PostgreSQL Source Code: src/fe_utils/mbprint.c Source File

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mbprint.c
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1/*-------------------------------------------------------------------------
2 *
3 * Multibyte character printing support for frontend code
4 *
5 *
6 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
8 *
9 * src/fe_utils/mbprint.c
10 *
11 *-------------------------------------------------------------------------
12 */
13#include "postgres_fe.h"
14
15#include "fe_utils/mbprint.h"
16
17#include "libpq-fe.h"
18
19
20/*
21 * To avoid version-skew problems, this file must not use declarations
22 * from pg_wchar.h: the encoding IDs we are dealing with are determined
23 * by the libpq.so we are linked with, and that might not match the
24 * numbers we see at compile time. (If this file were inside libpq,
25 * the problem would go away...)
26 *
27 * Hence, we have our own definition of pg_wchar, and we get the values
28 * of any needed encoding IDs on-the-fly.
29 */
30
31 typedef unsigned int pg_wchar;
32
33static int
34 pg_get_utf8_id(void)
35{
36 static int utf8_id = -1;
37
38 if (utf8_id < 0)
39 utf8_id = pg_char_to_encoding("utf8");
40 return utf8_id;
41}
42
43 #define PG_UTF8 pg_get_utf8_id()
44
45
46/*
47 * Convert a UTF-8 character to a Unicode code point.
48 * This is a one-character version of pg_utf2wchar_with_len.
49 *
50 * No error checks here, c must point to a long-enough string.
51 */
52static pg_wchar
53 utf8_to_unicode(const unsigned char *c)
54{
55 if ((*c & 0x80) == 0)
56 return (pg_wchar) c[0];
57 else if ((*c & 0xe0) == 0xc0)
58 return (pg_wchar) (((c[0] & 0x1f) << 6) |
59 (c[1] & 0x3f));
60 else if ((*c & 0xf0) == 0xe0)
61 return (pg_wchar) (((c[0] & 0x0f) << 12) |
62 ((c[1] & 0x3f) << 6) |
63 (c[2] & 0x3f));
64 else if ((*c & 0xf8) == 0xf0)
65 return (pg_wchar) (((c[0] & 0x07) << 18) |
66 ((c[1] & 0x3f) << 12) |
67 ((c[2] & 0x3f) << 6) |
68 (c[3] & 0x3f));
69 else
70 /* that is an invalid code on purpose */
71 return 0xffffffff;
72}
73
74
75/*
76 * Unicode 3.1 compliant validation : for each category, it checks the
77 * combination of each byte to make sure it maps to a valid range. It also
78 * returns -1 for the following UCS values: ucs > 0x10ffff ucs & 0xfffe =
79 * 0xfffe 0xfdd0 < ucs < 0xfdef ucs & 0xdb00 = 0xd800 (surrogates)
80 */
81static int
82 utf_charcheck(const unsigned char *c)
83{
84 if ((*c & 0x80) == 0)
85 return 1;
86 else if ((*c & 0xe0) == 0xc0)
87 {
88 /* two-byte char */
89 if (((c[1] & 0xc0) == 0x80) && ((c[0] & 0x1f) > 0x01))
90 return 2;
91 return -1;
92 }
93 else if ((*c & 0xf0) == 0xe0)
94 {
95 /* three-byte char */
96 if (((c[1] & 0xc0) == 0x80) &&
97 (((c[0] & 0x0f) != 0x00) || ((c[1] & 0x20) == 0x20)) &&
98 ((c[2] & 0xc0) == 0x80))
99 {
100 int z = c[0] & 0x0f;
101 int yx = ((c[1] & 0x3f) << 6) | (c[0] & 0x3f);
102 int lx = yx & 0x7f;
103
104 /* check 0xfffe/0xffff, 0xfdd0..0xfedf range, surrogates */
105 if (((z == 0x0f) &&
106 (((yx & 0xffe) == 0xffe) ||
107 (((yx & 0xf80) == 0xd80) && (lx >= 0x30) && (lx <= 0x4f)))) ||
108 ((z == 0x0d) && ((yx & 0xb00) == 0x800)))
109 return -1;
110 return 3;
111 }
112 return -1;
113 }
114 else if ((*c & 0xf8) == 0xf0)
115 {
116 int u = ((c[0] & 0x07) << 2) | ((c[1] & 0x30) >> 4);
117
118 /* four-byte char */
119 if (((c[1] & 0xc0) == 0x80) &&
120 (u > 0x00) && (u <= 0x10) &&
121 ((c[2] & 0xc0) == 0x80) && ((c[3] & 0xc0) == 0x80))
122 {
123 /* test for 0xzzzzfffe/0xzzzzfffff */
124 if (((c[1] & 0x0f) == 0x0f) && ((c[2] & 0x3f) == 0x3f) &&
125 ((c[3] & 0x3e) == 0x3e))
126 return -1;
127 return 4;
128 }
129 return -1;
130 }
131 return -1;
132}
133
134
135static void
136 mb_utf_validate(unsigned char *pwcs)
137{
138 unsigned char *p = pwcs;
139
140 while (*pwcs)
141 {
142 int len;
143
144 if ((len = utf_charcheck(pwcs)) > 0)
145 {
146 if (p != pwcs)
147 {
148 int i;
149
150 for (i = 0; i < len; i++)
151 *p++ = *pwcs++;
152 }
153 else
154 {
155 pwcs += len;
156 p += len;
157 }
158 }
159 else
160 /* we skip the char */
161 pwcs++;
162 }
163 if (p != pwcs)
164 *p = '0円';
165}
166
167/*
168 * public functions : wcswidth and mbvalidate
169 */
170
171/*
172 * pg_wcswidth is the dumb display-width function.
