[Python-checkins] cpython: Issue #13155: Optimize finding the optimal character width of an unicode string
antoine.pitrou
python-checkins at python.org
Thu Oct 13 00:08:06 CEST 2011
http://hg.python.org/cpython/rev/9c7d3207fc15
changeset: 72902:9c7d3207fc15
user: Antoine Pitrou <solipsis at pitrou.net>
date: Thu Oct 13 00:02:27 2011 +0200
summary:
Issue #13155: Optimize finding the optimal character width of an unicode string
files:
Makefile.pre.in | 1 +
Objects/stringlib/find_max_char.h | 136 +++++++++++++++
Objects/unicodeobject.c | 158 +++++++----------
3 files changed, 207 insertions(+), 88 deletions(-)
diff --git a/Makefile.pre.in b/Makefile.pre.in
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -631,6 +631,7 @@
$(srcdir)/Objects/stringlib/eq.h \
$(srcdir)/Objects/stringlib/fastsearch.h \
$(srcdir)/Objects/stringlib/find.h \
+ $(srcdir)/Objects/stringlib/find_max_char.h \
$(srcdir)/Objects/stringlib/partition.h \
$(srcdir)/Objects/stringlib/split.h \
$(srcdir)/Objects/stringlib/stringdefs.h \
diff --git a/Objects/stringlib/find_max_char.h b/Objects/stringlib/find_max_char.h
new file mode 100644
--- /dev/null
+++ b/Objects/stringlib/find_max_char.h
@@ -0,0 +1,136 @@
+/* Finding the optimal width of unicode characters in a buffer */
+
+#if STRINGLIB_IS_UNICODE
+
+/* Mask to check or force alignment of a pointer to C 'long' boundaries */
+#define LONG_PTR_MASK (size_t) (SIZEOF_LONG - 1)
+
+/* Mask to quickly check whether a C 'long' contains a
+ non-ASCII, UTF8-encoded char. */
+#if (SIZEOF_LONG == 8)
+# define UCS1_ASCII_CHAR_MASK 0x8080808080808080L
+#elif (SIZEOF_LONG == 4)
+# define UCS1_ASCII_CHAR_MASK 0x80808080L
+#else
+# error C 'long' size should be either 4 or 8!
+#endif
+
+#if STRINGLIB_SIZEOF_CHAR == 1
+
+Py_LOCAL_INLINE(Py_UCS4)
+STRINGLIB(find_max_char)(const STRINGLIB_CHAR *begin, const STRINGLIB_CHAR *end)
+{
+ const unsigned char *p = (const unsigned char *) begin;
+ const unsigned char *aligned_end = (const unsigned char *) ((size_t) end & ~LONG_PTR_MASK);
+
+ while (p < end) {
+ if (!((size_t) p & LONG_PTR_MASK)) {
+ /* Help register allocation */
+ register const unsigned char *_p = p;
+ while (_p < aligned_end) {
+ unsigned long value = *(unsigned long *) _p;
+ if (value & UCS1_ASCII_CHAR_MASK)
+ return 255;
+ _p += SIZEOF_LONG;
+ }
+ p = _p;
+ if (p == end)
+ break;
+ }
+ if (*p++ & 0x80)
+ return 255;
+ }
+ return 127;
+}
+
+#undef LONG_PTR_MASK
+#undef ASCII_CHAR_MASK
+
+#else /* STRINGLIB_SIZEOF_CHAR == 1 */
+
+#define MASK_ASCII 0xFFFFFF80
+#define MASK_UCS1 0xFFFFFF00
+#define MASK_UCS2 0xFFFF0000
+
+#define MAX_CHAR_ASCII 0x7f
+#define MAX_CHAR_UCS1 0xff
+#define MAX_CHAR_UCS2 0xffff
+#define MAX_CHAR_UCS4 0x10ffff
+
+Py_LOCAL_INLINE(Py_UCS4)
+STRINGLIB(find_max_char)(const STRINGLIB_CHAR *begin, const STRINGLIB_CHAR *end)
+{
+#if STRINGLIB_SIZEOF_CHAR == 2
+ const Py_UCS4 mask_limit = MASK_UCS1;
+ const Py_UCS4 max_char_limit = MAX_CHAR_UCS2;
+#elif STRINGLIB_SIZEOF_CHAR == 4
+ const Py_UCS4 mask_limit = MASK_UCS2;
+ const Py_UCS4 max_char_limit = MAX_CHAR_UCS4;
+#else
+#error Invalid STRINGLIB_SIZEOF_CHAR (must be 1, 2 or 4)
+#endif
+ register Py_UCS4 mask;
+ Py_ssize_t n = end - begin;
+ const STRINGLIB_CHAR *p = begin;
+ const STRINGLIB_CHAR *unrolled_end = begin + (n & ~ (Py_ssize_t) 3);
+ Py_UCS4 max_char;
+
+ max_char = MAX_CHAR_ASCII;
+ mask = MASK_ASCII;
+ while (p < unrolled_end) {
+ STRINGLIB_CHAR bits = p[0] | p[1] | p[2] | p[3];
+ if (bits & mask) {
+ if (mask == mask_limit) {
+ /* Limit reached */
+ return max_char_limit;
+ }
+ if (mask == MASK_ASCII) {
+ max_char = MAX_CHAR_UCS1;
+ mask = MASK_UCS1;
+ }
+ else {
+ /* mask can't be MASK_UCS2 because of mask_limit above */
+ assert(mask == MASK_UCS1);
+ max_char = MAX_CHAR_UCS2;
+ mask = MASK_UCS2;
+ }
+ /* We check the new mask on the same chars in the next iteration */
+ continue;
+ }
+ p += 4;
+ }
+ while (p < end) {
