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) 1996-2024, 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 "varatt.h"
43 :
44 : /*
45 : * We maintain a simple linked list caching the fmgr lookup info for the
46 : * currently selected conversion functions, as well as any that have been
47 : * selected previously in the current session. (We remember previous
48 : * settings because we must be able to restore a previous setting during
49 : * transaction rollback, without doing any fresh catalog accesses.)
50 : *
51 : * Since we'll never release this data, we just keep it in TopMemoryContext.
52 : */
53 : typedef struct ConvProcInfo
54 : {
55 : int s_encoding; /* server and client encoding IDs */
56 : int c_encoding;
57 : FmgrInfo to_server_info; /* lookup info for conversion procs */
58 : FmgrInfo to_client_info;
59 : } ConvProcInfo;
60 :
61 : static List *ConvProcList = NIL; /* List of ConvProcInfo */
62 :
63 : /*
64 : * These variables point to the currently active conversion functions,
65 : * or are NULL when no conversion is needed.
66 : */
67 : static FmgrInfo *ToServerConvProc = NULL;
68 : static FmgrInfo *ToClientConvProc = NULL;
69 :
70 : /*
71 : * This variable stores the conversion function to convert from UTF-8
72 : * to the server encoding. It's NULL if the server encoding *is* UTF-8,
73 : * or if we lack a conversion function for this.
74 : */
75 : static FmgrInfo *Utf8ToServerConvProc = NULL;
76 :
77 : /*
78 : * These variables track the currently-selected encodings.
79 : */
80 : static const pg_enc2name *ClientEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
81 : static const pg_enc2name *DatabaseEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
82 : static const pg_enc2name *MessageEncoding = &pg_enc2name_tbl[PG_SQL_ASCII];
83 :
84 : /*
85 : * During backend startup we can't set client encoding because we (a)
86 : * can't look up the conversion functions, and (b) may not know the database
87 : * encoding yet either. So SetClientEncoding() just accepts anything and
88 : * remembers it for InitializeClientEncoding() to apply later.
89 : */
90 : static bool backend_startup_complete = false;
91 : static int pending_client_encoding = PG_SQL_ASCII;
92 :
93 :
94 : /* Internal functions */
95 : static char *perform_default_encoding_conversion(const char *src,
96 : int len, bool is_client_to_server);
97 : static int cliplen(const char *str, int len, int limit);
98 :
99 :
100 : /*
101 : * Prepare for a future call to SetClientEncoding. Success should mean
102 : * that SetClientEncoding is guaranteed to succeed for this encoding request.
103 : *
104 : * (But note that success before backend_startup_complete does not guarantee
105 : * success after ...)
106 : *
107 : * Returns 0 if okay, -1 if not (bad encoding or can't support conversion)
108 : */
109 : int
110 57394 : PrepareClientEncoding(int encoding)
111 : {
112 : int current_server_encoding;
113 : ListCell *lc;
114 :
115 57394 : if (!PG_VALID_FE_ENCODING(encoding))
116 0 : return -1;
117 :
118 : /* Can't do anything during startup, per notes above */
119 57394 : if (!backend_startup_complete)
120 27392 : return 0;
121 :
122 30002 : current_server_encoding = GetDatabaseEncoding();
123 :
124 : /*
125 : * Check for cases that require no conversion function.
126 : */
127 30002 : if (current_server_encoding == encoding ||
128 5284 : current_server_encoding == PG_SQL_ASCII ||
129 : encoding == PG_SQL_ASCII)
130 29994 : return 0;
131 :
132 8 : if (IsTransactionState())
133 : {
134 : /*
135 : * If we're in a live transaction, it's safe to access the catalogs,
136 : * so look up the functions. We repeat the lookup even if the info is
137 : * already cached, so that we can react to changes in the contents of
138 : * pg_conversion.
139 : */
140 : Oid to_server_proc,
141 : to_client_proc;
142 : ConvProcInfo *convinfo;
143 : MemoryContext oldcontext;
144 :
145 8 : to_server_proc = FindDefaultConversionProc(encoding,
146 : current_server_encoding);
147 8 : if (!OidIsValid(to_server_proc))
148 0 : return -1;
149 8 : to_client_proc = FindDefaultConversionProc(current_server_encoding,
150 : encoding);
151 8 : if (!OidIsValid(to_client_proc))
152 0 : return -1;
153 :
154 : /*
155 : * Load the fmgr info into TopMemoryContext (could still fail here)
156 : */
157 8 : convinfo = (ConvProcInfo *) MemoryContextAlloc(TopMemoryContext,
158 : sizeof(ConvProcInfo));
159 8 : convinfo->s_encoding = current_server_encoding;
160 8 : convinfo->c_encoding = encoding;
161 8 : fmgr_info_cxt(to_server_proc, &convinfo->to_server_info,
162 : TopMemoryContext);
163 8 : fmgr_info_cxt(to_client_proc, &convinfo->to_client_info,
164 : TopMemoryContext);
165 :
166 : /* Attach new info to head of list */
167 8 : oldcontext = MemoryContextSwitchTo(TopMemoryContext);
168 8 : ConvProcList = lcons(convinfo, ConvProcList);
169 8 : MemoryContextSwitchTo(oldcontext);
170 :
171 : /*
172 : * We cannot yet remove any older entry for the same encoding pair,
173 : * since it could still be in use. SetClientEncoding will clean up.
174 : */
175 :
176 8 : return 0; /* success */
177 : }
178 : else
179 : {
180 : /*
181 : * If we're not in a live transaction, the only thing we can do is
182 : * restore a previous setting using the cache. This covers all
183 : * transaction-rollback cases. The only case it might not work for is
184 : * trying to change client_encoding on the fly by editing
185 : * postgresql.conf and SIGHUP'ing. Which would probably be a stupid
186 : * thing to do anyway.
187 : */
188 0 : foreach(lc, ConvProcList)
189 : {
190 0 : ConvProcInfo *oldinfo = (ConvProcInfo *) lfirst(lc);
191 :
192 0 : if (oldinfo->s_encoding == current_server_encoding &&
193 0 : oldinfo->c_encoding == encoding)
194 0 : return 0;
195 : }
196 :
197 0 : return -1; /* it's not cached, so fail */
198 : }
199 : }
200 :
201 : /*
202 : * Set the active client encoding and set up the conversion-function pointers.
203 : * PrepareClientEncoding should have been called previously for this encoding.
204 : *
205 : * Returns 0 if okay, -1 if not (bad encoding or can't support conversion)
206 : */
207 : int
208 51928 : SetClientEncoding(int encoding)
209 : {
210 : int current_server_encoding;
211 : bool found;
212 : ListCell *lc;
213 :
214 51928 : if (!PG_VALID_FE_ENCODING(encoding))
215 0 : return -1;
216 :
217 : /* Can't do anything during startup, per notes above */
218 51928 : if (!backend_startup_complete)
219 : {
220 24576 : pending_client_encoding = encoding;
221 24576 : return 0;
222 : }
223 :
224 27352 : current_server_encoding = GetDatabaseEncoding();
225 :
226 : /*
227 : * Check for cases that require no conversion function.
228 : */
229 27352 : if (current_server_encoding == encoding ||
230 2648 : current_server_encoding == PG_SQL_ASCII ||
231 : encoding == PG_SQL_ASCII)
232 : {
233 27344 : ClientEncoding = &pg_enc2name_tbl[encoding];
234 27344 : ToServerConvProc = NULL;
235 27344 : ToClientConvProc = NULL;
236 27344 : return 0;
237 : }
238 :
239 : /*
240 : * Search the cache for the entry previously prepared by
241 : * PrepareClientEncoding; if there isn't one, we lose. While at it,
242 : * release any duplicate entries so that repeated Prepare/Set cycles don't
243 : * leak memory.
244 : */
245 8 : found = false;
246 16 : foreach(lc, ConvProcList)
247 : {
248 8 : ConvProcInfo *convinfo = (ConvProcInfo *) lfirst(lc);
249 :
250 8 : if (convinfo->s_encoding == current_server_encoding &&
251 8 : convinfo->c_encoding == encoding)
252 : {
253 8 : if (!found)
254 : {
255 : /* Found newest entry, so set up */
256 8 : ClientEncoding = &pg_enc2name_tbl[encoding];
257 8 : ToServerConvProc = &convinfo->to_server_info;
258 8 : ToClientConvProc = &convinfo->to_client_info;
259 8 : found = true;
260 : }
261 : else
262 : {
263 : /* Duplicate entry, release it */
264 0 : ConvProcList = foreach_delete_current(ConvProcList, lc);
265 0 : pfree(convinfo);
266 : }
267 : }
268 : }
269 :
270 8 : if (found)
271 8 : return 0; /* success */
272 : else
273 0 : return -1; /* it's not cached, so fail */
274 : }
275 :
276 : /*
277 : * Initialize client encoding conversions.
