Click here to Skip to main content
Click here to Skip to main content
Articles » Database » Database » General » Downloads
 
Add your own
alternative version
Go to top

DarkSide SQL Mini Version 1, The embedded database

, 23 Mar 2006
An embedded database library in C++.
/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2002
 *	Sleepycat Software.  All rights reserved.
 *
 * $Id: shqueue.h,v 11.9 2002/01/11 15:52:30 bostic Exp $
 */

#ifndef	_SYS_SHQUEUE_H_
#define	_SYS_SHQUEUE_H_

/*
 * This file defines three types of data structures: lists, tail queues, and
 * circular queues, similarly to the include file <sys/queue.h>.
 *
 * The difference is that this set of macros can be used for structures that
 * reside in shared memory that may be mapped at different addresses in each
 * process.  In most cases, the macros for shared structures exactly mirror
 * the normal macros, although the macro calls require an additional type
 * parameter, only used by the HEAD and ENTRY macros of the standard macros.
 *
 * For details on the use of these macros, see the queue(3) manual page.
 */

#if defined(__cplusplus)
extern "C" {
#endif

/*
 * Shared list definitions.
 */
#define	SH_LIST_HEAD(name)						\
struct name {								\
	ssize_t slh_first;	/* first element */			\
}

#define	SH_LIST_ENTRY							\
struct {								\
	ssize_t sle_next;	/* relative offset next element */	\
	ssize_t sle_prev;	/* relative offset of prev element */	\
}

/*
 * Shared list functions.  Since we use relative offsets for pointers,
 * 0 is a valid offset.  Therefore, we use -1 to indicate end of list.
 * The macros ending in "P" return pointers without checking for end
 * of list, the others check for end of list and evaluate to either a
 * pointer or NULL.
 */

#define	SH_LIST_FIRSTP(head, type)					\
	((struct type *)(((u_int8_t *)(head)) + (head)->slh_first))

#define	SH_LIST_FIRST(head, type)					\
	((head)->slh_first == -1 ? NULL :				\
	((struct type *)(((u_int8_t *)(head)) + (head)->slh_first)))

#define	SH_LIST_NEXTP(elm, field, type)					\
	((struct type *)(((u_int8_t *)(elm)) + (elm)->field.sle_next))

#define	SH_LIST_NEXT(elm, field, type)					\
	((elm)->field.sle_next == -1 ? NULL :				\
	((struct type *)(((u_int8_t *)(elm)) + (elm)->field.sle_next)))

#define	SH_LIST_PREV(elm, field)					\
	((ssize_t *)(((u_int8_t *)(elm)) + (elm)->field.sle_prev))

#define	SH_PTR_TO_OFF(src, dest)					\
	((ssize_t)(((u_int8_t *)(dest)) - ((u_int8_t *)(src))))

/*
 * Take the element's next pointer and calculate what the corresponding
 * Prev pointer should be -- basically it is the negation plus the offset
 * of the next field in the structure.
 */
#define	SH_LIST_NEXT_TO_PREV(elm, field)				\
	(-(elm)->field.sle_next + SH_PTR_TO_OFF(elm, &(elm)->field.sle_next))

#define	SH_LIST_INIT(head) (head)->slh_first = -1

#define	SH_LIST_INSERT_AFTER(listelm, elm, field, type) do {		\
	if ((listelm)->field.sle_next != -1) {				\
		(elm)->field.sle_next = SH_PTR_TO_OFF(elm,		\
		    SH_LIST_NEXTP(listelm, field, type));		\
		SH_LIST_NEXTP(listelm, field, type)->field.sle_prev =	\
			SH_LIST_NEXT_TO_PREV(elm, field);		\
	} else								\
		(elm)->field.sle_next = -1;				\
	(listelm)->field.sle_next = SH_PTR_TO_OFF(listelm, elm);	\
	(elm)->field.sle_prev = SH_LIST_NEXT_TO_PREV(listelm, field);	\
} while (0)

