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Commit 4c6c96c0 authored by Christian Heimes's avatar Christian Heimes
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Patch #1970 by Antoine Pitrou: Speedup unicode whitespace and linebreak... 

Patch #1970 by Antoine Pitrou: Speedup unicode whitespace and linebreak detection. The speedup is about 25% for split() (571 / 457 usec) and 35% (175 / 127 usec )for splitlines()
parent 16a5e777
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Showing with 92 additions and 19 deletions
Include/unicodeobject.h
View file @ 4c6c96c0
......@@ -348,7 +348,14 @@ typedef PY_UNICODE_TYPE Py_UNICODE;
#else
#define Py_UNICODE_ISSPACE(ch) _PyUnicode_IsWhitespace(ch)
/* Since splitting on whitespace is an important use case, and whitespace
in most situations is solely ASCII whitespace, we optimize for the common
case by using a quick look-up table with an inlined check.
*/
extern const unsigned char _Py_ascii_whitespace[];
#define Py_UNICODE_ISSPACE(ch) \
((ch) < 128U ? _Py_ascii_whitespace[(ch)] : _PyUnicode_IsWhitespace(ch))
#define Py_UNICODE_ISLOWER(ch) _PyUnicode_IsLowercase(ch)
#define Py_UNICODE_ISUPPER(ch) _PyUnicode_IsUppercase(ch)
......
Misc/NEWS
View file @ 4c6c96c0
......@@ -12,6 +12,9 @@ What's New in Python 2.6 alpha 1?
Core and builtins
-----------------
- Patch #1970 by Antoine Pitrou: Speedup unicode whitespace and linebreak
detection
- Added ``PyType_ClearCache()`` and ``sys._cleartypecache`` to clear the
internal lookup cache for ref leak tests.
......
Objects/unicodeobject.c
View file @ 4c6c96c0
......@@ -112,6 +112,64 @@ static PyUnicodeObject *unicode_latin1[256];
*/
static char unicode_default_encoding[100];
/* Fast detection of the most frequent whitespace characters */
const unsigned char _Py_ascii_whitespace[] = {
0, 0, 0, 0, 0, 0, 0, 0,
// case 0x0009: /* HORIZONTAL TABULATION */
// case 0x000A: /* LINE FEED */
// case 0x000B: /* VERTICAL TABULATION */
// case 0x000C: /* FORM FEED */
// case 0x000D: /* CARRIAGE RETURN */
0, 1, 1, 1, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
// case 0x001C: /* FILE SEPARATOR */
// case 0x001D: /* GROUP SEPARATOR */
// case 0x001E: /* RECORD SEPARATOR */
// case 0x001F: /* UNIT SEPARATOR */
0, 0, 0, 0, 1, 1, 1, 1,
// case 0x0020: /* SPACE */
1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
};
/* Same for linebreaks */
static unsigned char ascii_linebreak[] = {
0, 0, 0, 0, 0, 0, 0, 0,
// 0x000A, /* LINE FEED */
// 0x000D, /* CARRIAGE RETURN */
0, 0, 1, 0, 0, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
// 0x001C, /* FILE SEPARATOR */
// 0x001D, /* GROUP SEPARATOR */
// 0x001E, /* RECORD SEPARATOR */
0, 0, 0, 0, 1, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
};
Py_UNICODE
PyUnicode_GetMax(void)
{
......@@ -138,8 +196,9 @@ static BLOOM_MASK bloom_linebreak;
#define BLOOM(mask, ch) ((mask & (1 << ((ch) & 0x1F))))
