AppPkg/Applications/Python/Python-2.7.10/PyMod-2.7.10/Objects/stringlib/localeutil.h

   1 /* stringlib: locale related helpers implementation */
   2
   3 #ifndef STRINGLIB_LOCALEUTIL_H
   4 #define STRINGLIB_LOCALEUTIL_H
   5
   6 #include <locale.h>
   7
   8 #define MAX(x, y) ((x) < (y) ? (y) : (x))
   9 #define MIN(x, y) ((x) < (y) ? (x) : (y))
  10
  11 typedef struct {
  12     const char *grouping;
  13     char previous;
  14     Py_ssize_t i; /* Where we're currently pointing in grouping. */
  15 } GroupGenerator;
  16
  17 static void
  18 _GroupGenerator_init(GroupGenerator *self, const char *grouping)
  19 {
  20     self->grouping = grouping;
  21     self->i = 0;
  22     self->previous = 0;
  23 }
  24
  25 /* Returns the next grouping, or 0 to signify end. */
  26 static Py_ssize_t
  27 _GroupGenerator_next(GroupGenerator *self)
  28 {
  29     /* Note that we don't really do much error checking here. If a
  30        grouping string contains just CHAR_MAX, for example, then just
  31        terminate the generator. That shouldn't happen, but at least we
  32        fail gracefully. */
  33     switch (self->grouping[self->i]) {
  34     case 0:
  35         return self->previous;
  36     case CHAR_MAX:
  37         /* Stop the generator. */
  38         return 0;
  39     default: {
  40         char ch = self->grouping[self->i];
  41         self->previous = ch;
  42         self->i++;
  43         return (Py_ssize_t)ch;
  44     }
  45     }
  46 }
  47
  48 /* Fill in some digits, leading zeros, and thousands separator. All
  49    are optional, depending on when we're called. */
  50 static void
  51 fill(STRINGLIB_CHAR **digits_end, STRINGLIB_CHAR **buffer_end,
  52      Py_ssize_t n_chars, Py_ssize_t n_zeros, const char* thousands_sep,
  53      Py_ssize_t thousands_sep_len)
  54 {
  55 #if STRINGLIB_IS_UNICODE
  56     Py_ssize_t i;
  57 #endif
  58
  59     if (thousands_sep) {
  60         *buffer_end -= thousands_sep_len;
  61
  62         /* Copy the thousands_sep chars into the buffer. */
  63 #if STRINGLIB_IS_UNICODE
  64         /* Convert from the char's of the thousands_sep from
  65            the locale into unicode. */
  66         for (i = 0; i < thousands_sep_len; ++i)
  67             (*buffer_end)[i] = thousands_sep[i];
  68 #else
  69         /* No conversion, just memcpy the thousands_sep. */
  70         memcpy(*buffer_end, thousands_sep, thousands_sep_len);
  71 #endif
  72     }
  73
  74     *buffer_end -= n_chars;
  75     *digits_end -= n_chars;
  76     memcpy(*buffer_end, *digits_end, n_chars * sizeof(STRINGLIB_CHAR));
  77
  78     *buffer_end -= n_zeros;
  79     STRINGLIB_FILL(*buffer_end, '0', n_zeros);
  80 }
  81
  82 /**
  83  * _Py_InsertThousandsGrouping:
  84  * @buffer: A pointer to the start of a string.
  85  * @n_buffer: Number of characters in @buffer.
  86  * @digits: A pointer to the digits we're reading from. If count
  87  *          is non-NULL, this is unused.
  88  * @n_digits: The number of digits in the string, in which we want
  89  *            to put the grouping chars.
  90  * @min_width: The minimum width of the digits in the output string.
  91  *             Output will be zero-padded on the left to fill.
  92  * @grouping: see definition in localeconv().
  93  * @thousands_sep: see definition in localeconv().
  94  *
  95  * There are 2 modes: counting and filling. If @buffer is NULL,
  96  *  we are in counting mode, else filling mode.
  97  * If counting, the required buffer size is returned.
  98  * If filling, we know the buffer will be large enough, so we don't
  99  *  need to pass in the buffer size.
 100  * Inserts thousand grouping characters (as defined by grouping and
 101  *  thousands_sep) into the string between buffer and buffer+n_digits.
 102  *
 103  * Return value: 0 on error, else 1.  Note that no error can occur if
 104  *  count is non-NULL.
