/* jcircle.h : Jon's Circular List */
/*
 * PUBLIC DOMAIN - NO COPYRIGHT CLAIMED - Jonathan Mayo - January 2005
 *
 * $Id: jcircle.h 252 2005-06-17 06:07:19Z orange $
 * $Date: 2005-06-16 23:07:19 -0700 (Thu, 16 Jun 2005) $
 */
#ifndef JCIRCLE_H
#define JCIRCLE_H
/******************************************************************************/
/* Circular List */
/******************************************************************************/
/* A set of circular linked list macros for general use
 * 
 * designed to use with the following style of structure:
 * 
 * struct entry {
 *     struct entry *next;
 *     struct entry **prev;
 *     unsigned long long value;
 *     ...
 * };
 *
 * struct entry *pq_head;
 * 
 */

/* remove an entry from a priority queue.
 * entry is a pointer to the entry to add
 * next is a member name. pointer to next entry
 * prev is a member name. pointer to last next pointer */
#define JCIRCLE_DELETE(entry, next, prev) do { \
            *(entry)->prev=(entry)->next; \
            if((entry)->next) (entry)->next->prev=(entry)->prev; \
            (entry)->next=0; \
            (entry)->prev=&((entry)->next); \
        } while(0)

/* insert/add an entry to a priority queue.
 * head is the start of the queue
 * entry is a pointer to the entry to add
 * next is a member name. pointer to next entry
 * prev is a member name. pointer to last next pointer
 * value is a member name. numeric value of some kind (int,float,etc) */
#define JCIRCLE_ADD(type, head, entry, next, prev, value) do { \
        type **curr; \
        JCIRCLE_DELETE(entry,next,prev); \
        for(curr=&(head) ; *curr ; curr=&(*curr)->next) { \
            if( (entry)->value < (*curr)->value ) { \
                (*curr)->prev=&(entry)->next; \
                break; \
            } \
        } \
        (entry)->next=*curr; \
        (entry)->prev=curr; \
        *curr=(entry); \
        } while(0)

/* list all entries in a priority queue
 * head is the start of the queue
 * next is a member name. pointer to next entry
 * prev is a member name. pointer to last next pointer
 * value is a member name. (unsigned long long) */
#define JCIRCLE_LIST(type, head, next, prev, valuestr, value) do { \
        type **curr; \
        for(curr=&(head) ; *curr ; curr=&(*curr)->next) { \
            printf("%p name=%s value=" valuestr " next=%p prev=%p (%p)\n",(void*)(*curr), (*curr)->name, (*curr)->value, (void*)((*curr)->next), (void*)((*curr)->prev), (void*)(*(*curr)->prev)); \
        } \
        } while(0)

/******************************************************************************/

#endif /* JCIRCLE_H */