add support for self-ref objects

lupa/_lupa.pyx

@@ -525,15 +525,15 @@ cdef class LuaRuntime:
  """
  return self.table_from(items, kwargs)
 
- def table_from(self, *args, int max_depth=1):
+ def table_from(self, *args, bint recursive=False):
  """Create a new table from Python mapping or iterable.
 
  table_from() accepts either a dict/mapping or an iterable with items.
  Items from dicts are set as key-value pairs; items from iterables
  are placed in the table in order.
 
  Nested mappings / iterables are passed to Lua as userdata
- (wrapped Python objects) if recursive depth is greater than `max_depth`, they are not converted to Lua tables.
+ (wrapped Python objects) if `recursive` is False, they are not converted to Lua tables.
  """
  assert self._state is not NULL
  cdef lua_State *L = self._state
@@ -547,8 +547,8 @@ cdef class LuaRuntime:
  for obj in args:
  if isinstance(obj, dict):
  for key, value in obj.iteritems():
- py_to_lua(self, L, key, wrap_none=True, max_depth=max_depth)
- py_to_lua(self, L, value, wrap_none=False, max_depth=max_depth)
+ py_to_lua(self, L, key, True, recursive)
+ py_to_lua(self, L, value, False, recursive)
  lua.lua_rawset(L, -3)
 
  elif isinstance(obj, _LuaTable):
@@ -564,12 +564,12 @@ cdef class LuaRuntime:
  elif isinstance(obj, Mapping):
  for key in obj:
  value = obj[key]
- py_to_lua(self, L, key, wrap_none=True, max_depth=max_depth)
- py_to_lua(self, L, value, wrap_none=False, max_depth=max_depth)
+ py_to_lua(self, L, key, True, recursive)
+ py_to_lua(self, L, value, False, recursive)
  lua.lua_rawset(L, -3)
  else:
  for arg in obj:
- py_to_lua(self, L, arg, wrap_none=False, max_depth=max_depth)
+ py_to_lua(self, L, arg, False, recursive)
  lua.lua_rawseti(L, -2, i)
  i += 1
  return py_from_lua(self, L, -1)
@@ -1550,7 +1550,7 @@ cdef int py_to_lua_handle_overflow(LuaRuntime runtime, lua_State *L, object o) e
  lua.lua_settop(L, old_top)
  raise
 
-cdef int py_to_lua(LuaRuntime runtime, lua_State *L, object o, bint wrap_none=False, int max_depth=1, int current_depth=0) except -1:
+cdef int py_to_lua(LuaRuntime runtime, lua_State *L, object o, bint wrap_none=False, bint recursive=False, dict mapped_objs = None) except -1:
  """Converts Python object to Lua
  Preconditions:
  1 extra slot in the Lua stack
@@ -1559,8 +1559,6 @@ cdef int py_to_lua(LuaRuntime runtime, lua_State *L, object o, bint wrap_none=Fa
  Returns 0 if cannot convert Python object to Lua
  Returns 1 if the Python object was converted successfully and pushed onto the stack
  """
- if current_depth >= max_depth:
- raise ValueError("max recursive depth reached")
  cdef int pushed_values_count = 0
  cdef int type_flags = 0
 