 105  *
 106  * This name won't be used, the includer of this file should define
 107  *  it to be the actual function name, based on unicode or string.
 108  *
 109  * As closely as possible, this code mimics the logic in decimal.py's
 110     _insert_thousands_sep().
 111  **/
 112 Py_ssize_t
 113 _Py_InsertThousandsGrouping(STRINGLIB_CHAR *buffer,
 114                             Py_ssize_t n_buffer,
 115                             STRINGLIB_CHAR *digits,
 116                             Py_ssize_t n_digits,
 117                             Py_ssize_t min_width,
 118                             const char *grouping,
 119                             const char *thousands_sep)
 120 {
 121     Py_ssize_t count = 0;
 122     Py_ssize_t n_zeros;
 123     int loop_broken = 0;
 124     int use_separator = 0; /* First time through, don't append the
 125                               separator. They only go between
 126                               groups. */
 127     STRINGLIB_CHAR *buffer_end = NULL;
 128     STRINGLIB_CHAR *digits_end = NULL;
 129     Py_ssize_t l;
 130     Py_ssize_t n_chars;
 131     Py_ssize_t thousands_sep_len = strlen(thousands_sep);
 132     Py_ssize_t remaining = n_digits; /* Number of chars remaining to
 133                                         be looked at */
 134     /* A generator that returns all of the grouping widths, until it
 135        returns 0. */
 136     GroupGenerator groupgen;
 137     _GroupGenerator_init(&groupgen, grouping);
 138
 139     if (buffer) {
 140         buffer_end = buffer + n_buffer;
 141         digits_end = digits + n_digits;
 142     }
 143
 144     while ((l = _GroupGenerator_next(&groupgen)) > 0) {
 145         l = MIN(l, MAX(MAX(remaining, min_width), 1));
 146         n_zeros = MAX(0, l - remaining);
 147         n_chars = MAX(0, MIN(remaining, l));
 148
 149         /* Use n_zero zero's and n_chars chars */
 150
 151         /* Count only, don't do anything. */
 152         count += (use_separator ? thousands_sep_len : 0) + n_zeros + n_chars;
 153
 154         if (buffer) {
 155             /* Copy into the output buffer. */
 156             fill(&digits_end, &buffer_end, n_chars, n_zeros,
 157                  use_separator ? thousands_sep : NULL, thousands_sep_len);
 158         }
 159
 160         /* Use a separator next time. */
 161         use_separator = 1;
 162
 163         remaining -= n_chars;
 164         min_width -= l;
 165
 166         if (remaining <= 0 && min_width <= 0) {
 167             loop_broken = 1;
 168             break;
 169         }
 170         min_width -= thousands_sep_len;
 171     }
 172     if (!loop_broken) {
 173         /* We left the loop without using a break statement. */
 174
 175         l = MAX(MAX(remaining, min_width), 1);
 176         n_zeros = MAX(0, l - remaining);
 177         n_chars = MAX(0, MIN(remaining, l));
 178
 179         /* Use n_zero zero's and n_chars chars */
 180         count += (use_separator ? thousands_sep_len : 0) + n_zeros + n_chars;
 181         if (buffer) {
 182             /* Copy into the output buffer. */
 183             fill(&digits_end, &buffer_end, n_chars, n_zeros,
 184                  use_separator ? thousands_sep : NULL, thousands_sep_len);
 185         }
 186     }
 187     return count;
 188 }
 189
 190 /**
 191  * _Py_InsertThousandsGroupingLocale:
 192  * @buffer: A pointer to the start of a string.
 193  * @n_digits: The number of digits in the string, in which we want
 194  *            to put the grouping chars.
 195  *
 196  * Reads thee current locale and calls _Py_InsertThousandsGrouping().
 197  **/
 198 Py_ssize_t
 199 _Py_InsertThousandsGroupingLocale(STRINGLIB_CHAR *buffer,
 200                                   Py_ssize_t n_buffer,
 201                                   STRINGLIB_CHAR *digits,
 202                                   Py_ssize_t n_digits,
 203                                   Py_ssize_t min_width)
 204 {
 205         struct lconv *locale_data = localeconv();
 206         const char *grouping = locale_data->grouping;
 207         const char *thousands_sep = locale_data->thousands_sep;
 208
 209         return _Py_InsertThousandsGrouping(buffer, n_buffer, digits, n_digits,
 210                                            min_width, grouping, thousands_sep);
 211 }
 212 #endif /* STRINGLIB_LOCALEUTIL_H */