source: trunk/src/lua/lua_state.cc @ 319

// Copyright (C) 2012-2014 ChaosForge Ltd
// 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/lua/lua_nova.hh"
#include "nv/core/logging.hh"
#include "nv/core/string.hh"

using namespace nv;

// stack_guard

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

}

lua::stack_guard::stack_guard( lua::state& aL )
        : L(&aL), m_level( lua_gettop(aL.m_state) )
{

}

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

// state_wrapper

void nv::lua::state_wrapper::push_global_table()
{
        lua_pushglobaltable( m_state );
}

void nv::lua::state_wrapper::pop_global_table()
{
        lua_replace( m_state, -2 );
}

void lua::state_wrapper::call_get()
{
        lua_gettable( m_state, -2 );
}

void lua::state_wrapper::call_get_raw()
{
        lua_rawget( m_state, -2 );
}

void lua::state_wrapper::register_native_function( lfunction f, const char* name )
{
        if ( m_global ) push_global_table();
        lua_pushcfunction( m_state, f );
        lua_setfield( m_state, -2, name );
        if ( m_global ) pop_global_table();
}

lua::state_wrapper::~state_wrapper()
{
        if (m_owner)
        {
                lua_close( m_state );
        }
}

bool nv::lua::state_wrapper::is_defined( const path& p, bool global )
{
        if ( !p.resolve( m_state, global ) )
        {
                return false;
        }
        bool result = !lua_isnil( m_state, -1 );
        lua_pop( m_state, 1 );
        return result;
}

bool nv::lua::state_wrapper::push_function( const path& p, bool global )
{
        if ( !p.resolve( m_state, global ) )
        {
                NV_LOG( LOG_ERROR, "Lua error : not a valid path - " + p.to_string() );
                return false;
        }

        if ( !lua_isfunction( m_state, -1 ) ) 
        {
                lua_pop( m_state, 1 );
                NV_LOG( LOG_ERROR, "Lua error : not a valid function - " + p.to_string() );
                return false;
        }
        return true;
}

int nv::lua::state_wrapper::call_function( int nargs, int nresults )
{
        int status = lua_pcall( m_state, nargs, nresults, 0 );
        if ( status != 0 )
        {
                std::string error = lua_tostring( m_state, -1 );
                lua_pop( m_state, 1 );
                NV_LOG( LOG_ERROR, "Lua error : " << error )
        }
        return status;
}

// table_guard

lua::table_guard::table_guard( lua::state* lstate, const path& p, bool global )
        : state_wrapper( lstate->get_raw(), false ), m_level(0)
{
        m_global = false;
        m_level  = lua_gettop( m_state );
        if ( !p.resolve( m_state, global ) || lua_type(m_state, -1) != LUA_TTABLE )
        {
                NV_LOG( LOG_ERROR, "Could not resolve table!" );
                // TODO : error handling
        }
}

lua::table_guard::table_guard( const table_guard& parent, const path& p )
        : state_wrapper( parent.m_state, false ), m_level(0)
{
        m_global = false;
        m_level  = lua_gettop( m_state );
        if ( !p.resolve( m_state, false ) || lua_type(m_state, -1) != LUA_TTABLE )
        {
                NV_LOG( LOG_ERROR, "Could not resolve table!" );
                // TODO : error handling
        }
}

lua::table_guard::~table_guard()
{
        lua_settop( m_state, m_level );
}

size_t lua::table_guard::get_size()
{
        return lua_rawlen( m_state, -1 );
}

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

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

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

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

unsigned lua::table_guard::get_unsigned( const string& element, unsigned defval /*= "" */ )
{
        lua_getfield( m_state, -1, element.c_str() );
        unsigned result = lua_type( m_state, -1 ) == LUA_TNUMBER ? lua_tounsigned( m_state, -1 ) : defval;
        lua_pop( m_state, 1 );
        return result;
}

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


float nv::lua::table_guard::get_float( const std::string& element, float defval /*= 0.0 */ )
{
        lua_getfield( m_state, -1, element.c_str() );
        float result = lua_type( m_state, -1 ) == LUA_TNUMBER ? (float)lua_tonumber( m_state, -1 ) : defval;
        lua_pop( m_state, 1 );
        return result;
}

