mp_obj_t mp_builtin___import__(size_t n_args, const mp_obj_t *args) {
#if DEBUG_PRINT
    DEBUG_printf("__import__:\n");
    for (size_t i = 0; i < n_args; i++) {
        DEBUG_printf("  ");
        mp_obj_print(args[i], PRINT_REPR);
        DEBUG_printf("\n");
    }
#endif

    mp_obj_t module_name = args[0];
    mp_obj_t fromtuple = mp_const_none;
    mp_int_t level = 0;
    if (n_args >= 4) {
        fromtuple = args[3];
        if (n_args >= 5) {
            level = MP_OBJ_SMALL_INT_VALUE(args[4]);
            if (level < 0) {
                mp_raise_ValueError(NULL);
            }
        }
    }

    size_t mod_len;
    const char *mod_str = mp_obj_str_get_data(module_name, &mod_len);

    if (level != 0) {
        // What we want to do here is to take name of current module,
        // chop <level> trailing components, and concatenate with passed-in
        // module name, thus resolving relative import name into absolute.
        // This even appears to be correct per
        // http://legacy.python.org/dev/peps/pep-0328/#relative-imports-and-name
        // "Relative imports use a module's __name__ attribute to determine that
        // module's position in the package hierarchy."
        level--;
        mp_obj_t this_name_q = mp_obj_dict_get(MP_OBJ_FROM_PTR(mp_globals_get()), MP_OBJ_NEW_QSTR(MP_QSTR___name__));
        assert(this_name_q != MP_OBJ_NULL);
        #if MICROPY_CPYTHON_COMPAT
        if (MP_OBJ_QSTR_VALUE(this_name_q) == MP_QSTR___main__) {
            // This is a module run by -m command-line switch, get its real name from backup attribute
            this_name_q = mp_obj_dict_get(MP_OBJ_FROM_PTR(mp_globals_get()), MP_OBJ_NEW_QSTR(MP_QSTR___main__));
        }
        #endif
        mp_map_t *globals_map = &mp_globals_get()->map;
        mp_map_elem_t *elem = mp_map_lookup(globals_map, MP_OBJ_NEW_QSTR(MP_QSTR___path__), MP_MAP_LOOKUP);
        bool is_pkg = (elem != NULL);

#if DEBUG_PRINT
        DEBUG_printf("Current module/package: ");
        mp_obj_print(this_name_q, PRINT_REPR);
        DEBUG_printf(", is_package: %d", is_pkg);
        DEBUG_printf("\n");
#endif

        size_t this_name_l;
        const char *this_name = mp_obj_str_get_data(this_name_q, &this_name_l);

        const char *p = this_name + this_name_l;
        if (!is_pkg) {
            // We have module, but relative imports are anchored at package, so
            // go there.
            chop_component(this_name, &p);
        }

        while (level--) {
            chop_component(this_name, &p);
        }

        // We must have some component left over to import from
        if (p == this_name) {
            mp_raise_ValueError("cannot perform relative import");
        }

        uint new_mod_l = (mod_len == 0 ? (size_t)(p - this_name) : (size_t)(p - this_name) + 1 + mod_len);
        char *new_mod = mp_local_alloc(new_mod_l);
        memcpy(new_mod, this_name, p - this_name);
        if (mod_len != 0) {
            new_mod[p - this_name] = '.';
            memcpy(new_mod + (p - this_name) + 1, mod_str, mod_len);
        }

        qstr new_mod_q = qstr_from_strn(new_mod, new_mod_l);
        mp_local_free(new_mod);
        DEBUG_printf("Resolved base name for relative import: '%s'\n", qstr_str(new_mod_q));
        module_name = MP_OBJ_NEW_QSTR(new_mod_q);
        mod_str = qstr_str(new_mod_q);
        mod_len = new_mod_l;
    }

    // check if module already exists
    qstr module_name_qstr = mp_obj_str_get_qstr(module_name);
    mp_obj_t module_obj = mp_module_get(module_name_qstr);
    if (module_obj != MP_OBJ_NULL) {
        DEBUG_printf("Module already loaded\n");
        // If it's not a package, return module right away
        char *p = strchr(mod_str, '.');
        if (p == NULL) {
            return module_obj;
        }
        // If fromlist is not empty, return leaf module
//.........这里部分代码省略.........

int					/* O - Number of options found */
cupsParseOptions(
    const char    *arg,			/* I - Argument to parse */
    int           num_options,		/* I - Number of options */
    cups_option_t **options)		/* O - Options found */
{
  char	*copyarg,			/* Copy of input string */
	*ptr,				/* Pointer into string */
	*name,				/* Pointer to name */
	*value,				/* Pointer to value */
	sep,				/* Separator character */
	quote;				/* Quote character */


  DEBUG_printf(("cupsParseOptions(arg=\"%s\", num_options=%d, options=%p)",
                arg, num_options, options));

 /*
  * Range check input...
  */

  if (!arg)
  {
    DEBUG_printf(("1cupsParseOptions: Returning %d", num_options));
    return (num_options);
  }

  if (!options || num_options < 0)
  {
    DEBUG_puts("1cupsParseOptions: Returning 0");
    return (0);
  }

 /*
  * Make a copy of the argument string and then divide it up...
  */

  if ((copyarg = strdup(arg)) == NULL)
  {
    DEBUG_puts("1cupsParseOptions: Unable to copy arg string");
    DEBUG_printf(("1cupsParseOptions: Returning %d", num_options));
    return (num_options);
  }

  if (*copyarg == '{')
  {
   /*
    * Remove surrounding {} so we can parse "{name=value ... name=value}"...
    */

    if ((ptr = copyarg + strlen(copyarg) - 1) > copyarg && *ptr == '}')
    {
      *ptr = '\0';
      ptr  = copyarg + 1;
    }
    else
      ptr = copyarg;
  }
  else
    ptr = copyarg;

