/* Copyright (C) 2000-2002, 2009-2018 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Bruno Haible <haible@clisp.cons.org>, 2000.


   NOTE: The canonical source of this file is maintained with the GNU C Library.
   See glibc/locale/programs/ld-ctype.c.
   Bugs can be reported to bug-glibc@gnu.org.

   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, 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 <https://www.gnu.org/licenses/>.  */

/* Construction of sparse 3-level tables.
   See wchar-lookup.h for their structure and the meaning of p and q.

   Before including this file, set
     TABLE        to the name of the structure to be defined
     ITERATE      if you want the TABLE_iterate function to be defined
     NO_FINALIZE  if you don't want the TABLE_finalize function to be defined

   This will define

     struct TABLE;
     void TABLE_init (struct TABLE *t);
     int TABLE_get (struct TABLE *t, uint32_t wc);
     void TABLE_add (struct TABLE *t, uint32_t wc);
     void TABLE_iterate (struct TABLE *t, void (*fn) (uint32_t wc));
     void TABLE_finalize (struct TABLE *t);
*/

#define CONCAT(a,b) CONCAT1(a,b)
#define CONCAT1(a,b) a##b

struct TABLE
{
  /* Parameters.  */
  unsigned int p;
  unsigned int q;
  /* Working representation.  */
  size_t level1_alloc;
  size_t level1_size;
  uint32_t *level1;
  size_t level2_alloc;
  size_t level2_size;
  uint32_t *level2;
  size_t level3_alloc;
  size_t level3_size;
  uint32_t *level3;
  /* Compressed representation.  */
  size_t result_size;
  char *result;
};

/* Initialize.  Assumes t->p and t->q have already been set.  */
static inline void
CONCAT(TABLE,_init) (struct TABLE *t)
{
  t->level1 = NULL;
  t->level1_alloc = t->level1_size = 0;
  t->level2 = NULL;
  t->level2_alloc = t->level2_size = 0;
  t->level3 = NULL;
  t->level3_alloc = t->level3_size = 0;
}

/* Marker for an empty slot.  This has the value 0xFFFFFFFF, regardless
   whether 'int' is 16 bit, 32 bit, or 64 bit.  */
#define EMPTY ((uint32_t) ~0)

/* Retrieve an entry.  */
static inline int
CONCAT(TABLE,_get) (struct TABLE *t, uint32_t wc)
{
  uint32_t index1 = wc >> (t->q + t->p + 5);
  if (index1 < t->level1_size)
    {
      uint32_t lookup1 = t->level1[index1];
      if (lookup1 != EMPTY)
        {
          uint32_t index2 = ((wc >> (t->p + 5)) & ((1 << t->q) - 1))
                            + (lookup1 << t->q);
          uint32_t lookup2 = t->level2[index2];
          if (lookup2 != EMPTY)
            {
              uint32_t index3 = ((wc >> 5) & ((1 << t->p) - 1))
                                + (lookup2 << t->p);
              uint32_t lookup3 = t->level3[index3];
              uint32_t index4 = wc & 0x1f;

              return (lookup3 >> index4) & 1;
            }
        }
    }
  return 0;
}

/* Add one entry.  */
static void
CONCAT(TABLE,_add) (struct TABLE *t, uint32_t wc)
{
  uint32_t index1 = wc >> (t->q + t->p + 5);
  uint32_t index2 = (wc >> (t->p + 5)) & ((1 << t->q) - 1);
  uint32_t index3 = (wc >> 5) & ((1 << t->p) - 1);
  uint32_t index4 = wc & 0x1f;
  size_t i, i1, i2;

  if (index1 >= t->level1_size)
    {
      if (index1 >= t->level1_alloc)
        {
          size_t alloc = 2 * t->level1_alloc;
          if (alloc <= index1)
            alloc = index1 + 1;
          t->level1 = (uint32_t *) xrealloc ((char *) t->level1,
                                             alloc * sizeof (uint32_t));
          t->level1_alloc = alloc;
        }
      while (index1 >= t->level1_size)
        t->level1[t->level1_size++] = EMPTY;
    }

  if (t->level1[index1] == EMPTY)
    {
      if (t->level2_size == t->level2_alloc)
        {
          size_t alloc = 2 * t->level2_alloc + 1;
          t->level2 = (uint32_t *) xrealloc ((char *) t->level2,
                                             (alloc << t->q) * sizeof (uint32_t));
          t->level2_alloc = alloc;
        }
      i1 = t->level2_size << t->q;
      i2 = (t->level2_size + 1) << t->q;
      for (i = i1; i < i2; i++)
        t->level2[i] = EMPTY;
      t->level1[index1] = t->level2_size++;
    }

  index2 += t->level1[index1] << t->q;

  if (t->level2[index2] == EMPTY)
    {
      if (t->level3_size == t->level3_alloc)
        {
          size_t alloc = 2 * t->level3_alloc + 1;
          t->level3 = (uint32_t *) xrealloc ((char *) t->level3,
                                            (alloc << t->p) * sizeof (uint32_t));
          t->level3_alloc = alloc;
        }
      i1 = t->level3_size << t->p;
      i2 = (t->level3_size + 1) << t->p;
      for (i = i1; i < i2; i++)
        t->level3[i] = 0;
      t->level2[index2] = t->level3_size++;
    }