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

bool nv::lua::table_guard::is_table( const std::string& element )
{
        lua_getfield( m_state, -1, element.c_str() );
        bool result = lua_type( m_state, -1 ) == LUA_TTABLE;
        lua_pop( m_state, 1 );
        return result;
}

bool nv::lua::table_guard::is_number( const std::string& element )
{
        lua_getfield( m_state, -1, element.c_str() );
        bool result = lua_type( m_state, -1 ) == LUA_TNUMBER;
        lua_pop( m_state, 1 );
        return result;
}

bool nv::lua::table_guard::is_boolean( const std::string& element )
{
        lua_getfield( m_state, -1, element.c_str() );
        bool result = lua_type( m_state, -1 ) == LUA_TBOOLEAN;
        lua_pop( m_state, 1 );
        return result;
}

bool nv::lua::table_guard::is_string( const std::string& element )
{
        lua_getfield( m_state, -1, element.c_str() );
        bool result = lua_type( m_state, -1 ) == LUA_TSTRING;
        lua_pop( m_state, 1 );
        return result;
}


// state

lua::state::state( lua_State* state ) : state_wrapper( state, false )
{

}

lua::state::state( bool load_libs /*= false*/ ) : state_wrapper( nullptr, true )
{
        load_lua_library();
        m_owner = true;
        m_state = luaL_newstate( );

        lua_pushcfunction(m_state, luaopen_base);
        lua_pushliteral(m_state, LUA_TABLIBNAME);
        lua_call(m_state, 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++)
                {
                        lua_pushcfunction( m_state, lib->func );
                        lua_call(m_state, 0, 1);
                        lua_setglobal( m_state, lib->name );
                }
                register_nova( this );
        }

        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( m_state, 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( m_state, filename.c_str() );
}

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

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

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

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

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

lua::ref lua::state::register_object( void* o, const char* lua_name )
{
        if ( o == nullptr ) return lua::ref( lua::ref::none );
        stack_guard guard( this );
        lua_getglobal( m_state, lua_name );
        if ( lua_isnil( m_state, -1 ) )
        {
                NV_THROW( runtime_error, std::string( lua_name ) + " type not registered!" );
        }
        deep_pointer_copy( -1, o );
        return lua::ref( luaL_ref( m_state, LUA_REGISTRYINDEX ) );
}

lua::ref lua::state::register_proto( const char* id, const char* storage )
{
        stack_guard guard( this );
        lua_getglobal( m_state, storage );
        if ( lua_isnil( m_state, -1 ) )
        {
                NV_THROW( runtime_error, std::string( storage ) + " storage not registered!" );
        }
        lua_getfield( m_state, -1, id );
        if ( lua_isnil( m_state, -1 ) )
        {
                NV_THROW( runtime_error, std::string( id ) + " not found in " + std::string( storage ) + " storage!" );
        }
        return lua::ref( luaL_ref( m_state, LUA_REGISTRYINDEX ) );
}

void lua::state::register_native_object_method( const char* lua_name, const char* name, lfunction f )
{
        stack_guard guard( this );
        lua_getglobal( m_state, lua_name );
        if ( lua_isnil( m_state, -1 ) )
        {
                NV_THROW( runtime_error, std::string( lua_name ) + " type not registered!" );
        }
        lua_pushcfunction( m_state, f );
        lua_setfield( m_state, -2, name );
}

void lua::state::unregister_object( ref object_index )
{
        if ( !object_index.is_valid() ) return;
        stack_guard guard( this );
        lua_rawgeti( m_state, LUA_REGISTRYINDEX, object_index.get() );
        lua_pushstring( m_state, "__ptr" );
        lua_pushboolean( m_state, false );
        lua_rawset( m_state, -3 );
        lua_pop( m_state, 1 );
        luaL_unref( m_state, LUA_REGISTRYINDEX, object_index.get() );
}


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

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

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

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

void nv::lua::state::store_metadata( ref object_index, const std::string& metaname, void* pointer )
{
        if ( !object_index.is_valid() ) return;
        lua_rawgeti( m_state, LUA_REGISTRYINDEX, object_index.get() );
        lua_pushstring( m_state, metaname.c_str() );
        lua_pushlightuserdata( m_state, pointer );
        lua_rawset( m_state, -3 );
        lua_pop( m_state, 1 );
}

void nv::lua::state::register_enum( const char* name, int value )
{
        lua_pushinteger( m_state, value );
        lua_setglobal( m_state, name );
}