blender-archive/source/blender/blenlib/intern/listbase.c

/*
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 */

/** \file
 * \ingroup bli
 *
 * Manipulations on double-linked list (#ListBase structs).
 *
 * For single linked lists see 'BLI_linklist.h'
 */

#include <stdlib.h>
#include <string.h>

#include "MEM_guardedalloc.h"

#include "DNA_listBase.h"

#include "BLI_listbase.h"

#include "BLI_strict_flags.h"

/* implementation */

/**
 * moves the entire contents of \a src onto the end of \a dst.
 */
void BLI_movelisttolist(ListBase *dst, ListBase *src)
{
  if (src->first == NULL) {
    return;
  }

  if (dst->first == NULL) {
    dst->first = src->first;
    dst->last = src->last;
  }
  else {
    ((Link *)dst->last)->next = src->first;
    ((Link *)src->first)->prev = dst->last;
    dst->last = src->last;
  }
  src->first = src->last = NULL;
}

/**
 * moves the entire contents of \a src at the beginning of \a dst.
 */
void BLI_movelisttolist_reverse(ListBase *dst, ListBase *src)
{
  if (src->first == NULL) {
    return;
  }

  if (dst->first == NULL) {
    dst->first = src->first;
    dst->last = src->last;
  }
  else {
    ((Link *)src->last)->next = dst->first;
    ((Link *)dst->first)->prev = src->last;
    dst->first = src->first;
  }

  src->first = src->last = NULL;
}

/**
 * Prepends \a vlink (assumed to begin with a Link) onto listbase.
 */
void BLI_addhead(ListBase *listbase, void *vlink)
{
  Link *link = vlink;

  if (link == NULL) {
    return;
  }

  link->next = listbase->first;
  link->prev = NULL;

  if (listbase->first) {
    ((Link *)listbase->first)->prev = link;
  }
  if (listbase->last == NULL) {
    listbase->last = link;
  }
  listbase->first = link;
}

/**
 * Appends \a vlink (assumed to begin with a Link) onto listbase.
 */
void BLI_addtail(ListBase *listbase, void *vlink)
{
  Link *link = vlink;

  if (link == NULL) {
    return;
  }

  link->next = NULL;
  link->prev = listbase->last;

  if (listbase->last) {
    ((Link *)listbase->last)->next = link;
  }
  if (listbase->first == NULL) {
    listbase->first = link;
  }
  listbase->last = link;
}

/**
 * Removes \a vlink from \a listbase. Assumes it is linked into there!
 */
void BLI_remlink(ListBase *listbase, void *vlink)
{
  Link *link = vlink;

  if (link == NULL) {
    return;
  }

  if (link->next) {
    link->next->prev = link->prev;
  }
  if (link->prev) {
    link->prev->next = link->next;
  }

  if (listbase->last == link) {
    listbase->last = link->prev;
  }
  if (listbase->first == link) {
    listbase->first = link->next;
  }
}

/**
 * Checks that \a vlink is linked into listbase, removing it from there if so.
 */
bool BLI_remlink_safe(ListBase *listbase, void *vlink)
{
  if (BLI_findindex(listbase, vlink) != -1) {
    BLI_remlink(listbase, vlink);
    return true;
  }

  return false;
}

/**
 * Swaps \a vlinka and \a vlinkb in the list. Assumes they are both already in the list!
 */
void BLI_listbase_swaplinks(ListBase *listbase, void *vlinka, void *vlinkb)
{
  Link *linka = vlinka;
  Link *linkb = vlinkb;

  if (!linka || !linkb) {
    return;
  }

  if (linkb->next == linka) {
    SWAP(Link *, linka, linkb);
  }

  if (linka->next == linkb) {
    linka->next = linkb->next;
    linkb->prev = linka->prev;
    linka->prev = linkb;
    linkb->next = linka;
  }
  else { /* Non-contiguous items, we can safely swap. */
    SWAP(Link *, linka->prev, linkb->prev);
    SWAP(Link *, linka->next, linkb->next);
  }

  /* Update neighbors of linka and linkb. */
  if (linka->prev) {
    linka->prev->next = linka;
  }
  if (linka->next) {
    linka->next->prev = linka;
  }
  if (linkb->prev) {
    linkb->prev->next = linkb;
  }
  if (linkb->next) {
    linkb->next->prev = linkb;
  }

  if (listbase->last == linka) {
    listbase->last = linkb;
  }
  else if (listbase->last == linkb) {
    listbase->last = linka;
  }

  if (listbase->first == linka) {
    listbase->first = linkb;
  }
  else if (listbase->first == linkb) {
    listbase->first = linka;
  }
}