#define	SH_LIST_INSERT_HEAD(head, elm, field, type) do {		\
	if ((head)->slh_first != -1) {					\
		(elm)->field.sle_next =				\
		    (head)->slh_first - SH_PTR_TO_OFF(head, elm);	\
		SH_LIST_FIRSTP(head, type)->field.sle_prev =		\
			SH_LIST_NEXT_TO_PREV(elm, field);		\
	} else								\
		(elm)->field.sle_next = -1;				\
	(head)->slh_first = SH_PTR_TO_OFF(head, elm);			\
	(elm)->field.sle_prev = SH_PTR_TO_OFF(elm, &(head)->slh_first);	\
} while (0)

#define	SH_LIST_REMOVE(elm, field, type) do {				\
	if ((elm)->field.sle_next != -1) {				\
		SH_LIST_NEXTP(elm, field, type)->field.sle_prev =	\
			(elm)->field.sle_prev - (elm)->field.sle_next;	\
		*SH_LIST_PREV(elm, field) += (elm)->field.sle_next;	\
	} else								\
		*SH_LIST_PREV(elm, field) = -1;				\
} while (0)

/*
 * Shared tail queue definitions.
 */
#define	SH_TAILQ_HEAD(name)						\
struct name {								\
	ssize_t stqh_first;	/* relative offset of first element */	\
	ssize_t stqh_last;	/* relative offset of last's next */	\
}

#define	SH_TAILQ_ENTRY							\
struct {								\
	ssize_t stqe_next;	/* relative offset of next element */	\
	ssize_t stqe_prev;	/* relative offset of prev's next */	\
}

/*
 * Shared tail queue functions.
 */
#define	SH_TAILQ_FIRSTP(head, type)					\
	((struct type *)((u_int8_t *)(head) + (head)->stqh_first))

#define	SH_TAILQ_FIRST(head, type)					\
	((head)->stqh_first == -1 ? NULL : SH_TAILQ_FIRSTP(head, type))

#define	SH_TAILQ_NEXTP(elm, field, type)				\
	((struct type *)((u_int8_t *)(elm) + (elm)->field.stqe_next))

#define	SH_TAILQ_NEXT(elm, field, type)					\
	((elm)->field.stqe_next == -1 ? NULL : SH_TAILQ_NEXTP(elm, field, type))

#define	SH_TAILQ_PREVP(elm, field)					\
	((ssize_t *)((u_int8_t *)(elm) + (elm)->field.stqe_prev))

#define	SH_TAILQ_LAST(head)						\
	((ssize_t *)(((u_int8_t *)(head)) + (head)->stqh_last))

#define	SH_TAILQ_NEXT_TO_PREV(elm, field)				\
	(-(elm)->field.stqe_next + SH_PTR_TO_OFF(elm, &(elm)->field.stqe_next))

#define	SH_TAILQ_INIT(head) {						\
	(head)->stqh_first = -1;					\
	(head)->stqh_last = SH_PTR_TO_OFF(head, &(head)->stqh_first);	\
}

#define	SH_TAILQ_INSERT_HEAD(head, elm, field, type) do {		\
	if ((head)->stqh_first != -1) {					\
		(elm)->field.stqe_next =				\
		    (head)->stqh_first - SH_PTR_TO_OFF(head, elm);	\
		SH_TAILQ_FIRSTP(head, type)->field.stqe_prev =		\
			SH_TAILQ_NEXT_TO_PREV(elm, field);		\
	} else {							\
		(elm)->field.stqe_next = -1;				\
		(head)->stqh_last =					\
		    SH_PTR_TO_OFF(head, &(elm)->field.stqe_next);	\
	}								\
	(head)->stqh_first = SH_PTR_TO_OFF(head, elm);			\
	(elm)->field.stqe_prev =					\
	    SH_PTR_TO_OFF(elm, &(head)->stqh_first);			\
} while (0)

#define	SH_TAILQ_INSERT_TAIL(head, elm, field) do {			\
	(elm)->field.stqe_next = -1;					\
	(elm)->field.stqe_prev =					\
	    -SH_PTR_TO_OFF(head, elm) + (head)->stqh_last;		\
	if ((head)->stqh_last ==					\
	    SH_PTR_TO_OFF((head), &(head)->stqh_first))			\
		(head)->stqh_first = SH_PTR_TO_OFF(head, elm);		\
	else								\
		*SH_TAILQ_LAST(head) = -(head)->stqh_last +		\
		    SH_PTR_TO_OFF((elm), &(elm)->field.stqe_next) +	\
		    SH_PTR_TO_OFF(head, elm);				\
	(head)->stqh_last =						\
	    SH_PTR_TO_OFF(head, &((elm)->field.stqe_next));		\
} while (0)