278 : * Called from InitPostgres() once during backend startup.
279 : */
280 : void
281 24400 : InitializeClientEncoding(void)
282 : {
283 : int current_server_encoding;
284 :
285 : Assert(!backend_startup_complete);
286 24400 : backend_startup_complete = true;
287 :
288 48800 : if (PrepareClientEncoding(pending_client_encoding) < 0 ||
289 24400 : SetClientEncoding(pending_client_encoding) < 0)
290 : {
291 : /*
292 : * Oops, the requested conversion is not available. We couldn't fail
293 : * before, but we can now.
294 : */
295 0 : ereport(FATAL,
296 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
297 : errmsg("conversion between %s and %s is not supported",
298 : pg_enc2name_tbl[pending_client_encoding].name,
299 : GetDatabaseEncodingName())));
300 : }
301 :
302 : /*
303 : * Also look up the UTF8-to-server conversion function if needed. Since
304 : * the server encoding is fixed within any one backend process, we don't
305 : * have to do this more than once.
306 : */
307 24400 : current_server_encoding = GetDatabaseEncoding();
308 24400 : if (current_server_encoding != PG_UTF8 &&
309 : current_server_encoding != PG_SQL_ASCII)
310 : {
311 : Oid utf8_to_server_proc;
312 :
313 : Assert(IsTransactionState());
314 : utf8_to_server_proc =
315 204 : FindDefaultConversionProc(PG_UTF8,
316 : current_server_encoding);
317 : /* If there's no such conversion, just leave the pointer as NULL */
318 204 : if (OidIsValid(utf8_to_server_proc))
319 : {
320 : FmgrInfo *finfo;
321 :
322 204 : finfo = (FmgrInfo *) MemoryContextAlloc(TopMemoryContext,
323 : sizeof(FmgrInfo));
324 204 : fmgr_info_cxt(utf8_to_server_proc, finfo,
325 : TopMemoryContext);
326 : /* Set Utf8ToServerConvProc only after data is fully valid */
327 204 : Utf8ToServerConvProc = finfo;
328 : }
329 : }
330 24400 : }
331 :
332 : /*
333 : * returns the current client encoding
334 : */
335 : int
336 9354 : pg_get_client_encoding(void)
337 : {
338 9354 : return ClientEncoding->encoding;
339 : }
340 :
341 : /*
342 : * returns the current client encoding name
343 : */
344 : const char *
345 0 : pg_get_client_encoding_name(void)
346 : {
347 0 : return ClientEncoding->name;
348 : }
349 :
350 : /*
351 : * Convert src string to another encoding (general case).
352 : *
353 : * See the notes about string conversion functions at the top of this file.
354 : */
355 : unsigned char *
356 2782 : pg_do_encoding_conversion(unsigned char *src, int len,
357 : int src_encoding, int dest_encoding)
358 : {
359 : unsigned char *result;
360 : Oid proc;
361 :
362 2782 : if (len <= 0)
363 30 : return src; /* empty string is always valid */
364 :
365 2752 : if (src_encoding == dest_encoding)
366 1968 : return src; /* no conversion required, assume valid */
367 :
368 784 : if (dest_encoding == PG_SQL_ASCII)
369 0 : return src; /* any string is valid in SQL_ASCII */
370 :
371 784 : if (src_encoding == PG_SQL_ASCII)
372 : {
373 : /* No conversion is possible, but we must validate the result */
374 16 : (void) pg_verify_mbstr(dest_encoding, (const char *) src, len, false);
375 16 : return src;
376 : }
377 :
378 768 : if (!IsTransactionState()) /* shouldn't happen */
379 0 : elog(ERROR, "cannot perform encoding conversion outside a transaction");
380 :
381 768 : proc = FindDefaultConversionProc(src_encoding, dest_encoding);
382 768 : if (!OidIsValid(proc))
383 0 : ereport(ERROR,
384 : (errcode(ERRCODE_UNDEFINED_FUNCTION),
385 : errmsg("default conversion function for encoding \"%s\" to \"%s\" does not exist",
386 : pg_encoding_to_char(src_encoding),
387 : pg_encoding_to_char(dest_encoding))));
388 :
389 : /*
390 : * Allocate space for conversion result, being wary of integer overflow.
391 : *
392 : * len * MAX_CONVERSION_GROWTH is typically a vast overestimate of the
393 : * required space, so it might exceed MaxAllocSize even though the result
394 : * would actually fit. We do not want to hand back a result string that
395 : * exceeds MaxAllocSize, because callers might not cope gracefully --- but
396 : * if we just allocate more than that, and don't use it, that's fine.
397 : */
398 768 : if ((Size) len >= (MaxAllocHugeSize / (Size) MAX_CONVERSION_GROWTH))
399 0 : ereport(ERROR,
400 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
401 : errmsg("out of memory"),
402 : errdetail("String of %d bytes is too long for encoding conversion.",
403 : len)));
404 :
405 : result = (unsigned char *)
406 768 : MemoryContextAllocHuge(CurrentMemoryContext,
407 768 : (Size) len * MAX_CONVERSION_GROWTH + 1);
408 :
409 768 : (void) OidFunctionCall6(proc,
410 : Int32GetDatum(src_encoding),
411 : Int32GetDatum(dest_encoding),
412 : CStringGetDatum((char *) src),
413 : CStringGetDatum((char *) result),
414 : Int32GetDatum(len),
415 : BoolGetDatum(false));
416 :
417 : /*
418 : * If the result is large, it's worth repalloc'ing to release any extra
419 : * space we asked for. The cutoff here is somewhat arbitrary, but we
420 : * *must* check when len * MAX_CONVERSION_GROWTH exceeds MaxAllocSize.
421 : */
422 768 : if (len > 1000000)
423 : {
424 0 : Size resultlen = strlen((char *) result);
425 :
426 0 : if (resultlen >= MaxAllocSize)
427 0 : ereport(ERROR,
428 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
429 : errmsg("out of memory"),
430 : errdetail("String of %d bytes is too long for encoding conversion.",
431 : len)));
432 :
433 0 : result = (unsigned char *) repalloc(result, resultlen + 1);
434 : }
435 :
436 768 : return result;
437 : }
438 :
439 : /*
440 : * Convert src string to another encoding.
441 : *
442 : * This function has a different API than the other conversion functions.
443 : * The caller should've looked up the conversion function using
444 : * FindDefaultConversionProc(). Unlike the other functions, the converted
445 : * result is not palloc'd. It is written to the caller-supplied buffer
446 : * instead.
447 : *
448 : * src_encoding - encoding to convert from
449 : * dest_encoding - encoding to convert to
450 : * src, srclen - input buffer and its length in bytes
451 : * dest, destlen - destination buffer and its size in bytes
452 : *
453 : * The output is null-terminated.
454 : *
455 : * If destlen < srclen * MAX_CONVERSION_INPUT_LENGTH + 1, the converted output
456 : * wouldn't necessarily fit in the output buffer, and the function will not
457 : * convert the whole input.
458 : *
459 : * TODO: The conversion function interface is not great. Firstly, it
460 : * would be nice to pass through the destination buffer size to the
461 : * conversion function, so that if you pass a shorter destination buffer, it
462 : * could still continue to fill up the whole buffer. Currently, we have to
463 : * assume worst case expansion and stop the conversion short, even if there
464 : * is in fact space left in the destination buffer. Secondly, it would be
465 : * nice to return the number of bytes written to the caller, to avoid a call
466 : * to strlen().
467 : */
468 : int
469 5706 : pg_do_encoding_conversion_buf(Oid proc,
470 : int src_encoding,
471 : int dest_encoding,
472 : unsigned char *src, int srclen,
473 : unsigned char *dest, int destlen,
474 : bool noError)
475 : {
476 : Datum result;
477 :
478 : /*
479 : * If the destination buffer is not large enough to hold the result in the
480 : * worst case, limit the input size passed to the conversion function.
481 : */
482 5706 : if ((Size) srclen >= ((destlen - 1) / (Size) MAX_CONVERSION_GROWTH))
483 5706 : srclen = ((destlen - 1) / (Size) MAX_CONVERSION_GROWTH);
484 :
485 5706 : result = OidFunctionCall6(proc,
486 : Int32GetDatum(src_encoding),
487 : Int32GetDatum(dest_encoding),
488 : CStringGetDatum((char *) src),
489 : CStringGetDatum((char *) dest),
490 : Int32GetDatum(srclen),
491 : BoolGetDatum(noError));
492 3366 : return DatumGetInt32(result);
493 : }
494 :
495 : /*
496 : * Convert string to encoding encoding_name. The source
497 : * encoding is the DB encoding.
