src/hd/sm_list.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 *  sm_list.c
 *   Routines for handling linked generic linked lists, stack, and
 *   circular lists. Data element is an int (can be cast to hold
 *   pointer to more general data element)
 */

#include "standard.h"
#include "sm_list.h" 

/* List of available edges */
static LIST *free_lists = NULL;
#ifdef DEBUG
extern int Malloc_cnt;   
#endif
LIST
/* NOTE: Memory is not initialized */
*new_list()
{
    LIST *l;

    /* check free list for available edges */
    if( free_lists )
    {
        l = free_lists;
        free_lists = LIST_NEXT(free_lists);
    }
    /* if no free edges- allocate the memory */
    else
    {
      if( !(l = (LIST *)malloc(sizeof(LIST))))
          error(SYSTEM,"new_list():Unable to allocate memory");
    }
    return(l);
}


/* attaches list a at the end of list b */
LIST
*append_list(a,b)
LIST *a,*b;
{
    LIST * l;

    if(!b)
       return(a);
    
    l = b;
    while(LIST_NEXT(l) && LIST_NEXT(l) != b)
       l = LIST_NEXT(l);

    SET_LIST_NEXT(l,a);
    
    return(b);
}

/* attaches list a at the end of list b */
LIST
*add_data(l,d,end)
LIST *l;
int d;
LIST **end;

{
    LIST *list,*lptr;

    list = new_list();
    SET_LIST_DATA(list,d);
    SET_LIST_NEXT(list,NULL);
    if(!l)
    {
      if(end)
        *end = list;
      return(list);
    }
    if(end)
      lptr = *end;
    else
    {
      lptr = l;
      while(LIST_NEXT(lptr))
        lptr = LIST_NEXT(lptr);
    }
    LIST_NEXT(lptr) = list;
    if(end)
      *end = list;

    return(l);
}

/* Adds data to the end of a circular list. If set, "end"
 * is a pointer to the last element in the list
 */
LIST
*add_data_to_circular_list(l,end,d)
LIST *l,**end;
int d;
{
    LIST *list;
    
    list = new_list();
    SET_LIST_DATA(list,d);

    if(!l)
       l = list;
    else
    {   
        if(*end)
          SET_LIST_NEXT(*end,list);
        else
           l = append_list(list,l);
    }

    *end = list;
    SET_LIST_NEXT(list,l);
    return(l);
}


/* frees the list */
LIST
*free_list(l)
LIST * l;
{
    if(!l)
       return(NULL);

    free_lists = append_list(free_lists,l);

    return(NULL);
}

/* Pushes data element d at the top of the list- returns pointer
   to new top of list
 */
LIST
*push_data(l,d)
LIST *l;
int d;
{
  LIST *list;

  list = new_list();
  SET_LIST_DATA(list,d);
  SET_LIST_NEXT(list,l);
  return(list);
}
/* Returns data element d at the top of the list- returns pointer
   to new top of list
 */
int
pop_list(l)
LIST **l;
{
    LIST *p;
    int d;
    
    if(!l)
       return(NULL);
    if(!(p = *l))
       return(NULL);

    d = LIST_DATA(p);
    
    *l = LIST_NEXT(p);

    LIST_NEXT(p) =NULL;
    free_list(p);
    
    return(d);
}    

/* Search through list for data element "d", and remove from
 *  list: Returns TRUE if found, false otherwise
 */
int
remove_from_list(d,list)
int d;
LIST **list;
{
    LIST *l,*prev;
    
    l = *list;
    prev = NULL;
    
    while(l)
    {
        if(LIST_DATA(l) == d)
        {
           if(l == *list)
              *list = LIST_NEXT(*list);
           else
              SET_LIST_NEXT(prev,LIST_NEXT(l));
        
           SET_LIST_NEXT(l,NULL);
           free_list(l);
           return(TRUE);
       }
        prev = l;
        l = LIST_NEXT(l);
    }
    return(FALSE);
}