#define	SH_TAILQ_INSERT_AFTER(head, listelm, elm, field, type) do {	\
	if ((listelm)->field.stqe_next != -1) {				\
		(elm)->field.stqe_next = (listelm)->field.stqe_next -	\
		    SH_PTR_TO_OFF(listelm, elm);			\
		SH_TAILQ_NEXTP(listelm, field, type)->field.stqe_prev =	\
		    SH_TAILQ_NEXT_TO_PREV(elm, field);			\
	} else {							\
		(elm)->field.stqe_next = -1;				\
		(head)->stqh_last =					\
		    SH_PTR_TO_OFF(head, &elm->field.stqe_next);		\
	}								\
	(listelm)->field.stqe_next = SH_PTR_TO_OFF(listelm, elm);	\
	(elm)->field.stqe_prev = SH_TAILQ_NEXT_TO_PREV(listelm, field);	\
} while (0)

#define	SH_TAILQ_REMOVE(head, elm, field, type) do {			\
	if ((elm)->field.stqe_next != -1) {				\
		SH_TAILQ_NEXTP(elm, field, type)->field.stqe_prev =	\
		    (elm)->field.stqe_prev +				\
		    SH_PTR_TO_OFF(SH_TAILQ_NEXTP(elm,			\
		    field, type), elm);					\
		*SH_TAILQ_PREVP(elm, field) += elm->field.stqe_next;	\
	} else {							\
		(head)->stqh_last = (elm)->field.stqe_prev +		\
			SH_PTR_TO_OFF(head, elm);			\
		*SH_TAILQ_PREVP(elm, field) = -1;			\
	}								\
} while (0)

/*
 * Shared circular queue definitions.
 */
#define	SH_CIRCLEQ_HEAD(name)						\
struct name {								\
	ssize_t scqh_first;		/* first element */		\
	ssize_t scqh_last;		/* last element */		\
}

#define	SH_CIRCLEQ_ENTRY						\
struct {								\
	ssize_t scqe_next;		/* next element */		\
	ssize_t scqe_prev;		/* previous element */		\
}

/*
 * Shared circular queue functions.
 */
#define	SH_CIRCLEQ_FIRSTP(head, type)					\
	((struct type *)(((u_int8_t *)(head)) + (head)->scqh_first))

#define	SH_CIRCLEQ_FIRST(head, type)					\
	((head)->scqh_first == -1 ?					\
	(void *)head : SH_CIRCLEQ_FIRSTP(head, type))

#define	SH_CIRCLEQ_LASTP(head, type)					\
	((struct type *)(((u_int8_t *)(head)) + (head)->scqh_last))

#define	SH_CIRCLEQ_LAST(head, type)					\
	((head)->scqh_last == -1 ? (void *)head : SH_CIRCLEQ_LASTP(head, type))

#define	SH_CIRCLEQ_NEXTP(elm, field, type)				\
	((struct type *)(((u_int8_t *)(elm)) + (elm)->field.scqe_next))

#define	SH_CIRCLEQ_NEXT(head, elm, field, type)				\
	((elm)->field.scqe_next == SH_PTR_TO_OFF(elm, head) ?		\
	    (void *)head : SH_CIRCLEQ_NEXTP(elm, field, type))

#define	SH_CIRCLEQ_PREVP(elm, field, type)				\
	((struct type *)(((u_int8_t *)(elm)) + (elm)->field.scqe_prev))

#define	SH_CIRCLEQ_PREV(head, elm, field, type)				\
	((elm)->field.scqe_prev == SH_PTR_TO_OFF(elm, head) ?		\
	    (void *)head : SH_CIRCLEQ_PREVP(elm, field, type))

#define	SH_CIRCLEQ_INIT(head) {						\
	(head)->scqh_first = 0;						\
	(head)->scqh_last = 0;						\
}