498 : *
499 : * BYTEA convert_to(TEXT string, NAME encoding_name) */
500 : Datum
501 216 : pg_convert_to(PG_FUNCTION_ARGS)
502 : {
503 216 : Datum string = PG_GETARG_DATUM(0);
504 216 : Datum dest_encoding_name = PG_GETARG_DATUM(1);
505 216 : Datum src_encoding_name = DirectFunctionCall1(namein,
506 : CStringGetDatum(DatabaseEncoding->name));
507 : Datum result;
508 :
509 : /*
510 : * pg_convert expects a bytea as its first argument. We're passing it a
511 : * text argument here, relying on the fact that they are both in fact
512 : * varlena types, and thus structurally identical.
513 : */
514 216 : result = DirectFunctionCall3(pg_convert, string,
515 : src_encoding_name, dest_encoding_name);
516 :
517 216 : PG_RETURN_DATUM(result);
518 : }
519 :
520 : /*
521 : * Convert string from encoding encoding_name. The destination
522 : * encoding is the DB encoding.
523 : *
524 : * TEXT convert_from(BYTEA string, NAME encoding_name) */
525 : Datum
526 568 : pg_convert_from(PG_FUNCTION_ARGS)
527 : {
528 568 : Datum string = PG_GETARG_DATUM(0);
529 568 : Datum src_encoding_name = PG_GETARG_DATUM(1);
530 568 : Datum dest_encoding_name = DirectFunctionCall1(namein,
531 : CStringGetDatum(DatabaseEncoding->name));
532 : Datum result;
533 :
534 568 : result = DirectFunctionCall3(pg_convert, string,
535 : src_encoding_name, dest_encoding_name);
536 :
537 : /*
538 : * pg_convert returns a bytea, which we in turn return as text, relying on
539 : * the fact that they are both in fact varlena types, and thus
540 : * structurally identical. Although not all bytea values are valid text,
541 : * in this case it will be because we've told pg_convert to return one
542 : * that is valid as text in the current database encoding.
543 : */
544 562 : PG_RETURN_DATUM(result);
545 : }
546 :
547 : /*
548 : * Convert string between two arbitrary encodings.
549 : *
550 : * BYTEA convert(BYTEA string, NAME src_encoding_name, NAME dest_encoding_name)
551 : */
552 : Datum
553 1552 : pg_convert(PG_FUNCTION_ARGS)
554 : {
555 1552 : bytea *string = PG_GETARG_BYTEA_PP(0);
556 1552 : char *src_encoding_name = NameStr(*PG_GETARG_NAME(1));
557 1552 : int src_encoding = pg_char_to_encoding(src_encoding_name);
558 1552 : char *dest_encoding_name = NameStr(*PG_GETARG_NAME(2));
559 1552 : int dest_encoding = pg_char_to_encoding(dest_encoding_name);
560 : const char *src_str;
561 : char *dest_str;
562 : bytea *retval;
563 : int len;
564 :
565 1552 : if (src_encoding < 0)
566 0 : ereport(ERROR,
567 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
568 : errmsg("invalid source encoding name \"%s\"",
569 : src_encoding_name)));
570 1552 : if (dest_encoding < 0)
571 0 : ereport(ERROR,
572 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
573 : errmsg("invalid destination encoding name \"%s\"",
574 : dest_encoding_name)));
575 :
576 : /* make sure that source string is valid */
577 1552 : len = VARSIZE_ANY_EXHDR(string);
578 1552 : src_str = VARDATA_ANY(string);
579 1552 : (void) pg_verify_mbstr(src_encoding, src_str, len, false);
580 :
581 : /* perform conversion */
582 1546 : dest_str = (char *) pg_do_encoding_conversion((unsigned char *) unconstify(char *, src_str),
583 : len,
584 : src_encoding,
585 : dest_encoding);
586 :
587 :
588 : /* return source string if no conversion happened */
589 1546 : if (dest_str == src_str)
590 778 : PG_RETURN_BYTEA_P(string);
591 :
592 : /*
593 : * build bytea data type structure.
594 : */
595 768 : len = strlen(dest_str);
596 768 : retval = (bytea *) palloc(len + VARHDRSZ);
597 768 : SET_VARSIZE(retval, len + VARHDRSZ);
598 768 : memcpy(VARDATA(retval), dest_str, len);
599 768 : pfree(dest_str);
600 :
601 : /* free memory if allocated by the toaster */
602 768 : PG_FREE_IF_COPY(string, 0);
603 :
604 768 : PG_RETURN_BYTEA_P(retval);
605 : }
606 :
607 : /*
608 : * get the length of the string considered as text in the specified
609 : * encoding. Raises an error if the data is not valid in that
610 : * encoding.
611 : *
612 : * INT4 length (BYTEA string, NAME src_encoding_name)
613 : */
614 : Datum
615 0 : length_in_encoding(PG_FUNCTION_ARGS)
616 : {
617 0 : bytea *string = PG_GETARG_BYTEA_PP(0);
618 0 : char *src_encoding_name = NameStr(*PG_GETARG_NAME(1));
619 0 : int src_encoding = pg_char_to_encoding(src_encoding_name);
620 : const char *src_str;
621 : int len;
622 : int retval;
623 :
624 0 : if (src_encoding < 0)
625 0 : ereport(ERROR,
626 : (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
627 : errmsg("invalid encoding name \"%s\"",
628 : src_encoding_name)));
629 :
630 0 : len = VARSIZE_ANY_EXHDR(string);
631 0 : src_str = VARDATA_ANY(string);
632 :
633 0 : retval = pg_verify_mbstr_len(src_encoding, src_str, len, false);
634 :
635 0 : PG_RETURN_INT32(retval);
636 : }
637 :
638 : /*
639 : * Get maximum multibyte character length in the specified encoding.
640 : *
641 : * Note encoding is specified numerically, not by name as above.
642 : */
643 : Datum
644 0 : pg_encoding_max_length_sql(PG_FUNCTION_ARGS)
645 : {
646 0 : int encoding = PG_GETARG_INT32(0);
647 :
648 0 : if (PG_VALID_ENCODING(encoding))
649 0 : PG_RETURN_INT32(pg_wchar_table[encoding].maxmblen);
650 : else
651 0 : PG_RETURN_NULL();
652 : }
653 :
654 : /*
655 : * Convert client encoding to server encoding.
656 : *
657 : * See the notes about string conversion functions at the top of this file.
658 : */
659 : char *
660 715870 : pg_client_to_server(const char *s, int len)
661 : {
662 715870 : return pg_any_to_server(s, len, ClientEncoding->encoding);
663 : }
664 :
665 : /*
666 : * Convert any encoding to server encoding.
667 : *
668 : * See the notes about string conversion functions at the top of this file.
669 : *
670 : * Unlike the other string conversion functions, this will apply validation
671 : * even if encoding == DatabaseEncoding->encoding. This is because this is
672 : * used to process data coming in from outside the database, and we never
673 : * want to just assume validity.
674 : */
675 : char *
676 795638 : pg_any_to_server(const char *s, int len, int encoding)
677 : {
678 795638 : if (len <= 0)
679 71902 : return unconstify(char *, s); /* empty string is always valid */
680 :
681 723736 : if (encoding == DatabaseEncoding->encoding ||
682 : encoding == PG_SQL_ASCII)
683 : {
684 : /*
685 : * No conversion is needed, but we must still validate the data.
686 : */
687 723632 : (void) pg_verify_mbstr(DatabaseEncoding->encoding, s, len, false);
688 723630 : return unconstify(char *, s);
689 : }
690 :
691 104 : if (DatabaseEncoding->encoding == PG_SQL_ASCII)
692 : {
693 : /*
694 : * No conversion is possible, but we must still validate the data,
695 : * because the client-side code might have done string escaping using
696 : * the selected client_encoding. If the client encoding is ASCII-safe
697 : * then we just do a straight validation under that encoding. For an
698 : * ASCII-unsafe encoding we have a problem: we dare not pass such data
699 : * to the parser but we have no way to convert it. We compromise by
700 : * rejecting the data if it contains any non-ASCII characters.
