/* Keep a unique copy of strings.

   Copyright (C) 2002, 2003, 2004, 2005, 2009, 2010 Free Software
   Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

   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>
#include "system.h"

#include <error.h>
#include <hash.h>
#include <quotearg.h>
#include <stdarg.h>

#include "uniqstr.h"

/*-----------------------.
| A uniqstr hash table.  |
`-----------------------*/

/* Initial capacity of uniqstr hash table.  */
#define HT_INITIAL_CAPACITY 257

static struct hash_table *uniqstrs_table = NULL;

/*-------------------------------------.
| Create the uniqstr for S if needed.  |
`-------------------------------------*/

uniqstr
uniqstr_new (char const *str)
{
  uniqstr res = hash_lookup (uniqstrs_table, str);
  if (!res)
    {
      /* First insertion in the hash. */
      res = xstrdup (str);
      if (!hash_insert (uniqstrs_table, res))
        xalloc_die ();
    }
  return res;
}

uniqstr
uniqstr_vsprintf (char const *format, ...)
{
  va_list args;
  size_t length;
  va_start (args, format);
  length = vsnprintf (NULL, 0, format, args);
  va_end (args);

  char res[length + 1];
  va_start (args, format);
  vsprintf (res, format, args);
  va_end (args);
  return uniqstr_new (res);
}

/*------------------------------.
| Abort if S is not a uniqstr.  |
`------------------------------*/

void
uniqstr_assert (char const *str)
{
  if (!hash_lookup (uniqstrs_table, str))
    {
      error (0, 0,
	     "not a uniqstr: %s", quotearg (str));
      abort ();
    }
}


/*--------------------.
| Print the uniqstr.  |
`--------------------*/

static inline bool
uniqstr_print (uniqstr ustr)
{
  fprintf (stderr, "%s\n", ustr);
  return true;
}

static bool
uniqstr_print_processor (void *ustr, void *null ATTRIBUTE_UNUSED)
{
  return uniqstr_print (ustr);
}


/*-----------------------.
| A uniqstr hash table.  |
`-----------------------*/

static bool
hash_compare_uniqstr (void const *m1, void const *m2)
{
  return strcmp (m1, m2) == 0;
}

static size_t
hash_uniqstr (void const *m, size_t tablesize)
{
  return hash_string (m, tablesize);
}

/*----------------------------.
| Create the uniqstrs table.  |
`----------------------------*/

void
uniqstrs_new (void)
{
  uniqstrs_table = hash_initialize (HT_INITIAL_CAPACITY,
				    NULL,
				    hash_uniqstr,
				    hash_compare_uniqstr,
				    free);
}


/*-------------------------------------.
| Perform a task on all the uniqstrs.  |
`-------------------------------------*/

static void
uniqstrs_do (Hash_processor processor, void *processor_data)
{
  hash_do_for_each (uniqstrs_table, processor, processor_data);
}


/*-----------------.
| Print them all.  |
`-----------------*/

void
uniqstrs_print (void)
{
  uniqstrs_do (uniqstr_print_processor, NULL);
}


/*--------------------.
| Free the uniqstrs.  |
`--------------------*/

void
uniqstrs_free (void)
{
  hash_free (uniqstrs_table);
}