cxx_int.h
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上传日期:2022-05-23
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- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1997-2002
- * Sleepycat Software. All rights reserved.
- *
- * $Id: cxx_int.h,v 11.20 2002/01/11 15:52:23 bostic Exp $
- */
- #ifndef _CXX_INT_H_
- #define _CXX_INT_H_
- // private data structures known to the implementation only
- //
- // Using FooImp classes will allow the implementation to change in the
- // future without any modification to user code or even to header files
- // that the user includes. FooImp * is just like void * except that it
- // provides a little extra protection, since you cannot randomly assign
- // any old pointer to a FooImp* as you can with void *. Currently, a
- // pointer to such an opaque class is always just a pointer to the
- // appropriate underlying implementation struct. These are converted
- // back and forth using the various overloaded wrap()/unwrap() methods.
- // This is essentially a use of the "Bridge" Design Pattern.
- //
- // WRAPPED_CLASS implements the appropriate wrap() and unwrap() methods
- // for a wrapper class that has an underlying pointer representation.
- //
- #define WRAPPED_CLASS(_WRAPPER_CLASS, _IMP_CLASS, _WRAPPED_TYPE)
-
- class _IMP_CLASS {};
-
- inline _WRAPPED_TYPE unwrap(_WRAPPER_CLASS *val)
- {
- if (!val) return (0);
- return ((_WRAPPED_TYPE)((void *)(val->imp())));
- }
-
- inline const _WRAPPED_TYPE unwrapConst(const _WRAPPER_CLASS *val)
- {
- if (!val) return (0);
- return ((const _WRAPPED_TYPE)((void *)(val->constimp())));
- }
-
- inline _IMP_CLASS *wrap(_WRAPPED_TYPE val)
- {
- return ((_IMP_CLASS*)((void *)val));
- }
- WRAPPED_CLASS(DbMpoolFile, DbMpoolFileImp, DB_MPOOLFILE*)
- WRAPPED_CLASS(Db, DbImp, DB*)
- WRAPPED_CLASS(DbEnv, DbEnvImp, DB_ENV*)
- WRAPPED_CLASS(DbTxn, DbTxnImp, DB_TXN*)
- // A tristate integer value used by the DB_ERROR macro below.
- // We chose not to make this an enumerated type so it can
- // be kept private, even though methods that return the
- // tristate int can be declared in db_cxx.h .
- //
- #define ON_ERROR_THROW 1
- #define ON_ERROR_RETURN 0
- #define ON_ERROR_UNKNOWN (-1)
- // Macros that handle detected errors, in case we want to
- // change the default behavior. The 'policy' is one of
- // the tristate values given above. If UNKNOWN is specified,
- // the behavior is taken from the last initialized DbEnv.
- //
- #define DB_ERROR(caller, ecode, policy)
- DbEnv::runtime_error(caller, ecode, policy)
- #define DB_ERROR_DBT(caller, dbt, policy)
- DbEnv::runtime_error_dbt(caller, dbt, policy)
- #define DB_OVERFLOWED_DBT(dbt)
- (F_ISSET(dbt, DB_DBT_USERMEM) && dbt->size > dbt->ulen)
- /* values for Db::flags_ */
- #define DB_CXX_PRIVATE_ENV 0x00000001
- #endif /* !_CXX_INT_H_ */