701 : */
702 68 : if (PG_VALID_BE_ENCODING(encoding))
703 68 : (void) pg_verify_mbstr(encoding, s, len, false);
704 : else
705 : {
706 : int i;
707 :
708 0 : for (i = 0; i < len; i++)
709 : {
710 0 : if (s[i] == '\0' || IS_HIGHBIT_SET(s[i]))
711 0 : ereport(ERROR,
712 : (errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
713 : errmsg("invalid byte value for encoding \"%s\": 0x%02x",
714 : pg_enc2name_tbl[PG_SQL_ASCII].name,
715 : (unsigned char) s[i])));
716 : }
717 : }
718 68 : return unconstify(char *, s);
719 : }
720 :
721 : /* Fast path if we can use cached conversion function */
722 36 : if (encoding == ClientEncoding->encoding)
723 36 : return perform_default_encoding_conversion(s, len, true);
724 :
725 : /* General case ... will not work outside transactions */
726 0 : return (char *) pg_do_encoding_conversion((unsigned char *) unconstify(char *, s),
727 : len,
728 : encoding,
729 0 : DatabaseEncoding->encoding);
730 : }
731 :
732 : /*
733 : * Convert server encoding to client encoding.
734 : *
735 : * See the notes about string conversion functions at the top of this file.
736 : */
737 : char *
738 28015002 : pg_server_to_client(const char *s, int len)
739 : {
740 28015002 : return pg_server_to_any(s, len, ClientEncoding->encoding);
741 : }
742 :
743 : /*
744 : * Convert server encoding to any encoding.
745 : *
746 : * See the notes about string conversion functions at the top of this file.
747 : */
748 : char *
749 28053298 : pg_server_to_any(const char *s, int len, int encoding)
750 : {
751 28053298 : if (len <= 0)
752 211586 : return unconstify(char *, s); /* empty string is always valid */
753 :
754 27841712 : if (encoding == DatabaseEncoding->encoding ||
755 : encoding == PG_SQL_ASCII)
756 27841300 : return unconstify(char *, s); /* assume data is valid */
757 :
758 412 : if (DatabaseEncoding->encoding == PG_SQL_ASCII)
759 : {
760 : /* No conversion is possible, but we must validate the result */
761 124 : (void) pg_verify_mbstr(encoding, s, len, false);
762 124 : return unconstify(char *, s);
763 : }
764 :
765 : /* Fast path if we can use cached conversion function */
766 288 : if (encoding == ClientEncoding->encoding)
767 288 : return perform_default_encoding_conversion(s, len, false);
768 :
769 : /* General case ... will not work outside transactions */
770 0 : return (char *) pg_do_encoding_conversion((unsigned char *) unconstify(char *, s),
771 : len,
772 0 : DatabaseEncoding->encoding,
773 : encoding);
774 : }
775 :
776 : /*
777 : * Perform default encoding conversion using cached FmgrInfo. Since
778 : * this function does not access database at all, it is safe to call
779 : * outside transactions. If the conversion has not been set up by
780 : * SetClientEncoding(), no conversion is performed.
781 : */
782 : static char *
783 324 : perform_default_encoding_conversion(const char *src, int len,
784 : bool is_client_to_server)
785 : {
786 : char *result;
787 : int src_encoding,
788 : dest_encoding;
789 : FmgrInfo *flinfo;
790 :
791 324 : if (is_client_to_server)
792 : {
793 36 : src_encoding = ClientEncoding->encoding;
794 36 : dest_encoding = DatabaseEncoding->encoding;
795 36 : flinfo = ToServerConvProc;
796 : }
797 : else
798 : {
799 288 : src_encoding = DatabaseEncoding->encoding;
800 288 : dest_encoding = ClientEncoding->encoding;
801 288 : flinfo = ToClientConvProc;
802 : }
803 :
804 324 : if (flinfo == NULL)
805 0 : return unconstify(char *, src);
806 :
807 : /*
808 : * Allocate space for conversion result, being wary of integer overflow.
809 : * See comments in pg_do_encoding_conversion.
810 : */
811 324 : if ((Size) len >= (MaxAllocHugeSize / (Size) MAX_CONVERSION_GROWTH))
812 0 : ereport(ERROR,
813 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
814 : errmsg("out of memory"),
815 : errdetail("String of %d bytes is too long for encoding conversion.",
816 : len)));
817 :
818 : result = (char *)
819 324 : MemoryContextAllocHuge(CurrentMemoryContext,
820 324 : (Size) len * MAX_CONVERSION_GROWTH + 1);
821 :
822 324 : FunctionCall6(flinfo,
823 : Int32GetDatum(src_encoding),
824 : Int32GetDatum(dest_encoding),
825 : CStringGetDatum(src),
826 : CStringGetDatum(result),
827 : Int32GetDatum(len),
828 : BoolGetDatum(false));
829 :
830 : /*
831 : * Release extra space if there might be a lot --- see comments in
832 : * pg_do_encoding_conversion.
833 : */
834 324 : if (len > 1000000)
835 : {
836 0 : Size resultlen = strlen(result);
837 :
838 0 : if (resultlen >= MaxAllocSize)
839 0 : ereport(ERROR,
840 : (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
841 : errmsg("out of memory"),
842 : errdetail("String of %d bytes is too long for encoding conversion.",
843 : len)));
844 :
845 0 : result = (char *) repalloc(result, resultlen + 1);
846 : }
847 :
848 324 : return result;
849 : }
850 :
851 : /*
852 : * Convert a single Unicode code point into a string in the server encoding.
853 : *
854 : * The code point given by "c" is converted and stored at *s, which must
855 : * have at least MAX_UNICODE_EQUIVALENT_STRING+1 bytes available.
856 : * The output will have a trailing '\0'. Throws error if the conversion
857 : * cannot be performed.
858 : *
859 : * Note that this relies on having previously looked up any required
860 : * conversion function. That's partly for speed but mostly because the parser
861 : * may call this outside any transaction, or in an aborted transaction.
862 : */
863 : void
864 638 : pg_unicode_to_server(pg_wchar c, unsigned char *s)
865 : {
866 : unsigned char c_as_utf8[MAX_MULTIBYTE_CHAR_LEN + 1];
867 : int c_as_utf8_len;
868 : int server_encoding;
869 :
870 : /*
871 : * Complain if invalid Unicode code point. The choice of errcode here is
872 : * debatable, but really our caller should have checked this anyway.
873 : */
874 638 : if (!is_valid_unicode_codepoint(c))
875 0 : ereport(ERROR,
876 : (errcode(ERRCODE_SYNTAX_ERROR),
877 : errmsg("invalid Unicode code point")));
878 :
879 : /* Otherwise, if it's in ASCII range, conversion is trivial */
880 638 : if (c <= 0x7F)
881 : {
882 262 : s[0] = (unsigned char) c;
883 262 : s[1] = '\0';
884 638 : return;
885 : }
886 :
887 : /* If the server encoding is UTF-8, we just need to reformat the code */
888 376 : server_encoding = GetDatabaseEncoding();
889 376 : if (server_encoding == PG_UTF8)
890 : {
891 376 : unicode_to_utf8(c, s);
892 376 : s[pg_utf_mblen(s)] = '\0';
893 376 : return;
894 : }
895 :
896 : /* For all other cases, we must have a conversion function available */
897 0 : if (Utf8ToServerConvProc == NULL)
898 0 : ereport(ERROR,
899 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
900 : errmsg("conversion between %s and %s is not supported",
901 : pg_enc2name_tbl[PG_UTF8].name,
902 : GetDatabaseEncodingName())));
903 :
904 : /* Construct UTF-8 source string */
905 0 : unicode_to_utf8(c, c_as_utf8);
906 0 : c_as_utf8_len = pg_utf_mblen(c_as_utf8);
907 0 : c_as_utf8[c_as_utf8_len] = '\0';
908 :
909 : /* Convert, or throw error if we can't */
910 0 : FunctionCall6(Utf8ToServerConvProc,
911 : Int32GetDatum(PG_UTF8),
912 : Int32GetDatum(server_encoding),
913 : CStringGetDatum((char *) c_as_utf8),
914 : CStringGetDatum((char *) s),
915 : Int32GetDatum(c_as_utf8_len),
916 : BoolGetDatum(false));
917 : }
918 :
919 : /*
920 : * Convert a single Unicode code point into a string in the server encoding.
921 : *
922 : * Same as pg_unicode_to_server(), except that we don't throw errors,
923 : * but simply return false on conversion failure.
924 : */
925 : bool
926 84 : pg_unicode_to_server_noerror(pg_wchar c, unsigned char *s)
927 : {
928 : unsigned char c_as_utf8[MAX_MULTIBYTE_CHAR_LEN + 1];
929 : int c_as_utf8_len;
930 : int converted_len;
931 : int server_encoding;
932 :
933 : /* Fail if invalid Unicode code point */
934 84 : if (!is_valid_unicode_codepoint(c))
935 0 : return false;
936 :
937 : /* Otherwise, if it's in ASCII range, conversion is trivial */
938 84 : if (c <= 0x7F)
939 : {
940 24 : s[0] = (unsigned char) c;
941 24 : s[1] = '\0';
942 24 : return true;
943 : }
944 :
945 : /* If the server encoding is UTF-8, we just need to reformat the code */
946 60 : server_encoding = GetDatabaseEncoding();
947 60 : if (server_encoding == PG_UTF8)
948 : {
949 60 : unicode_to_utf8(c, s);
950 60 : s[pg_utf_mblen(s)] = '\0';
951 60 : return true;
952 : }
953 :
954 : /* For all other cases, we must have a conversion function available */
955 0 : if (Utf8ToServerConvProc == NULL)
956 0 : return false;
957 :
958 : /* Construct UTF-8 source string */
959 0 : unicode_to_utf8(c, c_as_utf8);
960 0 : c_as_utf8_len = pg_utf_mblen(c_as_utf8);
961 0 : c_as_utf8[c_as_utf8_len] = '\0';
962 :
963 : /* Convert, but without throwing error if we can't */
964 0 : converted_len = DatumGetInt32(FunctionCall6(Utf8ToServerConvProc,
965 : Int32GetDatum(PG_UTF8),
966 : Int32GetDatum(server_encoding),
967 : CStringGetDatum((char *) c_as_utf8),
968 : CStringGetDatum((char *) s),
969 : Int32GetDatum(c_as_utf8_len),
970 : BoolGetDatum(true)));
971 :
972 : /* Conversion was successful iff it consumed the whole input */
973 0 : return (converted_len == c_as_utf8_len);
974 : }
975 :
976 :
977 : /* convert a multibyte string to a wchar */
978 : int
979 0 : pg_mb2wchar(const char *from, pg_wchar *to)
980 : {
981 0 : return pg_wchar_table[DatabaseEncoding->encoding].mb2wchar_with_len((const unsigned char *) from, to, strlen(from));
982 : }
983 :
984 : /* convert a multibyte string to a wchar with a limited length */
985 : int
986 970082 : pg_mb2wchar_with_len(const char *from, pg_wchar *to, int len)
987 : {
988 970082 : return pg_wchar_table[DatabaseEncoding->encoding].mb2wchar_with_len((const unsigned char *) from, to, len);
989 : }
990 :
991 : /* same, with any encoding */
992 : int
993 18280 : pg_encoding_mb2wchar_with_len(int encoding,
994 : const char *from, pg_wchar *to, int len)
995 : {
996 18280 : return pg_wchar_table[encoding].mb2wchar_with_len((const unsigned char *) from, to, len);
997 : }
998 :
999 : /* convert a wchar string to a multibyte */
1000 : int
1001 0 : pg_wchar2mb(const pg_wchar *from, char *to)
1002 : {
1003 0 : return pg_wchar_table[DatabaseEncoding->encoding].wchar2mb_with_len(from, (unsigned char *) to, pg_wchar_strlen(from));
1004 : }
1005 :
1006 : /* convert a wchar string to a multibyte with a limited length */
1007 : int
1008 1113076 : pg_wchar2mb_with_len(const pg_wchar *from, char *to, int len)
1009 : {
1010 1113076 : return pg_wchar_table[DatabaseEncoding->encoding].wchar2mb_with_len(from, (unsigned char *) to, len);
1011 : }
1012 :
1013 : /* same, with any encoding */
1014 : int
1015 0 : pg_encoding_wchar2mb_with_len(int encoding,
1016 : const pg_wchar *from, char *to, int len)
1017 : {
1018 0 : return pg_wchar_table[encoding].wchar2mb_with_len(from, (unsigned char *) to, len);
1019 : }
1020 :
1021 : /* returns the byte length of a multibyte character */
1022 : int
1023 249329366 : pg_mblen(const char *mbstr)
1024 : {
1025 249329366 : return pg_wchar_table[DatabaseEncoding->encoding].mblen((const unsigned char *) mbstr);
1026 : }
1027 :
1028 : /* returns the display length of a multibyte character */
1029 : int
1030 8724 : pg_dsplen(const char *mbstr)
1031 : {
1032 8724 : return pg_wchar_table[DatabaseEncoding->encoding].dsplen((const unsigned char *) mbstr);
1033 : }
1034 :
1035 : /* returns the length (counted in wchars) of a multibyte string */
1036 : int
1037 702 : pg_mbstrlen(const char *mbstr)
1038 : {
1039 702 : int len = 0;
1040 :
1041 : /* optimization for single byte encoding */
1042 702 : if (pg_database_encoding_max_length() == 1)
1043 0 : return strlen(mbstr);
1044 :
1045 1626 : while (*mbstr)
1046 : {
1047 924 : mbstr += pg_mblen(mbstr);
1048 924 : len++;
1049 : }
1050 702 : return len;
1051 : }
1052 :
1053 : /* returns the length (counted in wchars) of a multibyte string
1054 : * (not necessarily NULL terminated)
1055 : */
1056 : int
1057 1530758 : pg_mbstrlen_with_len(const char *mbstr, int limit)
1058 : {
1059 1530758 : int len = 0;
1060 :
1061 : /* optimization for single byte encoding */
1062 1530758 : if (pg_database_encoding_max_length() == 1)
1063 400010 : return limit;
1064 :
1065 217870004 : while (limit > 0 && *mbstr)
1066 : {
1067 216739256 : int l = pg_mblen(mbstr);
1068 :
1069 216739256 : limit -= l;
1070 216739256 : mbstr += l;
1071 216739256 : len++;
1072 : }
1073 1130748 : return len;
1074 : }
1075 :
1076 : /*
1077 : * returns the byte length of a multibyte string
1078 : * (not necessarily NULL terminated)
1079 : * that is no longer than limit.
1080 : * this function does not break multibyte character boundary.
1081 : */
1082 : int
1083 229668 : pg_mbcliplen(const char *mbstr, int len, int limit)
1084 : {
1085 229668 : return pg_encoding_mbcliplen(DatabaseEncoding->encoding, mbstr,
1086 : len, limit);
1087 : }
1088 :
1089 : /*
1090 : * pg_mbcliplen with specified encoding
1091 : */
1092 : int
1093 229668 : pg_encoding_mbcliplen(int encoding, const char *mbstr,
1094 : int len, int limit)
1095 : {
1096 : mblen_converter mblen_fn;
1097 229668 : int clen = 0;
1098 : int l;
1099 :
1100 : /* optimization for single byte encoding */
1101 229668 : if (pg_encoding_max_length(encoding) == 1)
1102 26230 : return cliplen(mbstr, len, limit);
1103 :
1104 203438 : mblen_fn = pg_wchar_table[encoding].mblen;
1105 :
1106 2190294 : while (len > 0 && *mbstr)
1107 : {
1108 2084300 : l = (*mblen_fn) ((const unsigned char *) mbstr);
1109 2084300 : if ((clen + l) > limit)
1110 82 : break;
1111 2084218 : clen += l;
1112 2084218 : if (clen == limit)
1113 97362 : break;
1114 1986856 : len -= l;
1115 1986856 : mbstr += l;
1116 : }
1117 203438 : return clen;
1118 : }
1119 :
1120 : /*
1121 : * Similar to pg_mbcliplen except the limit parameter specifies the
1122 : * character length, not the byte length.
1123 : */
1124 : int
1125 450 : pg_mbcharcliplen(const char *mbstr, int len, int limit)
1126 : {
1127 450 : int clen = 0;
1128 450 : int nch = 0;
1129 : int l;
1130 :
1131 : /* optimization for single byte encoding */
1132 450 : if (pg_database_encoding_max_length() == 1)
1133 0 : return cliplen(mbstr, len, limit);
1134 :
1135 2082 : while (len > 0 && *mbstr)
1136 : {
1137 2064 : l = pg_mblen(mbstr);
1138 2064 : nch++;
1139 2064 : if (nch > limit)
1140 432 : break;
1141 1632 : clen += l;
1142 1632 : len -= l;
1143 1632 : mbstr += l;
1144 : }
1145 450 : return clen;
1146 : }
1147 :
1148 : /* mbcliplen for any single-byte encoding */
1149 : static int
1150 26230 : cliplen(const char *str, int len, int limit)
1151 : {
1152 26230 : int l = 0;
1153 :
1154 26230 : len = Min(len, limit);
1155 220168 : while (l < len && str[l])
1156 193938 : l++;
1157 26230 : return l;
1158 : }
1159 :
1160 : void
1161 23510 : SetDatabaseEncoding(int encoding)
1162 : {
1163 23510 : if (!PG_VALID_BE_ENCODING(encoding))
1164 0 : elog(ERROR, "invalid database encoding: %d", encoding);
1165 :
1166 23510 : DatabaseEncoding = &pg_enc2name_tbl[encoding];
1167 : Assert(DatabaseEncoding->encoding == encoding);
1168 23510 : }
1169 :
1170 : void
1171 26588 : SetMessageEncoding(int encoding)
1172 : {
1173 : /* Some calls happen before we can elog()! */
1174 : Assert(PG_VALID_ENCODING(encoding));
1175 :
1176 26588 : MessageEncoding = &pg_enc2name_tbl[encoding];
1177 : Assert(MessageEncoding->encoding == encoding);
1178 26588 : }
1179 :
1180 : #ifdef ENABLE_NLS
1181 : /*
1182 : * Make one bind_textdomain_codeset() call, translating a pg_enc to a gettext
1183 : * codeset. Fails for MULE_INTERNAL, an encoding unknown to gettext; can also
1184 : * fail for gettext-internal causes like out-of-memory.