@@ -1608,18 +1606,32 @@ cdef int py_to_lua(LuaRuntime runtime, lua_State *L, object o, bint wrap_none=Fa
  type_flags = (<_PyProtocolWrapper> o)._type_flags
  o = (<_PyProtocolWrapper> o)._obj
  pushed_values_count = py_to_lua_custom(runtime, L, o, type_flags)
- elif max_depth>1 and isinstance(o, (list, Sequence)):
- lua.lua_createtable(L, _len_as_int(len(o)), 0) # create a table at the top of stack, with narr already known
- for i, v in enumerate(o, 1):
- py_to_lua(runtime, L, v, wrap_none, max_depth, current_depth+1)
- lua.lua_rawseti(L, -2, i)
+ elif recursive and isinstance(o, (list, Sequence)):
+ if mapped_objs is None:
+ mapped_objs = {}
+ if id(o) not in mapped_objs:
+ lua.lua_createtable(L, _len_as_int(len(o)), 0) # create a table at the top of stack, with narr already known
+ mapped_objs[id(o)] = lua.lua_gettop(L)
+ for i, v in enumerate(o, 1):
+ py_to_lua(runtime, L, v, wrap_none, recursive, mapped_objs)
+ lua.lua_rawseti(L, -2, i)
+ else: # self-reference detected
+ idx = mapped_objs[id(o)]
+ lua.lua_pushvalue(L, idx)
  pushed_values_count = 1
- elif max_depth>1 and isinstance(o, (dict, Mapping)):
- lua.lua_createtable(L, 0, _len_as_int(len(o))) # create a table at the top of stack, with nrec already known
- for key, value in o.items():
- py_to_lua(runtime, L, key, wrap_none, max_depth, current_depth+1)
- py_to_lua(runtime, L, value, wrap_none, max_depth, current_depth+1)
- lua.lua_rawset(L, -3)
+ elif recursive and isinstance(o, (dict, Mapping)):
+ if mapped_objs is None:
+ mapped_objs = {}
+ if id(o) not in mapped_objs:
+ lua.lua_createtable(L, 0, _len_as_int(len(o))) # create a table at the top of stack, with nrec already known
+ mapped_objs[id(o)] = lua.lua_gettop(L)
+ for key, value in o.items():
+ py_to_lua(runtime, L, key, wrap_none, recursive, mapped_objs)
+ py_to_lua(runtime, L, value, wrap_none, recursive, mapped_objs)
+ lua.lua_rawset(L, -3)
+ else: # self-reference detected
+ idx = mapped_objs[id(o)]
+ lua.lua_pushvalue(L, idx)
  pushed_values_count = 1
  else:
  # prefer __getitem__ over __getattr__ by default

lupa/tests/test.py

@@ -634,7 +634,7 @@ def test_table_from_table_iter_indirect(self):
 
  def test_table_from_nested_dict(self):
  data = {"a": {"a": "foo"}, "b": {"b": "bar"}}
- table = self.lua.table_from(data, max_depth=10)
+ table = self.lua.table_from(data, recursive=True)
  self.assertEqual(table["a"]["a"], "foo")
  self.assertEqual(table["b"]["b"], "bar")
  self.lua.globals()["data"] = table
@@ -659,7 +659,7 @@ def test_table_from_nested_dict(self):
 
  def test_table_from_nested_list(self):
  data = {"a": {"a": "foo"}, "b": [1, 2, 3]}
- table = self.lua.table_from(data, max_depth=10)
+ table = self.lua.table_from(data, recursive=True)
  self.assertEqual(table["a"]["a"], "foo")
  self.assertEqual(table["b"][1], 1)
  self.assertEqual(table["b"][2], 2)
@@ -686,7 +686,7 @@ def test_table_from_nested_list(self):
 
  def test_table_from_nested_list_bad(self):
  data = {"a": {"a": "foo"}, "b": [1, 2, 3]}
- table = self.lua.table_from(data, max_depth=10) # in this case, lua will get userdata instead of table
+ table = self.lua.table_from(data, recursive=True) # in this case, lua will get userdata instead of table
  self.assertEqual(table["a"]["a"], "foo")
  print(list(table["b"]))
  self.assertEqual(table["b"][1], 1)
@@ -699,11 +699,23 @@ def test_table_from_nested_list_bad(self):
 
  del self.lua.globals()["data"]
 
- def test_table_from_recursive_dict(self):
+ def test_table_from_self_ref_obj(self):
  data = {}
  data["key"] = data
- with self.assertRaises(ValueError):
- self.lua.table_from(data, max_depth=10)
+ l = []
+ l.append(l)
+ data["list"] = l
+ table = self.lua.table_from(data, recursive=True)
+ self.lua.globals()["data"] = table
+ self.lua.eval("assert(type(data)=='table', '')")
+ self.lua.eval("assert(type(data['key'])=='table', '')")
+ self.lua.eval("assert(type(data['list'])=='table', '')")
+ self.lua.eval("assert(data['list']==data['list'][1], 'wrong self-ref list')")
+ self.lua.eval("assert(type(data['key']['key']['key']['key'])=='table', 'wrong self-ref map')")
+ self.lua.eval("assert(type(data['key']['key']['key']['key']['list'])=='table', 'wrong self-ref map')")
+ # self.assertEqual(table["key"], table)
+ # self.assertEqual(table["list"], table["list"][0])
+ del self.lua.globals()["data"]
 
  # FIXME: it segfaults
  # def test_table_from_generator_calling_lua_functions(self):