  index3 += t->level2[index2] << t->p;

  t->level3[index3] |= (uint32_t)1 << index4;
}

#ifdef ITERATE
/* Apply a function to all entries in the table.  */
static void
CONCAT(TABLE,_iterate) (struct TABLE *t, void (*fn) (uint32_t wc))
{
  uint32_t index1;
  for (index1 = 0; index1 < t->level1_size; index1++)
    {
      uint32_t lookup1 = t->level1[index1];
      if (lookup1 != EMPTY)
        {
          uint32_t lookup1_shifted = lookup1 << t->q;
          uint32_t index2;
          for (index2 = 0; index2 < (1 << t->q); index2++)
            {
              uint32_t lookup2 = t->level2[index2 + lookup1_shifted];
              if (lookup2 != EMPTY)
                {
                  uint32_t lookup2_shifted = lookup2 << t->p;
                  uint32_t index3;
                  for (index3 = 0; index3 < (1 << t->p); index3++)
                    {
                      uint32_t lookup3 = t->level3[index3 + lookup2_shifted];
                      uint32_t index4;
                      for (index4 = 0; index4 < 32; index4++)
                        if ((lookup3 >> index4) & 1)
                          fn ((((((index1 << t->q) + index2) << t->p) + index3) << 5) + index4);
                    }
                }
            }
        }
    }
}
#endif

#ifndef NO_FINALIZE
/* Finalize and shrink.  */
static void
CONCAT(TABLE,_finalize) (struct TABLE *t)
{
  size_t i, j, k;
  uint32_t reorder3[t->level3_size];
  uint32_t reorder2[t->level2_size];
  uint32_t level1_offset, level2_offset, level3_offset;

  /* Uniquify level3 blocks.  */
  k = 0;
  for (j = 0; j < t->level3_size; j++)
    {
      for (i = 0; i < k; i++)
        if (memcmp (&t->level3[i << t->p], &t->level3[j << t->p],
                    (1 << t->p) * sizeof (uint32_t)) == 0)
          break;
      /* Relocate block j to block i.  */
      reorder3[j] = i;
      if (i == k)
        {
          if (i != j)
            memcpy (&t->level3[i << t->p], &t->level3[j << t->p],
                    (1 << t->p) * sizeof (uint32_t));
          k++;
        }
    }
  t->level3_size = k;

  for (i = 0; i < (t->level2_size << t->q); i++)
    if (t->level2[i] != EMPTY)
      t->level2[i] = reorder3[t->level2[i]];

  /* Uniquify level2 blocks.  */
  k = 0;
  for (j = 0; j < t->level2_size; j++)
    {
      for (i = 0; i < k; i++)
        if (memcmp (&t->level2[i << t->q], &t->level2[j << t->q],
                    (1 << t->q) * sizeof (uint32_t)) == 0)
          break;
      /* Relocate block j to block i.  */
      reorder2[j] = i;
      if (i == k)
        {
          if (i != j)
            memcpy (&t->level2[i << t->q], &t->level2[j << t->q],
                    (1 << t->q) * sizeof (uint32_t));
          k++;
        }
    }
  t->level2_size = k;

  for (i = 0; i < t->level1_size; i++)
    if (t->level1[i] != EMPTY)
      t->level1[i] = reorder2[t->level1[i]];

  /* Create and fill the resulting compressed representation.  */
  t->result_size =
    5 * sizeof (uint32_t)
    + t->level1_size * sizeof (uint32_t)
    + (t->level2_size << t->q) * sizeof (uint32_t)
    + (t->level3_size << t->p) * sizeof (uint32_t);
  t->result = (char *) xmalloc (t->result_size);

  level1_offset =
    5 * sizeof (uint32_t);
  level2_offset =
    5 * sizeof (uint32_t)
    + t->level1_size * sizeof (uint32_t);
  level3_offset =
    5 * sizeof (uint32_t)
    + t->level1_size * sizeof (uint32_t)
    + (t->level2_size << t->q) * sizeof (uint32_t);

  ((uint32_t *) t->result)[0] = t->q + t->p + 5;
  ((uint32_t *) t->result)[1] = t->level1_size;
  ((uint32_t *) t->result)[2] = t->p + 5;
  ((uint32_t *) t->result)[3] = (1 << t->q) - 1;
  ((uint32_t *) t->result)[4] = (1 << t->p) - 1;

  for (i = 0; i < t->level1_size; i++)
    ((uint32_t *) (t->result + level1_offset))[i] =
      (t->level1[i] == EMPTY
       ? 0
       : (t->level1[i] << t->q) * sizeof (uint32_t) + level2_offset);

  for (i = 0; i < (t->level2_size << t->q); i++)
    ((uint32_t *) (t->result + level2_offset))[i] =
      (t->level2[i] == EMPTY
       ? 0
       : (t->level2[i] << t->p) * sizeof (uint32_t) + level3_offset);

  for (i = 0; i < (t->level3_size << t->p); i++)
    ((uint32_t *) (t->result + level3_offset))[i] = t->level3[i];

  if (t->level1_alloc > 0)
    free (t->level1);
  if (t->level2_alloc > 0)
    free (t->level2);
  if (t->level3_alloc > 0)
    free (t->level3);
}
#endif

#undef EMPTY
#undef TABLE
#undef ITERATE
#undef NO_FINALIZE
