static Selectivity regex_selectivity(const char *patt, int pattlen,
bool case_insensitive,
int fixed_prefix_len);
-static int pattern_char_isalpha(char c, bool is_multibyte,
- pg_locale_t locale);
static Const *make_greater_string(const Const *str_const, FmgrInfo *ltproc,
Oid collation);
static Datum string_to_datum(const char *str, Oid datatype);
*/
static Pattern_Prefix_Status
-like_fixed_prefix(Const *patt_const, bool case_insensitive, Oid collation,
- Const **prefix_const, Selectivity *rest_selec)
+like_fixed_prefix(Const *patt_const, Const **prefix_const,
+ Selectivity *rest_selec)
{
char *match;
char *patt;
Oid typeid = patt_const->consttype;
int pos,
match_pos;
- bool is_multibyte = (pg_database_encoding_max_length() > 1);
- pg_locale_t locale = 0;
/* the right-hand const is type text or bytea */
Assert(typeid == BYTEAOID || typeid == TEXTOID);
- if (case_insensitive)
- {
- if (typeid == BYTEAOID)
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("case insensitive matching not supported on type bytea")));
-
- if (!OidIsValid(collation))
- {
- /*
- * This typically means that the parser could not resolve a
- * conflict of implicit collations, so report it that way.
- */
- ereport(ERROR,
- (errcode(ERRCODE_INDETERMINATE_COLLATION),
- errmsg("could not determine which collation to use for ILIKE"),
- errhint("Use the COLLATE clause to set the collation explicitly.")));
- }
-
- locale = pg_newlocale_from_collation(collation);
- }
-
if (typeid != BYTEAOID)
{
patt = TextDatumGetCString(patt_const->constvalue);
break;
}
- /* Stop if case-varying character (it's sort of a wildcard) */
- if (case_insensitive &&
- pattern_char_isalpha(patt[pos], is_multibyte, locale))
- break;
-
match[match_pos++] = patt[pos];
}
*prefix_const = string_to_bytea_const(match, match_pos);
if (rest_selec != NULL)
- *rest_selec = like_selectivity(&patt[pos], pattlen - pos,
- case_insensitive);
+ *rest_selec = like_selectivity(&patt[pos], pattlen - pos, false);
pfree(patt);
pfree(match);
return Pattern_Prefix_None;
}
+/*
+ * Case-insensitive variant of like_fixed_prefix(). Multibyte and
+ * locale-aware for detecting cased characters.
+ */
+static Pattern_Prefix_Status
+like_fixed_prefix_ci(Const *patt_const, Oid collation, Const **prefix_const,
+ Selectivity *rest_selec)
+{
+ text *val = DatumGetTextPP(patt_const->constvalue);
+ Oid typeid = patt_const->consttype;
+ int nbytes = VARSIZE_ANY_EXHDR(val);
+ int wpos;
+ pg_wchar *wpatt;
+ int wpattlen;
+ pg_wchar *wmatch;
+ int wmatch_pos = 0;
+ char *match;
+ int match_mblen;
+ pg_locale_t locale = 0;
+
+ /* the right-hand const is type text or bytea */
+ Assert(typeid == BYTEAOID || typeid == TEXTOID);
+
+ if (typeid == BYTEAOID)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("case insensitive matching not supported on type bytea")));
+
+ if (!OidIsValid(collation))
+ {
+ /*
+ * This typically means that the parser could not resolve a conflict
+ * of implicit collations, so report it that way.
+ */
+ ereport(ERROR,
+ (errcode(ERRCODE_INDETERMINATE_COLLATION),
+ errmsg("could not determine which collation to use for ILIKE"),
+ errhint("Use the COLLATE clause to set the collation explicitly.")));
+ }
+
+ locale = pg_newlocale_from_collation(collation);
+
+ wpatt = palloc((nbytes + 1) * sizeof(pg_wchar));
+ wpattlen = pg_mb2wchar_with_len(VARDATA_ANY(val), wpatt, nbytes);
+
+ wmatch = palloc((nbytes + 1) * sizeof(pg_wchar));
+ for (wpos = 0; wpos < wpattlen; wpos++)
+ {
+ /* % and _ are wildcard characters in LIKE */
+ if (wpatt[wpos] == '%' ||
+ wpatt[wpos] == '_')
+ break;
+
+ /* Backslash escapes the next character */
+ if (wpatt[wpos] == '\\')
+ {
+ wpos++;
+ if (wpos >= wpattlen)
+ break;
+ }
+
+ /*
+ * For ILIKE, stop if it's a case-varying character (it's sort of a
+ * wildcard).
+ */
+ if (pg_iswcased(wpatt[wpos], locale))
+ break;
+
+ wmatch[wmatch_pos++] = wpatt[wpos];
+ }
+
+ wmatch[wmatch_pos] = '\0';
+
+ match = palloc(pg_database_encoding_max_length() * wmatch_pos + 1);
+ match_mblen = pg_wchar2mb_with_len(wmatch, match, wmatch_pos);
+ match[match_mblen] = '\0';
+ pfree(wmatch);
+
+ *prefix_const = string_to_const(match, TEXTOID);
+ pfree(match);
+
+ if (rest_selec != NULL)
+ {
+ int wrestlen = wpattlen - wmatch_pos;
+ char *rest;
+ int rest_mblen;
+
+ rest = palloc(pg_database_encoding_max_length() * wrestlen + 1);
+ rest_mblen = pg_wchar2mb_with_len(&wpatt[wmatch_pos], rest, wrestlen);
+
+ *rest_selec = like_selectivity(rest, rest_mblen, true);
+ pfree(rest);
+ }
+
+ pfree(wpatt);
+
+ /* in LIKE, an empty pattern is an exact match! */
+ if (wpos == wpattlen)
+ return Pattern_Prefix_Exact; /* reached end of pattern, so exact */
+
+ if (wmatch_pos > 0)
+ return Pattern_Prefix_Partial;
+
+ return Pattern_Prefix_None;
+}
+
static Pattern_Prefix_Status
regex_fixed_prefix(Const *patt_const, bool case_insensitive, Oid collation,
Const **prefix_const, Selectivity *rest_selec)
switch (ptype)
{
case Pattern_Type_Like:
- result = like_fixed_prefix(patt, false, collation,
- prefix, rest_selec);
+ result = like_fixed_prefix(patt, prefix, rest_selec);
break;
case Pattern_Type_Like_IC:
- result = like_fixed_prefix(patt, true, collation,
- prefix, rest_selec);
+ result = like_fixed_prefix_ci(patt, collation, prefix,
+ rest_selec);
break;
case Pattern_Type_Regex:
result = regex_fixed_prefix(patt, false, collation,
return sel;
}
-/*
- * Check whether char is a letter (and, hence, subject to case-folding)
- *
- * In multibyte character sets or with ICU, we can't use isalpha, and it does
- * not seem worth trying to convert to wchar_t to use iswalpha or u_isalpha.
- * Instead, just assume any non-ASCII char is potentially case-varying, and
- * hard-wire knowledge of which ASCII chars are letters.
- */
-static int
-pattern_char_isalpha(char c, bool is_multibyte,
- pg_locale_t locale)
-{
- if (locale->ctype_is_c)
- return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
- else
- return char_is_cased(c, locale);
-}
-
/*
* For bytea, the increment function need only increment the current byte
projects / postgresql.git / commitdiff