minetest/src/script/cpp_api/s_base.cpp

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/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <cstdarg>
extern "C" {
#include "lua.h"
#include "lauxlib.h"
}
#include "cpp_api/s_base.h"
#include "lua_api/l_object.h"
#include "serverobject.h"
ScriptApiBase::ScriptApiBase() :
m_luastackmutex(),
#ifdef LOCK_DEBUG
m_locked(false),
#endif
m_luastack(0),
m_server(0),
m_environment(0)
{
}
void ScriptApiBase::realityCheck()
{
int top = lua_gettop(m_luastack);
if(top >= 30){
dstream<<"Stack is over 30:"<<std::endl;
stackDump(dstream);
scriptError("Stack is over 30 (reality check)");
}
}
void ScriptApiBase::scriptError(const char *fmt, ...)
{
va_list argp;
va_start(argp, fmt);
char buf[10000];
vsnprintf(buf, 10000, fmt, argp);
va_end(argp);
//errorstream<<"SCRIPT ERROR: "<<buf;
throw LuaError(m_luastack, buf);
}
void ScriptApiBase::stackDump(std::ostream &o)
{
int i;
int top = lua_gettop(m_luastack);
for (i = 1; i <= top; i++) { /* repeat for each level */
int t = lua_type(m_luastack, i);
switch (t) {
case LUA_TSTRING: /* strings */
o<<"\""<<lua_tostring(m_luastack, i)<<"\"";
break;
case LUA_TBOOLEAN: /* booleans */
o<<(lua_toboolean(m_luastack, i) ? "true" : "false");
break;
case LUA_TNUMBER: /* numbers */ {
char buf[10];
snprintf(buf, 10, "%g", lua_tonumber(m_luastack, i));
o<<buf;
break; }
default: /* other values */
o<<lua_typename(m_luastack, t);
break;
}
o<<" ";
}
o<<std::endl;
}
// Push the list of callbacks (a lua table).
// Then push nargs arguments.
// Then call this function, which
// - runs the callbacks
// - removes the table and arguments from the lua stack
// - pushes the return value, computed depending on mode
void ScriptApiBase::runCallbacks(int nargs,RunCallbacksMode mode)
{
lua_State *L = getStack();
// Insert the return value into the lua stack, below the table
assert(lua_gettop(L) >= nargs + 1);
lua_pushnil(L);
lua_insert(L, -(nargs + 1) - 1);
// Stack now looks like this:
// ... <return value = nil> <table> <arg#1> <arg#2> ... <arg#n>
int rv = lua_gettop(L) - nargs - 1;
int table = rv + 1;
int arg = table + 1;
luaL_checktype(L, table, LUA_TTABLE);
// Foreach
lua_pushnil(L);
bool first_loop = true;
while(lua_next(L, table) != 0){
// key at index -2 and value at index -1
luaL_checktype(L, -1, LUA_TFUNCTION);
// Call function
for(int i = 0; i < nargs; i++)
lua_pushvalue(L, arg+i);
if(lua_pcall(L, nargs, 1, 0))
scriptError("error: %s", lua_tostring(L, -1));
// Move return value to designated space in stack
// Or pop it
if(first_loop){
// Result of first callback is always moved
lua_replace(L, rv);
first_loop = false;
} else {
// Otherwise, what happens depends on the mode
if(mode == RUN_CALLBACKS_MODE_FIRST)
lua_pop(L, 1);
else if(mode == RUN_CALLBACKS_MODE_LAST)
lua_replace(L, rv);
else if(mode == RUN_CALLBACKS_MODE_AND ||
mode == RUN_CALLBACKS_MODE_AND_SC){
if((bool)lua_toboolean(L, rv) == true &&
(bool)lua_toboolean(L, -1) == false)
lua_replace(L, rv);
else
lua_pop(L, 1);
}
else if(mode == RUN_CALLBACKS_MODE_OR ||
mode == RUN_CALLBACKS_MODE_OR_SC){
if((bool)lua_toboolean(L, rv) == false &&
(bool)lua_toboolean(L, -1) == true)
lua_replace(L, rv);
else
lua_pop(L, 1);
}
else
assert(0);
}
// Handle short circuit modes
if(mode == RUN_CALLBACKS_MODE_AND_SC &&
(bool)lua_toboolean(L, rv) == false)
break;
else if(mode == RUN_CALLBACKS_MODE_OR_SC &&
(bool)lua_toboolean(L, rv) == true)
break;
// value removed, keep key for next iteration
}
// Remove stuff from stack, leaving only the return value
lua_settop(L, rv);
// Fix return value in case no callbacks were called
if(first_loop){
if(mode == RUN_CALLBACKS_MODE_AND ||
mode == RUN_CALLBACKS_MODE_AND_SC){
lua_pop(L, 1);
lua_pushboolean(L, true);
}
else if(mode == RUN_CALLBACKS_MODE_OR ||
mode == RUN_CALLBACKS_MODE_OR_SC){
lua_pop(L, 1);
lua_pushboolean(L, false);
}
}
}
void ScriptApiBase::addObjectReference(ServerActiveObject *cobj)
{
SCRIPTAPI_PRECHECKHEADER
//infostream<<"scriptapi_add_object_reference: id="<<cobj->getId()<<std::endl;
// Create object on stack
ObjectRef::create(L, cobj); // Puts ObjectRef (as userdata) on stack
int object = lua_gettop(L);
// Get minetest.object_refs table
lua_getglobal(L, "minetest");
lua_getfield(L, -1, "object_refs");
luaL_checktype(L, -1, LUA_TTABLE);
int objectstable = lua_gettop(L);
// object_refs[id] = object
lua_pushnumber(L, cobj->getId()); // Push id
lua_pushvalue(L, object); // Copy object to top of stack
lua_settable(L, objectstable);
}
void ScriptApiBase::removeObjectReference(ServerActiveObject *cobj)
{
SCRIPTAPI_PRECHECKHEADER
//infostream<<"scriptapi_rm_object_reference: id="<<cobj->getId()<<std::endl;
// Get minetest.object_refs table
lua_getglobal(L, "minetest");
lua_getfield(L, -1, "object_refs");
luaL_checktype(L, -1, LUA_TTABLE);
int objectstable = lua_gettop(L);
// Get object_refs[id]
lua_pushnumber(L, cobj->getId()); // Push id
lua_gettable(L, objectstable);
// Set object reference to NULL
ObjectRef::set_null(L);
lua_pop(L, 1); // pop object
// Set object_refs[id] = nil
lua_pushnumber(L, cobj->getId()); // Push id
lua_pushnil(L);
lua_settable(L, objectstable);
}
// Creates a new anonymous reference if cobj=NULL or id=0
void ScriptApiBase::objectrefGetOrCreate(
ServerActiveObject *cobj)
{
lua_State *L = getStack();
if(cobj == NULL || cobj->getId() == 0){
ObjectRef::create(L, cobj);
} else {
objectrefGet(cobj->getId());
}
}
void ScriptApiBase::objectrefGet(u16 id)
{
lua_State *L = getStack();
// Get minetest.object_refs[i]
lua_getglobal(L, "minetest");
lua_getfield(L, -1, "object_refs");
luaL_checktype(L, -1, LUA_TTABLE);
lua_pushnumber(L, id);
lua_gettable(L, -2);
lua_remove(L, -2); // object_refs
lua_remove(L, -2); // minetest
}