173 * It assumes that everything will appear on one line.
174 * OTOH it is easier to use than pg_wcssize if this applies to you.
175 */
176int
177 pg_wcswidth(const char *pwcs, size_t len, int encoding)
178{
179 int width = 0;
180
181 while (len > 0)
182 {
183 int chlen,
184 chwidth;
185
186 chlen = PQmblen(pwcs, encoding);
187 if (len < (size_t) chlen)
188 break; /* Invalid string */
189
190 chwidth = PQdsplen(pwcs, encoding);
191 if (chwidth > 0)
192 width += chwidth;
193
194 pwcs += chlen;
195 len -= chlen;
196 }
197 return width;
198}
199
200/*
201 * pg_wcssize takes the given string in the given encoding and returns three
202 * values:
203 * result_width: Width in display characters of the longest line in string
204 * result_height: Number of lines in display output
205 * result_format_size: Number of bytes required to store formatted
206 * representation of string
207 *
208 * This MUST be kept in sync with pg_wcsformat!
209 */
210void
211 pg_wcssize(const unsigned char *pwcs, size_t len, int encoding,
212 int *result_width, int *result_height, int *result_format_size)
213{
214 int w,
215 chlen = 0,
216 linewidth = 0;
217 int width = 0;
218 int height = 1;
219 int format_size = 0;
220
221 for (; *pwcs && len > 0; pwcs += chlen)
222 {
223 chlen = PQmblen((const char *) pwcs, encoding);
224 if (len < (size_t) chlen)
225 break;
226 w = PQdsplen((const char *) pwcs, encoding);
227
228 if (chlen == 1) /* single-byte char */
229 {
230 if (*pwcs == '\n') /* Newline */
231 {
232 if (linewidth > width)
233 width = linewidth;
234 linewidth = 0;
235 height += 1;
236 format_size += 1; /* For NUL char */
237 }
238 else if (*pwcs == '\r') /* Linefeed */
239 {
240 linewidth += 2;
241 format_size += 2;
242 }
243 else if (*pwcs == '\t') /* Tab */
244 {
245 do
246 {
247 linewidth++;
248 format_size++;
249 } while (linewidth % 8 != 0);
250 }
251 else if (w < 0) /* Other control char */
252 {
253 linewidth += 4;
254 format_size += 4;
255 }
256 else /* Output it as-is */
257 {
258 linewidth += w;
259 format_size += 1;
260 }
261 }
262 else if (w < 0) /* Non-ascii control char */
263 {
264 linewidth += 6; /* \u0000 */
265 format_size += 6;
266 }
267 else /* All other chars */
268 {
269 linewidth += w;
270 format_size += chlen;
271 }
272 len -= chlen;
273 }
274 if (linewidth > width)
275 width = linewidth;
276 format_size += 1; /* For NUL char */
277
278 /* Set results */
279 if (result_width)
280 *result_width = width;
281 if (result_height)
282 *result_height = height;
283 if (result_format_size)
284 *result_format_size = format_size;
285}
286
287/*
288 * Format a string into one or more "struct lineptr" lines.
289 * lines[i].ptr == NULL indicates the end of the array.
290 *
291 * This MUST be kept in sync with pg_wcssize!
