rx.c

ac3的解码程序

#endif
{
  int x;
  unsigned long hash = (unsigned long)rx_bitset_hash;

  for (x = rx_bitset_numb_subsets(size) - 1; x >= 0; --x)
    hash ^= rx_bitset_subset_val(b, x);

  return hash;
}


RX_DECL RX_subset rx_subset_singletons [RX_subset_bits] = 
{
  0x1,
  0x2,
  0x4,
  0x8,
  0x10,
  0x20,
  0x40,
  0x80,
  0x100,
  0x200,
  0x400,
  0x800,
  0x1000,
  0x2000,
  0x4000,
  0x8000,
  0x10000,
  0x20000,
  0x40000,
  0x80000,
  0x100000,
  0x200000,
  0x400000,
  0x800000,
  0x1000000,
  0x2000000,
  0x4000000,
  0x8000000,
  0x10000000,
  0x20000000,
  0x40000000,
  0x80000000
};

#ifdef RX_DEBUG

#ifdef __STDC__
static void
print_cset (struct rx *rx, rx_Bitset cset, FILE * fp)
#else
static void
print_cset (rx, cset, fp)
     struct rx *rx;
     rx_Bitset cset;
     FILE * fp;
#endif
{
  int x;
  fputc ('[', fp);
  for (x = 0; x < rx->local_cset_size; ++x)
    if (RX_bitset_member (cset, x))
      {
	if (isprint(x))
	  fputc (x, fp);
	else
	  fprintf (fp, "\\0%o ", x);
      }
  fputc (']', fp);
}

#endif /*  RX_DEBUG */



static unsigned long rx_hash_masks[4] =
{
  0x12488421,
  0x96699669,
  0xbe7dd7eb,
  0xffffffff
};


/* Hash tables */
#ifdef __STDC__
RX_DECL struct rx_hash_item * 
rx_hash_find (struct rx_hash * table,
	      unsigned long hash,
	      void * value,
	      struct rx_hash_rules * rules)
#else
RX_DECL struct rx_hash_item * 
rx_hash_find (table, hash, value, rules)
     struct rx_hash * table;
     unsigned long hash;
     void * value;
     struct rx_hash_rules * rules;
#endif
{
  rx_hash_eq eq = rules->eq;
  int maskc = 0;
  long mask = rx_hash_masks [0];
  int bucket = (hash & mask) % 13;

  while (table->children [bucket])
    {
      table = table->children [bucket];
      ++maskc;
      mask = rx_hash_masks[maskc];
      bucket = (hash & mask) % 13;
    }

  {
    struct rx_hash_item * it = table->buckets[bucket];
    while (it)
      if (eq (it->data, value))
	return it;
      else
	it = it->next_same_hash;
  }

  return 0;
}


#ifdef __STDC__
RX_DECL struct rx_hash_item *
rx_hash_store (struct rx_hash * table,
	       unsigned long hash,
	       void * value,
	       struct rx_hash_rules * rules)
#else
RX_DECL struct rx_hash_item *
rx_hash_store (table, hash, value, rules)
     struct rx_hash * table;
     unsigned long hash;
     void * value;
     struct rx_hash_rules * rules;
#endif
{
  rx_hash_eq eq = rules->eq;
  int maskc = 0;
  long mask = rx_hash_masks[0];
  int bucket = (hash & mask) % 13;
  int depth = 0;
  
  while (table->children [bucket])
    {
      table = table->children [bucket];
      ++maskc;
      mask = rx_hash_masks[maskc];
      bucket = (hash & mask) % 13;
      ++depth;
    }
  
  {
    struct rx_hash_item * it = table->buckets[bucket];
    while (it)
      if (eq (it->data, value))
	return it;
      else
	it = it->next_same_hash;
  }
  
  {
    if (   (depth < 3)
	&& (table->bucket_size [bucket] >= 4))
      {
	struct rx_hash * newtab = ((struct rx_hash *)
				   rules->hash_alloc (rules));
	if (!newtab)
	  goto add_to_bucket;
	bzero (newtab, sizeof (*newtab));
	newtab->parent = table;
	{
	  struct rx_hash_item * them = table->buckets[bucket];
	  unsigned long newmask = rx_hash_masks[maskc + 1];
	  while (them)
	    {
	      struct rx_hash_item * save = them->next_same_hash;
	      int new_buck = (them->hash & newmask) % 13;
	      them->next_same_hash = newtab->buckets[new_buck];
	      newtab->buckets[new_buck] = them;
	      them->table = newtab;
	      them = save;
	      ++newtab->bucket_size[new_buck];
	      ++newtab->refs;
	    }
	  table->refs = (table->refs - table->bucket_size[bucket] + 1);
	  table->bucket_size[bucket] = 0;
	  table->buckets[bucket] = 0;
	  table->children[bucket] = newtab;
	  table = newtab;
	  bucket = (hash & newmask) % 13;
	}
      }
  }
 add_to_bucket:
  {
    struct rx_hash_item  * it = ((struct rx_hash_item *)
				 rules->hash_item_alloc (rules, value));
    if (!it)
      return 0;
    it->hash = hash;
    it->table = table;
    /* DATA and BINDING are to be set in hash_item_alloc */
    it->next_same_hash = table->buckets [bucket];
    table->buckets[bucket] = it;
    ++table->bucket_size [bucket];
    ++table->refs;
    return it;
  }
}