 /*
  * Skip leading spaces...
  */

  while (_cups_isspace(*ptr))
    ptr ++;

 /*
  * Loop through the string...
  */

  while (*ptr != '\0')
  {
   /*
    * Get the name up to a SPACE, =, or end-of-string...
    */

    name = ptr;
    while (!strchr("\f\n\r\t\v =", *ptr) && *ptr)
      ptr ++;

   /*
    * Avoid an empty name...
    */

    if (ptr == name)
      break;

   /*
    * Skip trailing spaces...
    */

    while (_cups_isspace(*ptr))
      *ptr++ = '\0';

    if ((sep = *ptr) == '=')
      *ptr++ = '\0';

    DEBUG_printf(("2cupsParseOptions: name=\"%s\"", name));
//.........这里部分代码省略.........

static int				/* O - Index of match */
cups_find_option(
    const char    *name,		/* I - Option name */
    int           num_options,		/* I - Number of options */
    cups_option_t *options,		/* I - Options */
    int           prev,			/* I - Previous index */
    int           *rdiff)		/* O - Difference of match */
{
  int		left,			/* Low mark for binary search */
		right,			/* High mark for binary search */
		current,		/* Current index */
		diff;			/* Result of comparison */
  cups_option_t	key;			/* Search key */


  DEBUG_printf(("7cups_find_option(name=\"%s\", num_options=%d, options=%p, "
	        "prev=%d, rdiff=%p)", name, num_options, options, prev,
		rdiff));

#ifdef DEBUG
  for (left = 0; left < num_options; left ++)
    DEBUG_printf(("9cups_find_option: options[%d].name=\"%s\", .value=\"%s\"",
                  left, options[left].name, options[left].value));
#endif /* DEBUG */

  key.name = (char *)name;

  if (prev >= 0)
  {
   /*
    * Start search on either side of previous...
    */

    if ((diff = cups_compare_options(&key, options + prev)) == 0 ||
        (diff < 0 && prev == 0) ||
	(diff > 0 && prev == (num_options - 1)))
    {
      *rdiff = diff;
      return (prev);
    }
    else if (diff < 0)
    {
     /*
      * Start with previous on right side...
      */

      left  = 0;
      right = prev;
    }
    else
    {
     /*
      * Start wih previous on left side...
      */

      left  = prev;
      right = num_options - 1;
    }
  }
  else
  {
   /*
    * Start search in the middle...
    */

    left  = 0;
    right = num_options - 1;
  }

  do
  {
    current = (left + right) / 2;
    diff    = cups_compare_options(&key, options + current);

    if (diff == 0)
      break;
    else if (diff < 0)
      right = current;
    else
      left = current;
  }
  while ((right - left) > 1);

  if (diff != 0)
  {
   /*
    * Check the last 1 or 2 elements...
    */

    if ((diff = cups_compare_options(&key, options + left)) <= 0)
      current = left;
    else
    {
      diff    = cups_compare_options(&key, options + right);
      current = right;
    }
  }

 /*
  * Return the closest destination and the difference...
//.........这里部分代码省略.........

cups_dentry_t *				/* O - Directory entry or @code [email protected] when there are no more */
cupsDirRead(cups_dir_t *dp)		/* I - Directory pointer */
{
  struct dirent	*entry;			/* Pointer to entry */
  char		filename[1024];		/* Full filename */
#  ifdef HAVE_PTHREAD_H
  char		buffer[sizeof(struct dirent) + 1024];
					/* Directory entry buffer */
#  endif /* HAVE_PTHREAD_H */


  DEBUG_printf(("2cupsDirRead(dp=%p)", (void *)dp));

 /*
  * Range check input...
  */

  if (!dp)
    return (NULL);

 /*
  * Try reading an entry that is not "." or ".."...
  */

  for (;;)
  {
#  ifdef HAVE_PTHREAD_H
   /*
    * Read the next entry using the reentrant version of readdir...
    */

    if (readdir_r(dp->dir, (struct dirent *)buffer, &entry))
    {
      DEBUG_printf(("3cupsDirRead: readdir_r() failed - %s\n", strerror(errno)));
      return (NULL);
    }

    if (!entry)
    {
      DEBUG_puts("3cupsDirRead: readdir_r() returned a NULL pointer!");
      return (NULL);
    }

    DEBUG_printf(("4cupsDirRead: readdir_r() returned \"%s\"...",
                  entry->d_name));

#  else
   /*
    * Read the next entry using the original version of readdir...
    */

    if ((entry = readdir(dp->dir)) == NULL)
    {
      DEBUG_puts("3cupsDirRead: readdir() returned a NULL pointer!");
      return (NULL);
    }

    DEBUG_printf(("4cupsDirRead: readdir() returned \"%s\"...", entry->d_name));

#  endif /* HAVE_PTHREAD_H */

   /*
    * Skip "." and ".."...
    */

    if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, ".."))
      continue;

   /*
    * Copy the name over and get the file information...
    */

    strlcpy(dp->entry.filename, entry->d_name, sizeof(dp->entry.filename));

    snprintf(filename, sizeof(filename), "%s/%s", dp->directory, entry->d_name);

    if (stat(filename, &(dp->entry.fileinfo)))
    {
      DEBUG_printf(("3cupsDirRead: stat() failed for \"%s\" - %s...", filename,
                    strerror(errno)));
      continue;
    }

