source: trunk/src/lua/lua_state.cc @ 78

// Copyright (C) 2012-2013 ChaosForge / Kornel Kisielewicz
// http://chaosforge.org/
//
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

#include "nv/lua/lua_state.hh"

#include "nv/lua/lua_raw.hh"
#include "nv/logging.hh"
#include "nv/string.hh"
#include "nv/root.hh"
#include "nv/types.hh"

using namespace nv;

lua::stack_guard::stack_guard( lua::state* L )
        : L(L), m_level( lua_gettop(L->L) )
{

}

lua::stack_guard::~stack_guard()
{
        lua_settop( L->L, m_level );
}

lua::state::state( bool load_libs /*= false*/ )
{
        load_lua_library();
        m_owner = true;
        L = luaL_newstate( );

        lua_pushcfunction(L, luaopen_base);
        lua_pushliteral(L, LUA_TABLIBNAME);
        lua_call(L, 1, 0);

        if ( load_libs )
        {
                stack_guard guard( this );
                static const luaL_Reg lualibs[] =
                {
                        { "string", luaopen_string },
                        { "table",  luaopen_table },
                        { "math",   luaopen_math },
                        { NULL, NULL}
                };
                const luaL_Reg *lib = lualibs;
                for(; lib->func != NULL; lib++)
                {
                        lib->func( L );
                }
        }

        NV_LOG( nv::LOG_TRACE, "Lua state created" );
}

int lua::state::load_string( const std::string& code, const std::string& name )
{
        NV_LOG( nv::LOG_TRACE, "Loading Lua string '" << name << "'");
        return luaL_loadbuffer( L, code.c_str(), code.length(), name.c_str() );
}

int lua::state::load_stream( std::istream& stream, const std::string& name )
{
        NV_LOG( nv::LOG_NOTICE, "Loading Lua stream '" << name << "'");
        return load_string( std::string(
                (std::istreambuf_iterator<char>(stream)),
                std::istreambuf_iterator<char>()), name );
}

int lua::state::load_file( const std::string& filename )
{
        NV_LOG( nv::LOG_NOTICE, "Loading Lua file '" << filename << "'");
        return luaL_loadfile( L, filename.c_str() );
}

bool lua::state::do_string( const std::string& code, const std::string& name )
{
        lua::stack_guard( this );
        int result = load_string(code,name);
        if (result)
        {
                NV_LOG( nv::LOG_WARNING, "Failed to load string " << name << ": " << lua_tostring(L, -1));
                return false;
        }
        return do_current( name ) == 0;
}

bool lua::state::do_stream( std::istream& stream, const std::string& name )
{
        lua::stack_guard( this );
        int result = load_stream(stream,name);
        if (result)
        {
                NV_LOG( nv::LOG_WARNING, "Failed to open stream " << name << ": " << lua_tostring(L, -1));
                return false;
        }
        return do_current( name ) == 0;
}

bool lua::state::do_file( const std::string& filename )
{
        lua::stack_guard( this );
        int result = load_file(filename);
        if (result) 
        {
                NV_LOG( nv::LOG_WARNING, "Failed to open file " << filename << ": " << lua_tostring(L, -1));
                return false;
        }
        return do_current( filename ) == 0;
}

int lua::state::do_current( const std::string& name )
{
        int result = lua_pcall(L, 0, 0, 0);
        if (result) 
        {
                NV_LOG( nv::LOG_WARNING, "Failed to run script " << name << ": " << lua_tostring(L, -1));
                lua_pop( L, 1 );
        }
        return result;
}

lua::state::~state()
{
        if (m_owner)
        {
                lua_close( L );
        }
}

bool lua::state::push( const std::string& path, bool global )
{
        size_t point = path.find('.');

        if (point == std::string::npos)
        {
                if (global)
                {
                        lua_getglobal( L, path.c_str() );
                }
                else
                {
                        lua_getfield( L, -1, path.c_str() );
                }
                return !lua_isnil( L, -1 );
        }

        size_t idx = 0;
        size_t start = 0;

        while( point != std::string::npos )
        {
                if (idx == 0)
                {
                        if (global)
                        {
                                lua_getglobal( L, path.substr(start,point-start).c_str() );
                        }
                        else
                        {
                                lua_getfield( L, -1, path.substr(start,point-start).c_str() );
                        }
                }
                else
                {
                        if ( lua_istable( L, -1 ) )
                        {
                                lua_pushstring( L, path.substr(start,point-start).c_str() );
                                lua_gettable( L, -2 );
                                lua_insert( L, -2 );
                                lua_pop( L, 1 );
                        }
                        else
                        {
                                lua_pop(L, 1);
                                lua_pushnil(L);
                                return false;
                        }
                }
                start = point+1;
                point = path.find( '.', start );
        }
        return true;
}


int lua::state::get_stack_size()
{
        return lua_gettop( L );
}

lua::table_guard::table_guard( lua::state* lstate, const std::string& table, bool global )
        : L(lstate), m_guard(lstate)
{
        L->push( table, global );
}

lua::table_guard::table_guard( lua::state* lstate, const std::string& table, int index, bool global )
        : L(lstate), m_guard(lstate)
{
        L->push( table, global );
        lua_rawgeti( L->L, -1, index );
}