292 */
293void
294 pg_wcsformat(const unsigned char *pwcs, size_t len, int encoding,
295 struct lineptr *lines, int count)
296{
297 int w,
298 chlen = 0;
299 int linewidth = 0;
300 unsigned char *ptr = lines->ptr; /* Pointer to data area */
301
302 for (; *pwcs && len > 0; pwcs += chlen)
303 {
304 chlen = PQmblen((const char *) pwcs, encoding);
305 if (len < (size_t) chlen)
306 break;
307 w = PQdsplen((const char *) pwcs, encoding);
308
309 if (chlen == 1) /* single-byte char */
310 {
311 if (*pwcs == '\n') /* Newline */
312 {
313 *ptr++ = '0円';
314 lines->width = linewidth;
315 linewidth = 0;
316 lines++;
317 count--;
318 if (count <= 0)
319 exit(1); /* Screwup */
320
321 /* make next line point to remaining memory */
322 lines->ptr = ptr;
323 }
324 else if (*pwcs == '\r') /* Linefeed */
325 {
326 strcpy((char *) ptr, "\\r");
327 linewidth += 2;
328 ptr += 2;
329 }
330 else if (*pwcs == '\t') /* Tab */
331 {
332 do
333 {
334 *ptr++ = ' ';
335 linewidth++;
336 } while (linewidth % 8 != 0);
337 }
338 else if (w < 0) /* Other control char */
339 {
340 sprintf((char *) ptr, "\\x%02X", *pwcs);
341 linewidth += 4;
342 ptr += 4;
343 }
344 else /* Output it as-is */
345 {
346 linewidth += w;
347 *ptr++ = *pwcs;
348 }
349 }
350 else if (w < 0) /* Non-ascii control char */
351 {
352 if (encoding == PG_UTF8)
353 sprintf((char *) ptr, "\\u%04X", utf8_to_unicode(pwcs));
354 else
355 {
356 /*
357 * This case cannot happen in the current code because only
358 * UTF-8 signals multibyte control characters. But we may need
359 * to support it at some stage
360 */
361 sprintf((char *) ptr, "\\u????");
362 }
363 ptr += 6;
364 linewidth += 6;
365 }
366 else /* All other chars */
367 {
368 int i;
369
370 for (i = 0; i < chlen; i++)
371 *ptr++ = pwcs[i];
372 linewidth += w;
373 }
374 len -= chlen;
375 }
376 lines->width = linewidth;
377 *ptr++ = '0円'; /* Terminate formatted string */
378
379 if (count <= 0)
380 exit(1); /* Screwup */
381
382 (lines + 1)->ptr = NULL; /* terminate line array */
383}
384
385
386/*
387 * Encoding validation: delete any unvalidatable characters from the string
388 *
389 * This seems redundant with existing functionality elsewhere?
390 */
391unsigned char *
392 mbvalidate(unsigned char *pwcs, int encoding)
393{
394 if (encoding == PG_UTF8)
395 mb_utf_validate(pwcs);
396 else
397 {
398 /*
399 * other encodings needing validation should add their own routines
400 * here
401 */
402 }
403
404 return pwcs;
405}
int PQmblen(const char *s, int encoding)
Definition: fe-misc.c:1255
int PQdsplen(const char *s, int encoding)
Definition: fe-misc.c:1276
i
int i
Definition: isn.c:77
#define PG_UTF8
Definition: mbprint.c:43
static void mb_utf_validate(unsigned char *pwcs)
Definition: mbprint.c:136
void pg_wcssize(const unsigned char *pwcs, size_t len, int encoding, int *result_width, int *result_height, int *result_format_size)
Definition: mbprint.c:211
int pg_wcswidth(const char *pwcs, size_t len, int encoding)
Definition: mbprint.c:177
void pg_wcsformat(const unsigned char *pwcs, size_t len, int encoding, struct lineptr *lines, int count)
Definition: mbprint.c:294
static int utf_charcheck(const unsigned char *c)
Definition: mbprint.c:82
static int pg_get_utf8_id(void)
Definition: mbprint.c:34
static pg_wchar utf8_to_unicode(const unsigned char *c)
Definition: mbprint.c:53
unsigned int pg_wchar
Definition: mbprint.c:31
unsigned char * mbvalidate(unsigned char *pwcs, int encoding)
Definition: mbprint.c:392
const void size_t len
int32 encoding
Definition: pg_database.h:41
#define pg_char_to_encoding
Definition: pg_wchar.h:629
#define sprintf
Definition: port.h:241
c
char * c
Definition: preproc-cursor.c:31
Definition: mbprint.h:17
int width
Definition: mbprint.h:19
unsigned char * ptr
Definition: mbprint.h:18

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