Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * mbutils.c
4 : * This file contains functions for encoding conversion.
5 : *
6 : * The string-conversion functions in this file share some API quirks.
7 : * Note the following:
8 : *
9 : * The functions return a palloc'd, null-terminated string if conversion
10 : * is required. However, if no conversion is performed, the given source
11 : * string pointer is returned as-is.
12 : *
13 : * Although the presence of a length argument means that callers can pass
14 : * non-null-terminated strings, care is required because the same string
15 : * will be passed back if no conversion occurs. Such callers *must* check
16 : * whether result == src and handle that case differently.
17 : *
18 : * If the source and destination encodings are the same, the source string
19 : * is returned without any verification; it's assumed to be valid data.
20 : * If that might not be the case, the caller is responsible for validating
21 : * the string using a separate call to pg_verify_mbstr(). Whenever the
22 : * source and destination encodings are different, the functions ensure that
23 : * the result is validly encoded according to the destination encoding.
24 : *
25 : *
26 : * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
27 : * Portions Copyright (c) 1994, Regents of the University of California
28 : *
29 : *
30 : * IDENTIFICATION
31 : * src/backend/utils/mb/mbutils.c
32 : *
33 : *-------------------------------------------------------------------------
34 : */
35 : #include "postgres.h"
36 :
37 : #include "access/xact.h"
38 : #include "catalog/namespace.h"
39 : #include "mb/pg_wchar.h"
40 : #include "utils/fmgrprotos.h"
41 : #include "utils/memutils.h"
42 : #include "utils/relcache.h"
43 : #include "varatt.h"
44 :
45 : /*
46 : * We maintain a simple linked list caching the fmgr lookup info for the
47 : * currently selected conversion functions, as well as any that have been
48 : * selected previously in the current session. (We remember previous
49 : * settings because we must be able to restore a previous setting during
50 : * transaction rollback, without doing any fresh catalog accesses.)
51 : *
52 : * Since we'll never release this data, we just keep it in TopMemoryContext.
53 : */
54 : typedef struct ConvProcInfo
55 : {
56 : int s_encoding; /* server and client encoding IDs */
57 : int c_encoding;
58 : FmgrInfo to_server_info; /* lookup info for conversion procs */
59 : FmgrInfo to_client_info;
60 : } ConvProcInfo;
61 :
62 : static List *ConvProcList = NIL; /* List of ConvProcInfo */
63 :
64 : /*
65 : * These variables point to the currently active conversion functions,
66 : * or are NULL when no conversion is needed.
67 : */
68 : static FmgrInfo *ToServerConvProc = NULL;
69 : static FmgrInfo *ToClientConvProc = NULL;
70 :
71 : /*
72 : * This variable stores the conversion function to convert from UTF-8
73 : * to the server encoding. It's NULL if the server encoding *is* UTF-8,
74 : * or if we lack a conversion function for this.
75 : */
76 : static FmgrInfo *Utf8ToServerConvProc = NULL;
77 :
78 : /*
79 : * These variables track the currently-selected encodings.
80 : */
81 : static const pg_enc2name *ClientEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
82 : static const pg_enc2name *DatabaseEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
83 : static const pg_enc2name *MessageEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
84 :
85 : /*
86 : * During backend startup we can't set client encoding because we (a)
87 : * can't look up the conversion functions, and (b) may not know the database
88 : * encoding yet either. So SetClientEncoding() just accepts anything and
89 : * remembers it for InitializeClientEncoding() to apply later.
90 : */
91 : static bool backend_startup_complete = false;
92 : static int pending_client_encoding = PG_SQL_ASCII;
93 :
94 :
95 : /* Internal functions */
96 : static char *perform_default_encoding_conversion(const char *src,
97 : int len, bool is_client_to_server);
98 : static int cliplen(const char *str, int len, int limit);
99 :
100 :
101 : /*
102 : * Prepare for a future call to SetClientEncoding. Success should mean
103 : * that SetClientEncoding is guaranteed to succeed for this encoding request.
104 : *
105 : * (But note that success before backend_startup_complete does not guarantee
106 : * success after ...)
107 : *
108 : * Returns 0 if okay, -1 if not (bad encoding or can't support conversion)
109 : */
110 : int
111 65746 : PrepareClientEncoding(int encoding)
112 : {
113 : int current_server_encoding;
114 : ListCell *lc;
115 :
116 65746 : if (!PG_VALID_FE_ENCODING(encoding))
117 0 : return -1;
118 :
119 : /* Can't do anything during startup, per notes above */
120 65746 : if (!backend_startup_complete)
121 32958 : return 0;
122 :
123 32788 : current_server_encoding = GetDatabaseEncoding();
124 :
125 : /*
126 : * Check for cases that require no conversion function.
127 : */
128 32788 : if (current_server_encoding == encoding ||
129 2774 : current_server_encoding == PG_SQL_ASCII ||
130 : encoding == PG_SQL_ASCII)
131 32768 : return 0;
132 :
133 20 : if (IsTransactionState())
134 : {
135 : /*
136 : * If we're in a live transaction, it's safe to access the catalogs,
137 : * so look up the functions. We repeat the lookup even if the info is
138 : * already cached, so that we can react to changes in the contents of
139 : * pg_conversion.
140 : */
141 : Oid to_server_proc,
142 : to_client_proc;
143 : ConvProcInfo *convinfo;
144 : MemoryContext oldcontext;
145 :
146 20 : to_server_proc = FindDefaultConversionProc(encoding,
147 : current_server_encoding);
148 20 : if (!OidIsValid(to_server_proc))
149 0 : return -1;
150 20 : to_client_proc = FindDefaultConversionProc(current_server_encoding,
151 : encoding);
152 20 : if (!OidIsValid(to_client_proc))
153 0 : return -1;
154 :
155 : /*
156 : * Load the fmgr info into TopMemoryContext (could still fail here)
157 : */
158 20 : convinfo = (ConvProcInfo *) MemoryContextAlloc(TopMemoryContext,
159 : sizeof(ConvProcInfo));
160 20 : convinfo->s_encoding = current_server_encoding;
161 20 : convinfo->c_encoding = encoding;
162 20 : fmgr_info_cxt(to_server_proc, &convinfo->to_server_info,
163 : TopMemoryContext);
164 20 : fmgr_info_cxt(to_client_proc, &convinfo->to_client_info,
165 : TopMemoryContext);
166 :
167 : /* Attach new info to head of list */
168 20 : oldcontext = MemoryContextSwitchTo(TopMemoryContext);
169 20 : ConvProcList = lcons(convinfo, ConvProcList);
170 20 : MemoryContextSwitchTo(oldcontext);
171 :
172 : /*
173 : * We cannot yet remove any older entry for the same encoding pair,
174 : * since it could still be in use. SetClientEncoding will clean up.
175 : */
176 :
177 20 : return 0; /* success */
178 : }
179 : else
180 : {
181 : /*
182 : * If we're not in a live transaction, the only thing we can do is
183 : * restore a previous setting using the cache. This covers all
184 : * transaction-rollback cases. The only case it might not work for is
185 : * trying to change client_encoding on the fly by editing
186 : * postgresql.conf and SIGHUP'ing. Which would probably be a stupid
187 : * thing to do anyway.
188 : */
189 0 : foreach(lc, ConvProcList)
190 : {
191 0 : ConvProcInfo *oldinfo = (ConvProcInfo *) lfirst(lc);
192 :
193 0 : if (oldinfo->s_encoding == current_server_encoding &&
194 0 : oldinfo->c_encoding == encoding)
195 0 : return 0;
196 : }
197 :
198 0 : return -1; /* it's not cached, so fail */
199 : }
200 : }
201 :
202 : /*
203 : * Set the active client encoding and set up the conversion-function pointers.
204 : * PrepareClientEncoding should have been called previously for this encoding.
205 : *
206 : * Returns 0 if okay, -1 if not (bad encoding or can't support conversion)
207 : */
208 : int
209 68304 : SetClientEncoding(int encoding)
210 : {
211 : int current_server_encoding;
212 : bool found;
213 : ListCell *lc;
214 :
215 68304 : if (!PG_VALID_FE_ENCODING(encoding))
216 0 : return -1;
217 :
218 : /* Can't do anything during startup, per notes above */
219 68304 : if (!backend_startup_complete)
220 : {
221 32780 : pending_client_encoding = encoding;
222 32780 : return 0;
223 : }
224 :
225 35524 : current_server_encoding = GetDatabaseEncoding();
226 :
227 : /*
228 : * Check for cases that require no conversion function.
229 : */
230 35524 : if (current_server_encoding == encoding ||
231 2774 : current_server_encoding == PG_SQL_ASCII ||
232 : encoding == PG_SQL_ASCII)
233 : {
234 35504 : ClientEncoding = &pg_enc2name_tbl[encoding];
235 35504 : ToServerConvProc = NULL;
236 35504 : ToClientConvProc = NULL;
237 35504 : return 0;
238 : }
239 :
240 : /*
241 : * Search the cache for the entry previously prepared by
242 : * PrepareClientEncoding; if there isn't one, we lose. While at it,
243 : * release any duplicate entries so that repeated Prepare/Set cycles don't
244 : * leak memory.
