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grep: use static trans-case table 

In order to prepare the kwset machinery for a case-insensitive search, we
used to use a static table of 256 elements and filled it every time before
calling kwsalloc().  Because the kwset machinery will never modify this
table, just allocate a single instance globally and fill it at the compile
time.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
maint
Junio C Hamano 2012-02-28 14:20:53 -08:00
parent d0482e88a7
commit 0f871cf56e
3 changed files with 42 additions and 8 deletions
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3
cache.h
View File

@ -1258,4 +1258,7 @@ extern struct startup_info *startup_info;
/* builtin/merge.c */
int checkout_fast_forward(const unsigned char *from, const unsigned char *to);

/* in ctype.c, for kwset users */
extern const char tolower_trans_tbl[256];

#endif /* CACHE_H */

36
ctype.c
View File

@ -25,3 +25,39 @@ unsigned char sane_ctype[256] = {
A, A, A, A, A, A, A, A, A, A, A, R, R, 0, P, 0, /* 112..127 */
/* Nothing in the 128.. range */
};

/* For case-insensitive kwset */
const char tolower_trans_tbl[256] = {
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
' ', '!', '"', '#', '$', '%', '&', 0x27,
'(', ')', '*', '+', ',', '-', '.', '/',
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', ':', ';', '<', '=', '>', '?',
'@', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z', '[', 0x5c, ']', '^', '_',
'`', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
'x', 'y', 'z', '{', '|', '}', '~', 0x7f,
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
};

11
grep.c
View File

@ -168,15 +168,10 @@ static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
p->fixed = 0;

if (p->fixed) {
if (opt->regflags & REG_ICASE || p->ignore_case) {
static char trans[256];
int i;
for (i = 0; i < 256; i++)
trans[i] = tolower(i);
p->kws = kwsalloc(trans);
} else {
if (opt->regflags & REG_ICASE || p->ignore_case)
p->kws = kwsalloc(tolower_trans_tbl);
else
p->kws = kwsalloc(NULL);
}
kwsincr(p->kws, p->pattern, p->patternlen);
kwsprep(p->kws);
return;