#define	SH_CIRCLEQ_INSERT_AFTER(head, listelm, elm, field, type) do {	\
	(elm)->field.scqe_prev = SH_PTR_TO_OFF(elm, listelm);		\
	(elm)->field.scqe_next = (listelm)->field.scqe_next +		\
	    (elm)->field.scqe_prev;					\
	if (SH_CIRCLEQ_NEXTP(listelm, field, type) == (void *)head)	\
		(head)->scqh_last = SH_PTR_TO_OFF(head, elm);		\
	else								\
		SH_CIRCLEQ_NEXTP(listelm,				\
		    field, type)->field.scqe_prev =			\
		    SH_PTR_TO_OFF(SH_CIRCLEQ_NEXTP(listelm,		\
		    field, type), elm);					\
	(listelm)->field.scqe_next = -(elm)->field.scqe_prev;		\
} while (0)

#define	SH_CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field, type) do {	\
	(elm)->field.scqe_next = SH_PTR_TO_OFF(elm, listelm);		\
	(elm)->field.scqe_prev = (elm)->field.scqe_next -		\
		SH_CIRCLEQ_PREVP(listelm, field, type)->field.scqe_next;\
	if (SH_CIRCLEQ_PREVP(listelm, field, type) == (void *)(head))	\
		(head)->scqh_first = SH_PTR_TO_OFF(head, elm);		\
	else								\
		SH_CIRCLEQ_PREVP(listelm,				\
		    field, type)->field.scqe_next =			\
		    SH_PTR_TO_OFF(SH_CIRCLEQ_PREVP(listelm,		\
		    field, type), elm);					\
	(listelm)->field.scqe_prev = -(elm)->field.scqe_next;		\
} while (0)

#define	SH_CIRCLEQ_INSERT_HEAD(head, elm, field, type) do {		\
	(elm)->field.scqe_prev = SH_PTR_TO_OFF(elm, head);		\
	(elm)->field.scqe_next = (head)->scqh_first +			\
		(elm)->field.scqe_prev;					\
	if ((head)->scqh_last == 0)					\
		(head)->scqh_last = -(elm)->field.scqe_prev;		\
	else								\
		SH_CIRCLEQ_FIRSTP(head, type)->field.scqe_prev =	\
		    SH_PTR_TO_OFF(SH_CIRCLEQ_FIRSTP(head, type), elm);	\
	(head)->scqh_first = -(elm)->field.scqe_prev;			\
} while (0)

#define	SH_CIRCLEQ_INSERT_TAIL(head, elm, field, type) do {		\
	(elm)->field.scqe_next = SH_PTR_TO_OFF(elm, head);		\
	(elm)->field.scqe_prev = (head)->scqh_last +			\
	    (elm)->field.scqe_next;					\
	if ((head)->scqh_first == 0)					\
		(head)->scqh_first = -(elm)->field.scqe_next;		\
	else								\
		SH_CIRCLEQ_LASTP(head, type)->field.scqe_next =	\
		    SH_PTR_TO_OFF(SH_CIRCLEQ_LASTP(head, type), elm);	\
	(head)->scqh_last = -(elm)->field.scqe_next;			\
} while (0)

#define	SH_CIRCLEQ_REMOVE(head, elm, field, type) do {			\
	if (SH_CIRCLEQ_NEXTP(elm, field, type) == (void *)(head))	\
		(head)->scqh_last += (elm)->field.scqe_prev;		\
	else								\
		SH_CIRCLEQ_NEXTP(elm, field, type)->field.scqe_prev +=	\
		    (elm)->field.scqe_prev;				\
	if (SH_CIRCLEQ_PREVP(elm, field, type) == (void *)(head))	\
		(head)->scqh_first += (elm)->field.scqe_next;		\
	else								\
		SH_CIRCLEQ_PREVP(elm, field, type)->field.scqe_next +=	\
		    (elm)->field.scqe_next;				\
} while (0)

#if defined(__cplusplus)
}
#endif
#endif	/* !_SYS_SHQUEUE_H_ */

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The BSD License

Share

About the Author

No Biography provided

| Advertise | Privacy | Mobile
Web03 | 2.8.140916.1 | Last Updated 23 Mar 2006
Article Copyright 2003 by AnOldGreenHorn
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid