dcigettext.c

让你在linux命令行下轻松支持中文显示和中文输入

#if defined HAVE_TSEARCH || defined _LIBC
  struct known_translation_t *search;
  struct known_translation_t **foundp = NULL;
  size_t msgid_len;
#endif
  size_t domainname_len;

  /* If no real MSGID is given return NULL.  */
  if (msgid1 == NULL)
    return NULL;

  __libc_rwlock_rdlock (_nl_state_lock);

  /* If DOMAINNAME is NULL, we are interested in the default domain.  If
     CATEGORY is not LC_MESSAGES this might not make much sense but the
     definition left this undefined.  */
  if (domainname == NULL)
    domainname = _nl_current_default_domain;

#if defined HAVE_TSEARCH || defined _LIBC
  msgid_len = strlen (msgid1) + 1;

  /* Try to find the translation among those which we found at
     some time.  */
  search = (struct known_translation_t *)
	   alloca (offsetof (struct known_translation_t, msgid) + msgid_len);
  memcpy (search->msgid, msgid1, msgid_len);
  search->domainname = (char *) domainname;
  search->category = category;

  foundp = (struct known_translation_t **) tfind (search, &root, transcmp);
  if (foundp != NULL && (*foundp)->counter == _nl_msg_cat_cntr)
    {
      /* Now deal with plural.  */
      if (plural)
	retval = plural_lookup ((*foundp)->domain, n, (*foundp)->translation,
				(*foundp)->translation_length);
      else
	retval = (char *) (*foundp)->translation;

      __libc_rwlock_unlock (_nl_state_lock);
      return retval;
    }
#endif

  /* Preserve the `errno' value.  */
  saved_errno = errno;

  /* See whether this is a SUID binary or not.  */
  DETERMINE_SECURE;

  /* First find matching binding.  */
  for (binding = _nl_domain_bindings; binding != NULL; binding = binding->next)
    {
      int compare = strcmp (domainname, binding->domainname);
      if (compare == 0)
	/* We found it!  */
	break;
      if (compare < 0)
	{
	  /* It is not in the list.  */
	  binding = NULL;
	  break;
	}
    }

  if (binding == NULL)
    dirname = (char *) _nl_default_dirname;
  else if (IS_ABSOLUTE_PATH (binding->dirname))
    dirname = binding->dirname;
  else
    {
      /* We have a relative path.  Make it absolute now.  */
      size_t dirname_len = strlen (binding->dirname) + 1;
      size_t path_max;
      char *ret;

      path_max = (unsigned int) PATH_MAX;
      path_max += 2;		/* The getcwd docs say to do this.  */

      for (;;)
	{
	  dirname = (char *) alloca (path_max + dirname_len);
	  ADD_BLOCK (block_list, dirname);

	  __set_errno (0);
	  ret = getcwd (dirname, path_max);
	  if (ret != NULL || errno != ERANGE)
	    break;

	  path_max += path_max / 2;
	  path_max += PATH_INCR;
	}

      if (ret == NULL)
	{
	  /* We cannot get the current working directory.  Don't signal an
	     error but simply return the default string.  */
	  FREE_BLOCKS (block_list);
	  __set_errno (saved_errno);
	  return (plural == 0
		  ? (char *) msgid1
		  /* Use the Germanic plural rule.  */
		  : n == 1 ? (char *) msgid1 : (char *) msgid2);
	}

      stpcpy (stpcpy (strchr (dirname, '\0'), "/"), binding->dirname);
    }

  /* Now determine the symbolic name of CATEGORY and its value.  */
  categoryname = category_to_name (category);
  categoryvalue = guess_category_value (category, categoryname);

  domainname_len = strlen (domainname);
  xdomainname = (char *) alloca (strlen (categoryname)
				 + domainname_len + 5);
  ADD_BLOCK (block_list, xdomainname);

  stpcpy (mempcpy (stpcpy (stpcpy (xdomainname, categoryname), "/"),
		  domainname, domainname_len),
	  ".mo");

  /* Creating working area.  */
  single_locale = (char *) alloca (strlen (categoryvalue) + 1);
  ADD_BLOCK (block_list, single_locale);


