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()
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 91d76b7..a8e1205 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -112,6 +112,64 @@
*/
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 @@
#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 @@
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 @@
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 @@
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 @@
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;