245 : */
246 20 : found = false;
247 46 : foreach(lc, ConvProcList)
248 : {
249 26 : ConvProcInfo *convinfo = (ConvProcInfo *) lfirst(lc);
250 :
251 26 : if (convinfo->s_encoding == current_server_encoding &&
252 26 : convinfo->c_encoding == encoding)
253 : {
254 20 : if (!found)
255 : {
256 : /* Found newest entry, so set up */
257 20 : ClientEncoding = &pg_enc2name_tbl[encoding];
258 20 : ToServerConvProc = &convinfo->to_server_info;
259 20 : ToClientConvProc = &convinfo->to_client_info;
260 20 : found = true;
261 : }
262 : else
263 : {
264 : /* Duplicate entry, release it */
265 0 : ConvProcList = foreach_delete_current(ConvProcList, lc);
266 0 : pfree(convinfo);
267 : }
268 : }
269 : }
270 :
271 20 : if (found)
272 20 : return 0; /* success */
273 : else
274 0 : return -1; /* it's not cached, so fail */
275 : }
276 :
277 : /*
278 : * Initialize client encoding conversions.
279 : * Called from InitPostgres() once during backend startup.
280 : */
281 : void
282 32166 : InitializeClientEncoding(void)
283 : {
284 : int current_server_encoding;
285 :
286 : Assert(!backend_startup_complete);
287 32166 : backend_startup_complete = true;
288 :
289 64332 : if (PrepareClientEncoding(pending_client_encoding) < 0 ||
290 32166 : SetClientEncoding(pending_client_encoding) < 0)
291 : {
292 : /*
293 : * Oops, the requested conversion is not available. We couldn't fail
294 : * before, but we can now.
295 : */
296 0 : ereport(FATAL,
297 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
298 : errmsg("conversion between %s and %s is not supported",
299 : pg_enc2name_tbl[pending_client_encoding].name,
300 : GetDatabaseEncodingName())));
301 : }
302 :
303 : /*
304 : * Also look up the UTF8-to-server conversion function if needed. Since
305 : * the server encoding is fixed within any one backend process, we don't
306 : * have to do this more than once.
307 : */
308 32166 : current_server_encoding = GetDatabaseEncoding();
309 32166 : if (current_server_encoding != PG_UTF8 &&
310 : current_server_encoding != PG_SQL_ASCII)
311 : {
312 : Oid utf8_to_server_proc;
313 :
314 202 : AssertCouldGetRelation();
315 : utf8_to_server_proc =
316 202 : FindDefaultConversionProc(PG_UTF8,
317 : current_server_encoding);
318 : /* If there's no such conversion, just leave the pointer as NULL */
319 202 : if (OidIsValid(utf8_to_server_proc))
320 : {
321 : FmgrInfo *finfo;
322 :
323 202 : finfo = (FmgrInfo *) MemoryContextAlloc(TopMemoryContext,
324 : sizeof(FmgrInfo));
325 202 : fmgr_info_cxt(utf8_to_server_proc, finfo,
326 : TopMemoryContext);
327 : /* Set Utf8ToServerConvProc only after data is fully valid */
328 202 : Utf8ToServerConvProc = finfo;
329 : }
330 : }
331 32166 : }
332 :
333 : /*
334 : * returns the current client encoding
335 : */
336 : int
337 16204 : pg_get_client_encoding(void)
338 : {
339 16204 : return ClientEncoding->encoding;
340 : }
341 :
342 : /*
343 : * returns the current client encoding name
344 : */
345 : const char *
346 0 : pg_get_client_encoding_name(void)
347 : {
348 0 : return ClientEncoding->name;
349 : }
350 :
351 : /*
352 : * Convert src string to another encoding (general case).
353 : *
354 : * See the notes about string conversion functions at the top of this file.
355 : */
356 : unsigned char *
357 3056 : pg_do_encoding_conversion(unsigned char *src, int len,
358 : int src_encoding, int dest_encoding)
359 : {
360 : unsigned char *result;
361 : Oid proc;
362 :
363 3056 : if (len <= 0)
364 30 : return src; /* empty string is always valid */
365 :
366 3026 : if (src_encoding == dest_encoding)
367 2242 : return src; /* no conversion required, assume valid */
368 :
369 784 : if (dest_encoding == PG_SQL_ASCII)
370 0 : return src; /* any string is valid in SQL_ASCII */
371 :
372 784 : if (src_encoding == PG_SQL_ASCII)
373 : {
374 : /* No conversion is possible, but we must validate the result */
375 16 : (void) pg_verify_mbstr(dest_encoding, (const char *) src, len, false);
376 16 : return src;
377 : }
378 :
379 768 : if (!IsTransactionState()) /* shouldn't happen */
380 0 : elog(ERROR, "cannot perform encoding conversion outside a transaction");
381 :
382 768 : proc = FindDefaultConversionProc(src_encoding, dest_encoding);
383 768 : if (!OidIsValid(proc))
384 0 : ereport(ERROR,
385 : (errcode(ERRCODE_UNDEFINED_FUNCTION),
386 : errmsg("default conversion function for encoding \"%s\" to \"%s\" does not exist",
387 : pg_encoding_to_char(src_encoding),
388 : pg_encoding_to_char(dest_encoding))));
389 :
390 : /*
391 : * Allocate space for conversion result, being wary of integer overflow.
392 : *
393 : * len * MAX_CONVERSION_GROWTH is typically a vast overestimate of the
394 : * required space, so it might exceed MaxAllocSize even though the result
395 : * would actually fit. We do not want to hand back a result string that
396 : * exceeds MaxAllocSize, because callers might not cope gracefully --- but
397 : * if we just allocate more than that, and don't use it, that's fine.
398 : */
399 768 : if ((Size) len >= (MaxAllocHugeSize / (Size) MAX_CONVERSION_GROWTH))
400 0 : ereport(ERROR,
401 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
402 : errmsg("out of memory"),
403 : errdetail("String of %d bytes is too long for encoding conversion.",
404 : len)));
405 :
406 : result = (unsigned char *)
407 768 : MemoryContextAllocHuge(CurrentMemoryContext,
408 768 : (Size) len * MAX_CONVERSION_GROWTH + 1);
409 :
410 768 : (void) OidFunctionCall6(proc,
411 : Int32GetDatum(src_encoding),
412 : Int32GetDatum(dest_encoding),
413 : CStringGetDatum((char *) src),
414 : CStringGetDatum((char *) result),
415 : Int32GetDatum(len),
416 : BoolGetDatum(false));
417 :
418 : /*
419 : * If the result is large, it's worth repalloc'ing to release any extra
420 : * space we asked for. The cutoff here is somewhat arbitrary, but we
421 : * *must* check when len * MAX_CONVERSION_GROWTH exceeds MaxAllocSize.
422 : */
423 768 : if (len > 1000000)
424 : {
425 0 : Size resultlen = strlen((char *) result);
426 :
427 0 : if (resultlen >= MaxAllocSize)
428 0 : ereport(ERROR,
429 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
430 : errmsg("out of memory"),
431 : errdetail("String of %d bytes is too long for encoding conversion.",
432 : len)));
433 :
434 0 : result = (unsigned char *) repalloc(result, resultlen + 1);
435 : }
436 :
437 768 : return result;
438 : }
439 :
440 : /*
441 : * Convert src string to another encoding.
442 : *
443 : * This function has a different API than the other conversion functions.
444 : * The caller should've looked up the conversion function using
445 : * FindDefaultConversionProc(). Unlike the other functions, the converted
446 : * result is not palloc'd. It is written to the caller-supplied buffer
447 : * instead.
448 : *
449 : * src_encoding - encoding to convert from
450 : * dest_encoding - encoding to convert to
451 : * src, srclen - input buffer and its length in bytes
452 : * dest, destlen - destination buffer and its size in bytes
453 : *
454 : * The output is null-terminated.
455 : *
456 : * If destlen < srclen * MAX_CONVERSION_INPUT_LENGTH + 1, the converted output
457 : * wouldn't necessarily fit in the output buffer, and the function will not
458 : * convert the whole input.
459 : *
460 : * TODO: The conversion function interface is not great. Firstly, it
461 : * would be nice to pass through the destination buffer size to the
462 : * conversion function, so that if you pass a shorter destination buffer, it
463 : * could still continue to fill up the whole buffer. Currently, we have to
464 : * assume worst case expansion and stop the conversion short, even if there
465 : * is in fact space left in the destination buffer. Secondly, it would be
466 : * nice to return the number of bytes written to the caller, to avoid a call
467 : * to strlen().