#ifdef __STDC__
RX_DECL void
rx_hash_free (struct rx_hash_item * it, struct rx_hash_rules * rules)
#else
RX_DECL void
rx_hash_free (it, rules)
     struct rx_hash_item * it;
     struct rx_hash_rules * rules;
#endif
{
  if (it)
    {
      struct rx_hash * table = it->table;
      unsigned long hash = it->hash;
      int depth = (table->parent
		   ? (table->parent->parent
		      ? (table->parent->parent->parent
			 ? 3
			 : 2)
		      : 1)
		   : 0);
      int bucket = (hash & rx_hash_masks [depth]) % 13;
      struct rx_hash_item ** pos = &table->buckets [bucket];
      
      while (*pos != it)
	pos = &(*pos)->next_same_hash;
      *pos = it->next_same_hash;
      rules->free_hash_item (it, rules);
      --table->bucket_size[bucket];
      --table->refs;
      while (!table->refs && depth)
	{
	  struct rx_hash * save = table;
	  table = table->parent;
	  --depth;
	  bucket = (hash & rx_hash_masks [depth]) % 13;
	  --table->refs;
	  table->children[bucket] = 0;
	  rules->free_hash (save, rules);
	}
    }
}

#ifdef __STDC__
RX_DECL void
rx_free_hash_table (struct rx_hash * tab, rx_hash_freefn freefn,
		    struct rx_hash_rules * rules)
#else
RX_DECL void
rx_free_hash_table (tab, freefn, rules)
     struct rx_hash * tab;
     rx_hash_freefn freefn;
     struct rx_hash_rules * rules;
#endif
{
  int x;

  for (x = 0; x < 13; ++x)
    if (tab->children[x])
      {
	rx_free_hash_table (tab->children[x], freefn, rules);
	rules->free_hash (tab->children[x], rules);
      }
    else
      {
	struct rx_hash_item * them = tab->buckets[x];
	while (them)
	  {
	    struct rx_hash_item * that = them;
	    them = that->next_same_hash;
	    freefn (that);
	    rules->free_hash_item (that, rules);
	  }
      }
}



/* Utilities for manipulating bitset represntations of characters sets. */

#ifdef __STDC__
RX_DECL rx_Bitset
rx_cset (struct rx *rx)
#else
RX_DECL rx_Bitset
rx_cset (rx)
     struct rx *rx;
#endif
{
  rx_Bitset b = (rx_Bitset) malloc (rx_sizeof_bitset (rx->local_cset_size));
  if (b)
    rx_bitset_null (rx->local_cset_size, b);
  return b;
}


#ifdef __STDC__
RX_DECL rx_Bitset
rx_copy_cset (struct rx *rx, rx_Bitset a)
#else
RX_DECL rx_Bitset
rx_copy_cset (rx, a)
     struct rx *rx;
     rx_Bitset a;
#endif
{
  rx_Bitset cs = rx_cset (rx);

  if (cs)
    rx_bitset_union (rx->local_cset_size, cs, a);

  return cs;
}


#ifdef __STDC__
RX_DECL void
rx_free_cset (struct rx * rx, rx_Bitset c)
#else
RX_DECL void
rx_free_cset (rx, c)
     struct rx * rx;
     rx_Bitset c;
#endif
{
  if (c)
    free ((char *)c);
}


/* Hash table memory allocation policy for the regexp compiler */

#ifdef __STDC__
static struct rx_hash *
compiler_hash_alloc (struct rx_hash_rules * rules)
#else
static struct rx_hash *
compiler_hash_alloc (rules)
     struct rx_hash_rules * rules;
#endif
{
  return (struct rx_hash *)malloc (sizeof (struct rx_hash));
}


