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emacs/mps/code/ring.h
Peter Jackson 1d00afac81 Publish licence updates in code directory.
Publish minor changes to readme and configure files in main directory.
Main directory and code directory licence texts are now fully updated.

Copied from Perforce
 Change: 196994
2020-06-11 17:05:40 +01:00

144 lines
4.2 KiB
C

/* ring.h: RING INTERFACE
*
* $Id$
* Copyright (c) 2001-2020 Ravenbrook Limited. See end of file for license.
* Portions copyright (C) 2001 Global Graphics Software.
*/
#ifndef ring_h
#define ring_h
#include "check.h"
#include "mpmtypes.h"
/* RingStruct -- double-ended queue structure
*
* .ring: The ring structure is used as a field in other structures
* in order to link them together into "rings". See <code/ring.c>.
*/
typedef struct RingStruct *Ring;
typedef struct RingStruct { /* double-ended queue structure */
Ring next, prev; /* links to next and prev element */
} RingStruct;
#define RingNONE ((Ring)0)
extern Bool RingCheck(Ring ring);
extern Bool RingCheckSingle(Ring ring);
extern Bool RingIsSingle(Ring ring);
extern Count RingLength(Ring ring);
/* .ring.init: <design/ring#.init> */
extern void (RingInit)(Ring ring);
#define RingInit(ring) \
BEGIN \
Ring _ring = (ring); \
AVER(_ring != NULL); \
_ring->next = _ring; \
_ring->prev = _ring; \
AVER(RingCheck(_ring)); \
END
/* .ring.finish: <design/ring#.finish> */
extern void (RingFinish)(Ring ring);
#define RingFinish(ring) \
BEGIN \
Ring _ring = (ring); \
AVER(RingCheckSingle(_ring)); \
_ring->next = RingNONE; \
_ring->prev = RingNONE; \
END
/* .ring.append: <design/ring#.append> */
extern void (RingAppend)(Ring ring, Ring new);
#define RingAppend(ring, new) \
BEGIN \
Ring _ring = (ring), _new = (new); \
AVER(RingCheck(_ring)); \
AVER(RingCheckSingle(_new)); \
_new->prev = _ring->prev; \
_new->next = _ring; \
_ring->prev->next = _new; \
_ring->prev = _new; \
END
/* .ring.insert: */
extern void (RingInsert)(Ring ring, Ring new);
#define RingInsert(ring, new) \
BEGIN \
Ring _ring = (ring), _new = (new); \
AVER(RingCheck(_ring)); \
AVER(RingCheckSingle(_new)); \
_new->prev = _ring; \
_new->next = _ring->next; \
_ring->next->prev = _new; \
_ring->next = _new; \
END
/* .ring.remove: <design/ring#.remove> */
extern void (RingRemove)(Ring old);
#define RingRemove(old) \
BEGIN \
Ring _old = (old); \
AVER(RingCheck(_old)); \
AVER(!RingIsSingle(_old)); \
_old->next->prev = _old->prev; \
_old->prev->next = _old->next; \
_old->next = _old; \
_old->prev = _old; \
END
/* .ring.next: <design/ring#.next> */
extern Ring (RingNext)(Ring ring);
#define RingNext(ring) ((ring)->next)
/* .ring.prev: <design/ring#.prev> */
extern Ring (RingPrev)(Ring ring);
#define RingPrev(ring) ((ring)->prev)
/* .ring.elt: <design/ring#.elt> */
#define RING_ELT(type, field, node) \
PARENT(type ## Struct, field, node)
/* .ring.for: <design/ring#.for> */
#define RING_FOR(node, ring, next) \
for(node = RingNext(ring), next = RingNext(node); \
node != (ring); \
node = (next), next = RingNext(node))
#endif /* ring_h */
/* C. COPYRIGHT AND LICENSE
*
* Copyright (C) 2001-2020 Ravenbrook Limited <http://www.ravenbrook.com/>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/