468 : */
469 : int
470 5790 : pg_do_encoding_conversion_buf(Oid proc,
471 : int src_encoding,
472 : int dest_encoding,
473 : unsigned char *src, int srclen,
474 : unsigned char *dest, int destlen,
475 : bool noError)
476 : {
477 : Datum result;
478 :
479 : /*
480 : * If the destination buffer is not large enough to hold the result in the
481 : * worst case, limit the input size passed to the conversion function.
482 : */
483 5790 : if ((Size) srclen >= ((destlen - 1) / (Size) MAX_CONVERSION_GROWTH))
484 5742 : srclen = ((destlen - 1) / (Size) MAX_CONVERSION_GROWTH);
485 :
486 5790 : result = OidFunctionCall6(proc,
487 : Int32GetDatum(src_encoding),
488 : Int32GetDatum(dest_encoding),
489 : CStringGetDatum((char *) src),
490 : CStringGetDatum((char *) dest),
491 : Int32GetDatum(srclen),
492 : BoolGetDatum(noError));
493 3420 : return DatumGetInt32(result);
494 : }
495 :
496 : /*
497 : * Convert string to encoding encoding_name. The source
498 : * encoding is the DB encoding.
499 : *
500 : * BYTEA convert_to(TEXT string, NAME encoding_name) */
501 : Datum
502 396 : pg_convert_to(PG_FUNCTION_ARGS)
503 : {
504 396 : Datum string = PG_GETARG_DATUM(0);
505 396 : Datum dest_encoding_name = PG_GETARG_DATUM(1);
506 396 : Datum src_encoding_name = DirectFunctionCall1(namein,
507 : CStringGetDatum(DatabaseEncoding->name));
508 : Datum result;
509 :
510 : /*
511 : * pg_convert expects a bytea as its first argument. We're passing it a
512 : * text argument here, relying on the fact that they are both in fact
513 : * varlena types, and thus structurally identical.
514 : */
515 396 : result = DirectFunctionCall3(pg_convert, string,
516 : src_encoding_name, dest_encoding_name);
517 :
518 396 : PG_RETURN_DATUM(result);
519 : }
520 :
521 : /*
522 : * Convert string from encoding encoding_name. The destination
523 : * encoding is the DB encoding.
524 : *
525 : * TEXT convert_from(BYTEA string, NAME encoding_name) */
526 : Datum
527 580 : pg_convert_from(PG_FUNCTION_ARGS)
528 : {
529 580 : Datum string = PG_GETARG_DATUM(0);
530 580 : Datum src_encoding_name = PG_GETARG_DATUM(1);
531 580 : Datum dest_encoding_name = DirectFunctionCall1(namein,
532 : CStringGetDatum(DatabaseEncoding->name));
533 : Datum result;
534 :
535 580 : result = DirectFunctionCall3(pg_convert, string,
536 : src_encoding_name, dest_encoding_name);
537 :
538 : /*
539 : * pg_convert returns a bytea, which we in turn return as text, relying on
540 : * the fact that they are both in fact varlena types, and thus
541 : * structurally identical. Although not all bytea values are valid text,
542 : * in this case it will be because we've told pg_convert to return one
543 : * that is valid as text in the current database encoding.
544 : */
545 574 : PG_RETURN_DATUM(result);
546 : }
547 :
548 : /*
549 : * Convert string between two arbitrary encodings.
550 : *
551 : * BYTEA convert(BYTEA string, NAME src_encoding_name, NAME dest_encoding_name)
552 : */
553 : Datum
554 1744 : pg_convert(PG_FUNCTION_ARGS)
555 : {
556 1744 : bytea *string = PG_GETARG_BYTEA_PP(0);
557 1744 : char *src_encoding_name = NameStr(*PG_GETARG_NAME(1));
558 1744 : int src_encoding = pg_char_to_encoding(src_encoding_name);
559 1744 : char *dest_encoding_name = NameStr(*PG_GETARG_NAME(2));
560 1744 : int dest_encoding = pg_char_to_encoding(dest_encoding_name);
561 : const char *src_str;
562 : char *dest_str;
563 : bytea *retval;
564 : int len;
565 :
566 1744 : if (src_encoding < 0)
567 0 : ereport(ERROR,
568 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
569 : errmsg("invalid source encoding name \"%s\"",
570 : src_encoding_name)));
571 1744 : if (dest_encoding < 0)
572 0 : ereport(ERROR,
573 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
574 : errmsg("invalid destination encoding name \"%s\"",
575 : dest_encoding_name)));
576 :
577 : /* make sure that source string is valid */
578 1744 : len = VARSIZE_ANY_EXHDR(string);
579 1744 : src_str = VARDATA_ANY(string);
580 1744 : (void) pg_verify_mbstr(src_encoding, src_str, len, false);
581 :
582 : /* perform conversion */
583 1738 : dest_str = (char *) pg_do_encoding_conversion((unsigned char *) unconstify(char *, src_str),
584 : len,
585 : src_encoding,
586 : dest_encoding);
587 :
588 :
589 : /* return source string if no conversion happened */
590 1738 : if (dest_str == src_str)
591 970 : PG_RETURN_BYTEA_P(string);
592 :
593 : /*
594 : * build bytea data type structure.
595 : */
596 768 : len = strlen(dest_str);
597 768 : retval = (bytea *) palloc(len + VARHDRSZ);
598 768 : SET_VARSIZE(retval, len + VARHDRSZ);
599 768 : memcpy(VARDATA(retval), dest_str, len);
600 768 : pfree(dest_str);
601 :
602 : /* free memory if allocated by the toaster */
603 768 : PG_FREE_IF_COPY(string, 0);
604 :
605 768 : PG_RETURN_BYTEA_P(retval);
606 : }
607 :
608 : /*
609 : * get the length of the string considered as text in the specified
610 : * encoding. Raises an error if the data is not valid in that
611 : * encoding.
612 : *
613 : * INT4 length (BYTEA string, NAME src_encoding_name)
614 : */
615 : Datum
616 0 : length_in_encoding(PG_FUNCTION_ARGS)
617 : {
618 0 : bytea *string = PG_GETARG_BYTEA_PP(0);
619 0 : char *src_encoding_name = NameStr(*PG_GETARG_NAME(1));
620 0 : int src_encoding = pg_char_to_encoding(src_encoding_name);
621 : const char *src_str;
622 : int len;
623 : int retval;
624 :
625 0 : if (src_encoding < 0)
626 0 : ereport(ERROR,
627 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
628 : errmsg("invalid encoding name \"%s\"",
629 : src_encoding_name)));
630 :
631 0 : len = VARSIZE_ANY_EXHDR(string);
632 0 : src_str = VARDATA_ANY(string);
633 :
634 0 : retval = pg_verify_mbstr_len(src_encoding, src_str, len, false);
635 :
636 0 : PG_RETURN_INT32(retval);
637 : }
638 :
639 : /*
640 : * Get maximum multibyte character length in the specified encoding.
641 : *
642 : * Note encoding is specified numerically, not by name as above.
643 : */
644 : Datum
645 0 : pg_encoding_max_length_sql(PG_FUNCTION_ARGS)
646 : {
647 0 : int encoding = PG_GETARG_INT32(0);
648 :
649 0 : if (PG_VALID_ENCODING(encoding))
650 0 : PG_RETURN_INT32(pg_wchar_table[encoding].maxmblen);
651 : else
652 0 : PG_RETURN_NULL();
653 : }
654 :
655 : /*
656 : * Convert client encoding to server encoding.
657 : *
658 : * See the notes about string conversion functions at the top of this file.
659 : */
660 : char *
661 826530 : pg_client_to_server(const char *s, int len)
662 : {
663 826530 : return pg_any_to_server(s, len, ClientEncoding->encoding);
664 : }
665 :
666 : /*
667 : * Convert any encoding to server encoding.
668 : *
669 : * See the notes about string conversion functions at the top of this file.
670 : *
671 : * Unlike the other string conversion functions, this will apply validation
672 : * even if encoding == DatabaseEncoding->encoding. This is because this is
673 : * used to process data coming in from outside the database, and we never
674 : * want to just assume validity.
675 : */
676 : char *
677 912590 : pg_any_to_server(const char *s, int len, int encoding)
678 : {
679 912590 : if (len <= 0)
680 79732 : return unconstify(char *, s); /* empty string is always valid */
681 :
682 832858 : if (encoding == DatabaseEncoding->encoding ||
683 : encoding == PG_SQL_ASCII)
684 : {
685 : /*
686 : * No conversion is needed, but we must still validate the data.
687 : */
688 832490 : (void) pg_verify_mbstr(DatabaseEncoding->encoding, s, len, false);
689 832488 : return unconstify(char *, s);
690 : }
691 :
692 368 : if (DatabaseEncoding->encoding == PG_SQL_ASCII)
693 : {
694 : /*
695 : * No conversion is possible, but we must still validate the data,
696 : * because the client-side code might have done string escaping using
697 : * the selected client_encoding. If the client encoding is ASCII-safe
698 : * then we just do a straight validation under that encoding. For an
699 : * ASCII-unsafe encoding we have a problem: we dare not pass such data
700 : * to the parser but we have no way to convert it. We compromise by
701 : * rejecting the data if it contains any non-ASCII characters.
702 : */
703 308 : if (PG_VALID_BE_ENCODING(encoding))
704 248 : (void) pg_verify_mbstr(encoding, s, len, false);
705 : else
706 : {
707 : int i;
708 :
709 1908 : for (i = 0; i < len; i++)
710 : {
711 1848 : if (s[i] == '\0' || IS_HIGHBIT_SET(s[i]))
712 0 : ereport(ERROR,
713 : (errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
714 : errmsg("invalid byte value for encoding \"%s\": 0x%02x",
715 : pg_enc2name_tbl[PG_SQL_ASCII].name,
716 : (unsigned char) s[i])));
717 : }
718 : }
719 308 : return unconstify(char *, s);
720 : }
721 :
722 : /* Fast path if we can use cached conversion function */
723 60 : if (encoding == ClientEncoding->encoding)
724 60 : return perform_default_encoding_conversion(s, len, true);
725 :
726 : /* General case ... will not work outside transactions */
727 0 : return (char *) pg_do_encoding_conversion((unsigned char *) unconstify(char *, s),
728 : len,
729 : encoding,
730 0 : DatabaseEncoding->encoding);
731 : }
732 :
733 : /*
734 : * Convert server encoding to client encoding.
735 : *
736 : * See the notes about string conversion functions at the top of this file.
737 : */
738 : char *
739 42161626 : pg_server_to_client(const char *s, int len)
740 : {
741 42161626 : return pg_server_to_any(s, len, ClientEncoding->encoding);
742 : }
743 :
744 : /*
745 : * Convert server encoding to any encoding.
746 : *
747 : * See the notes about string conversion functions at the top of this file.
748 : */
749 : char *
750 42200446 : pg_server_to_any(const char *s, int len, int encoding)
751 : {
752 42200446 : if (len <= 0)
753 337944 : return unconstify(char *, s); /* empty string is always valid */
754 :
755 41862502 : if (encoding == DatabaseEncoding->encoding ||
756 : encoding == PG_SQL_ASCII)
757 41861950 : return unconstify(char *, s); /* assume data is valid */
758 :
759 552 : if (DatabaseEncoding->encoding == PG_SQL_ASCII)
760 : {
761 : /* No conversion is possible, but we must validate the result */
762 168 : (void) pg_verify_mbstr(encoding, s, len, false);
763 168 : return unconstify(char *, s);
764 : }
765 :
766 : /* Fast path if we can use cached conversion function */
767 384 : if (encoding == ClientEncoding->encoding)
768 384 : return perform_default_encoding_conversion(s, len, false);
769 :
770 : /* General case ... will not work outside transactions */
771 0 : return (char *) pg_do_encoding_conversion((unsigned char *) unconstify(char *, s),
772 : len,
773 0 : DatabaseEncoding->encoding,
774 : encoding);
775 : }
776 :
777 : /*
778 : * Perform default encoding conversion using cached FmgrInfo. Since
779 : * this function does not access database at all, it is safe to call
780 : * outside transactions. If the conversion has not been set up by
781 : * SetClientEncoding(), no conversion is performed.
782 : */
783 : static char *
784 444 : perform_default_encoding_conversion(const char *src, int len,
785 : bool is_client_to_server)
786 : {
787 : char *result;
788 : int src_encoding,
789 : dest_encoding;
790 : FmgrInfo *flinfo;
791 :
792 444 : if (is_client_to_server)
793 : {
794 60 : src_encoding = ClientEncoding->encoding;
795 60 : dest_encoding = DatabaseEncoding->encoding;
796 60 : flinfo = ToServerConvProc;
797 : }
798 : else
799 : {
800 384 : src_encoding = DatabaseEncoding->encoding;
801 384 : dest_encoding = ClientEncoding->encoding;
802 384 : flinfo = ToClientConvProc;
803 : }
804 :
805 444 : if (flinfo == NULL)
806 0 : return unconstify(char *, src);
807 :
808 : /*
809 : * Allocate space for conversion result, being wary of integer overflow.
810 : * See comments in pg_do_encoding_conversion.
811 : */
812 444 : if ((Size) len >= (MaxAllocHugeSize / (Size) MAX_CONVERSION_GROWTH))
813 0 : ereport(ERROR,
814 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
815 : errmsg("out of memory"),
816 : errdetail("String of %d bytes is too long for encoding conversion.",
817 : len)));
818 :
819 : result = (char *)
820 444 : MemoryContextAllocHuge(CurrentMemoryContext,
821 444 : (Size) len * MAX_CONVERSION_GROWTH + 1);
822 :
823 444 : FunctionCall6(flinfo,
824 : Int32GetDatum(src_encoding),
825 : Int32GetDatum(dest_encoding),
826 : CStringGetDatum(src),
827 : CStringGetDatum(result),
828 : Int32GetDatum(len),
829 : BoolGetDatum(false));
830 :
831 : /*
832 : * Release extra space if there might be a lot --- see comments in
833 : * pg_do_encoding_conversion.
834 : */
835 444 : if (len > 1000000)
836 : {
837 0 : Size resultlen = strlen(result);
838 :
839 0 : if (resultlen >= MaxAllocSize)
840 0 : ereport(ERROR,
841 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
842 : errmsg("out of memory"),
843 : errdetail("String of %d bytes is too long for encoding conversion.",
844 : len)));
845 :
846 0 : result = (char *) repalloc(result, resultlen + 1);
847 : }
848 :
849 444 : return result;
850 : }
851 :
852 : /*
853 : * Convert a single Unicode code point into a string in the server encoding.
854 : *
855 : * The code point given by "c" is converted and stored at *s, which must
856 : * have at least MAX_UNICODE_EQUIVALENT_STRING+1 bytes available.
857 : * The output will have a trailing '\0'. Throws error if the conversion
858 : * cannot be performed.
859 : *
860 : * Note that this relies on having previously looked up any required
861 : * conversion function. That's partly for speed but mostly because the parser
862 : * may call this outside any transaction, or in an aborted transaction.
863 : */
864 : void
865 1016 : pg_unicode_to_server(pg_wchar c, unsigned char *s)
866 : {
867 : unsigned char c_as_utf8[MAX_MULTIBYTE_CHAR_LEN + 1];
868 : int c_as_utf8_len;
869 : int server_encoding;
870 :
871 : /*
872 : * Complain if invalid Unicode code point. The choice of errcode here is
873 : * debatable, but really our caller should have checked this anyway.
874 : */
875 1016 : if (!is_valid_unicode_codepoint(c))
876 0 : ereport(ERROR,
877 : (errcode(ERRCODE_SYNTAX_ERROR),
878 : errmsg("invalid Unicode code point")));
879 :
880 : /* Otherwise, if it's in ASCII range, conversion is trivial */
881 1016 : if (c <= 0x7F)
882 : {
883 358 : s[0] = (unsigned char) c;
884 358 : s[1] = '\0';
885 1016 : return;
886 : }
887 :
888 : /* If the server encoding is UTF-8, we just need to reformat the code */
889 658 : server_encoding = GetDatabaseEncoding();
890 658 : if (server_encoding == PG_UTF8)
891 : {
892 658 : unicode_to_utf8(c, s);
893 658 : s[pg_utf_mblen(s)] = '\0';
894 658 : return;
895 : }
896 :
897 : /* For all other cases, we must have a conversion function available */
898 0 : if (Utf8ToServerConvProc == NULL)
899 0 : ereport(ERROR,
900 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
901 : errmsg("conversion between %s and %s is not supported",
902 : pg_enc2name_tbl[PG_UTF8].name,
903 : GetDatabaseEncodingName())));
904 :
905 : /* Construct UTF-8 source string */
906 0 : unicode_to_utf8(c, c_as_utf8);
907 0 : c_as_utf8_len = pg_utf_mblen(c_as_utf8);
908 0 : c_as_utf8[c_as_utf8_len] = '\0';
909 :
910 : /* Convert, or throw error if we can't */
911 0 : FunctionCall6(Utf8ToServerConvProc,
912 : Int32GetDatum(PG_UTF8),
913 : Int32GetDatum(server_encoding),
914 : CStringGetDatum((char *) c_as_utf8),
915 : CStringGetDatum((char *) s),
916 : Int32GetDatum(c_as_utf8_len),
917 : BoolGetDatum(false));
918 : }
919 :
920 : /*
921 : * Convert a single Unicode code point into a string in the server encoding.
922 : *
923 : * Same as pg_unicode_to_server(), except that we don't throw errors,
924 : * but simply return false on conversion failure.
