harfbuzz/src/hb-common.c

/*
 * Copyright (C) 2009,2010  Red Hat, Inc.
 *
 *  This is part of HarfBuzz, a text shaping library.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the
 * above copyright notice and the following two paragraphs appear in
 * all copies of this software.
 *
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * Red Hat Author(s): Behdad Esfahbod
 */

#include "hb-private.h"

HB_BEGIN_DECLS


/* hb_tag_t */

hb_tag_t
hb_tag_from_string (const char *s)
{
  char tag[4];
  unsigned int i;

  if (!s)
    return HB_TAG_NONE;

  for (i = 0; i < 4 && s[i]; i++)
    tag[i] = s[i];
  for (; i < 4; i++)
    tag[i] = ' ';

  return HB_TAG_CHAR4 (tag);
}


/* hb_language_t */

struct _hb_language_t {
  const char s[1];
};

static const char canon_map[256] = {
   0,   0,   0,   0,   0,   0,   0,   0,    0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,    0,   0,   0,   0,   0,   0,   0,   0,
   0,   0,   0,   0,   0,   0,   0,   0,    0,   0,   0,   0,   0,  '-',  0,   0,
  '0', '1', '2', '3', '4', '5', '6', '7',  '8', '9',  0,   0,   0,   0,   0,   0,
  '-', 'a', 'b', 'c', 'd', 'e', 'f', 'g',  'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
  'p', 'q', 'r', 's', 't', 'u', 'v', 'w',  'x', 'y', 'z',  0,   0,   0,   0,  '-',
   0,  'a', 'b', 'c', 'd', 'e', 'f', 'g',  'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
  'p', 'q', 'r', 's', 't', 'u', 'v', 'w',  'x', 'y', 'z',  0,   0,   0,   0,   0
};

static hb_bool_t
lang_equal (const void *v1,
	    const void *v2)
{
  const unsigned char *p1 = v1;
  const unsigned char *p2 = v2;

  while (canon_map[*p1] && canon_map[*p1] == canon_map[*p2])
    {
      p1++, p2++;
    }

  return (canon_map[*p1] == canon_map[*p2]);
}

#if 0
static unsigned int
lang_hash (const void *key)
{
  const unsigned char *p = key;
  unsigned int h = 0;
  while (canon_map[*p])
    {
      h = (h << 5) - h + canon_map[*p];
      p++;
    }

  return h;
}
#endif


hb_language_t
hb_language_from_string (const char *str)
{
  static unsigned int num_langs;
  static unsigned int num_alloced;
  static hb_language_t *langs;
  unsigned int i;
  unsigned char *p;

  /* TODO Use a hash table or something */

  if (!str || !*str)
    return NULL;

  for (i = 0; i < num_langs; i++)
    if (lang_equal (str, langs[i]->s))
      return langs[i];

  if (unlikely (num_langs == num_alloced)) {
    unsigned int new_alloced = 2 * (8 + num_alloced);
    hb_language_t *new_langs = realloc (langs, new_alloced * sizeof (langs[0]));
    if (!new_langs)
      return NULL;
    num_alloced = new_alloced;
    langs = new_langs;
  }

  langs[i] = (hb_language_t) strdup (str);
  for (p = (unsigned char *) langs[i]->s; *p; p++)
    *p = canon_map[*p];

  num_langs++;

  return langs[i];
}

const char *
hb_language_to_string (hb_language_t language)
{
  return language->s;
}


HB_END_DECLS