   /*
    * Return the entry...
    */

    return (&(dp->entry));
  }
}

void
_cupsRasterAddError(const char *f,	/* I - Printf-style error message */
                    ...)		/* I - Additional arguments as needed */
{
  _cups_raster_error_t	*buf = get_error_buffer();
					/* Error buffer */
  va_list	ap;			/* Pointer to additional arguments */
  char		s[2048];		/* Message string */
  ssize_t	bytes;			/* Bytes in message string */


  DEBUG_printf(("_cupsRasterAddError(f=\"%s\", ...)", f));

  va_start(ap, f);
  bytes = vsnprintf(s, sizeof(s), f, ap);
  va_end(ap);

  if (bytes <= 0)
    return;

  DEBUG_printf(("1_cupsRasterAddError: %s", s));

  bytes ++;

  if ((size_t)bytes >= sizeof(s))
    return;

  if (bytes > (ssize_t)(buf->end - buf->current))
  {
   /*
    * Allocate more memory...
    */

    char	*temp;			/* New buffer */
    size_t	size;			/* Size of buffer */


    size = (size_t)(buf->end - buf->start + 2 * bytes + 1024);

    if (buf->start)
      temp = realloc(buf->start, size);
    else
      temp = malloc(size);

    if (!temp)
      return;

   /*
    * Update pointers...
    */

    buf->end     = temp + size;
    buf->current = temp + (buf->current - buf->start);
    buf->start   = temp;
  }

 /*
  * Append the message to the end of the current string...
  */

  memcpy(buf->current, s, (size_t)bytes);
  buf->current += bytes - 1;
}

int					/* O - 1 on success, 0 on failure */
pwgFormatSizeName(char       *keyword,	/* I - Keyword buffer */
		  size_t     keysize,	/* I - Size of keyword buffer */
		  const char *prefix,	/* I - Prefix for PWG size or @code [email protected] for automatic */
		  const char *name,	/* I - Size name or @code [email protected] */
		  int        width,	/* I - Width of page in 2540ths */
		  int        length,	/* I - Length of page in 2540ths */
		  const char *units)	/* I - Units - "in", "mm", or @code [email protected] for automatic */
{
  char		usize[12 + 1 + 12 + 3],	/* Unit size: NNNNNNNNNNNNxNNNNNNNNNNNNuu */
		*uptr;			/* Pointer into unit size */
  char		*(*format)(char *, size_t, int);
					/* Formatting function */


 /*
  * Range check input...
  */

  DEBUG_printf(("pwgFormatSize(keyword=%p, keysize=" CUPS_LLFMT ", prefix=\"%s\", name=\"%s\", width=%d, length=%d, units=\"%s\")", (void *)keyword, CUPS_LLCAST keysize, prefix, name, width, length, units));

  if (keyword)
    *keyword = '\0';

  if (!keyword || keysize < 32 || width < 0 || length < 0 ||
      (units && strcmp(units, "in") && strcmp(units, "mm")))
  {
    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Invalid media name arguments."),
                  1);
    return (0);
  }

  if (name)
  {
   /*
    * Validate name...
    */

    const char *nameptr;		/* Pointer into name */

    for (nameptr = name; *nameptr; nameptr ++)
      if (!(*nameptr >= 'a' && *nameptr <= 'z') &&
          !(*nameptr >= '0' && *nameptr <= '9') &&
          *nameptr != '.' && *nameptr != '-')
      {
        _cupsSetError(IPP_STATUS_ERROR_INTERNAL,
                      _("Invalid media name arguments."), 1);
        return (0);
      }
  }
  else
    name = usize;

  if (prefix && !strcmp(prefix, "disc"))
    width = 4000;			/* Disc sizes use hardcoded 40mm inner diameter */

  if (!units)
  {
    if ((width % 635) == 0 && (length % 635) == 0)
    {
     /*
      * Use inches since the size is a multiple of 1/4 inch.
      */

      units = "in";
    }
    else
    {
     /*
      * Use millimeters since the size is not a multiple of 1/4 inch.
      */

      units = "mm";
    }
  }

  if (!strcmp(units, "in"))
  {
    format = pwg_format_inches;

    if (!prefix)
      prefix = "oe";
  }
  else
  {
    format = pwg_format_millimeters;

    if (!prefix)
      prefix = "om";
  }

 /*
  * Format the size string...
  */

  uptr = usize;
  (*format)(uptr, sizeof(usize) - (size_t)(uptr - usize), width);
  uptr += strlen(uptr);
  *uptr++ = 'x';
  (*format)(uptr, sizeof(usize) - (size_t)(uptr - usize), length);
//.........这里部分代码省略.........

STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
    // This function is pretty complicated.  It's main aim is to be efficient in speed and RAM
    // usage for the common case of positional only args.
    //
    // extra_args layout: def_args, var_arg tuple, kwonly args, var_kw dict

    DEBUG_printf("Input n_args: %d, n_kw: %d\n", n_args, n_kw);
    DEBUG_printf("Input pos args: ");
    dump_args(args, n_args);
    DEBUG_printf("Input kw args: ");
    dump_args(args + n_args, n_kw * 2);
    mp_obj_fun_bc_t *self = self_in;
    DEBUG_printf("Func n_def_args: %d\n", self->n_def_args);

    const mp_obj_t *kwargs = args + n_args;
    mp_obj_t *extra_args = self->extra_args + self->n_def_args;
    uint n_extra_args = 0;