1185 : */
1186 : static bool
1187 3132 : raw_pg_bind_textdomain_codeset(const char *domainname, int encoding)
1188 : {
1189 3132 : bool elog_ok = (CurrentMemoryContext != NULL);
1190 :
1191 3132 : if (!PG_VALID_ENCODING(encoding) || pg_enc2gettext_tbl[encoding] == NULL)
1192 0 : return false;
1193 :
1194 3132 : if (bind_textdomain_codeset(domainname,
1195 : pg_enc2gettext_tbl[encoding]) != NULL)
1196 3132 : return true;
1197 :
1198 0 : if (elog_ok)
1199 0 : elog(LOG, "bind_textdomain_codeset failed");
1200 : else
1201 0 : write_stderr("bind_textdomain_codeset failed");
1202 :
1203 0 : return false;
1204 : }
1205 :
1206 : /*
1207 : * Bind a gettext message domain to the codeset corresponding to the database
1208 : * encoding. For SQL_ASCII, instead bind to the codeset implied by LC_CTYPE.
1209 : * Return the MessageEncoding implied by the new settings.
1210 : *
1211 : * On most platforms, gettext defaults to the codeset implied by LC_CTYPE.
1212 : * When that matches the database encoding, we don't need to do anything. In
1213 : * CREATE DATABASE, we enforce or trust that the locale's codeset matches the
1214 : * database encoding, except for the C locale. (On Windows, we also permit a
1215 : * discrepancy under the UTF8 encoding.) For the C locale, explicitly bind
1216 : * gettext to the right codeset.
1217 : *
1218 : * On Windows, gettext defaults to the Windows ANSI code page. This is a
1219 : * convenient departure for software that passes the strings to Windows ANSI
1220 : * APIs, but we don't do that. Compel gettext to use database encoding or,
1221 : * failing that, the LC_CTYPE encoding as it would on other platforms.
1222 : *
1223 : * This function is called before elog() and palloc() are usable.
1224 : */
1225 : int
1226 30056 : pg_bind_textdomain_codeset(const char *domainname)
1227 : {
1228 30056 : bool elog_ok = (CurrentMemoryContext != NULL);
1229 30056 : int encoding = GetDatabaseEncoding();
1230 : int new_msgenc;
1231 :
1232 : #ifndef WIN32
1233 30056 : const char *ctype = setlocale(LC_CTYPE, NULL);
1234 :
1235 30056 : if (pg_strcasecmp(ctype, "C") == 0 || pg_strcasecmp(ctype, "POSIX") == 0)
1236 : #endif
1237 6974 : if (encoding != PG_SQL_ASCII &&
1238 3132 : raw_pg_bind_textdomain_codeset(domainname, encoding))
1239 3132 : return encoding;
1240 :
1241 26924 : new_msgenc = pg_get_encoding_from_locale(NULL, elog_ok);
1242 26924 : if (new_msgenc < 0)
1243 0 : new_msgenc = PG_SQL_ASCII;
1244 :
1245 : #ifdef WIN32
1246 : if (!raw_pg_bind_textdomain_codeset(domainname, new_msgenc))
1247 : /* On failure, the old message encoding remains valid. */
1248 : return GetMessageEncoding();
1249 : #endif
1250 :
1251 26924 : return new_msgenc;
1252 : }
1253 : #endif
1254 :
1255 : /*
1256 : * The database encoding, also called the server encoding, represents the
1257 : * encoding of data stored in text-like data types. Affected types include
1258 : * cstring, text, varchar, name, xml, and json.
1259 : */
1260 : int
1261 16097582 : GetDatabaseEncoding(void)
1262 : {
1263 16097582 : return DatabaseEncoding->encoding;
1264 : }
1265 :
1266 : const char *
1267 49072 : GetDatabaseEncodingName(void)
1268 : {
1269 49072 : return DatabaseEncoding->name;
1270 : }
1271 :
1272 : Datum
1273 100 : getdatabaseencoding(PG_FUNCTION_ARGS)
1274 : {
1275 100 : return DirectFunctionCall1(namein, CStringGetDatum(DatabaseEncoding->name));
1276 : }
1277 :
1278 : Datum
1279 0 : pg_client_encoding(PG_FUNCTION_ARGS)
1280 : {
1281 0 : return DirectFunctionCall1(namein, CStringGetDatum(ClientEncoding->name));
1282 : }
1283 :
1284 : Datum
1285 54 : PG_char_to_encoding(PG_FUNCTION_ARGS)
1286 : {
1287 54 : Name s = PG_GETARG_NAME(0);
1288 :
1289 54 : PG_RETURN_INT32(pg_char_to_encoding(NameStr(*s)));
1290 : }
1291 :
1292 : Datum
1293 3836 : PG_encoding_to_char(PG_FUNCTION_ARGS)
1294 : {
1295 3836 : int32 encoding = PG_GETARG_INT32(0);
1296 3836 : const char *encoding_name = pg_encoding_to_char(encoding);
1297 :
1298 3836 : return DirectFunctionCall1(namein, CStringGetDatum(encoding_name));
1299 : }
1300 :
1301 : /*
1302 : * gettext() returns messages in this encoding. This often matches the
1303 : * database encoding, but it differs for SQL_ASCII databases, for processes
1304 : * not attached to a database, and under a database encoding lacking iconv
1305 : * support (MULE_INTERNAL).
1306 : */
1307 : int
1308 0 : GetMessageEncoding(void)
1309 : {
1310 0 : return MessageEncoding->encoding;
1311 : }
1312 :
1313 :
1314 : /*
1315 : * Generic character incrementer function.
1316 : *
1317 : * Not knowing anything about the properties of the encoding in use, we just
1318 : * keep incrementing the last byte until we get a validly-encoded result,
1319 : * or we run out of values to try. We don't bother to try incrementing
1320 : * higher-order bytes, so there's no growth in runtime for wider characters.
1321 : * (If we did try to do that, we'd need to consider the likelihood that 255
1322 : * is not a valid final byte in the encoding.)
1323 : */
1324 : static bool
1325 104 : pg_generic_charinc(unsigned char *charptr, int len)
1326 : {
1327 104 : unsigned char *lastbyte = charptr + len - 1;
1328 : mbchar_verifier mbverify;
1329 :
1330 : /* We can just invoke the character verifier directly. */
1331 104 : mbverify = pg_wchar_table[GetDatabaseEncoding()].mbverifychar;
1332 :
1333 104 : while (*lastbyte < (unsigned char) 255)
1334 : {
1335 104 : (*lastbyte)++;
1336 104 : if ((*mbverify) (charptr, len) == len)
1337 104 : return true;
1338 : }
1339 :
1340 0 : return false;
1341 : }
1342 :
1343 : /*
1344 : * UTF-8 character incrementer function.
1345 : *
1346 : * For a one-byte character less than 0x7F, we just increment the byte.
1347 : *
1348 : * For a multibyte character, every byte but the first must fall between 0x80
1349 : * and 0xBF; and the first byte must be between 0xC0 and 0xF4. We increment
1350 : * the last byte that's not already at its maximum value. If we can't find a
1351 : * byte that's less than the maximum allowable value, we simply fail. We also
1352 : * need some special-case logic to skip regions used for surrogate pair
1353 : * handling, as those should not occur in valid UTF-8.
1354 : *
1355 : * Note that we don't reset lower-order bytes back to their minimums, since
1356 : * we can't afford to make an exhaustive search (see make_greater_string).
1357 : */
1358 : static bool
1359 2434 : pg_utf8_increment(unsigned char *charptr, int length)
1360 : {
1361 : unsigned char a;
1362 : unsigned char limit;
1363 :
1364 2434 : switch (length)
1365 : {
1366 0 : default:
1367 : /* reject lengths 5 and 6 for now */
1368 0 : return false;
1369 0 : case 4:
1370 0 : a = charptr[3];
1371 0 : if (a < 0xBF)
1372 : {
1373 0 : charptr[3]++;
1374 0 : break;
1375 : }
1376 : /* FALL THRU */
1377 : case 3:
1378 0 : a = charptr[2];
1379 0 : if (a < 0xBF)
1380 : {
1381 0 : charptr[2]++;
1382 0 : break;
1383 : }
1384 : /* FALL THRU */
1385 : case 2:
1386 0 : a = charptr[1];
1387 0 : switch (*charptr)
1388 : {
1389 0 : case 0xED:
1390 0 : limit = 0x9F;
1391 0 : break;
1392 0 : case 0xF4:
1393 0 : limit = 0x8F;
1394 0 : break;
1395 0 : default:
1396 0 : limit = 0xBF;
1397 0 : break;
1398 : }
1399 0 : if (a < limit)
1400 : {
1401 0 : charptr[1]++;
1402 0 : break;
1403 : }
1404 : /* FALL THRU */
1405 : case 1:
1406 2434 : a = *charptr;
1407 2434 : if (a == 0x7F || a == 0xDF || a == 0xEF || a == 0xF4)
1408 0 : return false;
1409 2434 : charptr[0]++;
1410 2434 : break;
1411 : }
1412 :
1413 2434 : return true;
1414 : }
1415 :
1416 : /*
1417 : * EUC-JP character incrementer function.
1418 : *
1419 : * If the sequence starts with SS2 (0x8e), it must be a two-byte sequence
1420 : * representing JIS X 0201 characters with the second byte ranging between
1421 : * 0xa1 and 0xdf. We just increment the last byte if it's less than 0xdf,
1422 : * and otherwise rewrite the whole sequence to 0xa1 0xa1.
1423 : *
1424 : * If the sequence starts with SS3 (0x8f), it must be a three-byte sequence
1425 : * in which the last two bytes range between 0xa1 and 0xfe. The last byte
1426 : * is incremented if possible, otherwise the second-to-last byte.
1427 : *
1428 : * If the sequence starts with a value other than the above and its MSB
1429 : * is set, it must be a two-byte sequence representing JIS X 0208 characters
1430 : * with both bytes ranging between 0xa1 and 0xfe. The last byte is
1431 : * incremented if possible, otherwise the second-to-last byte.
1432 : *
1433 : * Otherwise, the sequence is a single-byte ASCII character. It is
1434 : * incremented up to 0x7f.
1435 : */
1436 : static bool
1437 0 : pg_eucjp_increment(unsigned char *charptr, int length)
1438 : {
1439 : unsigned char c1,
1440 : c2;
1441 : int i;
1442 :
1443 0 : c1 = *charptr;
1444 :
1445 0 : switch (c1)
1446 : {
1447 0 : case SS2: /* JIS X 0201 */
1448 0 : if (length != 2)
1449 0 : return false;
1450 :
1451 0 : c2 = charptr[1];
1452 :
1453 0 : if (c2 >= 0xdf)
1454 0 : charptr[0] = charptr[1] = 0xa1;
1455 0 : else if (c2 < 0xa1)
1456 0 : charptr[1] = 0xa1;
1457 : else
1458 0 : charptr[1]++;
1459 0 : break;
1460 :
1461 0 : case SS3: /* JIS X 0212 */
1462 0 : if (length != 3)
1463 0 : return false;
1464 :
1465 0 : for (i = 2; i > 0; i--)
1466 : {
1467 0 : c2 = charptr[i];
1468 0 : if (c2 < 0xa1)
1469 : {
1470 0 : charptr[i] = 0xa1;
1471 0 : return true;
1472 : }
1473 0 : else if (c2 < 0xfe)
1474 : {
1475 0 : charptr[i]++;
1476 0 : return true;
1477 : }
1478 : }
1479 :
1480 : /* Out of 3-byte code region */
1481 0 : return false;
1482 :
1483 0 : default:
1484 0 : if (IS_HIGHBIT_SET(c1)) /* JIS X 0208? */
1485 : {
1486 0 : if (length != 2)
1487 0 : return false;
1488 :
1489 0 : for (i = 1; i >= 0; i--)
1490 : {
1491 0 : c2 = charptr[i];
1492 0 : if (c2 < 0xa1)
1493 : {
1494 0 : charptr[i] = 0xa1;
1495 0 : return true;
1496 : }
1497 0 : else if (c2 < 0xfe)
1498 : {
1499 0 : charptr[i]++;
1500 0 : return true;
1501 : }
1502 : }
1503 :
1504 : /* Out of 2 byte code region */
1505 0 : return false;
1506 : }
1507 : else
1508 : { /* ASCII, single byte */
1509 0 : if (c1 > 0x7e)
1510 0 : return false;
1511 0 : (*charptr)++;
1512 : }
1513 0 : break;
1514 : }
1515 :
1516 0 : return true;
1517 : }
1518 :
1519 : /*
1520 : * get the character incrementer for the encoding for the current database
1521 : */
1522 : mbcharacter_incrementer
1523 2538 : pg_database_encoding_character_incrementer(void)
1524 : {
1525 : /*
1526 : * Eventually it might be best to add a field to pg_wchar_table[], but for
1527 : * now we just use a switch.
1528 : */
1529 2538 : switch (GetDatabaseEncoding())
1530 : {
1531 2434 : case PG_UTF8:
1532 2434 : return pg_utf8_increment;
1533 :
1534 0 : case PG_EUC_JP:
1535 0 : return pg_eucjp_increment;
1536 :
1537 104 : default:
1538 104 : return pg_generic_charinc;
1539 : }
1540 : }
1541 :
1542 : /*
1543 : * fetch maximum length of the encoding for the current database
1544 : */
1545 : int
1546 12348722 : pg_database_encoding_max_length(void)
1547 : {
1548 12348722 : return pg_wchar_table[GetDatabaseEncoding()].maxmblen;
1549 : }
1550 :
1551 : /*
1552 : * Verify mbstr to make sure that it is validly encoded in the current
1553 : * database encoding. Otherwise same as pg_verify_mbstr().
1554 : */
1555 : bool
1556 4424 : pg_verifymbstr(const char *mbstr, int len, bool noError)
1557 : {
1558 4424 : return pg_verify_mbstr(GetDatabaseEncoding(), mbstr, len, noError);
1559 : }
1560 :
1561 : /*
1562 : * Verify mbstr to make sure that it is validly encoded in the specified
1563 : * encoding.
1564 : */
1565 : bool
1566 998516 : pg_verify_mbstr(int encoding, const char *mbstr, int len, bool noError)
1567 : {
1568 : int oklen;
1569 :
1570 : Assert(PG_VALID_ENCODING(encoding));
1571 :
1572 998516 : oklen = pg_wchar_table[encoding].mbverifystr((const unsigned char *) mbstr, len);
1573 998516 : if (oklen != len)
1574 : {
1575 8 : if (noError)
1576 0 : return false;
1577 8 : report_invalid_encoding(encoding, mbstr + oklen, len - oklen);
1578 : }
1579 998508 : return true;
1580 : }
1581 :
1582 : /*
1583 : * Verify mbstr to make sure that it is validly encoded in the specified
1584 : * encoding.
1585 : *
1586 : * mbstr is not necessarily zero terminated; length of mbstr is
1587 : * specified by len.
1588 : *
1589 : * If OK, return length of string in the encoding.
1590 : * If a problem is found, return -1 when noError is
1591 : * true; when noError is false, ereport() a descriptive message.
1592 : *
1593 : * Note: We cannot use the faster encoding-specific mbverifystr() function
1594 : * here, because we need to count the number of characters in the string.
1595 : */
1596 : int
1597 0 : pg_verify_mbstr_len(int encoding, const char *mbstr, int len, bool noError)
1598 : {
1599 : mbchar_verifier mbverifychar;
1600 : int mb_len;
1601 :
1602 : Assert(PG_VALID_ENCODING(encoding));
1603 :
1604 : /*
1605 : * In single-byte encodings, we need only reject nulls (\0).