#define BLOOM_LINEBREAK(ch)\
(BLOOM(bloom_linebreak, (ch)) && Py_UNICODE_ISLINEBREAK((ch)))
#define BLOOM_LINEBREAK(ch) \
((ch) < 128U ? ascii_linebreak[(ch)] : \
(BLOOM(bloom_linebreak, (ch)) && Py_UNICODE_ISLINEBREAK(ch)))
Py_LOCAL_INLINE(BLOOM_MASK) make_bloom_mask(Py_UNICODE* ptr, Py_ssize_t len)
{
......@@ -5505,25 +5564,26 @@ PyObject *split_whitespace(PyUnicodeObject *self,
register Py_ssize_t j;
Py_ssize_t len = self->length;
PyObject *str;
register const Py_UNICODE *buf = self->str;
for (i = j = 0; i < len; ) {
/* find a token */
while (i < len && Py_UNICODE_ISSPACE(self->str[i]))
while (i < len && Py_UNICODE_ISSPACE(buf[i]))
i++;
j = i;
while (i < len && !Py_UNICODE_ISSPACE(self->str[i]))
while (i < len && !Py_UNICODE_ISSPACE(buf[i]))
i++;
if (j < i) {
if (maxcount-- <= 0)
break;
SPLIT_APPEND(self->str, j, i);
while (i < len && Py_UNICODE_ISSPACE(self->str[i]))
SPLIT_APPEND(buf, j, i);
while (i < len && Py_UNICODE_ISSPACE(buf[i]))
i++;
j = i;
}
}
if (j < len) {
SPLIT_APPEND(self->str, j, len);
SPLIT_APPEND(buf, j, len);
}
return list;
......@@ -5596,18 +5656,19 @@ PyObject *split_char(PyUnicodeObject *self,
register Py_ssize_t j;
Py_ssize_t len = self->length;
PyObject *str;
register const Py_UNICODE *buf = self->str;
for (i = j = 0; i < len; ) {
if (self->str[i] == ch) {
if (buf[i] == ch) {
if (maxcount-- <= 0)
break;
SPLIT_APPEND(self->str, j, i);
SPLIT_APPEND(buf, j, i);
i = j = i + 1;
} else
i++;
}
if (j <= len) {
SPLIT_APPEND(self->str, j, len);
SPLIT_APPEND(buf, j, len);
}
return list;
......@@ -5656,25 +5717,26 @@ PyObject *rsplit_whitespace(PyUnicodeObject *self,
register Py_ssize_t j;
Py_ssize_t len = self->length;
PyObject *str;
register const Py_UNICODE *buf = self->str;
for (i = j = len - 1; i >= 0; ) {
/* find a token */
while (i >= 0 && Py_UNICODE_ISSPACE(self->str[i]))
while (i >= 0 && Py_UNICODE_ISSPACE(buf[i]))
i--;
j = i;
while (i >= 0 && !Py_UNICODE_ISSPACE(self->str[i]))
while (i >= 0 && !Py_UNICODE_ISSPACE(buf[i]))
i--;
if (j > i) {
if (maxcount-- <= 0)
break;
SPLIT_APPEND(self->str, i + 1, j + 1);
while (i >= 0 && Py_UNICODE_ISSPACE(self->str[i]))
SPLIT_APPEND(buf, i + 1, j + 1);
while (i >= 0 && Py_UNICODE_ISSPACE(buf[i]))
i--;
j = i;
}
}
if (j >= 0) {
SPLIT_APPEND(self->str, 0, j + 1);
SPLIT_APPEND(buf, 0, j + 1);
}
if (PyList_Reverse(list) < 0)
goto onError;
......@@ -5695,18 +5757,19 @@ PyObject *rsplit_char(PyUnicodeObject *self,
register Py_ssize_t j;
Py_ssize_t len = self->length;
PyObject *str;
register const Py_UNICODE *buf = self->str;
for (i = j = len - 1; i >= 0; ) {
if (self->str[i] == ch) {
if (buf[i] == ch) {
if (maxcount-- <= 0)
break;
SPLIT_APPEND(self->str, i + 1, j + 1);
SPLIT_APPEND(buf, i + 1, j + 1);
j = i = i - 1;
} else
i--;
}
if (j >= -1) {
SPLIT_APPEND(self->str, 0, j + 1);
SPLIT_APPEND(buf, 0, j + 1);
}
if (PyList_Reverse(list) < 0)
goto onError;
......
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