wplua: move under modules/module-lua-scripting

It's unlikely that wplua will ever be useful outside the context
of module-lua-scripting, so let's move it to keep all the code in one place

modules/module-lua-scripting/wplua/boxed.c

@@ -0,0 +1,108 @@
+/* WirePlumber
+ *
+ * Copyright © 2020 Collabora Ltd.
+ *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "wplua.h"
+#include "private.h"
+#include <wp/wp.h>
+
+static lua_CFunction
+find_method_in_luaL_Reg (luaL_Reg *reg, const gchar *method)
+{
+  if (reg) {
+    while (reg->name) {
+      if (!g_strcmp0 (method, reg->name))
+        return reg->func;
+      reg++;
+    }
+  }
+  return NULL;
+}
+
+static int
+_wplua_gboxed___index (lua_State *L)
+{
+  luaL_argcheck (L, wplua_isboxed (L, 1, G_TYPE_BOXED), 1,
+      "expected userdata storing GValue<GBoxed>");
+  GValue *obj_v = lua_touserdata (L, 1);
+  const gchar *key = luaL_checkstring (L, 2);
+  lua_CFunction func = NULL;
+  GHashTable *vtables;
+
+  lua_pushliteral (L, "wplua_vtables");
+  lua_gettable (L, LUA_REGISTRYINDEX);
+  vtables = wplua_toboxed (L, -1);
+  lua_pop (L, 1);
+
+  /* search in registered vtables */
+  if (!func) {
+    GType type = G_VALUE_TYPE (obj_v);
+    while (!func && type) {
+      luaL_Reg *reg = g_hash_table_lookup (vtables, GUINT_TO_POINTER (type));
+      func = find_method_in_luaL_Reg (reg, key);
+      type = g_type_parent (type);
+    }
+  }
+
+  if (func) {
+    lua_pushcfunction (L, func);
+    return 1;
+  }
+  return 0;
+}
+
+void
+_wplua_init_gboxed (lua_State *L)
+{
+  static const luaL_Reg gboxed_meta[] = {
+    { "__gc", _wplua_gvalue_userdata___gc },
+    { "__eq", _wplua_gvalue_userdata___eq },
+    { "__index", _wplua_gboxed___index },
+    { NULL, NULL }
+  };
+
+  luaL_newmetatable (L, "GBoxed");
+  luaL_setfuncs (L, gboxed_meta, 0);
+  lua_pop (L, 1);
+}
+
+void
+wplua_pushboxed (lua_State * L, GType type, gpointer object)
+{
+  g_return_if_fail (G_TYPE_FUNDAMENTAL (type) == G_TYPE_BOXED);
+
+  GValue *v = _wplua_pushgvalue_userdata (L, type);
+  wp_trace_boxed (type, object, "pushing to Lua, v=%p", v);
+  g_value_take_boxed (v, object);
+
+  luaL_getmetatable (L, "GBoxed");
+  lua_setmetatable (L, -2);
+}
+
+gpointer
+wplua_toboxed (lua_State *L, int idx)
+{
+  g_return_val_if_fail (_wplua_isgvalue_userdata (L, idx, G_TYPE_BOXED), NULL);
+  return g_value_get_boxed ((GValue *) lua_touserdata (L, idx));
+}
+
+gpointer
+wplua_checkboxed (lua_State *L, int idx, GType type)
+{
+  if (G_UNLIKELY (!_wplua_isgvalue_userdata (L, idx, type))) {
+    wp_critical ("expected userdata storing GValue<%s>", g_type_name (type));
+    luaL_argerror (L, idx, "expected userdata storing GValue<GBoxed>");
+  }
+  return g_value_get_boxed ((GValue *) lua_touserdata (L, idx));
+}
+
+gboolean
+wplua_isboxed (lua_State *L, int idx, GType type)
+{
+  if (!g_type_is_a (type, G_TYPE_BOXED)) return FALSE;
+  return _wplua_isgvalue_userdata (L, idx, type);
+}