admin/mruby-mruby
1
0
Fork 0
mirror of https://github.com/mruby/mruby synced 2026-06-08 16:11:16 +00:00
Code Issues Packages Projects Releases Wiki Activity

string.c (mrb_memsearch): remove simple search and quick search

Browse Source 
Since mrb_memsearch_ss() is fast enough for most of the cases, we try to
simplify the code.
This commit is contained in:
Yukihiro "Matz" Matsumoto
2024-01-27 00:01:47 +09:00
parent 2943ca2685
commit 06d9a54760
1 changed files with 1 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/string.c
+1 -48
View File
@@ -576,9 +576,6 @@ str_index_str_by_char(mrb_state *mrb, mrb_value str, mrb_value sub, mrb_int pos)
static inline mrb_int
mrb_memsearch_ss(const unsigned char *xs, long m, const unsigned char *ys, long n)
{
/* maximum pattern length */
#define MAX_PATLEN 100
#ifdef MRB_64BIT
#define bitint uint64_t
#define MASK1 0x0101010101010101llu
@@ -628,32 +625,6 @@ mrb_memsearch_ss(const unsigned char *xs, long m, const unsigned char *ys, long
return -1;
}
static inline mrb_int
mrb_memsearch_qs(const unsigned char *xs, mrb_int m, const unsigned char *ys, mrb_int n)
{
const unsigned char *y = ys;
ptrdiff_t qstable[256];
/* Preprocessing */
for (int i = 0; i < 256; i++)
qstable[i] = m + 1;
const unsigned char *x = xs, *xe = xs + m;
for (; x < xe; x++)
qstable[*x] = xe - x;
/* Searching */
for (; y + m <= ys + n; y += qstable[y[m]]) {
if (*xs == *y && memcmp(xs, y, m) == 0)
return (mrb_int)(y - ys);
}
return -1;
}
#ifndef MRB_SEARCH_SHORT_STRING_LENGTH
#define MRB_SEARCH_SHORT_STRING_LENGTH 2048
#endif
static mrb_int
mrb_memsearch(const char *x0, mrb_int m, const char *y0, mrb_int n)
{
@@ -674,25 +645,7 @@ mrb_memsearch(const char *x0, mrb_int m, const char *y0, mrb_int n)
else
return -1;
}
if (n + m < MRB_SEARCH_SHORT_STRING_LENGTH) {
const unsigned char *ys = (unsigned char*)y0;
const unsigned char *y = ys;
const unsigned char *ye = ys+n-m+1;
for (;;) {
y = (const unsigned char*)memchr(y, x[0], (size_t)(ye-y));
if (y == NULL) return -1;
if (memcmp(x, y, m) == 0) {
return (mrb_int)(y - ys);
}
y++;
}
return -1;
}
if (m <= MAX_PATLEN) {
return mrb_memsearch_ss((const unsigned char*)x0, m, (const unsigned char*)y0, n);
}
return mrb_memsearch_qs((const unsigned char*)x0, m, (const unsigned char*)y0, n);
return mrb_memsearch_ss((const unsigned char*)x0, m, (const unsigned char*)y0, n);
}
static void