  /* Search for the given string.  This is a loop because we perhaps
     got an ordered list of languages to consider for the translation.  */
  while (1)
    {
      /* Make CATEGORYVALUE point to the next element of the list.  */
      while (categoryvalue[0] != '\0' && categoryvalue[0] == ':')
	++categoryvalue;
      if (categoryvalue[0] == '\0')
	{
	  /* The whole contents of CATEGORYVALUE has been searched but
	     no valid entry has been found.  We solve this situation
	     by implicitly appending a "C" entry, i.e. no translation
	     will take place.  */
	  single_locale[0] = 'C';
	  single_locale[1] = '\0';
	}
      else
	{
	  char *cp = single_locale;
	  while (categoryvalue[0] != '\0' && categoryvalue[0] != ':')
	    *cp++ = *categoryvalue++;
	  *cp = '\0';

	  /* When this is a SUID binary we must not allow accessing files
	     outside the dedicated directories.  */
	  if (ENABLE_SECURE && IS_PATH_WITH_DIR (single_locale))
	    /* Ingore this entry.  */
	    continue;
	}

      /* If the current locale value is C (or POSIX) we don't load a
	 domain.  Return the MSGID.  */
      if (strcmp (single_locale, "C") == 0
	  || strcmp (single_locale, "POSIX") == 0)
	{
	  FREE_BLOCKS (block_list);
	  __libc_rwlock_unlock (_nl_state_lock);
	  __set_errno (saved_errno);
	  return (plural == 0
		  ? (char *) msgid1
		  /* Use the Germanic plural rule.  */
		  : n == 1 ? (char *) msgid1 : (char *) msgid2);
	}


      /* Find structure describing the message catalog matching the
	 DOMAINNAME and CATEGORY.  */
      domain = _nl_find_domain (dirname, single_locale, xdomainname, binding);

      if (domain != NULL)
	{
	  retval = _nl_find_msg (domain, binding, msgid1, &retlen);

	  if (retval == NULL)
	    {
	      int cnt;

	      for (cnt = 0; domain->successor[cnt] != NULL; ++cnt)
		{
		  retval = _nl_find_msg (domain->successor[cnt], binding,
					 msgid1, &retlen);

		  if (retval != NULL)
		    {
		      domain = domain->successor[cnt];
		      break;
		    }
		}
	    }

	  if (retval != NULL)
	    {
	      /* Found the translation of MSGID1 in domain DOMAIN:
		 starting at RETVAL, RETLEN bytes.  */
	      FREE_BLOCKS (block_list);
	      __set_errno (saved_errno);
#if defined HAVE_TSEARCH || defined _LIBC
	      if (foundp == NULL)
		{
		  /* Create a new entry and add it to the search tree.  */
		  struct known_translation_t *newp;

		  newp = (struct known_translation_t *)
		    malloc (offsetof (struct known_translation_t, msgid)
			    + msgid_len + domainname_len + 1);
		  if (newp != NULL)
		    {
		      newp->domainname =
			mempcpy (newp->msgid, msgid1, msgid_len);
		      memcpy (newp->domainname, domainname, domainname_len + 1);
		      newp->category = category;
		      newp->counter = _nl_msg_cat_cntr;
		      newp->domain = domain;
		      newp->translation = retval;
		      newp->translation_length = retlen;

		      /* Insert the entry in the search tree.  */
		      foundp = (struct known_translation_t **)
			tsearch (newp, &root, transcmp);
		      if (foundp == NULL
			  || __builtin_expect (*foundp != newp, 0))
			/* The insert failed.  */
			free (newp);
		    }
		}
	      else
		{
		  /* We can update the existing entry.  */
		  (*foundp)->counter = _nl_msg_cat_cntr;
		  (*foundp)->domain = domain;
		  (*foundp)->translation = retval;
		  (*foundp)->translation_length = retlen;
		}
#endif
	      /* Now deal with plural.  */
	      if (plural)
		retval = plural_lookup (domain, n, retval, retlen);

	      __libc_rwlock_unlock (_nl_state_lock);
	      return retval;
	    }
	}
    }
  /* NOTREACHED */
}


char *
internal_function
_nl_find_msg (domain_file, domainbinding, msgid, lengthp)
     struct loaded_l10nfile *domain_file;
     struct binding *domainbinding;
     const char *msgid;
     size_t *lengthp;
{
  struct loaded_domain *domain;
  size_t act;
  char *result;
  size_t resultlen;

  if (domain_file->decided == 0)
    _nl_load_domain (domain_file, domainbinding);

  if (domain_file->data == NULL)
    return NULL;

  domain = (struct loaded_domain *) domain_file->data;

