1/*-
2 * See the file LICENSE for redistribution information.
3 *
4 * Copyright (c) 1997,2008 Oracle.  All rights reserved.
5 *
6 * $Id: cxx_int.h,v 12.8 2008/01/08 20:58:17 bostic Exp $
7 */
8
9#ifndef _DB_CXX_INT_H_
10#define	_DB_CXX_INT_H_
11
12// private data structures known to the implementation only
13
14//
15// Using FooImp classes will allow the implementation to change in the
16// future without any modification to user code or even to header files
17// that the user includes. FooImp * is just like void * except that it
18// provides a little extra protection, since you cannot randomly assign
19// any old pointer to a FooImp* as you can with void *.  Currently, a
20// pointer to such an opaque class is always just a pointer to the
21// appropriate underlying implementation struct.  These are converted
22// back and forth using the various overloaded wrap()/unwrap() methods.
23// This is essentially a use of the "Bridge" Design Pattern.
24//
25// WRAPPED_CLASS implements the appropriate wrap() and unwrap() methods
26// for a wrapper class that has an underlying pointer representation.
27//
28#define	WRAPPED_CLASS(_WRAPPER_CLASS, _IMP_CLASS, _WRAPPED_TYPE)           \
29	class _IMP_CLASS {};                                               \
30									   \
31	inline _WRAPPED_TYPE *unwrap(_WRAPPER_CLASS *val)                  \
32	{                                                                  \
33		if (!val) return (0);                                      \
34		return (val->get_##_WRAPPED_TYPE());                       \
35	}                                                                  \
36									   \
37	inline const _WRAPPED_TYPE *unwrapConst(const _WRAPPER_CLASS *val) \
38	{                                                                  \
39		if (!val) return (0);                                      \
40		return (val->get_const_##_WRAPPED_TYPE());                 \
41	}
42
43WRAPPED_CLASS(Db, DbImp, DB)
44WRAPPED_CLASS(DbEnv, DbEnvImp, DB_ENV)
45WRAPPED_CLASS(DbMpoolFile, DbMpoolFileImp, DB_MPOOLFILE)
46WRAPPED_CLASS(DbSequence, DbSequenceImp, DB_SEQUENCE)
47WRAPPED_CLASS(DbTxn, DbTxnImp, DB_TXN)
48
49// A tristate integer value used by the DB_ERROR macro below.
50// We chose not to make this an enumerated type so it can
51// be kept private, even though methods that return the
52// tristate int can be declared in db_cxx.h .
53//
54#define	ON_ERROR_THROW     1
55#define	ON_ERROR_RETURN    0
56#define	ON_ERROR_UNKNOWN   (-1)
57
58// Macros that handle detected errors, in case we want to
59// change the default behavior.  The 'policy' is one of
60// the tristate values given above.  If UNKNOWN is specified,
61// the behavior is taken from the last initialized DbEnv.
62//
63#define	DB_ERROR(dbenv, caller, ecode, policy) \
64    DbEnv::runtime_error(dbenv, caller, ecode, policy)
65
66#define	DB_ERROR_DBT(dbenv, caller, dbt, policy) \
67    DbEnv::runtime_error_dbt(dbenv, caller, dbt, policy)
68
69#define	DB_OVERFLOWED_DBT(dbt) \
70	(F_ISSET(dbt, DB_DBT_USERMEM) && dbt->size > dbt->ulen)
71
72/* values for Db::flags_ */
73#define	DB_CXX_PRIVATE_ENV      0x00000001
74
75#endif /* !_DB_CXX_INT_H_ */
76