PostgreSQL Source Code git master
like.c
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1/*-------------------------------------------------------------------------
2 *
3 * like.c
4 * like expression handling code.
5 *
6 * NOTES
7 * A big hack of the regexp.c code!! Contributed by
8 * Keith Parks <emkxp01@mtcc.demon.co.uk> (7/95).
9 *
10 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
11 * Portions Copyright (c) 1994, Regents of the University of California
12 *
13 * IDENTIFICATION
14 * src/backend/utils/adt/like.c
15 *
16 *-------------------------------------------------------------------------
17 */
18#include "postgres.h"
19
20#include <ctype.h>
21
23#include "mb/pg_wchar.h"
24#include "miscadmin.h"
25#include "utils/fmgrprotos.h"
26#include "utils/pg_locale.h"
27#include "varatt.h"
28
29
30#define LIKE_TRUE 1
31#define LIKE_FALSE 0
32#define LIKE_ABORT (-1)
33
34
35static int SB_MatchText(const char *t, int tlen, const char *p, int plen,
37static text *SB_do_like_escape(text *pat, text *esc);
38
39static int MB_MatchText(const char *t, int tlen, const char *p, int plen,
41static text *MB_do_like_escape(text *pat, text *esc);
42
43static int UTF8_MatchText(const char *t, int tlen, const char *p, int plen,
45
46static int SB_IMatchText(const char *t, int tlen, const char *p, int plen,
48
49static int GenericMatchText(const char *s, int slen, const char *p, int plen, Oid collation);
50static int Generic_Text_IC_like(text *str, text *pat, Oid collation);
51
52/*--------------------
53 * Support routine for MatchText. Compares given multibyte streams
54 * as wide characters. If they match, returns 1 otherwise returns 0.
55 *--------------------
56 */
57static inline int
58wchareq(const char *p1, const char *p2)
59{
60 int p1_len;
61
62 /* Optimization: quickly compare the first byte. */
63 if (*p1 != *p2)
64 return 0;
65
66 p1_len = pg_mblen(p1);
67 if (pg_mblen(p2) != p1_len)
68 return 0;
69
70 /* They are the same length */
71 while (p1_len--)
72 {
73 if (*p1++ != *p2++)
74 return 0;
75 }
76 return 1;
77}
78
79/*
80 * Formerly we had a routine iwchareq() here that tried to do case-insensitive
81 * comparison of multibyte characters. It did not work at all, however,
82 * because it relied on tolower() which has a single-byte API ... and
83 * towlower() wouldn't be much better since we have no suitably cheap way
84 * of getting a single character transformed to the system's wchar_t format.
85 * So now, we just downcase the strings using lower() and apply regular LIKE
86 * comparison. This should be revisited when we install better locale support.
87 */
88
89/*
90 * We do handle case-insensitive matching for single-byte encodings using
91 * fold-on-the-fly processing, however.
92 */
93static char
95{
96 if (locale->ctype_is_c)
97 return pg_ascii_tolower(c);
98 else if (locale->is_default)
99 return pg_tolower(c);
100 else
101 return tolower_l(c, locale->info.lt);
102}
103
104
105#define NextByte(p, plen) ((p)++, (plen)--)
106
107/* Set up to compile like_match.c for multibyte characters */
108#define CHAREQ(p1, p2) wchareq((p1), (p2))
109#define NextChar(p, plen) \
110 do { int __l = pg_mblen(p); (p) +=__l; (plen) -=__l; } while (0)
111#define CopyAdvChar(dst, src, srclen) \
112 do { int __l = pg_mblen(src); \
113 (srclen) -= __l; \
114 while (__l-- > 0) \
115 *(dst)++ = *(src)++; \
116 } while (0)
117
118#define MatchText MB_MatchText
119#define do_like_escape MB_do_like_escape
120
121#include "like_match.c"
122
123/* Set up to compile like_match.c for single-byte characters */
124#define CHAREQ(p1, p2) (*(p1) == *(p2))
125#define NextChar(p, plen) NextByte((p), (plen))
126#define CopyAdvChar(dst, src, srclen) (*(dst)++ = *(src)++, (srclen)--)
127
128#define MatchText SB_MatchText
129#define do_like_escape SB_do_like_escape
130
131#include "like_match.c"
132
133/* setup to compile like_match.c for single byte case insensitive matches */
134#define MATCH_LOWER(t, locale) SB_lower_char((unsigned char) (t), locale)
135#define NextChar(p, plen) NextByte((p), (plen))
136#define MatchText SB_IMatchText
137
138#include "like_match.c"
139
140/* setup to compile like_match.c for UTF8 encoding, using fast NextChar */
141
142#define NextChar(p, plen) \
143 do { (p)++; (plen)--; } while ((plen) > 0 && (*(p) & 0xC0) == 0x80 )
144#define MatchText UTF8_MatchText
145
146#include "like_match.c"
147
148/* Generic for all cases not requiring inline case-folding */
149static inline int
150GenericMatchText(const char *s, int slen, const char *p, int plen, Oid collation)
151{
153
154 if (!OidIsValid(collation))
155 {
156 /*
157 * This typically means that the parser could not resolve a conflict
158 * of implicit collations, so report it that way.
