Function luaPushError

src/tendisplus/script/lua_state.cpp:151–172

This function is used in order to push an error on the Lua stack in the * format used by redis.pcall to return errors, which is a lua table * with a single "err" field set to the error string. Note that this * table is never a valid reply by proper commands, since the returned * tables are otherwise always indexed by integers, never by strings. */

 * table is never a valid reply by proper commands, since the returned
 * tables are otherwise always indexed by integers, never by strings. */
void luaPushError(lua_State* lua, const char* error) {
  lua_Debug dbg;

  // TODO(takenliu): lua debug
  /* If debugging is active and in step mode, log errors resulting from
   * Redis commands. */

  lua_newtable(lua);
  lua_pushstring(lua, "err");

  /* Attempt to figure out where this function was called, if possible */
  if (lua_getstack(lua, 1, &dbg) && lua_getinfo(lua, "nSl", &dbg)) {
    std::string msg = std::string(dbg.source) + ": " +
      std::to_string(dbg.currentline) + ": " + std::string(error);
    LOG(INFO) << "luaPushError:" << msg;
    lua_pushstring(lua, msg.c_str());
  } else {
    LOG(INFO) << "luaPushError:" << error;
    lua_pushstring(lua, error);
  }
  lua_settable(lua, -3);
}

/* In case the error set into the Lua stack by luaPushError() was generated
 * by the non-error-trapping version of redis.pcall(), which is redis.call(),