/**
 * Swaps \a vlinka and \a vlinkb from their respective lists.
 * Assumes they are both already in their \a listbasea!
 */
void BLI_listbases_swaplinks(ListBase *listbasea, ListBase *listbaseb, void *vlinka, void *vlinkb)
{
  Link *linka = vlinka;
  Link *linkb = vlinkb;
  Link linkc = {NULL};

  if (!linka || !linkb) {
    return;
  }

  /* Temporary link to use as placeholder of the links positions */
  BLI_insertlinkafter(listbasea, linka, &linkc);

  /* Bring linka into linkb position */
  BLI_remlink(listbasea, linka);
  BLI_insertlinkafter(listbaseb, linkb, linka);

  /* Bring linkb into linka position */
  BLI_remlink(listbaseb, linkb);
  BLI_insertlinkafter(listbasea, &linkc, linkb);

  /* Remove temporary link */
  BLI_remlink(listbasea, &linkc);
}

/**
 * Removes the head from \a listbase and returns it.
 */
void *BLI_pophead(ListBase *listbase)
{
  Link *link;
  if ((link = listbase->first)) {
    BLI_remlink(listbase, link);
  }
  return link;
}

/**
 * Removes the tail from \a listbase and returns it.
 */
void *BLI_poptail(ListBase *listbase)
{
  Link *link;
  if ((link = listbase->last)) {
    BLI_remlink(listbase, link);
  }
  return link;
}

/**
 * Removes \a vlink from listbase and disposes of it. Assumes it is linked into there!
 */
void BLI_freelinkN(ListBase *listbase, void *vlink)
{
  Link *link = vlink;

  if (link == NULL) {
    return;
  }

  BLI_remlink(listbase, link);
  MEM_freeN(link);
}

/**
 * Assigns all #Link.prev pointers from #Link.next
 */
static void listbase_double_from_single(Link *iter, ListBase *listbase)
{
  Link *prev = NULL;
  listbase->first = iter;
  do {
    iter->prev = prev;
    prev = iter;
  } while ((iter = iter->next));
  listbase->last = prev;
}

#define SORT_IMPL_LINKTYPE Link

/* regular call */
#define SORT_IMPL_FUNC listbase_sort_fn
#include "list_sort_impl.h"
#undef SORT_IMPL_FUNC

/* re-entrant call */
#define SORT_IMPL_USE_THUNK
#define SORT_IMPL_FUNC listbase_sort_fn_r
#include "list_sort_impl.h"
#undef SORT_IMPL_FUNC
#undef SORT_IMPL_USE_THUNK

#undef SORT_IMPL_LINKTYPE

/**
 * Sorts the elements of listbase into the order defined by cmp
 * (which should return 1 if its first arg should come after its second arg).
 * This uses insertion sort, so NOT ok for large list.
 */
void BLI_listbase_sort(ListBase *listbase, int (*cmp)(const void *, const void *))
{
  if (listbase->first != listbase->last) {
    Link *head = listbase->first;
    head = listbase_sort_fn(head, cmp);
    listbase_double_from_single(head, listbase);
  }
}

void BLI_listbase_sort_r(ListBase *listbase,
                         int (*cmp)(void *, const void *, const void *),
                         void *thunk)
{
  if (listbase->first != listbase->last) {
    Link *head = listbase->first;
    head = listbase_sort_fn_r(head, cmp, thunk);
    listbase_double_from_single(head, listbase);
  }
}

/**
 * Inserts \a vnewlink immediately following \a vprevlink in \a listbase.
 * Or, if \a vprevlink is NULL, puts \a vnewlink at the front of the list.
 */
void BLI_insertlinkafter(ListBase *listbase, void *vprevlink, void *vnewlink)
{
  Link *prevlink = vprevlink;
  Link *newlink = vnewlink;

  /* newlink before nextlink */
  if (newlink == NULL) {
    return;
  }

  /* empty list */
  if (listbase->first == NULL) {
    listbase->first = newlink;
    listbase->last = newlink;
    return;
  }

  /* insert at head of list */
  if (prevlink == NULL) {
    newlink->prev = NULL;
    newlink->next = listbase->first;
    newlink->next->prev = newlink;
    listbase->first = newlink;
    return;
  }