925 : */
926 : bool
927 84 : pg_unicode_to_server_noerror(pg_wchar c, unsigned char *s)
928 : {
929 : unsigned char c_as_utf8[MAX_MULTIBYTE_CHAR_LEN + 1];
930 : int c_as_utf8_len;
931 : int converted_len;
932 : int server_encoding;
933 :
934 : /* Fail if invalid Unicode code point */
935 84 : if (!is_valid_unicode_codepoint(c))
936 0 : return false;
937 :
938 : /* Otherwise, if it's in ASCII range, conversion is trivial */
939 84 : if (c <= 0x7F)
940 : {
941 24 : s[0] = (unsigned char) c;
942 24 : s[1] = '\0';
943 24 : return true;
944 : }
945 :
946 : /* If the server encoding is UTF-8, we just need to reformat the code */
947 60 : server_encoding = GetDatabaseEncoding();
948 60 : if (server_encoding == PG_UTF8)
949 : {
950 60 : unicode_to_utf8(c, s);
951 60 : s[pg_utf_mblen(s)] = '\0';
952 60 : return true;
953 : }
954 :
955 : /* For all other cases, we must have a conversion function available */
956 0 : if (Utf8ToServerConvProc == NULL)
957 0 : return false;
958 :
959 : /* Construct UTF-8 source string */
960 0 : unicode_to_utf8(c, c_as_utf8);
961 0 : c_as_utf8_len = pg_utf_mblen(c_as_utf8);
962 0 : c_as_utf8[c_as_utf8_len] = '\0';
963 :
964 : /* Convert, but without throwing error if we can't */
965 0 : converted_len = DatumGetInt32(FunctionCall6(Utf8ToServerConvProc,
966 : Int32GetDatum(PG_UTF8),
967 : Int32GetDatum(server_encoding),
968 : CStringGetDatum((char *) c_as_utf8),
969 : CStringGetDatum((char *) s),
970 : Int32GetDatum(c_as_utf8_len),
971 : BoolGetDatum(true)));
972 :
973 : /* Conversion was successful iff it consumed the whole input */
974 0 : return (converted_len == c_as_utf8_len);
975 : }
976 :
977 :
978 : /* convert a multibyte string to a wchar */
979 : int
980 0 : pg_mb2wchar(const char *from, pg_wchar *to)
981 : {
982 0 : return pg_wchar_table[DatabaseEncoding->encoding].mb2wchar_with_len((const unsigned char *) from, to, strlen(from));
983 : }
984 :
985 : /* convert a multibyte string to a wchar with a limited length */
986 : int
987 7079240 : pg_mb2wchar_with_len(const char *from, pg_wchar *to, int len)
988 : {
989 7079240 : return pg_wchar_table[DatabaseEncoding->encoding].mb2wchar_with_len((const unsigned char *) from, to, len);
990 : }
991 :
992 : /* same, with any encoding */
993 : int
994 18350 : pg_encoding_mb2wchar_with_len(int encoding,
995 : const char *from, pg_wchar *to, int len)
996 : {
997 18350 : return pg_wchar_table[encoding].mb2wchar_with_len((const unsigned char *) from, to, len);
998 : }
999 :
1000 : /* convert a wchar string to a multibyte */
1001 : int
1002 0 : pg_wchar2mb(const pg_wchar *from, char *to)
1003 : {
1004 0 : return pg_wchar_table[DatabaseEncoding->encoding].wchar2mb_with_len(from, (unsigned char *) to, pg_wchar_strlen(from));
1005 : }
1006 :
1007 : /* convert a wchar string to a multibyte with a limited length */
1008 : int
1009 1115278 : pg_wchar2mb_with_len(const pg_wchar *from, char *to, int len)
1010 : {
1011 1115278 : return pg_wchar_table[DatabaseEncoding->encoding].wchar2mb_with_len(from, (unsigned char *) to, len);
1012 : }
1013 :
1014 : /* same, with any encoding */
1015 : int
1016 0 : pg_encoding_wchar2mb_with_len(int encoding,
1017 : const pg_wchar *from, char *to, int len)
1018 : {
1019 0 : return pg_wchar_table[encoding].wchar2mb_with_len(from, (unsigned char *) to, len);
1020 : }
1021 :
1022 : /* returns the byte length of a multibyte character */
1023 : int
1024 250204966 : pg_mblen(const char *mbstr)
1025 : {
1026 250204966 : return pg_wchar_table[DatabaseEncoding->encoding].mblen((const unsigned char *) mbstr);
1027 : }
1028 :
1029 : /* returns the display length of a multibyte character */
1030 : int
1031 8724 : pg_dsplen(const char *mbstr)
1032 : {
1033 8724 : return pg_wchar_table[DatabaseEncoding->encoding].dsplen((const unsigned char *) mbstr);
1034 : }
1035 :
1036 : /* returns the length (counted in wchars) of a multibyte string */
1037 : int
1038 702 : pg_mbstrlen(const char *mbstr)
1039 : {
1040 702 : int len = 0;
1041 :
1042 : /* optimization for single byte encoding */
1043 702 : if (pg_database_encoding_max_length() == 1)
1044 0 : return strlen(mbstr);
1045 :
1046 1626 : while (*mbstr)
1047 : {
1048 924 : mbstr += pg_mblen(mbstr);
1049 924 : len++;
1050 : }
1051 702 : return len;
1052 : }
1053 :
1054 : /* returns the length (counted in wchars) of a multibyte string
1055 : * (not necessarily NULL terminated)
1056 : */
1057 : int
1058 1537814 : pg_mbstrlen_with_len(const char *mbstr, int limit)
1059 : {
1060 1537814 : int len = 0;
1061 :
1062 : /* optimization for single byte encoding */
1063 1537814 : if (pg_database_encoding_max_length() == 1)
1064 400014 : return limit;
1065 :
1066 218646030 : while (limit > 0 && *mbstr)
1067 : {
1068 217508230 : int l = pg_mblen(mbstr);
1069 :
1070 217508230 : limit -= l;
1071 217508230 : mbstr += l;
1072 217508230 : len++;
1073 : }
1074 1137800 : return len;
1075 : }
1076 :
1077 : /*
1078 : * returns the byte length of a multibyte string
1079 : * (not necessarily NULL terminated)
1080 : * that is no longer than limit.
1081 : * this function does not break multibyte character boundary.
1082 : */
1083 : int
1084 310048 : pg_mbcliplen(const char *mbstr, int len, int limit)
1085 : {
1086 310048 : return pg_encoding_mbcliplen(DatabaseEncoding->encoding, mbstr,
1087 : len, limit);
1088 : }
1089 :
1090 : /*
1091 : * pg_mbcliplen with specified encoding; string must be valid in encoding
1092 : */
1093 : int
1094 310048 : pg_encoding_mbcliplen(int encoding, const char *mbstr,
1095 : int len, int limit)
1096 : {
1097 : mblen_converter mblen_fn;
1098 310048 : int clen = 0;
1099 : int l;
1100 :
1101 : /* optimization for single byte encoding */
1102 310048 : if (pg_encoding_max_length(encoding) == 1)
1103 36586 : return cliplen(mbstr, len, limit);
1104 :
1105 273462 : mblen_fn = pg_wchar_table[encoding].mblen;
1106 :
1107 2914658 : while (len > 0 && *mbstr)
1108 : {
1109 2775742 : l = (*mblen_fn) ((const unsigned char *) mbstr);
1110 2775742 : if ((clen + l) > limit)
1111 94 : break;
1112 2775648 : clen += l;
1113 2775648 : if (clen == limit)
1114 134452 : break;
1115 2641196 : len -= l;
1116 2641196 : mbstr += l;
1117 : }
1118 273462 : return clen;
1119 : }
1120 :
1121 : /*
1122 : * Similar to pg_mbcliplen except the limit parameter specifies the
1123 : * character length, not the byte length.
