diff options
Diffstat (limited to 'string')
| -rw-r--r-- | string/strcoll_l.c | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/string/strcoll_l.c b/string/strcoll_l.c index 658d5b9b90..0fa005f0f9 100644 --- a/string/strcoll_l.c +++ b/string/strcoll_l.c @@ -29,6 +29,7 @@ # define STRING_TYPE char # define USTRING_TYPE unsigned char # define STRCOLL __strcoll_l +# define STRDIFF __strdiff # define STRCMP strcmp # define WEIGHT_H "../locale/weight.h" # define SUFFIX MB @@ -41,6 +42,20 @@ #include "../locale/localeinfo.h" #include WEIGHT_H +#define MASK_UTF8_7BIT (1 << 7) +#define MASK_UTF8_START (3 << 6) + +size_t +STRDIFF (const STRING_TYPE *s, const STRING_TYPE *t) +{ + size_t n; + + for (n = 0; *s != '\0' && *s++ == *t++; ++n) + continue; + + return n; +} + /* Track status while looking for sequences in a string. */ typedef struct { @@ -255,9 +270,29 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2, __locale_t l) const USTRING_TYPE *extra; const int32_t *indirect; + /* In case there is no locale specific sort order (C / POSIX). */ if (nrules == 0) return STRCMP (s1, s2); + /* Fast forward to the position of the first difference. Needs to be + encoding aware as the byte-by-byte comparison can stop in the middle + of a char sequence for multibyte encodings like UTF-8. */ + uint_fast32_t encoding = + current->values[_NL_ITEM_INDEX (_NL_COLLATE_ENCODING_TYPE)].word; + if (encoding != __cet_other) + { + size_t diff = STRDIFF (s1, s2); + if (diff > 0) + { + if (encoding == __cet_utf8 && (*(s1 + diff) & MASK_UTF8_7BIT) != 0) + do + diff--; + while (diff > 0 && (*(s1 + diff) & MASK_UTF8_START) != MASK_UTF8_START); + s1 += diff; + s2 += diff; + } + } + /* Catch empty strings. */ if (__glibc_unlikely (*s1 == '\0') || __glibc_unlikely (*s2 == '\0')) return (*s1 != '\0') - (*s2 != '\0'); @@ -321,7 +356,8 @@ STRCOLL (const STRING_TYPE *s1, const STRING_TYPE *s2, __locale_t l) byte-level comparison to ensure that we don't waste time going through multiple passes for totally equal strings before proceeding to subsequent passes. */ - if (pass == 0 && STRCMP (s1, s2) == 0) + if (pass == 0 && encoding == __cet_other && + STRCMP (s1, s2) == 0) return result; else break; |