  /* at end of list */
  if (listbase->last == prevlink) {
    listbase->last = newlink;
  }

  newlink->next = prevlink->next;
  newlink->prev = prevlink;
  prevlink->next = newlink;
  if (newlink->next) {
    newlink->next->prev = newlink;
  }
}

/**
 * Inserts \a vnewlink immediately preceding \a vnextlink in listbase.
 * Or, if \a vnextlink is NULL, puts \a vnewlink at the end of the list.
 */
void BLI_insertlinkbefore(ListBase *listbase, void *vnextlink, void *vnewlink)
{
  Link *nextlink = vnextlink;
  Link *newlink = vnewlink;

  /* newlink before nextlink */
  if (newlink == NULL) {
    return;
  }

  /* empty list */
  if (listbase->first == NULL) {
    listbase->first = newlink;
    listbase->last = newlink;
    return;
  }

  /* insert at end of list */
  if (nextlink == NULL) {
    newlink->prev = listbase->last;
    newlink->next = NULL;
    ((Link *)listbase->last)->next = newlink;
    listbase->last = newlink;
    return;
  }

  /* at beginning of list */
  if (listbase->first == nextlink) {
    listbase->first = newlink;
  }

  newlink->next = nextlink;
  newlink->prev = nextlink->prev;
  nextlink->prev = newlink;
  if (newlink->prev) {
    newlink->prev->next = newlink;
  }
}

/**
 * Insert a link in place of another, without changing its position in the list.
 *
 * Puts `vnewlink` in the position of `vreplacelink`, removing `vreplacelink`.
 * - `vreplacelink` *must* be in the list.
 * - `vnewlink` *must not* be in the list.
 */
void BLI_insertlinkreplace(ListBase *listbase, void *vreplacelink, void *vnewlink)
{
  Link *l_old = vreplacelink;
  Link *l_new = vnewlink;

  /* update adjacent links */
  if (l_old->next != NULL) {
    l_old->next->prev = l_new;
  }
  if (l_old->prev != NULL) {
    l_old->prev->next = l_new;
  }

  /* set direct links */
  l_new->next = l_old->next;
  l_new->prev = l_old->prev;

  /* update list */
  if (listbase->first == l_old) {
    listbase->first = l_new;
  }
  if (listbase->last == l_old) {
    listbase->last = l_new;
  }
}

/**
 * Reinsert \a vlink relative to its current position but offset by \a step. Doesn't move
 * item if new position would exceed list (could optionally move to head/tail).
 *
 * \param step: Absolute value defines step size, sign defines direction. E.g pass -1
 *              to move \a vlink before previous, or 1 to move behind next.
 * \return If position of \a vlink has changed.
 */
bool BLI_listbase_link_move(ListBase *listbase, void *vlink, int step)
{
  Link *link = vlink;
  Link *hook = link;
  const bool is_up = step < 0;

  if (step == 0) {
    return false;
  }
  BLI_assert(BLI_findindex(listbase, link) != -1);

  /* find link to insert before/after */
  const int abs_step = abs(step);
  for (int i = 0; i < abs_step; i++) {
    hook = is_up ? hook->prev : hook->next;
    if (!hook) {
      return false;
    }
  }

  /* reinsert link */
  BLI_remlink(listbase, vlink);
  if (is_up) {
    BLI_insertlinkbefore(listbase, hook, vlink);
  }
  else {
    BLI_insertlinkafter(listbase, hook, vlink);
  }
  return true;
}

/**
 * Move the link at the index \a from to the position at index \a to.
 *
 * \return If the move was successful.
 */
bool BLI_listbase_move_index(ListBase *listbase, int from, int to)
{
  if (from == to) {
    return false;
  }

  /* Find the link to move. */
  void *link = BLI_findlink(listbase, from);

  if (!link) {
    return false;
  }

  return BLI_listbase_link_move(listbase, link, to - from);
}

/**
 * Removes and disposes of the entire contents of listbase using direct free(3).
 */
void BLI_freelist(ListBase *listbase)
{
  Link *link, *next;

  link = listbase->first;
  while (link) {
    next = link->next;
    free(link);
    link = next;
  }

  BLI_listbase_clear(listbase);
}

/**
 * Removes and disposes of the entire contents of \a listbase using guardedalloc.
 */
void BLI_freelistN(ListBase *listbase)
{
  Link *link, *next;

  link = listbase->first;
  while (link) {
    next = link->next;
    MEM_freeN(link);
    link = next;
  }