    // check positional arguments

    if (n_args > self->n_pos_args) {
        // given more than enough arguments
        if (!self->takes_var_args) {
            fun_pos_args_mismatch(self, self->n_pos_args, n_args);
        }
        // put extra arguments in varargs tuple
        *extra_args = mp_obj_new_tuple(n_args - self->n_pos_args, args + self->n_pos_args);
        n_extra_args = 1;
        n_args = self->n_pos_args;
    } else {
        if (self->takes_var_args) {
            DEBUG_printf("passing empty tuple as *args\n");
            *extra_args = mp_const_empty_tuple;
            n_extra_args = 1;
        }
        // Apply processing and check below only if we don't have kwargs,
        // otherwise, kw handling code below has own extensive checks.
        if (n_kw == 0) {
            if (n_args >= self->n_pos_args - self->n_def_args) {
                // given enough arguments, but may need to use some default arguments
                extra_args -= self->n_pos_args - n_args;
                n_extra_args += self->n_pos_args - n_args;
            } else {
                fun_pos_args_mismatch(self, self->n_pos_args - self->n_def_args, n_args);
            }
        }
    }

    // check keyword arguments

    if (n_kw != 0) {
        // We cannot use dynamically-sized array here, because GCC indeed
        // deallocates it on leaving defining scope (unlike most static stack allocs).
        // So, we have 2 choices: allocate it unconditionally at the top of function
        // (wastes stack), or use alloca which is guaranteed to dealloc on func exit.
        //mp_obj_t flat_args[self->n_args];
        mp_obj_t *flat_args = alloca((self->n_pos_args + self->n_kwonly_args) * sizeof(mp_obj_t));
        for (int i = self->n_pos_args + self->n_kwonly_args - 1; i >= 0; i--) {
            flat_args[i] = MP_OBJ_NULL;
        }
        memcpy(flat_args, args, sizeof(*args) * n_args);
        DEBUG_printf("Initial args: ");
        dump_args(flat_args, self->n_pos_args + self->n_kwonly_args);

        mp_obj_t dict = MP_OBJ_NULL;
        if (self->takes_kw_args) {
            dict = mp_obj_new_dict(n_kw); // TODO: better go conservative with 0?
        }
        for (uint i = 0; i < n_kw; i++) {
            qstr arg_name = MP_OBJ_QSTR_VALUE(kwargs[2 * i]);
            for (uint j = 0; j < self->n_pos_args + self->n_kwonly_args; j++) {
                if (arg_name == self->args[j]) {
                    if (flat_args[j] != MP_OBJ_NULL) {
                        nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError,
                            "function got multiple values for argument '%s'", qstr_str(arg_name)));
                    }
                    flat_args[j] = kwargs[2 * i + 1];
                    goto continue2;
                }
            }
            // Didn't find name match with positional args
            if (!self->takes_kw_args) {
                nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "function does not take keyword arguments"));
            }
            mp_obj_dict_store(dict, kwargs[2 * i], kwargs[2 * i + 1]);
continue2:;
        }
        DEBUG_printf("Args with kws flattened: ");
        dump_args(flat_args, self->n_pos_args + self->n_kwonly_args);

        // Now fill in defaults for positional args
        mp_obj_t *d = &flat_args[self->n_pos_args - 1];
        mp_obj_t *s = &self->extra_args[self->n_def_args - 1];
        for (int i = self->n_def_args; i > 0; i--, d--, s--) {
            if (*d == MP_OBJ_NULL) {
                *d = *s;
            }
        }
        DEBUG_printf("Args after filling defaults: ");
        dump_args(flat_args, self->n_pos_args + self->n_kwonly_args);
//.........这里部分代码省略.........

char *					/* O  - Line read or @code [email protected] on end of file or error */
cupsFileGetConf(cups_file_t *fp,	/* I  - CUPS file */
                char        *buf,	/* O  - String buffer */
		size_t      buflen,	/* I  - Size of string buffer */
                char        **value,	/* O  - Pointer to value */
		int         *linenum)	/* IO - Current line number */
{
  char	*ptr;				/* Pointer into line */


 /*
  * Range check input...
  */

  DEBUG_printf(("2cupsFileGetConf(fp=%p, buf=%p, buflen=" CUPS_LLFMT
                ", value=%p, linenum=%p)", fp, buf, CUPS_LLCAST buflen,
		value, linenum));

  if (!fp || (fp->mode != 'r' && fp->mode != 's') ||
      !buf || buflen < 2 || !value)
  {
    if (value)
      *value = NULL;

    return (NULL);
  }

 /*
  * Read the next non-comment line...
  */

  *value = NULL;

  while (cupsFileGets(fp, buf, buflen))
  {
    (*linenum) ++;

   /*
    * Strip any comments...
    */

    if ((ptr = strchr(buf, '#')) != NULL)
    {
      if (ptr > buf && ptr[-1] == '\\')
      {
        // Unquote the #...
	_cups_strcpy(ptr - 1, ptr);
      }
      else
      {
        // Strip the comment and any trailing whitespace...
	while (ptr > buf)
	{
	  if (!_cups_isspace(ptr[-1]))
	    break;

	  ptr --;
	}

	*ptr = '\0';
      }
    }

   /*
    * Strip leading whitespace...
    */

    for (ptr = buf; _cups_isspace(*ptr); ptr ++);

    if (ptr > buf)
      _cups_strcpy(buf, ptr);

   /*
    * See if there is anything left...
    */

    if (buf[0])
    {
     /*
      * Yes, grab any value and return...
      */

      for (ptr = buf; *ptr; ptr ++)
        if (_cups_isspace(*ptr))
	  break;

      if (*ptr)
      {
       /*
        * Have a value, skip any other spaces...
	*/

        while (_cups_isspace(*ptr))
	  *ptr++ = '\0';

        if (*ptr)
	  *value = ptr;