1606 : */
1607 0 : if (pg_encoding_max_length(encoding) <= 1)
1608 : {
1609 0 : const char *nullpos = memchr(mbstr, 0, len);
1610 :
1611 0 : if (nullpos == NULL)
1612 0 : return len;
1613 0 : if (noError)
1614 0 : return -1;
1615 0 : report_invalid_encoding(encoding, nullpos, 1);
1616 : }
1617 :
1618 : /* fetch function pointer just once */
1619 0 : mbverifychar = pg_wchar_table[encoding].mbverifychar;
1620 :
1621 0 : mb_len = 0;
1622 :
1623 0 : while (len > 0)
1624 : {
1625 : int l;
1626 :
1627 : /* fast path for ASCII-subset characters */
1628 0 : if (!IS_HIGHBIT_SET(*mbstr))
1629 : {
1630 0 : if (*mbstr != '\0')
1631 : {
1632 0 : mb_len++;
1633 0 : mbstr++;
1634 0 : len--;
1635 0 : continue;
1636 : }
1637 0 : if (noError)
1638 0 : return -1;
1639 0 : report_invalid_encoding(encoding, mbstr, len);
1640 : }
1641 :
1642 0 : l = (*mbverifychar) ((const unsigned char *) mbstr, len);
1643 :
1644 0 : if (l < 0)
1645 : {
1646 0 : if (noError)
1647 0 : return -1;
1648 0 : report_invalid_encoding(encoding, mbstr, len);
1649 : }
1650 :
1651 0 : mbstr += l;
1652 0 : len -= l;
1653 0 : mb_len++;
1654 : }
1655 0 : return mb_len;
1656 : }
1657 :
1658 : /*
1659 : * check_encoding_conversion_args: check arguments of a conversion function
1660 : *
1661 : * "expected" arguments can be either an encoding ID or -1 to indicate that
1662 : * the caller will check whether it accepts the ID.
1663 : *
1664 : * Note: the errors here are not really user-facing, so elog instead of
1665 : * ereport seems sufficient. Also, we trust that the "expected" encoding
1666 : * arguments are valid encoding IDs, but we don't trust the actuals.
1667 : */
1668 : void
1669 6862 : check_encoding_conversion_args(int src_encoding,
1670 : int dest_encoding,
1671 : int len,
1672 : int expected_src_encoding,
1673 : int expected_dest_encoding)
1674 : {
1675 6862 : if (!PG_VALID_ENCODING(src_encoding))
1676 0 : elog(ERROR, "invalid source encoding ID: %d", src_encoding);
1677 6862 : if (src_encoding != expected_src_encoding && expected_src_encoding >= 0)
1678 0 : elog(ERROR, "expected source encoding \"%s\", but got \"%s\"",
1679 : pg_enc2name_tbl[expected_src_encoding].name,
1680 : pg_enc2name_tbl[src_encoding].name);
1681 6862 : if (!PG_VALID_ENCODING(dest_encoding))
1682 0 : elog(ERROR, "invalid destination encoding ID: %d", dest_encoding);
1683 6862 : if (dest_encoding != expected_dest_encoding && expected_dest_encoding >= 0)
1684 0 : elog(ERROR, "expected destination encoding \"%s\", but got \"%s\"",
1685 : pg_enc2name_tbl[expected_dest_encoding].name,
1686 : pg_enc2name_tbl[dest_encoding].name);
1687 6862 : if (len < 0)
1688 0 : elog(ERROR, "encoding conversion length must not be negative");
1689 6862 : }
1690 :
1691 : /*
1692 : * report_invalid_encoding: complain about invalid multibyte character
1693 : *
1694 : * note: len is remaining length of string, not length of character;
1695 : * len must be greater than zero, as we always examine the first byte.
1696 : */
1697 : void
1698 2942 : report_invalid_encoding(int encoding, const char *mbstr, int len)
1699 : {
1700 2942 : int l = pg_encoding_mblen(encoding, mbstr);
1701 : char buf[8 * 5 + 1];
1702 2942 : char *p = buf;
1703 : int j,
1704 : jlimit;
1705 :
1706 2942 : jlimit = Min(l, len);
1707 2942 : jlimit = Min(jlimit, 8); /* prevent buffer overrun */
1708 :
1709 9118 : for (j = 0; j < jlimit; j++)
1710 : {
1711 6176 : p += sprintf(p, "0x%02x", (unsigned char) mbstr[j]);
1712 6176 : if (j < jlimit - 1)
1713 3234 : p += sprintf(p, " ");
1714 : }
1715 :
1716 2942 : ereport(ERROR,
1717 : (errcode(ERRCODE_CHARACTER_NOT_IN_REPERTOIRE),
1718 : errmsg("invalid byte sequence for encoding \"%s\": %s",
1719 : pg_enc2name_tbl[encoding].name,
1720 : buf)));
1721 : }
1722 :
1723 : /*
1724 : * report_untranslatable_char: complain about untranslatable character
1725 : *
1726 : * note: len is remaining length of string, not length of character;
1727 : * len must be greater than zero, as we always examine the first byte.
1728 : */
1729 : void
1730 936 : report_untranslatable_char(int src_encoding, int dest_encoding,
1731 : const char *mbstr, int len)
1732 : {
1733 936 : int l = pg_encoding_mblen(src_encoding, mbstr);
1734 : char buf[8 * 5 + 1];
1735 936 : char *p = buf;
1736 : int j,
1737 : jlimit;
1738 :
1739 936 : jlimit = Min(l, len);
1740 936 : jlimit = Min(jlimit, 8); /* prevent buffer overrun */
1741 :
1742 3528 : for (j = 0; j < jlimit; j++)
1743 : {
1744 2592 : p += sprintf(p, "0x%02x", (unsigned char) mbstr[j]);
1745 2592 : if (j < jlimit - 1)
1746 1656 : p += sprintf(p, " ");
1747 : }
1748 :
1749 936 : ereport(ERROR,
1750 : (errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
1751 : errmsg("character with byte sequence %s in encoding \"%s\" has no equivalent in encoding \"%s\"",
1752 : buf,
1753 : pg_enc2name_tbl[src_encoding].name,
1754 : pg_enc2name_tbl[dest_encoding].name)));
1755 : }
1756 :
1757 :
1758 : #ifdef WIN32
1759 : /*
1760 : * Convert from MessageEncoding to a palloc'ed, null-terminated utf16
1761 : * string. The character length is also passed to utf16len if not
1762 : * null. Returns NULL iff failed. Before MessageEncoding initialization, "str"
1763 : * should be ASCII-only; this will function as though MessageEncoding is UTF8.
1764 : */
1765 : WCHAR *
1766 : pgwin32_message_to_UTF16(const char *str, int len, int *utf16len)
1767 : {
1768 : int msgenc = GetMessageEncoding();
1769 : WCHAR *utf16;
1770 : int dstlen;
1771 : UINT codepage;
1772 :
1773 : if (msgenc == PG_SQL_ASCII)
1774 : /* No conversion is possible, and SQL_ASCII is never utf16. */
1775 : return NULL;
1776 :
1777 : codepage = pg_enc2name_tbl[msgenc].codepage;
1778 :
1779 : /*
1780 : * Use MultiByteToWideChar directly if there is a corresponding codepage,
1781 : * or double conversion through UTF8 if not. Double conversion is needed,
1782 : * for example, in an ENCODING=LATIN8, LC_CTYPE=C database.
1783 : */
1784 : if (codepage != 0)
1785 : {
1786 : utf16 = (WCHAR *) palloc(sizeof(WCHAR) * (len + 1));
1787 : dstlen = MultiByteToWideChar(codepage, 0, str, len, utf16, len);
1788 : utf16[dstlen] = (WCHAR) 0;
1789 : }
1790 : else
1791 : {
1792 : char *utf8;
1793 :
1794 : /*
1795 : * XXX pg_do_encoding_conversion() requires a transaction. In the
1796 : * absence of one, hope for the input to be valid UTF8.
1797 : */
1798 : if (IsTransactionState())
1799 : {
1800 : utf8 = (char *) pg_do_encoding_conversion((unsigned char *) str,
1801 : len,
1802 : msgenc,
1803 : PG_UTF8);
1804 : if (utf8 != str)
1805 : len = strlen(utf8);
1806 : }
1807 : else
1808 : utf8 = (char *) str;
1809 :
1810 : utf16 = (WCHAR *) palloc(sizeof(WCHAR) * (len + 1));
1811 : dstlen = MultiByteToWideChar(CP_UTF8, 0, utf8, len, utf16, len);
1812 : utf16[dstlen] = (WCHAR) 0;
1813 :
1814 : if (utf8 != str)
1815 : pfree(utf8);
1816 : }
1817 :
1818 : if (dstlen == 0 && len > 0)
1819 : {
1820 : pfree(utf16);
1821 : return NULL; /* error */
1822 : }
1823 :
1824 : if (utf16len)
1825 : *utf16len = dstlen;
1826 : return utf16;
1827 : }
1828 :
1829 : #endif /* WIN32 */
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