  BLI_listbase_clear(listbase);
}

/**
 * Returns the number of elements in \a listbase, up until (and including count_max)
 *
 * \note Use to avoid redundant looping.
 */
int BLI_listbase_count_at_most(const ListBase *listbase, const int count_max)
{
  Link *link;
  int count = 0;

  for (link = listbase->first; link && count != count_max; link = link->next) {
    count++;
  }

  return count;
}

/**
 * Returns the number of elements in \a listbase.
 */
int BLI_listbase_count(const ListBase *listbase)
{
  Link *link;
  int count = 0;

  for (link = listbase->first; link; link = link->next) {
    count++;
  }

  return count;
}

/**
 * Returns the nth element of \a listbase, numbering from 0.
 */
void *BLI_findlink(const ListBase *listbase, int number)
{
  Link *link = NULL;

  if (number >= 0) {
    link = listbase->first;
    while (link != NULL && number != 0) {
      number--;
      link = link->next;
    }
  }

  return link;
}

/**
 * Returns the nth-last element of \a listbase, numbering from 0.
 */
void *BLI_rfindlink(const ListBase *listbase, int number)
{
  Link *link = NULL;

  if (number >= 0) {
    link = listbase->last;
    while (link != NULL && number != 0) {
      number--;
      link = link->prev;
    }
  }

  return link;
}

/**
 * Returns the position of \a vlink within \a listbase, numbering from 0, or -1 if not found.
 */
int BLI_findindex(const ListBase *listbase, const void *vlink)
{
  Link *link = NULL;
  int number = 0;

  if (vlink == NULL) {
    return -1;
  }

  link = listbase->first;
  while (link) {
    if (link == vlink) {
      return number;
    }

    number++;
    link = link->next;
  }

  return -1;
}

/**
 * Finds the first element of \a listbase which contains the null-terminated
 * string \a id at the specified offset, returning NULL if not found.
 */
void *BLI_findstring(const ListBase *listbase, const char *id, const int offset)
{
  Link *link = NULL;
  const char *id_iter;

  if (id == NULL) {
    return NULL;
  }

  for (link = listbase->first; link; link = link->next) {
    id_iter = ((const char *)link) + offset;

    if (id[0] == id_iter[0] && STREQ(id, id_iter)) {
      return link;
    }
  }

  return NULL;
}
/* same as above but find reverse */
/**
 * Finds the last element of \a listbase which contains the
 * null-terminated string \a id at the specified offset, returning NULL if not found.
 */
void *BLI_rfindstring(const ListBase *listbase, const char *id, const int offset)
{
  Link *link = NULL;
  const char *id_iter;

  for (link = listbase->last; link; link = link->prev) {
    id_iter = ((const char *)link) + offset;

    if (id[0] == id_iter[0] && STREQ(id, id_iter)) {
      return link;
    }
  }

  return NULL;
}

/**
 * Finds the first element of \a listbase which contains a pointer to the
 * null-terminated string \a id at the specified offset, returning NULL if not found.
 */
void *BLI_findstring_ptr(const ListBase *listbase, const char *id, const int offset)
{
  Link *link = NULL;
  const char *id_iter;

  for (link = listbase->first; link; link = link->next) {
    /* exact copy of BLI_findstring(), except for this line */
    id_iter = *((const char **)(((const char *)link) + offset));

    if (id[0] == id_iter[0] && STREQ(id, id_iter)) {
      return link;
    }
  }

  return NULL;
}
/* same as above but find reverse */
/**
 * Finds the last element of \a listbase which contains a pointer to the
 * null-terminated string \a id at the specified offset, returning NULL if not found.
 */
void *BLI_rfindstring_ptr(const ListBase *listbase, const char *id, const int offset)
{
  Link *link = NULL;
  const char *id_iter;

  for (link = listbase->last; link; link = link->prev) {
    /* exact copy of BLI_rfindstring(), except for this line */
    id_iter = *((const char **)(((const char *)link) + offset));

    if (id[0] == id_iter[0] && STREQ(id, id_iter)) {
      return link;
    }
  }

  return NULL;
}

/**
 * Finds the first element of listbase which contains the specified pointer value
 * at the specified offset, returning NULL if not found.
 */
void *BLI_findptr(const ListBase *listbase, const void *ptr, const int offset)
{
  Link *link = NULL;
  const void *ptr_iter;

  for (link = listbase->first; link; link = link->next) {
    /* exact copy of BLI_findstring(), except for this line */
    ptr_iter = *((const void **)(((const char *)link) + offset));

