mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-04 08:59:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

Merged revisions 77461 via svnmerge from

Browse source 
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r77461 | antoine.pitrou | 2010-01-13 08:55:48 +0100 (mer., 13 janv. 2010) | 5 lines

  Issue #7622: Improve the split(), rsplit(), splitlines() and replace()
  methods of bytes, bytearray and unicode objects by using a common
  implementation based on stringlib's fast search.  Patch by Florent Xicluna.
........
This commit is contained in:
Antoine Pitrou 2010-01-13 08:07:53 +00:00
parent 5efea0430c
commit f2c5484f9e
16 changed files with 1123 additions and 1418 deletions
Download patch file Download diff file Expand all files Collapse all files

40
Objects/stringlib/fastsearch.h
View file

@ -18,10 +18,13 @@
#define FAST_SEARCH 1
#define FAST_RSEARCH 2
#define BLOOM_ADD(mask, ch) ((mask |= (1 << ((ch) & (LONG_BIT - 1)))))
#define BLOOM(mask, ch) ((mask & (1 << ((ch) & (LONG_BIT - 1)))))
Py_LOCAL_INLINE(Py_ssize_t)
fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
const STRINGLIB_CHAR* p, Py_ssize_t m,
int mode)
Py_ssize_t maxcount, int mode)
{
long mask;
Py_ssize_t skip, count = 0;
@ -29,7 +32,7 @@ fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
w = n - m;
if (w < 0)
if (w < 0 || (mode == FAST_COUNT && maxcount == 0))
return -1;
/* look for special cases */
@ -39,8 +42,11 @@ fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
/* use special case for 1-character strings */
if (mode == FAST_COUNT) {
for (i = 0; i < n; i++)
if (s[i] == p[0])
if (s[i] == p[0]) {
count++;
if (count == maxcount)
return maxcount;
}
return count;
} else if (mode == FAST_SEARCH) {
for (i = 0; i < n; i++)
@ -56,19 +62,20 @@ fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
mlast = m - 1;
skip = mlast - 1;
mask = 0;
if (mode != FAST_RSEARCH) {
/* create compressed boyer-moore delta 1 table */
/* process pattern[:-1] */
for (mask = i = 0; i < mlast; i++) {
mask |= (1 << (p[i] & 0x1F));
for (i = 0; i < mlast; i++) {
BLOOM_ADD(mask, p[i]);
if (p[i] == p[mlast])
skip = mlast - i - 1;
}
/* process pattern[-1] outside the loop */
mask |= (1 << (p[mlast] & 0x1F));
BLOOM_ADD(mask, p[mlast]);
for (i = 0; i <= w; i++) {
/* note: using mlast in the skip path slows things down on x86 */
@ -82,17 +89,19 @@ fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
if (mode != FAST_COUNT)
return i;
count++;
if (count == maxcount)
return maxcount;
i = i + mlast;
continue;
}
/* miss: check if next character is part of pattern */
if (!(mask & (1 << (s[i+m] & 0x1F))))
if (!BLOOM(mask, s[i+m]))
i = i + m;
else
i = i + skip;
} else {
/* skip: check if next character is part of pattern */
if (!(mask & (1 << (s[i+m] & 0x1F))))
if (!BLOOM(mask, s[i+m]))
i = i + m;
}
}
@ -101,10 +110,10 @@ fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
/* create compressed boyer-moore delta 1 table */
/* process pattern[0] outside the loop */
mask = (1 << (p[0] & 0x1F));
BLOOM_ADD(mask, p[0]);
/* process pattern[:0:-1] */
for (i = mlast; i > 0; i--) {
mask |= (1 << (p[i] & 0x1F));
BLOOM_ADD(mask, p[i]);
if (p[i] == p[0])
skip = i - 1;
}
@ -119,13 +128,13 @@ fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
/* got a match! */
return i;
/* miss: check if previous character is part of pattern */
if (!(mask & (1 << (s[i-1] & 0x1F))))
if (!BLOOM(mask, s[i-1]))
i = i - m;
else
i = i - skip;
} else {
/* skip: check if previous character is part of pattern */
if (!(mask & (1 << (s[i-1] & 0x1F))))
if (!BLOOM(mask, s[i-1]))
i = i - m;
}
}
@ -137,10 +146,3 @@ fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
}
#endif
/*
Local variables:
c-basic-offset: 4
indent-tabs-mode: nil
End:
*/