35 lines
959 B
C
35 lines
959 B
C
/*
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* Copyright (C) 1999-2001, 2004-2007, 2016 Internet Systems Consortium, Inc. ("ISC")
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*/
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/* $Id: magic.h,v 1.18 2007/06/19 23:47:18 tbox Exp $ */
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#ifndef ISC_MAGIC_H
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#define ISC_MAGIC_H 1
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#include <isc/util.h>
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/*! \file isc/magic.h */
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typedef struct {
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unsigned int magic;
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} isc__magic_t;
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/*%
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* To use this macro the magic number MUST be the first thing in the
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* structure, and MUST be of type "unsigned int".
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* The intent of this is to allow magic numbers to be checked even though
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* the object is otherwise opaque.
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*/
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#define ISC_MAGIC_VALID(a,b) (ISC_LIKELY((a) != NULL) && \
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ISC_LIKELY(((const isc__magic_t *)(a))->magic == (b)))
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#define ISC_MAGIC(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d))
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#endif /* ISC_MAGIC_H */
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