       /*
        * Strip trailing whitespace and > for lines that begin with <...
//.........这里部分代码省略.........

size_t					/* O - Number of bytes on line or 0 on end of file */
cupsFileGetLine(cups_file_t *fp,	/* I - File to read from */
                char        *buf,	/* I - Buffer */
                size_t      buflen)	/* I - Size of buffer */
{
  int		ch;			/* Character from file */
  char		*ptr,			/* Current position in line buffer */
		*end;			/* End of line buffer */


 /*
  * Range check input...
  */

  DEBUG_printf(("2cupsFileGetLine(fp=%p, buf=%p, buflen=" CUPS_LLFMT ")",
                fp, buf, CUPS_LLCAST buflen));

  if (!fp || (fp->mode != 'r' && fp->mode != 's') || !buf || buflen < 3)
    return (0);

 /*
  * Now loop until we have a valid line...
  */

  for (ptr = buf, end = buf + buflen - 2; ptr < end ;)
  {
    if (fp->ptr >= fp->end)
      if (cups_fill(fp) <= 0)
        break;

    *ptr++ = ch = *(fp->ptr)++;
    fp->pos ++;

    if (ch == '\r')
    {
     /*
      * Check for CR LF...
      */

      if (fp->ptr >= fp->end)
	if (cups_fill(fp) <= 0)
          break;

      if (*(fp->ptr) == '\n')
      {
        *ptr++ = *(fp->ptr)++;
	fp->pos ++;
      }

      break;
    }
    else if (ch == '\n')
    {
     /*
      * Line feed ends a line...
      */

      break;
    }
  }

  *ptr = '\0';

  DEBUG_printf(("4cupsFileGetLine: pos=" CUPS_LLFMT, CUPS_LLCAST fp->pos));

  return (ptr - buf);
}

ipp_status_t				/* O - Request status - @code [email protected] on success. */
cupsGetDevices(
    http_t           *http,		/* I - Connection to server or @code [email protected] */
    int              timeout,		/* I - Timeout in seconds or @code [email protected] */
    const char       *include_schemes,	/* I - Comma-separated URI schemes to include or @code [email protected] */
    const char       *exclude_schemes,	/* I - Comma-separated URI schemes to exclude or @code [email protected] */
    cups_device_cb_t callback,		/* I - Callback function */
    void             *user_data)	/* I - User data pointer */
{
  ipp_t		*request,		/* CUPS-Get-Devices request */
		*response;		/* CUPS-Get-Devices response */
  ipp_attribute_t *attr;		/* Current attribute */
  const char	*device_class,		/* device-class value */
		*device_id,		/* device-id value */
		*device_info,		/* device-info value */
		*device_location,	/* device-location value */
		*device_make_and_model,	/* device-make-and-model value */
		*device_uri;		/* device-uri value */
  int		blocking;		/* Current blocking-IO mode */
  cups_option_t	option;			/* in/exclude-schemes option */
  http_status_t	status;			/* HTTP status of request */
  ipp_state_t	state;			/* IPP response state */


 /*
  * Range check input...
  */

  DEBUG_printf(("cupsGetDevices(http=%p, timeout=%d, include_schemes=\"%s\", exclude_schemes=\"%s\", callback=%p, user_data=%p)", (void *)http, timeout, include_schemes, exclude_schemes, (void *)callback, user_data));

  if (!callback)
    return (IPP_STATUS_ERROR_INTERNAL);

  if (!http)
    http = _cupsConnect();

  if (!http)
    return (IPP_STATUS_ERROR_SERVICE_UNAVAILABLE);

 /*
  * Create a CUPS-Get-Devices request...
  */

  request = ippNewRequest(IPP_OP_CUPS_GET_DEVICES);

  if (timeout > 0)
    ippAddInteger(request, IPP_TAG_OPERATION, IPP_TAG_INTEGER, "timeout",
                  timeout);

  if (include_schemes)
  {
    option.name  = "include-schemes";
    option.value = (char *)include_schemes;

    cupsEncodeOptions2(request, 1, &option, IPP_TAG_OPERATION);
  }

  if (exclude_schemes)
  {
    option.name  = "exclude-schemes";
    option.value = (char *)exclude_schemes;

    cupsEncodeOptions2(request, 1, &option, IPP_TAG_OPERATION);
  }

 /*
  * Send the request and do any necessary authentication...
  */

  do
  {
    DEBUG_puts("2cupsGetDevices: Sending request...");
    status = cupsSendRequest(http, request, "/", ippLength(request));

    DEBUG_puts("2cupsGetDevices: Waiting for response status...");
    while (status == HTTP_STATUS_CONTINUE)
      status = httpUpdate(http);

    if (status != HTTP_STATUS_OK)
    {
      httpFlush(http);

      if (status == HTTP_STATUS_UNAUTHORIZED)
      {
       /*
	* See if we can do authentication...
	*/

	DEBUG_puts("2cupsGetDevices: Need authorization...");

	if (!cupsDoAuthentication(http, "POST", "/"))
	  httpReconnect2(http, 30000, NULL);
	else
	{
	  status = HTTP_STATUS_CUPS_AUTHORIZATION_CANCELED;
	  break;
	}
      }

#ifdef HAVE_SSL
//.........这里部分代码省略.........

const char *				/* O - Full path to file or @code [email protected] if not found */
cupsFileFind(const char *filename,	/* I - File to find */
             const char *path,		/* I - Colon/semicolon-separated path */
             int        executable,	/* I - 1 = executable files, 0 = any file/dir */
	     char       *buffer,	/* I - Filename buffer */
	     int        bufsize)	/* I - Size of filename buffer */
{
  char	*bufptr,			/* Current position in buffer */
	*bufend;			/* End of buffer */