  /* Locate the MSGID and its translation.  */
  if (domain->hash_size > 2 && domain->hash_tab != NULL)
    {
      /* Use the hashing table.  */
      nls_uint32 len = strlen (msgid);
      nls_uint32 hash_val = hash_string (msgid);
      nls_uint32 idx = hash_val % domain->hash_size;
      nls_uint32 incr = 1 + (hash_val % (domain->hash_size - 2));

      while (1)
	{
	  nls_uint32 nstr = W (domain->must_swap, domain->hash_tab[idx]);

	  if (nstr == 0)
	    /* Hash table entry is empty.  */
	    return NULL;

	  /* Compare msgid with the original string at index nstr-1.
	     We compare the lengths with >=, not ==, because plural entries
	     are represented by strings with an embedded NUL.  */
	  if (W (domain->must_swap, domain->orig_tab[nstr - 1].length) >= len
	      && (strcmp (msgid,
			  domain->data + W (domain->must_swap,
					    domain->orig_tab[nstr - 1].offset))
		  == 0))
	    {
	      act = nstr - 1;
	      goto found;
	    }

	  if (idx >= domain->hash_size - incr)
	    idx -= domain->hash_size - incr;
	  else
	    idx += incr;
	}
      /* NOTREACHED */
    }
  else
    {
      /* Try the default method:  binary search in the sorted array of
	 messages.  */
      size_t top, bottom;

      bottom = 0;
      top = domain->nstrings;
      while (bottom < top)
	{
	  int cmp_val;

	  act = (bottom + top) / 2;
	  cmp_val = strcmp (msgid, (domain->data
				    + W (domain->must_swap,
					 domain->orig_tab[act].offset)));
	  if (cmp_val < 0)
	    top = act;
	  else if (cmp_val > 0)
	    bottom = act + 1;
	  else
	    goto found;
	}
      /* No translation was found.  */
      return NULL;
    }

 found:
  /* The translation was found at index ACT.  If we have to convert the
     string to use a different character set, this is the time.  */
  result = ((char *) domain->data
	    + W (domain->must_swap, domain->trans_tab[act].offset));
  resultlen = W (domain->must_swap, domain->trans_tab[act].length) + 1;

#if defined _LIBC || HAVE_ICONV
  if (domain->codeset_cntr
      != (domainbinding != NULL ? domainbinding->codeset_cntr : 0))
    {
      /* The domain's codeset has changed through bind_textdomain_codeset()
	 since the message catalog was initialized or last accessed.  We
	 have to reinitialize the converter.  */
      _nl_free_domain_conv (domain);
      _nl_init_domain_conv (domain_file, domain, domainbinding);
    }

  if (
# ifdef _LIBC
      domain->conv != (__gconv_t) -1
# else
#  if HAVE_ICONV
      domain->conv != (iconv_t) -1
#  endif
# endif
      )
    {
      /* We are supposed to do a conversion.  First allocate an
	 appropriate table with the same structure as the table
	 of translations in the file, where we can put the pointers
	 to the converted strings in.
	 There is a slight complication with plural entries.  They
	 are represented by consecutive NUL terminated strings.  We
	 handle this case by converting RESULTLEN bytes, including
	 NULs.  */

      if (domain->conv_tab == NULL
	  && ((domain->conv_tab = (char **) calloc (domain->nstrings,
						    sizeof (char *)))
	      == NULL))
	/* Mark that we didn't succeed allocating a table.  */
	domain->conv_tab = (char **) -1;

      if (__builtin_expect (domain->conv_tab == (char **) -1, 0))
	/* Nothing we can do, no more memory.  */
	goto converted;

      if (domain->conv_tab[act] == NULL)
	{
	  /* We haven't used this string so far, so it is not
	     translated yet.  Do this now.  */
	  /* We use a bit more efficient memory handling.
	     We allocate always larger blocks which get used over
	     time.  This is faster than many small allocations.   */
	  __libc_lock_define_initialized (static, lock)
# define INITIAL_BLOCK_SIZE	4080
	  static unsigned char *freemem;
	  static size_t freemem_size;

	  const unsigned char *inbuf;
	  unsigned char *outbuf;
	  int malloc_count;
# ifndef _LIBC
	  transmem_block_t *transmem_list = NULL;
# endif

	  __libc_lock_lock (lock);

	  inbuf = (const unsigned char *) result;
	  outbuf = freemem + sizeof (size_t);

	  malloc_count = 0;
	  while (1)
	    {
	      transmem_block_t *newmem;
# ifdef _LIBC
	      size_t non_reversible;
	      int res;

	      if (freemem_size < sizeof (size_t))