+
−/* Ordered set data type implemented by an array.
+
−   Copyright (C) 2006-2007, 2009-2013 Free Software Foundation, Inc.
+
−   Written by Bruno Haible <bruno@clisp.org>, 2006.
+
−
+
−   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 3 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, see <http://www.gnu.org/licenses/>.  */
+
−
+
−#include <config.h>
+
−
+
−/* Specification.  */
+
−#include "gl_array_oset.h"
+
−
+
−#include <stdlib.h>
+
−
+
−/* Checked size_t computations.  */
+
−#include "xsize.h"
+
−
+
−/* -------------------------- gl_oset_t Data Type -------------------------- */
+
−
+
−/* Concrete gl_oset_impl type, valid for this file only.  */
+
−struct gl_oset_impl
+
−{
+
−  struct gl_oset_impl_base base;
+
−  /* An array of ALLOCATED elements, of which the first COUNT are used.
+
−     0 <= COUNT <= ALLOCATED.  */
+
−  const void **elements;
+
−  size_t count;
+
−  size_t allocated;
+
−};
+
−
+
−static gl_oset_t
+
−gl_array_nx_create_empty (gl_oset_implementation_t implementation,
+
−                          gl_setelement_compar_fn compar_fn,
+
−                          gl_setelement_dispose_fn dispose_fn)
+
−{
+
−  struct gl_oset_impl *set =
+
−    (struct gl_oset_impl *) malloc (sizeof (struct gl_oset_impl));
+
−
+
−  if (set == NULL)
+
−    return NULL;
+
−
+
−  set->base.vtable = implementation;
+
−  set->base.compar_fn = compar_fn;
+
−  set->base.dispose_fn = dispose_fn;
+
−  set->elements = NULL;
+
−  set->count = 0;
+
−  set->allocated = 0;
+
−
+
−  return set;
+
−}
+
−
+
−static size_t
+
−gl_array_size (gl_oset_t set)
+
−{
+
−  return set->count;
+
−}
+
−
+
−static size_t
+
−gl_array_indexof (gl_oset_t set, const void *elt)
+
−{
+
−  size_t count = set->count;
+
−
+
−  if (count > 0)
+
−    {
+
−      gl_setelement_compar_fn compar = set->base.compar_fn;
+
−      size_t low = 0;
+
−      size_t high = count;
+
−
+
−      /* At each loop iteration, low < high; for indices < low the values
+
−         are smaller than ELT; for indices >= high the values are greater
+
−         than ELT.  So, if the element occurs in the list, it is at
+
−         low <= position < high.  */
+
−      do
+
−        {
+
−          size_t mid = low + (high - low) / 2; /* low <= mid < high */
+
−          int cmp = (compar != NULL
+
−                     ? compar (set->elements[mid], elt)
+
−                     : (set->elements[mid] > elt ? 1 :
+
−                        set->elements[mid] < elt ? -1 : 0));
+
−
+
−          if (cmp < 0)
+
−            low = mid + 1;
+
−          else if (cmp > 0)
+
−            high = mid;
+
−          else /* cmp == 0 */
+
−            /* We have an element equal to ELT at index MID.  */
+
−            return mid;
+
−        }
+
−      while (low < high);
+
−    }
+
−  return (size_t)(-1);
+
−}
+
−
+
−static bool
+
−gl_array_search (gl_oset_t set, const void *elt)
+
−{
+
−  return gl_array_indexof (set, elt) != (size_t)(-1);
+
−}
+
−
+
−static bool
+
−gl_array_search_atleast (gl_oset_t set,
+
−                         gl_setelement_threshold_fn threshold_fn,
+
−                         const void *threshold,
+
−                         const void **eltp)
+
−{
+
−  size_t count = set->count;
+
−
+
−  if (count > 0)
+
−    {
+
−      size_t low = 0;
+
−      size_t high = count;
+
−
+
−      /* At each loop iteration, low < high; for indices < low the values are
+
−         smaller than THRESHOLD; for indices >= high the values are nonexistent.