 /*
  * Range check input...
  */

  DEBUG_printf(("cupsFileFind(filename=\"%s\", path=\"%s\", executable=%d, "
                "buffer=%p, bufsize=%d)", filename, path, executable, buffer,
		bufsize));

  if (!filename || !buffer || bufsize < 2)
    return (NULL);

  if (!path)
  {
   /*
    * No path, so check current directory...
    */

    if (!access(filename, 0))
    {
      strlcpy(buffer, filename, bufsize);
      return (buffer);
    }
    else
      return (NULL);
  }

 /*
  * Now check each path and return the first match...
  */

  bufend = buffer + bufsize - 1;
  bufptr = buffer;

  while (*path)
  {
#ifdef WIN32
    if (*path == ';' || (*path == ':' && ((bufptr - buffer) > 1 || !isalpha(buffer[0] & 255))))
#else
    if (*path == ';' || *path == ':')
#endif /* WIN32 */
    {
      if (bufptr > buffer && bufptr[-1] != '/' && bufptr < bufend)
        *bufptr++ = '/';

      strlcpy(bufptr, filename, bufend - bufptr);

#ifdef WIN32
      if (!access(buffer, 0))
#else
      if (!access(buffer, executable ? X_OK : 0))
#endif /* WIN32 */
      {
        DEBUG_printf(("1cupsFileFind: Returning \"%s\"", buffer));
        return (buffer);
      }

      bufptr = buffer;
    }
    else if (bufptr < bufend)
      *bufptr++ = *path;

    path ++;
  }

 /*
  * Check the last path...
  */

  if (bufptr > buffer && bufptr[-1] != '/' && bufptr < bufend)
    *bufptr++ = '/';

  strlcpy(bufptr, filename, bufend - bufptr);

  if (!access(buffer, 0))
  {
    DEBUG_printf(("1cupsFileFind: Returning \"%s\"", buffer));
    return (buffer);
  }
  else
  {
    DEBUG_puts("1cupsFileFind: Returning NULL");
    return (NULL);
  }
}

//.........这里部分代码省略.........

      /* Group */
      acl_create_entry(&acl, &entry);
      acl_get_permset(entry, &permset);
      acl_add_perm(permset, ACL_READ);
      acl_set_tag_type(entry, ACL_GROUP_OBJ);
      acl_set_permset(entry, permset);

      /* Others */
      acl_create_entry(&acl, &entry);
      acl_get_permset(entry, &permset);
      acl_add_perm(permset, 0);
      acl_set_tag_type(entry, ACL_OTHER);
      acl_set_permset(entry, permset);

      /* Mask */
      acl_create_entry(&acl, &entry);
      acl_get_permset(entry, &permset);
      acl_add_perm(permset, ACL_READ);
      acl_set_tag_type(entry, ACL_MASK);
      acl_set_permset(entry, permset);

      for (i = 1; i < NumSystemGroups; i ++)
      {
       /*
        * Add each group ID to the ACL...
	*/

        for (j = 0; j < i; j ++)
	  if (SystemGroupIDs[j] == SystemGroupIDs[i])
            break;

        if (j < i)
          continue;			/* Skip duplicate groups */

        acl_create_entry(&acl, &entry);
	acl_get_permset(entry, &permset);
	acl_add_perm(permset, ACL_READ);
	acl_set_tag_type(entry, ACL_GROUP);
	acl_set_qualifier(entry, SystemGroupIDs + i);
	acl_set_permset(entry, permset);
      }

      if (acl_valid(acl))
      {
        char *text, *textptr;		/* Temporary string */

        cupsdLogMessage(CUPSD_LOG_ERROR, "ACL did not validate: %s",
	                strerror(errno));
        text = acl_to_text(acl, NULL);
	for (textptr = strchr(text, '\n');
	     textptr;
	     textptr = strchr(textptr + 1, '\n'))
	  *textptr = ',';

	cupsdLogMessage(CUPSD_LOG_ERROR, "ACL: %s", text);
	acl_free(text);
      }
#  endif /* HAVE_MBR_UID_TO_UUID */

      if (acl_set_fd(fd, acl))
      {
	if (errno != EOPNOTSUPP || !acls_not_supported)
	  cupsdLogMessage(CUPSD_LOG_ERROR,
			  "Unable to set ACLs on root certificate \"%s\" - %s",
			  filename, strerror(errno));

	if (errno == EOPNOTSUPP)
	  acls_not_supported = 1;
      }

      acl_free(acl);
    }
#endif /* HAVE_ACL_INIT */

    RootCertTime = time(NULL);
  }
  else
  {
   /*
    * CGI certificate...
    */

    fchmod(fd, 0400);
    fchown(fd, User, Group);
  }

  DEBUG_printf(("ADD pid=%d, username=%s, cert=%s\n", pid, username,
                cert->certificate));

  write(fd, cert->certificate, strlen(cert->certificate));
  close(fd);

 /*
  * Insert the certificate at the front of the list...
  */

  cert->next = Certs;
  Certs      = cert;
}

//.........这里部分代码省略.........
    // sanity check the ptr is pointing to the head of a block
    if (ATB_GET_KIND(block) != AT_HEAD) {
        return NULL;
    }

    // compute number of new blocks that are requested
    size_t new_blocks = (n_bytes + BYTES_PER_BLOCK - 1) / BYTES_PER_BLOCK;