lua::table_guard::table_guard( lua::state* lstate, const std::string& table, const std::string& index, bool global /*= true */ )
        : L(lstate), m_guard(lstate)
{
        L->push( table, global );
        lua_pushstring( L->L, index.c_str() );
        lua_rawget( L->L, -2 );
}

lua::table_guard::table_guard( const table_guard& parent, const std::string& index )
        : L( parent.L ), m_guard( parent.L )
{
        lua_getfield( L->L, -1, index.c_str() );
}

lua::table_guard::table_guard( const table_guard& parent, int index )
        : L( parent.L ), m_guard( parent.L )
{
        lua_rawgeti( L->L, -1, index );
}

bool lua::table_guard::has_field( const string& element )
{
        lua_getfield( L->L, -1, element.c_str() );
        bool result = lua_isnil( L->L, -1 );
        lua_pop( L->L, 1 );
        return result;
}

string lua::table_guard::get_string( const string& element, const string& defval /*= "" */ )
{
        lua_getfield( L->L, -1, element.c_str() );
        string result( ( lua_type( L->L, -1 ) == LUA_TSTRING ) ? lua_tostring( L->L, -1 ) : defval );
        lua_pop( L->L, 1 );
        return result;
}

char lua::table_guard::get_char( const string& element, char defval /*= "" */ )
{
        lua_getfield( L->L, -1, element.c_str() );
        char result = ( lua_type( L->L, -1 ) == LUA_TSTRING && lua_rawlen( L->L, -1 ) > 0 ) ? lua_tostring( L->L, -1 )[0] : defval;
        lua_pop( L->L, 1 );
        return result;
}

int lua::table_guard::get_integer( const string& element, int defval /*= "" */ )
{
        lua_getfield( L->L, -1, element.c_str() );
        int result = lua_type( L->L, -1 ) == LUA_TNUMBER ? lua_tointeger( L->L, -1 ) : defval;
        lua_pop( L->L, 1 );
        return result;
}

double lua::table_guard::get_double( const string& element, double defval /*= "" */ )
{
        lua_getfield( L->L, -1, element.c_str() );
        double result = lua_type( L->L, -1 ) == LUA_TNUMBER ? lua_tonumber( L->L, -1 ) : defval;
        lua_pop( L->L, 1 );
        return result;
}

bool lua::table_guard::get_boolean( const string& element, bool defval /*= "" */ )
{
        lua_getfield( L->L, -1, element.c_str() );
        bool result = lua_type( L->L, -1 ) == LUA_TBOOLEAN ? lua_toboolean( L->L, -1 ) != 0 : defval;
        lua_pop( L->L, 1 );
        return result;
}

void lua::state::log_stack()
{
        int top = lua_gettop(L);
        NV_LOG( LOG_DEBUG, "Stack dump (" << top << ")");
        for ( int i = 0; i < top; ++i )
        {
                NV_LOG( LOG_DEBUG, "#" << i+1 << " - " << lua_typename(L, lua_type(L, i+1) ) << " = " << nlua_typecontent(L, i+1) );
        }
}

lua_State* lua::state::get_raw()
{
        return L;
}

lua::reference lua::state::register_object( object * o )
{
        if (!o) return ref_none;
        type_database *db = o->get_root()->get_type_database();
        if (!db) return ref_none;
        type_entry* t = db->get_type(typeid(o));
        if (!t) return ref_none;
        stack_guard guard( this );
        lua_getglobal( L, t->name.c_str() );
        if ( lua_isnil( L, -1 ) )
        {
                NV_THROW( runtime_error, std::string( t->name ) + " type not registered!" );
        }
        deep_pointer_copy( -1, o );
    return luaL_ref( L, LUA_REGISTRYINDEX );
}

void lua::state::unregister_object( object * o )
{
        if (!o) return;
        stack_guard guard( this );
        lua_rawgeti( L, LUA_REGISTRYINDEX, o->get_lua_index() );
        lua_pushstring( L, "__ptr" );
        lua_pushboolean( L, false );
        lua_rawset( L, -3 );
        lua_pop( L, 1 );
        luaL_unref( L, LUA_REGISTRYINDEX, o->get_lua_index() );
}

void lua::state::deep_pointer_copy( int index, void* obj )
{
        index = lua_absindex( L, index );
        lua_newtable( L );
        lua_pushnil( L );
        bool has_functions = false;
        bool has_metatable = false;

        while ( lua_next( L, index ) != 0 )
        {
                if ( lua_isfunction( L, -1 ) ) 
                        has_functions = true;
                else if ( lua_istable( L, -1 ) )
                {
                        deep_pointer_copy( -1, obj );
                        lua_insert( L, -2 );
                        lua_pop( L, 1 );
                }
                lua_pushvalue( L, -2 );
                lua_insert( L, -2 );
                lua_settable( L, -4 );
        }

        if ( lua_getmetatable( L, -2 ) )
        {
                lua_setmetatable( L, -2 );
                has_metatable = true;
        }

        if ( has_functions || has_metatable )
        {
                lua_pushstring( L, "__ptr" );
                lua_pushlightuserdata( L, obj );
                lua_rawset( L, -3 );
        }
}