+
−         So, if an element >= THRESHOLD occurs in the list, it is at
+
−         low <= position < high.  */
+
−      do
+
−        {
+
−          size_t mid = low + (high - low) / 2; /* low <= mid < high */
+
−
+
−          if (! threshold_fn (set->elements[mid], threshold))
+
−            low = mid + 1;
+
−          else
+
−            {
+
−              /* We have an element >= THRESHOLD at index MID.  But we need the
+
−                 minimal such index.  */
+
−              high = mid;
+
−              /* At each loop iteration, low <= high and
+
−                   compar (list->elements[high], value) >= 0,
+
−                 and we know that the first occurrence of the element is at
+
−                 low <= position <= high.  */
+
−              while (low < high)
+
−                {
+
−                  size_t mid2 = low + (high - low) / 2; /* low <= mid2 < high */
+
−
+
−                  if (! threshold_fn (set->elements[mid2], threshold))
+
−                    low = mid2 + 1;
+
−                  else
+
−                    high = mid2;
+
−                }
+
−              *eltp = set->elements[low];
+
−              return true;
+
−            }
+
−        }
+
−      while (low < high);
+
−    }
+
−  return false;
+
−}
+
−
+
−/* Ensure that set->allocated > set->count.
+
−   Return 0 upon success, -1 upon out-of-memory.  */
+
−static int
+
−grow (gl_oset_t set)
+
−{
+
−  size_t new_allocated;
+
−  size_t memory_size;
+
−  const void **memory;
+
−
+
−  new_allocated = xtimes (set->allocated, 2);
+
−  new_allocated = xsum (new_allocated, 1);
+
−  memory_size = xtimes (new_allocated, sizeof (const void *));
+
−  if (size_overflow_p (memory_size))
+
−    /* Overflow, would lead to out of memory.  */
+
−    return -1;
+
−  memory = (const void **) realloc (set->elements, memory_size);
+
−  if (memory == NULL)
+
−    /* Out of memory.  */
+
−    return -1;
+
−  set->elements = memory;
+
−  set->allocated = new_allocated;
+
−  return 0;
+
−}
+
−
+
−/* Add the given element ELT at the given position,
+
−   0 <= position <= gl_oset_size (set).
+
−   Return 1 upon success, -1 upon out-of-memory.  */
+
−static int
+
−gl_array_nx_add_at (gl_oset_t set, size_t position, const void *elt)
+
−{
+
−  size_t count = set->count;
+
−  const void **elements;
+
−  size_t i;
+
−
+
−  if (count == set->allocated)
+
−    if (grow (set) < 0)
+
−      return -1;
+
−  elements = set->elements;
+
−  for (i = count; i > position; i--)
+
−    elements[i] = elements[i - 1];
+
−  elements[position] = elt;
+
−  set->count = count + 1;
+
−  return 1;
+
−}
+
−
+
−/* Remove the element at the given position,
+
−   0 <= position < gl_oset_size (set).  */
+
−static void
+
−gl_array_remove_at (gl_oset_t set, size_t position)
+
−{
+
−  size_t count = set->count;
+
−  const void **elements;
+
−  size_t i;
+
−
+
−  elements = set->elements;
+
−  if (set->base.dispose_fn != NULL)
+
−    set->base.dispose_fn (elements[position]);
+
−  for (i = position + 1; i < count; i++)
+
−    elements[i - 1] = elements[i];
+
−  set->count = count - 1;
+
−}
+
−
+
−static int
+
−gl_array_nx_add (gl_oset_t set, const void *elt)
+
−{
+
−  size_t count = set->count;
+
−  size_t low = 0;
+
−
+
−  if (count > 0)
+
−    {
+
−      gl_setelement_compar_fn compar = set->base.compar_fn;
+
−      size_t high = count;
+
−
+