    // Get the total number of consecutive blocks that are already allocated to
    // this chunk of memory, and then count the number of free blocks following
    // it.  Stop if we reach the end of the heap, or if we find enough extra
    // free blocks to satisfy the realloc.  Note that we need to compute the
    // total size of the existing memory chunk so we can correctly and
    // efficiently shrink it (see below for shrinking code).
    size_t n_free   = 0;
    size_t n_blocks = 1; // counting HEAD block
    size_t max_block = MP_STATE_MEM(gc_alloc_table_byte_len) * BLOCKS_PER_ATB;
    for (size_t bl = block + n_blocks; bl < max_block; bl++) {
        byte block_type = ATB_GET_KIND(bl);
        if (block_type == AT_TAIL) {
            n_blocks++;
            continue;
        }
        if (block_type == AT_FREE) {
            n_free++;
            if (n_blocks + n_free >= new_blocks) {
                // stop as soon as we find enough blocks for n_bytes
                break;
            }
            continue;
        }
        break;
    }

    // return original ptr if it already has the requested number of blocks
    if (new_blocks == n_blocks) {
        return ptr_in;
    }

    // check if we can shrink the allocated area
    if (new_blocks < n_blocks) {
        // free unneeded tail blocks
        for (size_t bl = block + new_blocks, count = n_blocks - new_blocks; count > 0; bl++, count--) {
            ATB_ANY_TO_FREE(bl);
        }

        // set the last_free pointer to end of this block if it's earlier in the heap
        if ((block + new_blocks) / BLOCKS_PER_ATB < MP_STATE_MEM(gc_last_free_atb_index)) {
            MP_STATE_MEM(gc_last_free_atb_index) = (block + new_blocks) / BLOCKS_PER_ATB;
        }

        #if EXTENSIVE_HEAP_PROFILING
        gc_dump_alloc_table();
        #endif

        return ptr_in;
    }

    // check if we can expand in place
    if (new_blocks <= n_blocks + n_free) {
        // mark few more blocks as used tail
        for (size_t bl = block + n_blocks; bl < block + new_blocks; bl++) {
            assert(ATB_GET_KIND(bl) == AT_FREE);
            ATB_FREE_TO_TAIL(bl);
        }

        // zero out the additional bytes of the newly allocated blocks (see comment above in gc_alloc)
        memset((byte*)ptr_in + n_bytes, 0, new_blocks * BYTES_PER_BLOCK - n_bytes);

        #if EXTENSIVE_HEAP_PROFILING
        gc_dump_alloc_table();
        #endif

        return ptr_in;
    }

    if (!allow_move) {
        // not allowed to move memory block so return failure
        return NULL;
    }

    // can't resize inplace; try to find a new contiguous chain
    void *ptr_out = gc_alloc(n_bytes,
#if MICROPY_ENABLE_FINALISER
        FTB_GET(block)
#else
        false
#endif
    );

    // check that the alloc succeeded
    if (ptr_out == NULL) {
        return NULL;
    }

    DEBUG_printf("gc_realloc(%p -> %p)\n", ptr_in, ptr_out);
    memcpy(ptr_out, ptr_in, n_blocks * BYTES_PER_BLOCK);
    gc_free(ptr_in);
    return ptr_out;
}

void *gc_alloc(size_t n_bytes, bool has_finaliser) {
    size_t n_blocks = ((n_bytes + BYTES_PER_BLOCK - 1) & (~(BYTES_PER_BLOCK - 1))) / BYTES_PER_BLOCK;
    DEBUG_printf("gc_alloc(" UINT_FMT " bytes -> " UINT_FMT " blocks)\n", n_bytes, n_blocks);

    // check if GC is locked
    if (MP_STATE_MEM(gc_lock_depth) > 0) {
        return NULL;
    }

    // check for 0 allocation
    if (n_blocks == 0) {
        return NULL;
    }

    size_t i;
    size_t end_block;
    size_t start_block;
    size_t n_free = 0;
    int collected = !MP_STATE_MEM(gc_auto_collect_enabled);
    for (;;) {

        // look for a run of n_blocks available blocks
        for (i = MP_STATE_MEM(gc_last_free_atb_index); i < MP_STATE_MEM(gc_alloc_table_byte_len); i++) {
            byte a = MP_STATE_MEM(gc_alloc_table_start)[i];
            if (ATB_0_IS_FREE(a)) { if (++n_free >= n_blocks) { i = i * BLOCKS_PER_ATB + 0; goto found; } } else { n_free = 0; }
            if (ATB_1_IS_FREE(a)) { if (++n_free >= n_blocks) { i = i * BLOCKS_PER_ATB + 1; goto found; } } else { n_free = 0; }
            if (ATB_2_IS_FREE(a)) { if (++n_free >= n_blocks) { i = i * BLOCKS_PER_ATB + 2; goto found; } } else { n_free = 0; }
            if (ATB_3_IS_FREE(a)) { if (++n_free >= n_blocks) { i = i * BLOCKS_PER_ATB + 3; goto found; } } else { n_free = 0; }
        }

        // nothing found!
        if (collected) {
            return NULL;
        }
        DEBUG_printf("gc_alloc(" UINT_FMT "): no free mem, triggering GC\n", n_bytes);
        gc_collect();
        collected = 1;
    }

    // found, ending at block i inclusive
found:
    // get starting and end blocks, both inclusive
    end_block = i;
    start_block = i - n_free + 1;