159 */
161 (errcode(ERRCODE_INDETERMINATE_COLLATION),
162 errmsg("could not determine which collation to use for LIKE"),
163 errhint("Use the COLLATE clause to set the collation explicitly.")));
164 }
165
167
169 return SB_MatchText(s, slen, p, plen, locale);
170 else if (GetDatabaseEncoding() == PG_UTF8)
171 return UTF8_MatchText(s, slen, p, plen, locale);
172 else
173 return MB_MatchText(s, slen, p, plen, locale);
174}
175
176static inline int
178{
179 char *s,
180 *p;
181 int slen,
182 plen;
184
185 if (!OidIsValid(collation))
186 {
187 /*
188 * This typically means that the parser could not resolve a conflict
189 * of implicit collations, so report it that way.
190 */
192 (errcode(ERRCODE_INDETERMINATE_COLLATION),
193 errmsg("could not determine which collation to use for ILIKE"),
194 errhint("Use the COLLATE clause to set the collation explicitly.")));
195 }
196
198
199 if (!locale->deterministic)
201 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
202 errmsg("nondeterministic collations are not supported for ILIKE")));
203
204 /*
205 * For efficiency reasons, in the single byte case we don't call lower()
206 * on the pattern and text, but instead call SB_lower_char on each
207 * character. In the multi-byte case we don't have much choice :-(. Also,
208 * ICU does not support single-character case folding, so we go the long
209 * way.
210 */
211
212 if (pg_database_encoding_max_length() > 1 || (locale->provider == COLLPROVIDER_ICU))
213 {
215 PointerGetDatum(pat)));
216 p = VARDATA_ANY(pat);
217 plen = VARSIZE_ANY_EXHDR(pat);
220 s = VARDATA_ANY(str);
221 slen = VARSIZE_ANY_EXHDR(str);
223 return UTF8_MatchText(s, slen, p, plen, 0);
224 else
225 return MB_MatchText(s, slen, p, plen, 0);
226 }
227 else
228 {
229 p = VARDATA_ANY(pat);
230 plen = VARSIZE_ANY_EXHDR(pat);
231 s = VARDATA_ANY(str);
232 slen = VARSIZE_ANY_EXHDR(str);
233 return SB_IMatchText(s, slen, p, plen, locale);
234 }
235}
236
237/*
238 * interface routines called by the function manager
239 */
240
241Datum
243{
245 text *pat = PG_GETARG_TEXT_PP(1);
246 bool result;
247 char *s,
248 *p;
249 int slen,
250 plen;
251
252 s = NameStr(*str);
253 slen = strlen(s);
254 p = VARDATA_ANY(pat);
255 plen = VARSIZE_ANY_EXHDR(pat);
256
257 result = (GenericMatchText(s, slen, p, plen, PG_GET_COLLATION()) == LIKE_TRUE);
258
259 PG_RETURN_BOOL(result);
260}
261
262Datum
264{
266 text *pat = PG_GETARG_TEXT_PP(1);
267 bool result;
268 char *s,
269 *p;
270 int slen,
271 plen;
272
273 s = NameStr(*str);
274 slen = strlen(s);
275 p = VARDATA_ANY(pat);
276 plen = VARSIZE_ANY_EXHDR(pat);
277
278 result = (GenericMatchText(s, slen, p, plen, PG_GET_COLLATION()) != LIKE_TRUE);
279
280 PG_RETURN_BOOL(result);
281}
282
283Datum
285{
287 text *pat = PG_GETARG_TEXT_PP(1);
288 bool result;
289 char *s,
290 *p;
291 int slen,
292 plen;
293
294 s = VARDATA_ANY(str);
295 slen = VARSIZE_ANY_EXHDR(str);
296 p = VARDATA_ANY(pat);
297 plen = VARSIZE_ANY_EXHDR(pat);
298
