/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */


#ifndef ISC_REGION_H
#define ISC_REGION_H 1

/*! \file isc/region.h */

#include <isc/types.h>
#include <isc/lang.h>

struct isc_region {
	unsigned char *	base;
	unsigned int	length;
};

struct isc_textregion {
	char *		base;
	unsigned int	length;
};

/* XXXDCL questionable ... bears discussion.  we have been putting off
 * discussing the region api.
 */
struct isc_constregion {
	const void *	base;
	unsigned int	length;
};

struct isc_consttextregion {
	const char *	base;
	unsigned int	length;
};

/*@{*/
/*!
 * The region structure is not opaque, and is usually directly manipulated.
 * Some macros are defined below for convenience.
 */

#define isc_region_consume(r,l) \
	do { \
		isc_region_t *_r = (r); \
		unsigned int _l = (l); \
		INSIST(_r->length >= _l); \
		_r->base += _l; \
		_r->length -= _l; \
	} while (0)

#define isc_textregion_consume(r,l) \
	do { \
		isc_textregion_t *_r = (r); \
		unsigned int _l = (l); \
		INSIST(_r->length >= _l); \
		_r->base += _l; \
		_r->length -= _l; \
	} while (0)

#define isc_constregion_consume(r,l) \
	do { \
		isc_constregion_t *_r = (r); \
		unsigned int _l = (l); \
		INSIST(_r->length >= _l); \
		_r->base += _l; \
		_r->length -= _l; \
	} while (0)
/*@}*/

ISC_LANG_BEGINDECLS

int
isc_region_compare(isc_region_t *r1, isc_region_t *r2);
/*%<
 * Compares the contents of two regions
 *
 * Requires:
 *\li	'r1' is a valid region
 *\li	'r2' is a valid region
 *
 * Returns:
 *\li	 < 0 if r1 is lexicographically less than r2
 *\li	 = 0 if r1 is lexicographically identical to r2
 *\li	 > 0 if r1 is lexicographically greater than r2
 */

ISC_LANG_ENDDECLS

#endif /* ISC_REGION_H */
