linklist.c

CFL是Unix下的通用抽象库,以简化Unix下的系统软件开发,CFL库中包含几个分组的函数和宏

/* ----------------------------------------------------------------------------
   CFL - A C Foundation Library
   Copyright (C) 1994-2003  Mark A Lindner

   This file is part of CFL.
   
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
   
   This library 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
   Library General Public License for more details.
   
   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   ----------------------------------------------------------------------------
   $Log: linklist.c,v $
   Revision 1.1  2003/03/03 08:20:07  markl
   Initial checkin (clean compile on Solaris & OS X)

   ----------------------------------------------------------------------------
*/

/* Feature test switches */

#include "config.h"

/* Local headers */

#include "cfl/defs.h"
#include "cfl/data.h"
#include "cfl/system.h"

/* Functions */

static c_link_t *__C_linklist_unlink_r(c_linklist_t *l, c_link_t **p)
  {
  c_link_t *r;

  r = *p;
  if(l->head == r)
    l->head = r->next;
  if(l->tail == r)
    l->tail = r->prev;
  if((*p)->prev)
    (*p)->prev->next = (*p)->next;
  if((*p)->next)
    (*p)->next->prev = (*p)->prev;
  (*p) = (*p)->next;
  l->size--;

  return(r);
  }

/*
 */

c_linklist_t *C_linklist_create(void)
  {
  c_linklist_t *l = C_new(c_linklist_t);

  l->head = l->tail = l->p = NULL;
  l->size = 0L;

  return(l);
  }

/*
 */

void C_linklist_destroy(c_linklist_t *l)
  {
  c_link_t *p, *q;

  if(!l)
    return;

  for(p = l->head; p; )
    {
    q = p;
    p = p->next;

    if(l->destructor)
      l->destructor(q->data);
    
    C_free(q);
    }
  C_free(l);
  }

/*
 */

c_bool_t C_linklist_set_destructor(c_linklist_t *l,
                                   void (*destructor)(void *data))
  {
  if(!l)
    return(FALSE);
  
  l->destructor = destructor;
  return(TRUE);
  }

/*
 */

c_bool_t C_linklist_store(c_linklist_t *l, const void *data)
  {
  if(!l)
    return(FALSE);

  return(C_linklist_store_r(l, data, &(l->p)));
  }
  
/*
 */

c_bool_t C_linklist_store_r(c_linklist_t *l, const void *data, c_link_t **p)
  {
  c_link_t *q;

  if(!l || !data)
    return(FALSE);

  q = C_new(c_link_t);
  q->data = (void *)data;

  if(*p == l->head) /* new head? */
    {
    q->next = l->head;
    q->prev = NULL;
    if(l->head)
      l->head->prev = q;
    l->head = q;
    if(!l->tail)
      l->tail = q;
    }
  else if(!(*p)) /* new tail? */
    {
    q->next = NULL;
    q->prev = l->tail;
    if(l->tail)
      l->tail->next = q;
    l->tail = q;
    }
  else
    {
    q->next = *p;
    q->prev = (*p)->prev;
    if((*p)->prev)
      (*p)->prev->next = q;
    (*p)->prev = q;
    }
  *p = q;
  l->size++;
  
  return(TRUE);
  }

/*
 */

void *C_linklist_restore(c_linklist_t *l)
  {
  if(!l)
    return(NULL);
  
  return(C_linklist_restore_r(l, &(l->p)));
  }

/*
 */

void *C_linklist_restore_r(c_linklist_t *l, c_link_t **p)
  {
  
  if(!l)
    return(NULL);

  return(*p ? (*p)->data : NULL);
  }

/*
 */

c_bool_t C_linklist_search(c_linklist_t *l, const void *data)
  {
  if(!l)
    return(FALSE);

  return(C_linklist_search_r(l, data, &(l->p)));
  }

/*
 */

c_bool_t C_linklist_search_r(c_linklist_t *l, const void *data, c_link_t **p)
  {
  void *d;

  for(C_linklist_move_head_r(l, p);
      (d = C_linklist_restore_r(l, p)) != NULL;
      C_linklist_move_next_r(l, p))
    {
    if(d == data)
      return(TRUE);
    }

  return(FALSE);
  }

/*
 */

c_bool_t C_linklist_push(c_linklist_t *l, const void *data)
  {
  c_link_t *p;
  
  if(!l || !data)
    return(FALSE);

  C_linklist_move_head_r(l, &p);
  return(C_linklist_store_r(l, data, &p));
  }

/*
 */

void *C_linklist_pop(c_linklist_t *l)
  {
  void *r;
  c_link_t *p, *q;

  if(!l)
    return(NULL);
  if(!l->size)
    return(NULL);

  C_linklist_move_head_r(l, &p);
  q = __C_linklist_unlink_r(l, &p);
  r = q->data;
  C_free(q);

  return(r);
  }

/*
 */

void *C_linklist_peek(c_linklist_t *l)
  {
  c_link_t *p;
  
  if(!l)
    return(NULL);
  if(!l->size)
    return(NULL);

  C_linklist_move_head_r(l, &p);
  return(C_linklist_restore_r(l, &p));
  }

/*
 */

c_bool_t C_linklist_enqueue(c_linklist_t *l, const void *data)
  {
  c_link_t *p;

  if(!l || !data)
    return(FALSE);

  C_linklist_move_tail_r(l, &p);
  return(C_linklist_store_r(l, data, &p));
  }

/*
 */

c_bool_t C_linklist_delete(c_linklist_t *l)
  {
  if(!l)
    return(FALSE);
  if(!l->p)
    return(FALSE);

  return(C_linklist_delete_r(l, &(l->p)));
  }

/*
 */

c_bool_t C_linklist_delete_r(c_linklist_t *l, c_link_t **p)
  {
  c_link_t *r;

  if(!l)
    return(FALSE);
  if(!*p)
    return(FALSE);

  r = __C_linklist_unlink_r(l, p);

  if(l->destructor)
    l->destructor(r->data);
  
  C_free(r);

  return(TRUE);
  }

/*
 */

c_bool_t C_linklist_move(c_linklist_t *l, int where)
  {
  if(!l)
    return(FALSE);
  
  return(C_linklist_move_r(l, where, &(l->p)));
  }

/*
 */

c_bool_t C_linklist_move_r(c_linklist_t *l, int where, c_link_t **p)
  {

  if(!l)
    return(FALSE);

  switch(where)
    {
    case C_LINKLIST_HEAD:
      *p = l->head;
      return(TRUE);

    case C_LINKLIST_TAIL:
      *p = NULL;
      return(TRUE);

    case C_LINKLIST_NEXT:
      if(*p)
	{
	*p = (*p)->next;
	return(TRUE);
	}
      break;

    case C_LINKLIST_PREV:
      if(*p)
        if((*p)->prev)
	  {
	  *p = (*p)->prev;
	  return(TRUE);
	  }
      break;
    }

  return(FALSE);
  }

/* end of source file */