299 result = (GenericMatchText(s, slen, p, plen, PG_GET_COLLATION()) == LIKE_TRUE);
300
301 PG_RETURN_BOOL(result);
302}
303
304Datum
306{
308 text *pat = PG_GETARG_TEXT_PP(1);
309 bool result;
310 char *s,
311 *p;
312 int slen,
313 plen;
314
315 s = VARDATA_ANY(str);
316 slen = VARSIZE_ANY_EXHDR(str);
317 p = VARDATA_ANY(pat);
318 plen = VARSIZE_ANY_EXHDR(pat);
319
320 result = (GenericMatchText(s, slen, p, plen, PG_GET_COLLATION()) != LIKE_TRUE);
321
322 PG_RETURN_BOOL(result);
323}
324
325Datum
327{
329 bytea *pat = PG_GETARG_BYTEA_PP(1);
330 bool result;
331 char *s,
332 *p;
333 int slen,
334 plen;
335
336 s = VARDATA_ANY(str);
337 slen = VARSIZE_ANY_EXHDR(str);
338 p = VARDATA_ANY(pat);
339 plen = VARSIZE_ANY_EXHDR(pat);
340
341 result = (SB_MatchText(s, slen, p, plen, 0) == LIKE_TRUE);
342
343 PG_RETURN_BOOL(result);
344}
345
346Datum
348{
350 bytea *pat = PG_GETARG_BYTEA_PP(1);
351 bool result;
352 char *s,
353 *p;
354 int slen,
355 plen;
356
357 s = VARDATA_ANY(str);
358 slen = VARSIZE_ANY_EXHDR(str);
359 p = VARDATA_ANY(pat);
360 plen = VARSIZE_ANY_EXHDR(pat);
361
362 result = (SB_MatchText(s, slen, p, plen, 0) != LIKE_TRUE);
363
364 PG_RETURN_BOOL(result);
365}
366
367/*
368 * Case-insensitive versions
369 */
370
371Datum
373{
375 text *pat = PG_GETARG_TEXT_PP(1);
376 bool result;
377 text *strtext;
378
380 NameGetDatum(str)));
381 result = (Generic_Text_IC_like(strtext, pat, PG_GET_COLLATION()) == LIKE_TRUE);
382
383 PG_RETURN_BOOL(result);
384}
385
386Datum
388{
390 text *pat = PG_GETARG_TEXT_PP(1);
391 bool result;
392 text *strtext;
393
395 NameGetDatum(str)));
396 result = (Generic_Text_IC_like(strtext, pat, PG_GET_COLLATION()) != LIKE_TRUE);
397
398 PG_RETURN_BOOL(result);
399}
400
401Datum
403{
405 text *pat = PG_GETARG_TEXT_PP(1);
406 bool result;
407
408 result = (Generic_Text_IC_like(str, pat, PG_GET_COLLATION()) == LIKE_TRUE);
409
410 PG_RETURN_BOOL(result);
411}
412
413Datum
415{
417 text *pat = PG_GETARG_TEXT_PP(1);
418 bool result;
419
420 result = (Generic_Text_IC_like(str, pat, PG_GET_COLLATION()) != LIKE_TRUE);
421
422 PG_RETURN_BOOL(result);
423}
424
425/*
426 * like_escape() --- given a pattern and an ESCAPE string,
427 * convert the pattern to use Postgres' standard backslash escape convention.
428 */
429Datum
431{
432 text *pat = PG_GETARG_TEXT_PP(0);
433 text *esc = PG_GETARG_TEXT_PP(1);
434 text *result;
435
437 result = SB_do_like_escape(pat, esc);
438 else
439 result = MB_do_like_escape(pat, esc);
440
441 PG_RETURN_TEXT_P(result);
442}
443
444/*
445 * like_escape_bytea() --- given a pattern and an ESCAPE string,
446 * convert the pattern to use Postgres' standard backslash escape convention.
447 */
448Datum
450{
451 bytea *pat = PG_GETARG_BYTEA_PP(0);
452 bytea *esc = PG_GETARG_BYTEA_PP(1);
453 bytea *result = SB_do_like_escape((text *) pat, (text *) esc);
454
455 PG_RETURN_BYTEA_P((bytea *) result);
456}
#define NameStr(name)
Definition: c.h:703
#define OidIsValid(objectId)
Definition: c.h:732
int errhint(const char *fmt,...)