1124 : */
1125 : int
1126 528 : pg_mbcharcliplen(const char *mbstr, int len, int limit)
1127 : {
1128 528 : int clen = 0;
1129 528 : int nch = 0;
1130 : int l;
1131 :
1132 : /* optimization for single byte encoding */
1133 528 : if (pg_database_encoding_max_length() == 1)
1134 0 : return cliplen(mbstr, len, limit);
1135 :
1136 2328 : while (len > 0 && *mbstr)
1137 : {
1138 2310 : l = pg_mblen(mbstr);
1139 2310 : nch++;
1140 2310 : if (nch > limit)
1141 510 : break;
1142 1800 : clen += l;
1143 1800 : len -= l;
1144 1800 : mbstr += l;
1145 : }
1146 528 : return clen;
1147 : }
1148 :
1149 : /* mbcliplen for any single-byte encoding */
1150 : static int
1151 36586 : cliplen(const char *str, int len, int limit)
1152 : {
1153 36586 : int l = 0;
1154 :
1155 36586 : len = Min(len, limit);
1156 285920 : while (l < len && str[l])
1157 249334 : l++;
1158 36586 : return l;
1159 : }
1160 :
1161 : void
1162 31170 : SetDatabaseEncoding(int encoding)
1163 : {
1164 31170 : if (!PG_VALID_BE_ENCODING(encoding))
1165 0 : elog(ERROR, "invalid database encoding: %d", encoding);
1166 :
1167 31170 : DatabaseEncoding = &pg_enc2name_tbl[encoding];
1168 : Assert(DatabaseEncoding->encoding == encoding);
1169 31170 : }
1170 :
1171 : void
1172 34830 : SetMessageEncoding(int encoding)
1173 : {
1174 : /* Some calls happen before we can elog()! */
1175 : Assert(PG_VALID_ENCODING(encoding));
1176 :
1177 34830 : MessageEncoding = &pg_enc2name_tbl[encoding];
1178 : Assert(MessageEncoding->encoding == encoding);
1179 34830 : }
1180 :
1181 : #ifdef ENABLE_NLS
1182 : /*
1183 : * Make one bind_textdomain_codeset() call, translating a pg_enc to a gettext
1184 : * codeset. Fails for MULE_INTERNAL, an encoding unknown to gettext; can also
1185 : * fail for gettext-internal causes like out-of-memory.
1186 : */
1187 : static bool
1188 3174 : raw_pg_bind_textdomain_codeset(const char *domainname, int encoding)
1189 : {
1190 3174 : bool elog_ok = (CurrentMemoryContext != NULL);
1191 :
1192 3174 : if (!PG_VALID_ENCODING(encoding) || pg_enc2gettext_tbl[encoding] == NULL)
1193 0 : return false;
1194 :
1195 3174 : if (bind_textdomain_codeset(domainname,
1196 : pg_enc2gettext_tbl[encoding]) != NULL)
1197 3174 : return true;
1198 :
1199 0 : if (elog_ok)
1200 0 : elog(LOG, "bind_textdomain_codeset failed");
1201 : else
1202 0 : write_stderr("bind_textdomain_codeset failed");
1203 :
1204 0 : return false;
1205 : }
1206 :
1207 : /*
1208 : * Bind a gettext message domain to the codeset corresponding to the database
1209 : * encoding. For SQL_ASCII, instead bind to the codeset implied by LC_CTYPE.
1210 : * Return the MessageEncoding implied by the new settings.
1211 : *
1212 : * On most platforms, gettext defaults to the codeset implied by LC_CTYPE.
1213 : * When that matches the database encoding, we don't need to do anything. In
1214 : * CREATE DATABASE, we enforce or trust that the locale's codeset matches the
1215 : * database encoding, except for the C locale. (On Windows, we also permit a
1216 : * discrepancy under the UTF8 encoding.) For the C locale, explicitly bind
1217 : * gettext to the right codeset.
1218 : *
1219 : * On Windows, gettext defaults to the Windows ANSI code page. This is a
1220 : * convenient departure for software that passes the strings to Windows ANSI
1221 : * APIs, but we don't do that. Compel gettext to use database encoding or,
1222 : * failing that, the LC_CTYPE encoding as it would on other platforms.
1223 : *
1224 : * This function is called before elog() and palloc() are usable.
1225 : */
1226 : int
1227 38498 : pg_bind_textdomain_codeset(const char *domainname)
1228 : {
1229 38498 : bool elog_ok = (CurrentMemoryContext != NULL);
1230 38498 : int encoding = GetDatabaseEncoding();
1231 : int new_msgenc;
1232 :
1233 : #ifndef WIN32
1234 38498 : const char *ctype = setlocale(LC_CTYPE, NULL);
1235 :
1236 38498 : if (pg_strcasecmp(ctype, "C") == 0 || pg_strcasecmp(ctype, "POSIX") == 0)
1237 : #endif
1238 7126 : if (encoding != PG_SQL_ASCII &&
1239 3174 : raw_pg_bind_textdomain_codeset(domainname, encoding))
1240 3174 : return encoding;
1241 :
1242 35324 : new_msgenc = pg_get_encoding_from_locale(NULL, elog_ok);
1243 35324 : if (new_msgenc < 0)
1244 0 : new_msgenc = PG_SQL_ASCII;
1245 :
1246 : #ifdef WIN32
1247 : if (!raw_pg_bind_textdomain_codeset(domainname, new_msgenc))
1248 : /* On failure, the old message encoding remains valid. */
1249 : return GetMessageEncoding();
1250 : #endif
1251 :
1252 35324 : return new_msgenc;
1253 : }
1254 : #endif
1255 :
1256 : /*
1257 : * The database encoding, also called the server encoding, represents the
1258 : * encoding of data stored in text-like data types. Affected types include
1259 : * cstring, text, varchar, name, xml, and json.
1260 : */
1261 : int
1262 21893058 : GetDatabaseEncoding(void)
1263 : {
1264 21893058 : return DatabaseEncoding->encoding;
1265 : }
1266 :
1267 : const char *
1268 64738 : GetDatabaseEncodingName(void)
1269 : {
1270 64738 : return DatabaseEncoding->name;
1271 : }
1272 :
1273 : Datum
1274 88 : getdatabaseencoding(PG_FUNCTION_ARGS)
1275 : {
1276 88 : return DirectFunctionCall1(namein, CStringGetDatum(DatabaseEncoding->name));
1277 : }
1278 :
1279 : Datum
1280 0 : pg_client_encoding(PG_FUNCTION_ARGS)
1281 : {
1282 0 : return DirectFunctionCall1(namein, CStringGetDatum(ClientEncoding->name));
1283 : }
1284 :
1285 : Datum
1286 36 : PG_char_to_encoding(PG_FUNCTION_ARGS)
1287 : {
1288 36 : Name s = PG_GETARG_NAME(0);
1289 :
1290 36 : PG_RETURN_INT32(pg_char_to_encoding(NameStr(*s)));
1291 : }
1292 :
1293 : Datum
1294 5016 : PG_encoding_to_char(PG_FUNCTION_ARGS)
1295 : {
1296 5016 : int32 encoding = PG_GETARG_INT32(0);
1297 5016 : const char *encoding_name = pg_encoding_to_char(encoding);
1298 :
1299 5016 : return DirectFunctionCall1(namein, CStringGetDatum(encoding_name));
1300 : }
1301 :
1302 : /*
1303 : * gettext() returns messages in this encoding. This often matches the
1304 : * database encoding, but it differs for SQL_ASCII databases, for processes
1305 : * not attached to a database, and under a database encoding lacking iconv
1306 : * support (MULE_INTERNAL).
1307 : */
1308 : int
1309 0 : GetMessageEncoding(void)
1310 : {
1311 0 : return MessageEncoding->encoding;
1312 : }
1313 :
1314 :
1315 : /*
1316 : * Generic character incrementer function.
1317 : *
1318 : * Not knowing anything about the properties of the encoding in use, we just
1319 : * keep incrementing the last byte until we get a validly-encoded result,
1320 : * or we run out of values to try. We don't bother to try incrementing
1321 : * higher-order bytes, so there's no growth in runtime for wider characters.
1322 : * (If we did try to do that, we'd need to consider the likelihood that 255
1323 : * is not a valid final byte in the encoding.)
1324 : */
1325 : static bool
1326 104 : pg_generic_charinc(unsigned char *charptr, int len)
1327 : {
1328 104 : unsigned char *lastbyte = charptr + len - 1;
1329 : mbchar_verifier mbverify;
1330 :
1331 : /* We can just invoke the character verifier directly. */
1332 104 : mbverify = pg_wchar_table[GetDatabaseEncoding()].mbverifychar;
1333 :
1334 104 : while (*lastbyte < (unsigned char) 255)
1335 : {
1336 104 : (*lastbyte)++;
1337 104 : if ((*mbverify) (charptr, len) == len)
1338 104 : return true;
1339 : }
1340 :
1341 0 : return false;
1342 : }
1343 :
1344 : /*
1345 : * UTF-8 character incrementer function.
1346 : *
1347 : * For a one-byte character less than 0x7F, we just increment the byte.
1348 : *
1349 : * For a multibyte character, every byte but the first must fall between 0x80
1350 : * and 0xBF; and the first byte must be between 0xC0 and 0xF4. We increment
1351 : * the last byte that's not already at its maximum value. If we can't find a
1352 : * byte that's less than the maximum allowable value, we simply fail. We also
1353 : * need some special-case logic to skip regions used for surrogate pair
1354 : * handling, as those should not occur in valid UTF-8.
1355 : *
1356 : * Note that we don't reset lower-order bytes back to their minimums, since
1357 : * we can't afford to make an exhaustive search (see make_greater_string).
