return lua_toboolean(lua_handle, index); }
        const char* tolstring(int index, size_t *len) { return lua_tolstring(lua_handle, index, len); }
        void pushboolean(int b) { lua_pushboolean(lua_handle, b); }
        lua_Number tonumber(int index) { return lua_tonumber(lua_handle, index); }
        void gettable(int index) { lua_gettable(lua_handle, index); }
#if LUA_VERSION_NUM == 501
        int load(lua_Reader reader, void* data, const char* chunkname) { return lua_load(lua_handle, reader, data,
                chunkname); }
#endif
#if LUA_VERSION_NUM == 502
        int load(lua_Reader reader, void* data, const char* chunkname, const char* mode) { return lua_load(lua_handle,
                reader, data, chunkname, mode); }
#endif
        const char* tostring(int index) { return lua_tostring(lua_handle, index); }
        const char* tolstring(int index, size_t& len) { return lua_tolstring(lua_handle, index, &len); }
        void pushlstring(const char* s, size_t len) { lua_pushlstring(lua_handle, s, len); }
        void pushlstring(const std::string& s) { lua_pushlstring(lua_handle, s.c_str(), s.length()); }
        void pushlstring(const char32_t* s, size_t len) { pushlstring(utf8::to8(std::u32string(s, len))); }
        int pcall(int nargs, int nresults, int errfunc) { return lua_pcall(lua_handle, nargs, nresults, errfunc); }
        int next(int index) { return lua_next(lua_handle, index); }
        int isnoneornil(int index) { return lua_isnoneornil(lua_handle, index); }
        lua_Integer tointeger(int index) { return lua_tointeger(lua_handle, index); }
        void rawgeti(int index, int n) { lua_rawgeti(lua_handle, index, n); }
        callback_proxy cbproxy;
private:
        static void builtin_oom();
        static void* builtin_alloc(void* user, void* old, size_t olds, size_t news);
        void (*oom_handler)();
        state* master;
        lua_State* lua_handle;
        std::set<std::pair<function_group*, int>> function_groups;
        std::map<std::string, callback_list*> callbacks;
        state(state&);
        state& operator=(state&);
};

}

#endif