/*
* ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
* tools.h: Header for the various tool functions.
*
* Copyright (C) 2002 by the past and present ircd coders, and others.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
* $Id: tools.h 33 2005-10-02 20:50:00Z knight $
*/
#ifndef __TOOLS_H__
#define __TOOLS_H__
#include "stdinc.h"
/*
* double-linked-list and single-linked-list stuff
*/
typedef struct _dlink_node dlink_node;
typedef struct _dlink_list dlink_list;
struct _dlink_node
{
void *data;
dlink_node *prev;
dlink_node *next;
};
struct _dlink_list
{
dlink_node *head;
dlink_node *tail;
unsigned long length;
};
extern void dlinkAdd(void *data, dlink_node * m, dlink_list * list);
extern void dlinkAddBefore(dlink_node *b, void *data, dlink_node *m, dlink_list *list);
extern void dlinkAddTail(void *data, dlink_node *m, dlink_list *list);
extern void dlinkDelete(dlink_node *m, dlink_list *list);
extern void dlinkMoveList(dlink_list *from, dlink_list *to);
extern dlink_node *dlinkFind(dlink_list *m, void *data);
extern dlink_node *dlinkFindDelete(dlink_list *m, void *data);
#ifndef NDEBUG
void mem_frob(void *data, int len);
#else
#define mem_frob(x, y)
#endif
/* These macros are basically swiped from the linux kernel
* they are simple yet effective
*/
/*
* Walks forward of a list.
* pos is your node
* head is your list head
*/
#define DLINK_FOREACH(pos, head) for (pos = (head); pos != NULL; pos = pos->next)
/*
* Walks forward of a list safely while removing nodes
* pos is your node
* n is another list head for temporary storage
* head is your list head
*/
#define DLINK_FOREACH_SAFE(pos, n, head) for (pos = (head), n = pos ? pos->next : NULL; pos != NULL; pos = n, n = pos ? pos->next : NULL)
#define DLINK_FOREACH_PREV(pos, head) for (pos = (head); pos != NULL; pos = pos->prev)
/* Returns the list length */
#define dlink_list_length(list) (list)->length
/*
* The functions below are included for the sake of inlining
* hopefully this will speed up things just a bit
*
*/
/* forte (and maybe others) dont like these being declared twice,
* so we dont declare the inlines unless GNUC.
*/
#ifdef __GNUC__
/*
* dlink_ routines are stolen from squid, except for dlinkAddBefore,
* which is mine.
* -- adrian
*/
extern inline void
dlinkAdd(void *data, dlink_node * m, dlink_list * list)
{
m->data = data;
m->prev = NULL;
m->next = list->head;
/* Assumption: If list->tail != NULL, list->head != NULL */
if (list->head != NULL)
list->head->prev = m;
else if (list->tail == NULL)
list->tail = m;
list->head = m;
list->length++;
}
extern inline void
dlinkAddBefore(dlink_node *b, void *data, dlink_node *m, dlink_list *list)
{
/* Shortcut - if its the first one, call dlinkAdd only */
if (b == list->head)
dlinkAdd(data, m, list);
else {
m->data = data;
b->prev->next = m;
m->prev = b->prev;
b->prev = m;
m->next = b;
list->length++;
}
}
extern inline void
dlinkAddTail(void *data, dlink_node *m, dlink_list *list)
{
m->data = data;
m->next = NULL;
m->prev = list->tail;
/* Assumption: If list->tail != NULL, list->head != NULL */
if (list->tail != NULL)
list->tail->next = m;
else if (list->head == NULL)
list->head = m;
list->tail = m;
list->length++;
}
/* Execution profiles show that this function is called the most
* often of all non-spontaneous functions. So it had better be
* efficient. */
extern inline void
dlinkDelete(dlink_node *m, dlink_list *list)
{
/* Assumption: If m->next == NULL, then list->tail == m
* and: If m->prev == NULL, then list->head == m
*/
if (m->next)
m->next->prev = m->prev;
else {
assert(list->tail == m);
list->tail = m->prev;
}
if (m->prev)
m->prev->next = m->next;
else {
assert(list->head == m);
list->head = m->next;
}
/* Set this to NULL does matter */
m->next = m->prev = NULL;
list->length--;
}
/*
* dlinkFind
* inputs - list to search
* - data
* output - pointer to link or NULL if not found
* side effects - Look for ptr in the linked listed pointed to by link.
*/
extern inline dlink_node *
dlinkFind(dlink_list *list, void *data)
{
dlink_node *ptr;
DLINK_FOREACH(ptr, list->head)
{
if (ptr->data == data)
return(ptr);
}
return(NULL);
}
extern inline void
dlinkMoveList(dlink_list *from, dlink_list *to)
{
/* There are three cases */
/* case one, nothing in from list */
if (from->head == NULL)
return;
/* case two, nothing in to list */
/* actually if to->head is NULL and to->tail isn't, thats a bug */
if (to->head == NULL)
{
to->head = from->head;
to->tail = from->tail;
from->head = from->tail = NULL;
to->length = from->length;
from->length = 0;
return;
}
/* third case play with the links */
from->tail->next = to->head;
from->head->prev = to->head->prev;
to->head->prev = from->tail;
to->head = from->head;
from->head = from->tail = NULL;
to->length += from->length;
from->length = 0;
/* I think I got that right */
}
extern inline dlink_node *
dlinkFindDelete(dlink_list *list, void *data)
{
dlink_node *m;
DLINK_FOREACH(m, list->head)
{
if (m->data == data)
{
if (m->next)
m->next->prev = m->prev;
else
{
assert(list->tail == m);
list->tail = m->prev;
}
if (m->prev)
m->prev->next = m->next;
else
{
assert(list->head == m);
list->head = m->next;
}
/* Set this to NULL does matter */
m->next = m->prev = NULL;
list->length--;
return(m);
}
}
return(NULL);
}
#endif /* __GNUC__ */
#endif /* __TOOLS_H__ */