1358 : */
1359 : static bool
1360 3262 : pg_utf8_increment(unsigned char *charptr, int length)
1361 : {
1362 : unsigned char a;
1363 : unsigned char limit;
1364 :
1365 3262 : switch (length)
1366 : {
1367 0 : default:
1368 : /* reject lengths 5 and 6 for now */
1369 0 : return false;
1370 0 : case 4:
1371 0 : a = charptr[3];
1372 0 : if (a < 0xBF)
1373 : {
1374 0 : charptr[3]++;
1375 0 : break;
1376 : }
1377 : /* FALL THRU */
1378 : case 3:
1379 0 : a = charptr[2];
1380 0 : if (a < 0xBF)
1381 : {
1382 0 : charptr[2]++;
1383 0 : break;
1384 : }
1385 : /* FALL THRU */
1386 : case 2:
1387 0 : a = charptr[1];
1388 0 : switch (*charptr)
1389 : {
1390 0 : case 0xED:
1391 0 : limit = 0x9F;
1392 0 : break;
1393 0 : case 0xF4:
1394 0 : limit = 0x8F;
1395 0 : break;
1396 0 : default:
1397 0 : limit = 0xBF;
1398 0 : break;
1399 : }
1400 0 : if (a < limit)
1401 : {
1402 0 : charptr[1]++;
1403 0 : break;
1404 : }
1405 : /* FALL THRU */
1406 : case 1:
1407 3262 : a = *charptr;
1408 3262 : if (a == 0x7F || a == 0xDF || a == 0xEF || a == 0xF4)
1409 0 : return false;
1410 3262 : charptr[0]++;
1411 3262 : break;
1412 : }
1413 :
1414 3262 : return true;
1415 : }
1416 :
1417 : /*
1418 : * EUC-JP character incrementer function.
1419 : *
1420 : * If the sequence starts with SS2 (0x8e), it must be a two-byte sequence
1421 : * representing JIS X 0201 characters with the second byte ranging between
1422 : * 0xa1 and 0xdf. We just increment the last byte if it's less than 0xdf,
1423 : * and otherwise rewrite the whole sequence to 0xa1 0xa1.
1424 : *
1425 : * If the sequence starts with SS3 (0x8f), it must be a three-byte sequence
1426 : * in which the last two bytes range between 0xa1 and 0xfe. The last byte
1427 : * is incremented if possible, otherwise the second-to-last byte.
1428 : *
1429 : * If the sequence starts with a value other than the above and its MSB
1430 : * is set, it must be a two-byte sequence representing JIS X 0208 characters
1431 : * with both bytes ranging between 0xa1 and 0xfe. The last byte is
1432 : * incremented if possible, otherwise the second-to-last byte.
1433 : *
1434 : * Otherwise, the sequence is a single-byte ASCII character. It is
1435 : * incremented up to 0x7f.
1436 : */
1437 : static bool
1438 0 : pg_eucjp_increment(unsigned char *charptr, int length)
1439 : {
1440 : unsigned char c1,
1441 : c2;
1442 : int i;
1443 :
1444 0 : c1 = *charptr;
1445 :
1446 0 : switch (c1)
1447 : {
1448 0 : case SS2: /* JIS X 0201 */
1449 0 : if (length != 2)
1450 0 : return false;
1451 :
1452 0 : c2 = charptr[1];
1453 :
1454 0 : if (c2 >= 0xdf)
1455 0 : charptr[0] = charptr[1] = 0xa1;
1456 0 : else if (c2 < 0xa1)
1457 0 : charptr[1] = 0xa1;
1458 : else
1459 0 : charptr[1]++;
1460 0 : break;
1461 :
1462 0 : case SS3: /* JIS X 0212 */
1463 0 : if (length != 3)
1464 0 : return false;
1465 :
1466 0 : for (i = 2; i > 0; i--)
1467 : {
1468 0 : c2 = charptr[i];
1469 0 : if (c2 < 0xa1)
1470 : {
1471 0 : charptr[i] = 0xa1;
1472 0 : return true;
1473 : }
1474 0 : else if (c2 < 0xfe)
1475 : {
1476 0 : charptr[i]++;
1477 0 : return true;
1478 : }
1479 : }
1480 :
1481 : /* Out of 3-byte code region */
1482 0 : return false;
1483 :
1484 0 : default:
1485 0 : if (IS_HIGHBIT_SET(c1)) /* JIS X 0208? */
1486 : {
1487 0 : if (length != 2)
1488 0 : return false;
1489 :
1490 0 : for (i = 1; i >= 0; i--)
1491 : {
1492 0 : c2 = charptr[i];
1493 0 : if (c2 < 0xa1)
1494 : {
1495 0 : charptr[i] = 0xa1;
1496 0 : return true;
1497 : }
1498 0 : else if (c2 < 0xfe)
1499 : {
1500 0 : charptr[i]++;
1501 0 : return true;
1502 : }
1503 : }
1504 :
1505 : /* Out of 2 byte code region */
1506 0 : return false;
1507 : }
1508 : else
1509 : { /* ASCII, single byte */
1510 0 : if (c1 > 0x7e)
1511 0 : return false;
1512 0 : (*charptr)++;
1513 : }
1514 0 : break;
1515 : }
1516 :
1517 0 : return true;
1518 : }
1519 :
1520 : /*
1521 : * get the character incrementer for the encoding for the current database
1522 : */
1523 : mbcharacter_incrementer
1524 3366 : pg_database_encoding_character_incrementer(void)
1525 : {
1526 : /*
1527 : * Eventually it might be best to add a field to pg_wchar_table[], but for
1528 : * now we just use a switch.
1529 : */
1530 3366 : switch (GetDatabaseEncoding())
1531 : {
1532 3262 : case PG_UTF8:
1533 3262 : return pg_utf8_increment;
1534 :
1535 0 : case PG_EUC_JP:
1536 0 : return pg_eucjp_increment;
1537 :
1538 104 : default:
1539 104 : return pg_generic_charinc;
1540 : }
1541 : }
1542 :
1543 : /*
1544 : * fetch maximum length of the encoding for the current database
1545 : */
1546 : int
1547 14065456 : pg_database_encoding_max_length(void)
1548 : {
1549 14065456 : return pg_wchar_table[GetDatabaseEncoding()].maxmblen;
1550 : }
1551 :
1552 : /*
1553 : * Verify mbstr to make sure that it is validly encoded in the current
1554 : * database encoding. Otherwise same as pg_verify_mbstr().
1555 : */
1556 : bool
1557 4446 : pg_verifymbstr(const char *mbstr, int len, bool noError)
1558 : {
1559 4446 : return pg_verify_mbstr(GetDatabaseEncoding(), mbstr, len, noError);
1560 : }
1561 :
1562 : /*
1563 : * Verify mbstr to make sure that it is validly encoded in the specified
1564 : * encoding.
1565 : */
1566 : bool
1567 1147002 : pg_verify_mbstr(int encoding, const char *mbstr, int len, bool noError)
1568 : {
1569 : int oklen;
1570 :
1571 : Assert(PG_VALID_ENCODING(encoding));
1572 :
1573 1147002 : oklen = pg_wchar_table[encoding].mbverifystr((const unsigned char *) mbstr, len);
1574 1147002 : if (oklen != len)
1575 : {
1576 8 : if (noError)
1577 0 : return false;
1578 8 : report_invalid_encoding(encoding, mbstr + oklen, len - oklen);
1579 : }
1580 1146994 : return true;
1581 : }
1582 :
1583 : /*
1584 : * Verify mbstr to make sure that it is validly encoded in the specified
1585 : * encoding.
1586 : *
1587 : * mbstr is not necessarily zero terminated; length of mbstr is
1588 : * specified by len.
1589 : *
1590 : * If OK, return length of string in the encoding.
1591 : * If a problem is found, return -1 when noError is
1592 : * true; when noError is false, ereport() a descriptive message.
1593 : *
1594 : * Note: We cannot use the faster encoding-specific mbverifystr() function
1595 : * here, because we need to count the number of characters in the string.
1596 : */
1597 : int
1598 0 : pg_verify_mbstr_len(int encoding, const char *mbstr, int len, bool noError)
1599 : {
1600 : mbchar_verifier mbverifychar;
1601 : int mb_len;
1602 :
1603 : Assert(PG_VALID_ENCODING(encoding));
1604 :
1605 : /*
1606 : * In single-byte encodings, we need only reject nulls (\0).