    // Set last free ATB index to block after last block we found, for start of
    // next scan.  To reduce fragmentation, we only do this if we were looking
    // for a single free block, which guarantees that there are no free blocks
    // before this one.  Also, whenever we free or shink a block we must check
    // if this index needs adjusting (see gc_realloc and gc_free).
    if (n_free == 1) {
        MP_STATE_MEM(gc_last_free_atb_index) = (i + 1) / BLOCKS_PER_ATB;
    }

    // mark first block as used head
    ATB_FREE_TO_HEAD(start_block);

    // mark rest of blocks as used tail
    // TODO for a run of many blocks can make this more efficient
    for (size_t bl = start_block + 1; bl <= end_block; bl++) {
        ATB_FREE_TO_TAIL(bl);
    }

    // get pointer to first block
    void *ret_ptr = (void*)(MP_STATE_MEM(gc_pool_start) + start_block * BYTES_PER_BLOCK);
    DEBUG_printf("gc_alloc(%p)\n", ret_ptr);

    // zero out the additional bytes of the newly allocated blocks
    // This is needed because the blocks may have previously held pointers
    // to the heap and will not be set to something else if the caller
    // doesn't actually use the entire block.  As such they will continue
    // to point to the heap and may prevent other blocks from being reclaimed.
    memset((byte*)ret_ptr + n_bytes, 0, (end_block - start_block + 1) * BYTES_PER_BLOCK - n_bytes);

    #if MICROPY_ENABLE_FINALISER
    if (has_finaliser) {
        // clear type pointer in case it is never set
        ((mp_obj_base_t*)ret_ptr)->type = NULL;
        // set mp_obj flag only if it has a finaliser
        FTB_SET(start_block);
    }
    #else
    (void)has_finaliser;
    #endif

    #if EXTENSIVE_HEAP_PROFILING
    gc_dump_alloc_table();
    #endif

    return ret_ptr;
}

STATIC mp_uint_t lwip_socket_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t arg, int *errcode) {
    lwip_socket_obj_t *socket = self_in;
    mp_uint_t ret;

    if (request == MP_STREAM_POLL) {
        uintptr_t flags = arg;
        ret = 0;

        if (flags & MP_STREAM_POLL_RD && socket->incoming.pbuf != NULL) {
            ret |= MP_STREAM_POLL_RD;
        }

        // Note: pcb.tcp==NULL if state<0, and in this case we can't call tcp_sndbuf
        if (flags & MP_STREAM_POLL_WR && socket->pcb.tcp != NULL && tcp_sndbuf(socket->pcb.tcp) > 0) {
            ret |= MP_STREAM_POLL_WR;
        }

        if (socket->state == STATE_NEW) {
            // New sockets are not connected so set HUP
            ret |= flags & MP_STREAM_POLL_HUP;
        } else if (socket->state == STATE_PEER_CLOSED) {
            // Peer-closed socket is both readable and writable: read will
            // return EOF, write - error. Without this poll will hang on a
            // socket which was closed by peer.
            ret |= flags & (MP_STREAM_POLL_RD | MP_STREAM_POLL_WR);
        } else if (socket->state == ERR_RST) {
            // Socket was reset by peer, a write will return an error
            ret |= flags & (MP_STREAM_POLL_WR | MP_STREAM_POLL_HUP);
        } else if (socket->state < 0) {
            // Socket in some other error state, use catch-all ERR flag
            // TODO: may need to set other return flags here
            ret |= flags & MP_STREAM_POLL_ERR;
        }

    } else if (request == MP_STREAM_CLOSE) {
        bool socket_is_listener = false;

        if (socket->pcb.tcp == NULL) {
            return 0;
        }
        switch (socket->type) {
            case MOD_NETWORK_SOCK_STREAM: {
                if (socket->pcb.tcp->state == LISTEN) {
                    socket_is_listener = true;
                }
                if (tcp_close(socket->pcb.tcp) != ERR_OK) {
                    DEBUG_printf("lwip_close: had to call tcp_abort()\n");
                    tcp_abort(socket->pcb.tcp);
                }
                break;
            }
            case MOD_NETWORK_SOCK_DGRAM: udp_remove(socket->pcb.udp); break;
            //case MOD_NETWORK_SOCK_RAW: raw_remove(socket->pcb.raw); break;
        }
        socket->pcb.tcp = NULL;
        socket->state = _ERR_BADF;
        if (socket->incoming.pbuf != NULL) {
            if (!socket_is_listener) {
                pbuf_free(socket->incoming.pbuf);
            } else {
                tcp_abort(socket->incoming.connection);
            }
            socket->incoming.pbuf = NULL;
        }
        ret = 0;

    } else {
        *errcode = MP_EINVAL;
        ret = MP_STREAM_ERROR;
    }

    return ret;
}

char *					/* O - Line read or @code [email protected] on end of file or error */
cupsFileGets(cups_file_t *fp,		/* I - CUPS file */
             char        *buf,		/* O - String buffer */
	     size_t      buflen)	/* I - Size of string buffer */
{
  int		ch;			/* Character from file */
  char		*ptr,			/* Current position in line buffer */
		*end;			/* End of line buffer */


 /*
  * Range check input...
  */

  DEBUG_printf(("2cupsFileGets(fp=%p, buf=%p, buflen=" CUPS_LLFMT ")", fp, buf,
                CUPS_LLCAST buflen));

  if (!fp || (fp->mode != 'r' && fp->mode != 's') || !buf || buflen < 2)
    return (NULL);

 /*
  * Now loop until we have a valid line...
  */

  for (ptr = buf, end = buf + buflen - 1; ptr < end ;)
  {
    if (fp->ptr >= fp->end)
      if (cups_fill(fp) <= 0)
      {
        if (ptr == buf)
	  return (NULL);
	else
          break;
      }

    ch = *(fp->p