Definition: elog.c:1317
int errcode(int sqlerrcode)
Definition: elog.c:853
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define ERROR
Definition: elog.h:39
#define ereport(elevel,...)
Definition: elog.h:149
Datum DirectFunctionCall1Coll(PGFunction func, Oid collation, Datum arg1)
Definition: fmgr.c:792
#define PG_GETARG_BYTEA_PP(n)
Definition: fmgr.h:308
#define PG_GETARG_TEXT_PP(n)
Definition: fmgr.h:309
#define PG_RETURN_BYTEA_P(x)
Definition: fmgr.h:371
#define DatumGetTextPP(X)
Definition: fmgr.h:292
#define DirectFunctionCall1(func, arg1)
Definition: fmgr.h:641
#define PG_GETARG_NAME(n)
Definition: fmgr.h:278
#define PG_RETURN_TEXT_P(x)
Definition: fmgr.h:372
#define PG_GET_COLLATION()
Definition: fmgr.h:198
#define PG_FUNCTION_ARGS
Definition: fmgr.h:193
#define PG_RETURN_BOOL(x)
Definition: fmgr.h:359
const char * str
static char * locale
Definition: initdb.c:140
static int UTF8_MatchText(const char *t, int tlen, const char *p, int plen, pg_locale_t locale)
static int MB_MatchText(const char *t, int tlen, const char *p, int plen, pg_locale_t locale)
static text * MB_do_like_escape(text *pat, text *esc)
#define LIKE_TRUE
Definition: like.c:30
Datum texticnlike(PG_FUNCTION_ARGS)
Definition: like.c:414
Datum textlike(PG_FUNCTION_ARGS)
Definition: like.c:284
Datum namelike(PG_FUNCTION_ARGS)
Definition: like.c:242
Datum nameiclike(PG_FUNCTION_ARGS)
Definition: like.c:372
Datum byteanlike(PG_FUNCTION_ARGS)
Definition: like.c:347
Datum like_escape(PG_FUNCTION_ARGS)
Definition: like.c:430
static int wchareq(const char *p1, const char *p2)
Definition: like.c:58
Datum namenlike(PG_FUNCTION_ARGS)
Definition: like.c:263
Datum textnlike(PG_FUNCTION_ARGS)
Definition: like.c:305
static int SB_IMatchText(const char *t, int tlen, const char *p, int plen, pg_locale_t locale)
Datum nameicnlike(PG_FUNCTION_ARGS)
Definition: like.c:387
static char SB_lower_char(unsigned char c, pg_locale_t locale)
Definition: like.c:94
Datum like_escape_bytea(PG_FUNCTION_ARGS)
Definition: like.c:449
static text * SB_do_like_escape(text *pat, text *esc)
Datum texticlike(PG_FUNCTION_ARGS)
Definition: like.c:402
static int SB_MatchText(const char *t, int tlen, const char *p, int plen, pg_locale_t locale)
static int Generic_Text_IC_like(text *str, text *pat, Oid collation)
Definition: like.c:177
Datum bytealike(PG_FUNCTION_ARGS)
Definition: like.c:326
static int GenericMatchText(const char *s, int slen, const char *p, int plen, Oid collation)
Definition: like.c:150
int GetDatabaseEncoding(void)
Definition: mbutils.c:1261
int pg_database_encoding_max_length(void)
Definition: mbutils.c:1546
int pg_mblen(const char *mbstr)
Definition: mbutils.c:1023
Datum lower(PG_FUNCTION_ARGS)
Definition: oracle_compat.c:49
pg_locale_t pg_newlocale_from_collation(Oid collid)
Definition: pg_locale.c:1332
@ PG_UTF8
Definition: pg_wchar.h:232
unsigned char pg_tolower(unsigned char ch)
Definition: pgstrcasecmp.c:122
unsigned char pg_ascii_tolower(unsigned char ch)
Definition: pgstrcasecmp.c:146
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:327
uintptr_t Datum
Definition: postgres.h:69
static Datum NameGetDatum(const NameData *X)
Definition: postgres.h:378
unsigned int Oid
Definition: postgres_ext.h:32
char * c
Definition: c.h:698
Definition: c.h:644
#define VARDATA_ANY(PTR)
Definition: varatt.h:324
#define VARSIZE_ANY_EXHDR(PTR)
Definition: varatt.h:317
Datum name_text(PG_FUNCTION_ARGS)
Definition: varlena.c:3357
#define tolower_l
Definition: win32_port.h:433