    if (ptr == ptr_iter) {
      return link;
    }
  }

  return NULL;
}
/* same as above but find reverse */
/**
 * Finds the last element of listbase which contains the specified pointer value
 * at the specified offset, returning NULL if not found.
 */
void *BLI_rfindptr(const ListBase *listbase, const void *ptr, const int offset)
{
  Link *link = NULL;
  const void *ptr_iter;

  for (link = listbase->last; link; link = link->prev) {
    /* exact copy of BLI_rfindstring(), except for this line */
    ptr_iter = *((const void **)(((const char *)link) + offset));

    if (ptr == ptr_iter) {
      return link;
    }
  }

  return NULL;
}

/**
 * Finds the first element of listbase which contains the specified bytes
 * at the specified offset, returning NULL if not found.
 */
void *BLI_listbase_bytes_find(const ListBase *listbase,
                              const void *bytes,
                              const size_t bytes_size,
                              const int offset)
{
  Link *link = NULL;
  const void *ptr_iter;

  for (link = listbase->first; link; link = link->next) {
    ptr_iter = (const void *)(((const char *)link) + offset);

    if (memcmp(bytes, ptr_iter, bytes_size) == 0) {
      return link;
    }
  }

  return NULL;
}
/* same as above but find reverse */
/**
 * Finds the last element of listbase which contains the specified bytes
 * at the specified offset, returning NULL if not found.
 */
void *BLI_listbase_bytes_rfind(const ListBase *listbase,
                               const void *bytes,
                               const size_t bytes_size,
                               const int offset)
{
  Link *link = NULL;
  const void *ptr_iter;

  for (link = listbase->last; link; link = link->prev) {
    ptr_iter = (const void *)(((const char *)link) + offset);

    if (memcmp(bytes, ptr_iter, bytes_size) == 0) {
      return link;
    }
  }

  return NULL;
}

/**
 * Returns the 0-based index of the first element of listbase which contains the specified
 * null-terminated string at the specified offset, or -1 if not found.
 */
int BLI_findstringindex(const ListBase *listbase, const char *id, const int offset)
{
  Link *link = NULL;
  const char *id_iter;
  int i = 0;

  link = listbase->first;
  while (link) {
    id_iter = ((const char *)link) + offset;

    if (id[0] == id_iter[0] && STREQ(id, id_iter)) {
      return i;
    }
    i++;
    link = link->next;
  }

  return -1;
}

/**
 * Sets dst to a duplicate of the entire contents of src. dst may be the same as src.
 */
void BLI_duplicatelist(ListBase *dst, const ListBase *src)
{
  struct Link *dst_link, *src_link;

  /* in this order, to ensure it works if dst == src */
  src_link = src->first;
  dst->first = dst->last = NULL;

  while (src_link) {
    dst_link = MEM_dupallocN(src_link);
    BLI_addtail(dst, dst_link);

    src_link = src_link->next;
  }
}

void BLI_listbase_reverse(ListBase *lb)
{
  struct Link *curr = lb->first;
  struct Link *prev = NULL;
  struct Link *next = NULL;
  while (curr) {
    next = curr->next;
    curr->next = prev;
    curr->prev = next;
    prev = curr;
    curr = next;
  }

  /* swap first/last */
  curr = lb->first;
  lb->first = lb->last;
  lb->last = curr;
}

/**
 * \param vlink: Link to make first.
 */
void BLI_listbase_rotate_first(ListBase *lb, void *vlink)
{
  /* make circular */
  ((Link *)lb->first)->prev = lb->last;
  ((Link *)lb->last)->next = lb->first;

  lb->first = vlink;
  lb->last = ((Link *)vlink)->prev;

  ((Link *)lb->first)->prev = NULL;
  ((Link *)lb->last)->next = NULL;
}

/**
 * \param vlink: Link to make last.
 */
void BLI_listbase_rotate_last(ListBase *lb, void *vlink)
{
  /* make circular */
  ((Link *)lb->first)->prev = lb->last;
  ((Link *)lb->last)->next = lb->first;

  lb->first = ((Link *)vlink)->next;
  lb->last = vlink;

  ((Link *)lb->first)->prev = NULL;
  ((Link *)lb->last)->next = NULL;
}

/* create a generic list node containing link to provided data */
LinkData *BLI_genericNodeN(void *data)
{
  LinkData *ld;

  if (data == NULL) {
    return NULL;
  }

  /* create new link, and make it hold the given data */
  ld = MEM_callocN(sizeof(LinkData), __func__);
  ld->data = data;

  return ld;
}