1607 : */
1608 0 : if (pg_encoding_max_length(encoding) <= 1)
1609 : {
1610 0 : const char *nullpos = memchr(mbstr, 0, len);
1611 :
1612 0 : if (nullpos == NULL)
1613 0 : return len;
1614 0 : if (noError)
1615 0 : return -1;
1616 0 : report_invalid_encoding(encoding, nullpos, 1);
1617 : }
1618 :
1619 : /* fetch function pointer just once */
1620 0 : mbverifychar = pg_wchar_table[encoding].mbverifychar;
1621 :
1622 0 : mb_len = 0;
1623 :
1624 0 : while (len > 0)
1625 : {
1626 : int l;
1627 :
1628 : /* fast path for ASCII-subset characters */
1629 0 : if (!IS_HIGHBIT_SET(*mbstr))
1630 : {
1631 0 : if (*mbstr != '\0')
1632 : {
1633 0 : mb_len++;
1634 0 : mbstr++;
1635 0 : len--;
1636 0 : continue;
1637 : }
1638 0 : if (noError)
1639 0 : return -1;
1640 0 : report_invalid_encoding(encoding, mbstr, len);
1641 : }
1642 :
1643 0 : l = (*mbverifychar) ((const unsigned char *) mbstr, len);
1644 :
1645 0 : if (l < 0)
1646 : {
1647 0 : if (noError)
1648 0 : return -1;
1649 0 : report_invalid_encoding(encoding, mbstr, len);
1650 : }
1651 :
1652 0 : mbstr += l;
1653 0 : len -= l;
1654 0 : mb_len++;
1655 : }
1656 0 : return mb_len;
1657 : }
1658 :
1659 : /*
1660 : * check_encoding_conversion_args: check arguments of a conversion function
1661 : *
1662 : * "expected" arguments can be either an encoding ID or -1 to indicate that
1663 : * the caller will check whether it accepts the ID.
1664 : *
1665 : * Note: the errors here are not really user-facing, so elog instead of
1666 : * ereport seems sufficient. Also, we trust that the "expected" encoding
1667 : * arguments are valid encoding IDs, but we don't trust the actuals.
1668 : */
1669 : void
1670 7066 : check_encoding_conversion_args(int src_encoding,
1671 : int dest_encoding,
1672 : int len,
1673 : int expected_src_encoding,
1674 : int expected_dest_encoding)
1675 : {
1676 7066 : if (!PG_VALID_ENCODING(src_encoding))
1677 0 : elog(ERROR, "invalid source encoding ID: %d", src_encoding);
1678 7066 : if (src_encoding != expected_src_encoding && expected_src_encoding >= 0)
1679 0 : elog(ERROR, "expected source encoding \"%s\", but got \"%s\"",
1680 : pg_enc2name_tbl[expected_src_encoding].name,
1681 : pg_enc2name_tbl[src_encoding].name);
1682 7066 : if (!PG_VALID_ENCODING(dest_encoding))
1683 0 : elog(ERROR, "invalid destination encoding ID: %d", dest_encoding);
1684 7066 : if (dest_encoding != expected_dest_encoding && expected_dest_encoding >= 0)
1685 0 : elog(ERROR, "expected destination encoding \"%s\", but got \"%s\"",
1686 : pg_enc2name_tbl[expected_dest_encoding].name,
1687 : pg_enc2name_tbl[dest_encoding].name);
1688 7066 : if (len < 0)
1689 0 : elog(ERROR, "encoding conversion length must not be negative");
1690 7066 : }
1691 :
1692 : /*
1693 : * report_invalid_encoding: complain about invalid multibyte character
1694 : *
1695 : * note: len is remaining length of string, not length of character;
1696 : * len must be greater than zero (or we'd neglect initializing "buf").
1697 : */
1698 : void
1699 2990 : report_invalid_encoding(int encoding, const char *mbstr, int len)
1700 : {
1701 2990 : int l = pg_encoding_mblen_or_incomplete(encoding, mbstr, len);
1702 : char buf[8 * 5 + 1];
1703 2990 : char *p = buf;
1704 : int j,
1705 : jlimit;
1706 :
1707 2990 : jlimit = Min(l, len);
1708 2990 : jlimit = Min(jlimit, 8); /* prevent buffer overrun */
1709 :
1710 9226 : for (j = 0; j < jlimit; j++)
1711 : {
1712 6236 : p += sprintf(p, "0x%02x", (unsigned char) mbstr[j]);
1713 6236 : if (j < jlimit - 1)
1714 3246 : p += sprintf(p, " ");
1715 : }
1716 :
1717 2990 : ereport(ERROR,
1718 : (errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
1719 : errmsg("invalid byte sequence for encoding \"%s\": %s",
1720 : pg_enc2name_tbl[encoding].name,
1721 : buf)));
1722 : }
1723 :
1724 : /*
1725 : * report_untranslatable_char: complain about untranslatable character
1726 : *
1727 : * note: len is remaining length of string, not length of character;
1728 : * len must be greater than zero (or we'd neglect initializing "buf").
1729 : */
1730 : void
1731 936 : report_untranslatable_char(int src_encoding, int dest_encoding,
1732 : const char *mbstr, int len)
1733 : {
1734 : int l;
1735 : char buf[8 * 5 + 1];
1736 936 : char *p = buf;
1737 : int j,
1738 : jlimit;
1739 :
1740 : /*
1741 : * We probably could use plain pg_encoding_mblen(), because
1742 : * gb18030_to_utf8() verifies before it converts. All conversions should.
1743 : * For src_encoding!=GB18030, len>0 meets pg_encoding_mblen() needs. Even
1744 : * so, be defensive, since a buggy conversion might pass invalid data.
1745 : * This is not a performance-critical path.
1746 : */
1747 936 : l = pg_encoding_mblen_or_incomplete(src_encoding, mbstr, len);
1748 936 : jlimit = Min(l, len);
1749 936 : jlimit = Min(jlimit, 8); /* prevent buffer overrun */
1750 :
1751 3528 : for (j = 0; j < jlimit; j++)
1752 : {
1753 2592 : p += sprintf(p, "0x%02x", (unsigned char) mbstr[j]);
1754 2592 : if (j < jlimit - 1)
1755 1656 : p += sprintf(p, " ");
1756 : }
1757 :
1758 936 : ereport(ERROR,
1759 : (errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
1760 : errmsg("character with byte sequence %s in encoding \"%s\" has no equivalent in encoding \"%s\"",
1761 : buf,
1762 : pg_enc2name_tbl[src_encoding].name,
1763 : pg_enc2name_tbl[dest_encoding].name)));
1764 : }
1765 :
1766 :
1767 : #ifdef WIN32
1768 : /*
1769 : * Convert from MessageEncoding to a palloc'ed, null-terminated utf16
1770 : * string. The character length is also passed to utf16len if not
1771 : * null. Returns NULL iff failed. Before MessageEncoding initialization, "str"
1772 : * should be ASCII-only; this will function as though MessageEncoding is UTF8.
1773 : */
1774 : WCHAR *
1775 : pgwin32_message_to_UTF16(const char *str, int len, int *utf16len)
1776 : {
1777 : int msgenc = GetMessageEncoding();
1778 : WCHAR *utf16;
1779 : int dstlen;
1780 : UINT codepage;
1781 :
1782 : if (msgenc == PG_SQL_ASCII)
1783 : /* No conversion is possible, and SQL_ASCII is never utf16. */
1784 : return NULL;
1785 :
1786 : codepage = pg_enc2name_tbl[msgenc].codepage;
1787 :
1788 : /*
1789 : * Use MultiByteToWideChar directly if there is a corresponding codepage,
1790 : * or double conversion through UTF8 if not. Double conversion is needed,
1791 : * for example, in an ENCODING=LATIN8, LC_CTYPE=C database.
1792 : */
1793 : if (codepage != 0)
1794 : {
1795 : utf16 = (WCHAR *) palloc(sizeof(WCHAR) * (len + 1));
1796 : dstlen = MultiByteToWideChar(codepage, 0, str, len, utf16, len);
1797 : utf16[dstlen] = (WCHAR) 0;
1798 : }
1799 : else
1800 : {
1801 : char *utf8;
1802 :
1803 : /*
1804 : * XXX pg_do_encoding_conversion() requires a transaction. In the
1805 : * absence of one, hope for the input to be valid UTF8.
1806 : */
1807 : if (IsTransactionState())
1808 : {
1809 : utf8 = (char *) pg_do_encoding_conversion((unsigned char *) str,
1810 : len,
1811 : msgenc,
1812 : PG_UTF8);
1813 : if (utf8 != str)
1814 : len = strlen(utf8);
1815 : }
1816 : else
1817 : utf8 = (char *) str;
1818 :
1819 : utf16 = (WCHAR *) palloc(sizeof(WCHAR) * (len + 1));
1820 : dstlen = MultiByteToWideChar(CP_UTF8, 0, utf8, len, utf16, len);
1821 : utf16[dstlen] = (WCHAR) 0;
1822 :
1823 : if (utf8 != str)
1824 : pfree(utf8);
1825 : }
1826 :
1827 : if (dstlen == 0 && len > 0)
1828 : {
1829 : pfree(utf16);
1830 : return NULL; /* error */
1831 : }
1832 :
1833 : if (utf16len)
1834 : *utf16len = dstlen;
1835 : return utf16;
1836 : }
1837 :
1838 : #endif /* WIN32 */
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