Revision:	3.8
Committed:	Sat Feb 22 02:07:25 2003 UTC (21 years, 2 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R6P1, rad3R5, rad3R6
Changes since 3.7:	+1 -4 lines
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	Content
1	#ifndef lint
2	static const char RCSid[] = "$Id$";
3	#endif
4	/*
5	* sm_list.c
6	* Routines for handling linked generic linked lists, stack, and
7	* circular lists. Data element is an int (can be cast to hold
8	* pointer to more general data element)
9	*/
10
11	#include "standard.h"
12	#include "sm_list.h"
13
14	/* List of available edges */
15	static LIST *free_lists = NULL;
16	#ifdef DEBUG
17	extern int Malloc_cnt;
18	#endif
19	LIST
20	/* NOTE: Memory is not initialized */
21	*new_list()
22	{
23	LIST *l;
24
25	/* check free list for available edges */
26	if( free_lists )
27	{
28	l = free_lists;
29	free_lists = LIST_NEXT(free_lists);
30	}
31	/* if no free edges- allocate the memory */
32	else
33	{
34	if( !(l = (LIST *)malloc(sizeof(LIST))))
35	error(SYSTEM,"new_list():Unable to allocate memory");
36	}
37	return(l);
38	}
39
40
41	/* attaches list a at the end of list b */
42	LIST
43	*append_list(a,b)
44	LIST a,b;
45	{
46	LIST * l;
47
48	if(!b)
49	return(a);
50
51	l = b;
52	while(LIST_NEXT(l) && LIST_NEXT(l) != b)
53	l = LIST_NEXT(l);
54
55	SET_LIST_NEXT(l,a);
56
57	return(b);
58	}
59
60	/* attaches list a at the end of list b */
61	LIST
62	*add_data(l,d,end)
63	LIST *l;
64	int d;
65	LIST **end;
66
67	{
68	LIST list,lptr;
69
70	list = new_list();
71	SET_LIST_DATA(list,d);
72	SET_LIST_NEXT(list,NULL);
73	if(!l)
74	{
75	if(end)
76	*end = list;
77	return(list);
78	}
79	if(end)
80	lptr = *end;
81	else
82	{
83	lptr = l;
84	while(LIST_NEXT(lptr))
85	lptr = LIST_NEXT(lptr);
86	}
87	LIST_NEXT(lptr) = list;
88	if(end)
89	*end = list;
90
91	return(l);
92	}
93
94	/* Adds data to the end of a circular list. If set, "end"
95	* is a pointer to the last element in the list
96	*/
97	LIST
98	*add_data_to_circular_list(l,end,d)
99	LIST l,*end;
100	int d;
101	{
102	LIST *list;
103
104	list = new_list();
105	SET_LIST_DATA(list,d);
106
107	if(!l)
108	l = list;
109	else
110	{
111	if(*end)
112	SET_LIST_NEXT(*end,list);
113	else
114	l = append_list(list,l);
115	}
116
117	*end = list;
118	SET_LIST_NEXT(list,l);
119	return(l);
120	}
121
122
123
124	/* frees the list */
125	LIST
126	*free_list(l)
127	LIST * l;
128	{
129	if(!l)
130	return(NULL);
131
132	free_lists = append_list(free_lists,l);
133
134	return(NULL);
135	}
136
137	/* Pushes data element d at the top of the list- returns pointer
138	to new top of list
139	*/
140	LIST
141	*push_data(l,d)
142	LIST *l;
143	int d;
144	{
145	LIST *list;
146
147	list = new_list();
148	SET_LIST_DATA(list,d);
149	SET_LIST_NEXT(list,l);
150	return(list);
151	}
152	/* Returns data element d at the top of the list- returns pointer
153	to new top of list
154	*/
155	int
156	pop_list(l)
157	LIST **l;
158	{
159	LIST *p;
160	int d;
161
162	if(!l)
163	return(NULL);
164	if(!(p = *l))
165	return(NULL);
166
167	d = LIST_DATA(p);
168
169	*l = LIST_NEXT(p);
170
171	LIST_NEXT(p) =NULL;
172	free_list(p);
173
174	return(d);
175	}
176
177	/* Search through list for data element "d", and remove from
178	* list: Returns TRUE if found, false otherwise
179	*/
180	int
181	remove_from_list(d,list)
182	int d;
183	LIST **list;
184	{
185	LIST l,prev;
186
187	l = *list;
188	prev = NULL;
189
190	while(l)
191	{
192	if(LIST_DATA(l) == d)
193	{
194	if(l == *list)
195	list = LIST_NEXT(list);
196	else
197	SET_LIST_NEXT(prev,LIST_NEXT(l));
198
199	SET_LIST_NEXT(l,NULL);
200	free_list(l);
201	return(TRUE);
202	}
203	prev = l;
204	l = LIST_NEXT(l);
205	}
206	return(FALSE);
207	}
208
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