prepare sharing C++ class instances across lua-interpreters

in particular: lua-lifefime (!) C++ instances.
This allows for dynamic allocation of custom user-data, bound to
the lifetime of the allocating lua-context.
This commit is contained in:
Robin Gareus 2016-07-07 04:44:36 +02:00
parent 225a8a47a4
commit 44a3f042a7
5 changed files with 217 additions and 1 deletions

View File

@ -181,6 +181,46 @@ namespace ARDOUR { namespace LuaOSC {
lo_address _addr;
};
} } /* namespace */
}
class LuaTableRef {
public:
LuaTableRef ();
~LuaTableRef ();
int get (lua_State* L);
int set (lua_State* L);
private:
struct LuaTableEntry {
LuaTableEntry (int kt, int vt)
: keytype (kt)
, valuetype (vt)
{ }
int keytype;
std::string k_s;
unsigned int k_n;
int valuetype;
// LUA_TUSERDATA
const void* c;
void* p;
// LUA_TBOOLEAN
bool b;
// LUA_TSTRING:
std::string s;
// LUA_TNUMBER:
double n;
};
std::vector<LuaTableEntry> _data;
static void* findclasskey (lua_State *L, const void* key);
template<typename T>
static void assign (luabridge::LuaRef* rv, T key, const LuaTableEntry& s);
};
} /* namespace */
#endif // _ardour_lua_api_h_

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@ -345,3 +345,153 @@ ARDOUR::LuaAPI::hsla_to_rgba (lua_State *L)
luabridge::Stack<double>::push (L, a);
return 4;
}
luabridge::LuaRef::Proxy&
luabridge::LuaRef::Proxy::clone_instance (const void* classkey, void* p) {
lua_rawgeti (m_L, LUA_REGISTRYINDEX, m_tableRef);
lua_rawgeti (m_L, LUA_REGISTRYINDEX, m_keyRef);
luabridge::UserdataPtr::push_raw (m_L, p, classkey);
lua_rawset (m_L, -3);
lua_pop (m_L, 1);
return *this;
}
LuaTableRef::LuaTableRef () {}
LuaTableRef::~LuaTableRef () {}
int
LuaTableRef::get (lua_State* L)
{
luabridge::LuaRef rv (luabridge::newTable (L));
for (std::vector<LuaTableEntry>::const_iterator i = _data.begin (); i != _data.end (); ++i) {
switch ((*i).keytype) {
case LUA_TSTRING:
assign(&rv, i->k_s, *i);
break;
case LUA_TNUMBER:
assign(&rv, i->k_n, *i);
break;
}
}
luabridge::push (L, rv);
return 1;
}
int
LuaTableRef::set (lua_State* L)
{
if (!lua_istable (L, -1)) { return luaL_error (L, "argument is not a table"); }
_data.clear ();
lua_pushvalue (L, -1);
lua_pushnil (L);
while (lua_next (L, -2)) {
lua_pushvalue (L, -2);
LuaTableEntry s (lua_type(L, -1), lua_type(L, -2));
switch (lua_type(L, -1)) {
case LUA_TSTRING:
s.k_s = luabridge::Stack<std::string>::get (L, -1);
break;
;
case LUA_TNUMBER:
s.k_n = luabridge::Stack<unsigned int>::get (L, -1);
break;
default:
// invalid key
lua_pop (L, 2);
continue;
}
switch(lua_type(L, -2)) {
case LUA_TSTRING:
s.s = luabridge::Stack<std::string>::get (L, -2);
break;
case LUA_TBOOLEAN:
s.b = lua_toboolean (L, -2);
break;
case LUA_TNUMBER:
s.n = lua_tonumber (L, -2);
break;
case LUA_TUSERDATA:
{
bool ok = false;
lua_getmetatable (L, -2);
lua_rawgetp (L, -1, luabridge::getIdentityKey ());
if (lua_isboolean (L, -1)) {
lua_pop (L, 1);
const void* key = lua_topointer (L, -1);
lua_pop (L, 1);
void const* classkey = findclasskey (L, key);
if (classkey) {
ok = true;
s.c = classkey;
s.p = luabridge::Userdata::get_ptr (L, -2);
}
} else {
lua_pop (L, 2);
}
if (ok) {
break;
}
// invalid userdata -- fall through
}
// no break
case LUA_TFUNCTION: // no support -- we could... string.format("%q", string.dump(value, true))
case LUA_TTABLE: // no nested tables, sorry.
case LUA_TNIL: // fallthrough
default:
// invalid value
lua_pop (L, 2);
continue;
}
_data.push_back(s);
lua_pop (L, 2);
}
return 0;
}
void*
LuaTableRef::findclasskey (lua_State *L, const void* key)
{
lua_pushvalue(L, LUA_REGISTRYINDEX);
lua_pushnil (L);
while (lua_next (L, -2)) {
lua_pushvalue (L, -2);
if (lua_topointer(L, -2) == key) {
void* rv = lua_touserdata (L, -1);
lua_pop (L, 4);
return rv;
}
lua_pop (L, 2);
}
lua_pop (L, 1);
return NULL;
}
template<typename T>
void LuaTableRef::assign (luabridge::LuaRef* rv, T key, const LuaTableEntry& s)
{
switch (s.valuetype) {
case LUA_TSTRING:
(*rv)[key] = s.s;
break;
case LUA_TBOOLEAN:
(*rv)[key] = s.b;
break;
case LUA_TNUMBER:
(*rv)[key] = s.n;
break;
case LUA_TUSERDATA:
(*rv)[key].clone_instance (s.c, s.p);
break;
default:
assert (0);
break;
}
}

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@ -169,6 +169,7 @@ CLASSKEYS(ARDOUR::Session);
CLASSKEYS(ARDOUR::BufferSet);
CLASSKEYS(ARDOUR::ChanMapping);
CLASSKEYS(ARDOUR::DSP::DspShm);
CLASSKEYS(ARDOUR::LuaTableRef);
CLASSKEYS(PBD::ID);
CLASSKEYS(ARDOUR::Location);
CLASSKEYS(ARDOUR::PluginInfo);
@ -1373,6 +1374,12 @@ LuaBindings::dsp (lua_State* L)
.endClass ()
.endNamespace () // DSP
.beginClass <LuaTableRef> ("LuaTableRef")
.addCFunction ("get", &LuaTableRef::get)
.addCFunction ("set", &LuaTableRef::set)
.endClass ()
.endNamespace (); // ARDOUR
}

View File

@ -180,6 +180,11 @@ private:
return *this;
}
// the implementation needs UserdataPtr, which
// is not yet defined here.
// -> libs/ardour/lua_api.cc
Proxy& clone_instance (const void* key, void* p);
//--------------------------------------------------------------------------
/**
Assign a new value to this table key.

View File

@ -302,6 +302,11 @@ ud __parent (nil)
public:
virtual ~Userdata () { }
static void* get_ptr (lua_State* L, int index) {
Userdata* ud = static_cast <Userdata*> (lua_touserdata (L, index));
return ud->m_p;
}
//--------------------------------------------------------------------------
/**
Returns the Userdata* if the class on the Lua stack matches.
@ -457,6 +462,15 @@ private:
assert (m_p != 0);
}
friend class LuaRef;
static inline void push_raw (lua_State* const L, void* p, const void* classkey)
{
new (lua_newuserdata (L, sizeof (UserdataPtr))) UserdataPtr (p);
lua_rawgetp (L, LUA_REGISTRYINDEX, classkey);
assert (lua_istable (L, -1));
lua_setmetatable (L, -2);
}
public:
/** Push non-const pointer to object.
*/