source: python/trunk/Objects/stringlib/localeutil.h@ 6

Last change on this file since 6 was 2, checked in by Yuri Dario, 15 years ago

Initial import for vendor code.
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Line 
1/* stringlib: locale related helpers implementation */
2
3#ifndef STRINGLIB_LOCALEUTIL_H
4#define STRINGLIB_LOCALEUTIL_H
5
6#include <locale.h>
7
8/**
9 * _Py_InsertThousandsGrouping:
10 * @buffer: A pointer to the start of a string.
11 * @n_buffer: The length of the string.
12 * @n_digits: The number of digits in the string, in which we want
13 * to put the grouping chars.
14 * @buf_size: The maximum size of the buffer pointed to by buffer.
15 * @count: If non-NULL, points to a variable that will receive the
16 * number of characters we need to insert (and no formatting
17 * will actually occur).
18 * @append_zero_char: If non-zero, put a trailing zero at the end of
19 * of the resulting string, if and only if we modified the
20 * string.
21 *
22 * Inserts thousand grouping characters (as defined in the current
23 * locale) into the string between buffer and buffer+n_digits. If
24 * count is non-NULL, don't do any formatting, just count the number
25 * of characters to insert. This is used by the caller to
26 * appropriately resize the buffer, if needed. If count is non-NULL,
27 * buffer can be NULL (it is not dereferenced at all in that case).
28 *
29 * Return value: 0 on error, else 1. Note that no error can occur if
30 * count is non-NULL.
31 *
32 * This name won't be used, the includer of this file should define
33 * it to be the actual function name, based on unicode or string.
34 **/
35int
36_Py_InsertThousandsGrouping(STRINGLIB_CHAR *buffer,
37 Py_ssize_t n_buffer,
38 Py_ssize_t n_digits,
39 Py_ssize_t buf_size,
40 Py_ssize_t *count,
41 int append_zero_char)
42{
43 struct lconv *locale_data = localeconv();
44 const char *grouping = locale_data->grouping;
45 const char *thousands_sep = locale_data->thousands_sep;
46 Py_ssize_t thousands_sep_len = strlen(thousands_sep);
47 STRINGLIB_CHAR *pend = NULL; /* current end of buffer */
48 STRINGLIB_CHAR *pmax = NULL; /* max of buffer */
49 char current_grouping;
50 Py_ssize_t remaining = n_digits; /* Number of chars remaining to
51 be looked at */
52
53 /* Initialize the character count, if we're just counting. */
54 if (count)
55 *count = 0;
56 else {
57 /* We're not just counting, we're modifying buffer */
58 pend = buffer + n_buffer;
59 pmax = buffer + buf_size;
60 }
61
62 /* Starting at the end and working right-to-left, keep track of
63 what grouping needs to be added and insert that. */
64 current_grouping = *grouping++;
65
66 /* If the first character is 0, perform no grouping at all. */
67 if (current_grouping == 0)
68 return 1;
69
70 while (remaining > current_grouping) {
71 /* Always leave buffer and pend valid at the end of this
72 loop, since we might leave with a return statement. */
73
74 remaining -= current_grouping;
75 if (count) {
76 /* We're only counting, not touching the memory. */
77 *count += thousands_sep_len;
78 }
79 else {
80 /* Do the formatting. */
81
82 STRINGLIB_CHAR *plast = buffer + remaining;
83
84 /* Is there room to insert thousands_sep_len chars? */
85 if (pmax - pend < thousands_sep_len)
86 /* No room. */
87 return 0;
88
89 /* Move the rest of the string down. */
90 memmove(plast + thousands_sep_len,
91 plast,
92 (pend - plast) * sizeof(STRINGLIB_CHAR));
93 /* Copy the thousands_sep chars into the buffer. */
94#if STRINGLIB_IS_UNICODE
95 /* Convert from the char's of the thousands_sep from
96 the locale into unicode. */
97 {
98 Py_ssize_t i;
99 for (i = 0; i < thousands_sep_len; ++i)
100 plast[i] = thousands_sep[i];
101 }
102#else
103 /* No conversion, just memcpy the thousands_sep. */
104 memcpy(plast, thousands_sep, thousands_sep_len);
105#endif
106 }
107
108 /* Adjust end pointer. */
109 pend += thousands_sep_len;
110
111 /* Move to the next grouping character, unless we're
112 repeating (which is designated by a grouping of 0). */
113 if (*grouping != 0) {
114 current_grouping = *grouping++;
115 if (current_grouping == CHAR_MAX)
116 /* We're done. */
117 break;
118 }
119 }
120 if (append_zero_char) {
121 /* Append a zero character to mark the end of the string,
122 if there's room. */
123 if (pend - (buffer + remaining) < 1)
124 /* No room, error. */
125 return 0;
126 *pend = 0;
127 }
128 return 1;
129}
130#endif /* STRINGLIB_LOCALEUTIL_H */
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