ceph/src/rocksdb/include/rocksdb/utilities/lua/rocks_lua_custom_library.h

   1 //  Copyright (c) 2016, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5
   6 #pragma once
   7 #ifdef LUA
   8
   9 // lua headers
  10 extern "C" {
  11 #include <lauxlib.h>
  12 #include <lua.h>
  13 #include <lualib.h>
  14 }
  15
  16 namespace ROCKSDB_NAMESPACE {
  17 namespace lua {
  18 // A class that used to define custom C Library that is callable
  19 // from Lua script
  20 class RocksLuaCustomLibrary {
  21  public:
  22   virtual ~RocksLuaCustomLibrary() {}
  23   // The name of the C library.  This name will also be used as the table
  24   // (namespace) in Lua that contains the C library.
  25   virtual const char* Name() const = 0;
  26
  27   // Returns a "static const struct luaL_Reg[]", which includes a list of
  28   // C functions.  Note that the last entry of this static array must be
  29   // {nullptr, nullptr} as required by Lua.
  30   //
  31   // More details about how to implement Lua C libraries can be found
  32   // in the official Lua document http://www.lua.org/pil/26.2.html
  33   virtual const struct luaL_Reg* Lib() const = 0;
  34
  35   // A function that will be called right after the library has been created
  36   // and pushed on the top of the lua_State.  This custom setup function
  37   // allows developers to put additional table or constant values inside
  38   // the same table / namespace.
  39   virtual void CustomSetup(lua_State* /*L*/) const {}
  40 };
  41 }  // namespace lua
  42 }  // namespace ROCKSDB_NAMESPACE
  43 #endif  // LUA