#ifdef __STDC__
static struct rx_hash_item *
compiler_hash_item_alloc (struct rx_hash_rules * rules, void * value)
#else
static struct rx_hash_item *
compiler_hash_item_alloc (rules, value)
     struct rx_hash_rules * rules;
     void * value;
#endif
{
  struct rx_hash_item * it;
  it = (struct rx_hash_item *)malloc (sizeof (*it));
  if (it)
    {
      it->data = value;
      it->binding = 0;
    }
  return it;
}


#ifdef __STDC__
static void
compiler_free_hash (struct rx_hash * tab,
		    struct rx_hash_rules * rules)
#else
static void
compiler_free_hash (tab, rules)
     struct rx_hash * tab;
     struct rx_hash_rules * rules;
#endif
{
  free ((char *)tab);
}


#ifdef __STDC__
static void
compiler_free_hash_item (struct rx_hash_item * item,
			 struct rx_hash_rules * rules)
#else
static void
compiler_free_hash_item (item, rules)
     struct rx_hash_item * item;
     struct rx_hash_rules * rules;
#endif
{
  free ((char *)item);
}


/* This page: REXP_NODE (expression tree) structures. */

#ifdef __STDC__
RX_DECL struct rexp_node *
rexp_node (struct rx *rx,
	   enum rexp_node_type type)
#else
RX_DECL struct rexp_node *
rexp_node (rx, type)
     struct rx *rx;
     enum rexp_node_type type;
#endif
{
  struct rexp_node *n;

  n = (struct rexp_node *)malloc (sizeof (*n));
  bzero (n, sizeof (*n));
  if (n)
    n->type = type;
  return n;
}


/* free_rexp_node assumes that the bitset passed to rx_mk_r_cset
 * can be freed using rx_free_cset.
 */
#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_cset (struct rx * rx,
	      rx_Bitset b)
#else
RX_DECL struct rexp_node *
rx_mk_r_cset (rx, b)
     struct rx * rx;
     rx_Bitset b;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_cset);
  if (n)
    n->params.cset = b;
  return n;
}


#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_concat (struct rx * rx,
		struct rexp_node * a,
		struct rexp_node * b)
#else
RX_DECL struct rexp_node *
rx_mk_r_concat (rx, a, b)
     struct rx * rx;
     struct rexp_node * a;
     struct rexp_node * b;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_concat);
  if (n)
    {
      n->params.pair.left = a;
      n->params.pair.right = b;
    }
  return n;
}


#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_alternate (struct rx * rx,
		   struct rexp_node * a,
		   struct rexp_node * b)
#else
RX_DECL struct rexp_node *
rx_mk_r_alternate (rx, a, b)
     struct rx * rx;
     struct rexp_node * a;
     struct rexp_node * b;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_alternate);
  if (n)
    {
      n->params.pair.left = a;
      n->params.pair.right = b;
    }
  return n;
}


#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_opt (struct rx * rx,
	     struct rexp_node * a)
#else
RX_DECL struct rexp_node *
rx_mk_r_opt (rx, a)
     struct rx * rx;
     struct rexp_node * a;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_opt);
  if (n)
    {
      n->params.pair.left = a;
      n->params.pair.right = 0;
    }
  return n;
}


#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_star (struct rx * rx,
	      struct rexp_node * a)
#else
RX_DECL struct rexp_node *
rx_mk_r_star (rx, a)
     struct rx * rx;
     struct rexp_node * a;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_star);
  if (n)
    {
      n->params.pair.left = a;
      n->params.pair.right = 0;
    }
  return n;
}


#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_2phase_star (struct rx * rx,
		     struct rexp_node * a,
		     struct rexp_node * b)
#else
RX_DECL struct rexp_node *
rx_mk_r_2phase_star (rx, a, b)
     struct rx * rx;
     struct rexp_node * a;
     struct rexp_node * b;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_2phase_star);
  if (n)
    {
      n->params.pair.left = a;
      n->params.pair.right = b;
    }
  return n;
}


#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_side_effect (struct rx * rx,
		     rx_side_effect a)
#else
RX_DECL struct rexp_node *
rx_mk_r_side_effect (rx, a)
     struct rx * rx;
     rx_side_effect a;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_side_effect);
  if (n)
    {
      n->params.side_effect = a;
      n->params.pair.right = 0;
    }
  return n;
}


#ifdef __STDC__
RX_DECL struct rexp_node *
rx_mk_r_data  (struct rx * rx,
	       void * a)
#else
RX_DECL struct rexp_node *
rx_mk_r_data  (rx, a)
     struct rx * rx;
     void * a;
#endif
{
  struct rexp_node * n = rexp_node (rx, r_data);
  if (n)