−      /* At each loop iteration, low < high; for indices < low the values
+
−         are smaller than ELT; for indices >= high the values are greater
+
−         than ELT.  So, if the element occurs in the list, it is at
+
−         low <= position < high.  */
+
−      do
+
−        {
+
−          size_t mid = low + (high - low) / 2; /* low <= mid < high */
+
−          int cmp = (compar != NULL
+
−                     ? compar (set->elements[mid], elt)
+
−                     : (set->elements[mid] > elt ? 1 :
+
−                        set->elements[mid] < elt ? -1 : 0));
+
−
+
−          if (cmp < 0)
+
−            low = mid + 1;
+
−          else if (cmp > 0)
+
−            high = mid;
+
−          else /* cmp == 0 */
+
−            return false;
+
−        }
+
−      while (low < high);
+
−    }
+
−  return gl_array_nx_add_at (set, low, elt);
+
−}
+
−
+
−static bool
+
−gl_array_remove (gl_oset_t set, const void *elt)
+
−{
+
−  size_t index = gl_array_indexof (set, elt);
+
−  if (index != (size_t)(-1))
+
−    {
+
−      gl_array_remove_at (set, index);
+
−      return true;
+
−    }
+
−  else
+
−    return false;
+
−}
+
−
+
−static void
+
−gl_array_free (gl_oset_t set)
+
−{
+
−  if (set->elements != NULL)
+
−    {
+
−      if (set->base.dispose_fn != NULL)
+
−        {
+
−          size_t count = set->count;
+
−
+
−          if (count > 0)
+
−            {
+
−              gl_setelement_dispose_fn dispose = set->base.dispose_fn;
+
−              const void **elements = set->elements;
+
−
+
−              do
+
−                dispose (*elements++);
+
−              while (--count > 0);
+
−            }
+
−        }
+
−      free (set->elements);
+
−    }
+
−  free (set);
+
−}
+
−
+
−/* --------------------- gl_oset_iterator_t Data Type --------------------- */
+
−
+
−static gl_oset_iterator_t
+
−gl_array_iterator (gl_oset_t set)
+
−{
+
−  gl_oset_iterator_t result;
+
−
+
−  result.vtable = set->base.vtable;
+
−  result.set = set;
+
−  result.count = set->count;
+
−  result.p = set->elements + 0;
+
−  result.q = set->elements + set->count;
+
−#ifdef lint
+
−  result.i = 0;
+
−  result.j = 0;
+
−#endif
+
−
+
−  return result;
+
−}
+
−
+
−static bool
+
−gl_array_iterator_next (gl_oset_iterator_t *iterator, const void **eltp)
+
−{
+
−  gl_oset_t set = iterator->set;
+
−  if (iterator->count != set->count)
+
−    {
+
−      if (iterator->count != set->count + 1)
+
−        /* Concurrent modifications were done on the set.  */
+
−        abort ();
+
−      /* The last returned element was removed.  */
+
−      iterator->count--;
+
−      iterator->p = (const void **) iterator->p - 1;
+
−      iterator->q = (const void **) iterator->q - 1;
+
−    }
+
−  if (iterator->p < iterator->q)
+
−    {
+
−      const void **p = (const void **) iterator->p;
+
−      *eltp = *p;
+
−      iterator->p = p + 1;
+
−      return true;
+
−    }
+
−  else
+
−    return false;
+
−}
+
−
+
−static void
+
−gl_array_iterator_free (gl_oset_iterator_t *iterator)
+
−{
+
−}
+
−
+
−
+
−const struct gl_oset_implementation gl_array_oset_implementation =
+
−  {
+
−    gl_array_nx_create_empty,
+
−    gl_array_size,
+
−    gl_array_search,
+
−    gl_array_search_atleast,
+
−    gl_array_nx_add,
+
−    gl_array_remove,
+
−    gl_array_free,
+
−    gl_array_iterator,
+
−    gl_array_iterator_next,
+
−    gl_array_iterator_free
+
−  };