+ if (p[0] & mask) {
+ if (mask == mask_limit) {
+ /* Limit reached */
+ return max_char_limit;
+ }
+ if (mask == MASK_ASCII) {
+ max_char = MAX_CHAR_UCS1;
+ mask = MASK_UCS1;
+ }
+ else {
+ /* mask can't be MASK_UCS2 because of mask_limit above */
+ assert(mask == MASK_UCS1);
+ max_char = MAX_CHAR_UCS2;
+ mask = MASK_UCS2;
+ }
+ /* We check the new mask on the same chars in the next iteration */
+ continue;
+ }
+ p++;
+ }
+ return max_char;
+}
+
+#undef MASK_ASCII
+#undef MASK_UCS1
+#undef MASK_UCS2
+#undef MAX_CHAR_ASCII
+#undef MAX_CHAR_UCS1
+#undef MAX_CHAR_UCS2
+#undef MAX_CHAR_UCS4
+
+#endif /* STRINGLIB_SIZEOF_CHAR == 1 */
+#endif /* STRINGLIB_IS_UNICODE */
+
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -260,6 +260,15 @@
#endif
static PyObject *
+unicode_fromascii(const unsigned char *s, Py_ssize_t size);
+static PyObject *
+_PyUnicode_FromUCS1(const unsigned char *s, Py_ssize_t size);
+static PyObject *
+_PyUnicode_FromUCS2(const Py_UCS2 *s, Py_ssize_t size);
+static PyObject *
+_PyUnicode_FromUCS4(const Py_UCS4 *s, Py_ssize_t size);
+
+static PyObject *
unicode_encode_call_errorhandler(const char *errors,
PyObject **errorHandler,const char *encoding, const char *reason,
const Py_UNICODE *unicode, Py_ssize_t size, PyObject **exceptionObject,
@@ -468,6 +477,48 @@
(BLOOM(mask, chr) \
&& (PyUnicode_FindChar(str, chr, 0, PyUnicode_GET_LENGTH(str), 1) >= 0))
+/* Compilation of templated routines */
+
+#include "stringlib/asciilib.h"
+#include "stringlib/fastsearch.h"
+#include "stringlib/partition.h"
+#include "stringlib/split.h"
+#include "stringlib/count.h"
+#include "stringlib/find.h"
+#include "stringlib/find_max_char.h"
+#include "stringlib/localeutil.h"
+#include "stringlib/undef.h"
+
+#include "stringlib/ucs1lib.h"
+#include "stringlib/fastsearch.h"
+#include "stringlib/partition.h"
+#include "stringlib/split.h"
+#include "stringlib/count.h"
+#include "stringlib/find.h"
+#include "stringlib/find_max_char.h"
+#include "stringlib/localeutil.h"
+#include "stringlib/undef.h"
+
+#include "stringlib/ucs2lib.h"
+#include "stringlib/fastsearch.h"
+#include "stringlib/partition.h"
+#include "stringlib/split.h"
+#include "stringlib/count.h"
+#include "stringlib/find.h"
+#include "stringlib/find_max_char.h"
+#include "stringlib/localeutil.h"
+#include "stringlib/undef.h"
+
+#include "stringlib/ucs4lib.h"
+#include "stringlib/fastsearch.h"
+#include "stringlib/partition.h"
+#include "stringlib/split.h"
+#include "stringlib/count.h"
+#include "stringlib/find.h"
+#include "stringlib/find_max_char.h"
+#include "stringlib/localeutil.h"
+#include "stringlib/undef.h"
+
/* --- Unicode Object ----------------------------------------------------- */
static PyObject *
@@ -1689,17 +1740,11 @@
{
PyObject *res;
unsigned char max_char = 127;
- Py_ssize_t i;
assert(size >= 0);
if (size == 1)
return get_latin1_char(u[0]);
- for (i = 0; i < size; i++) {
- if (u[i] & 0x80) {
- max_char = 255;
- break;
- }
- }
+ max_char = ucs1lib_find_max_char(u, u + size);
res = PyUnicode_New(size, max_char);
if (!res)
return NULL;
@@ -1713,26 +1758,20 @@
{
PyObject *res;
Py_UCS2 max_char = 0;
- Py_ssize_t i;
assert(size >= 0);
if (size == 1 && u[0] < 256)
return get_latin1_char((unsigned char)u[0]);
- for (i = 0; i < size; i++) {
- if (u[i] > max_char) {
- max_char = u[i];
- if (max_char >= 256)
- break;
- }
- }
+ max_char = ucs2lib_find_max_char(u, u + size);
res = PyUnicode_New(size, max_char);
if (!res)
return NULL;
if (max_char >= 256)
memcpy(PyUnicode_2BYTE_DATA(res), u, sizeof(Py_UCS2)*size);
- else
- for (i = 0; i < size; i++)
- PyUnicode_1BYTE_DATA(res)[i] = (Py_UCS1)u[i];
+ else {
+ _PyUnicode_CONVERT_BYTES(
+ Py_UCS2, Py_UCS1, u, u + size, PyUnicode_1BYTE_DATA(res));
+ }
assert(_PyUnicode_CheckConsistency(res, 1));
return res;
}
@@ -1742,18 +1781,11 @@
{
PyObject *res;
Py_UCS4 max_char = 0;
- Py_ssize_t i;
assert(size >= 0);
if (size == 1 && u[0] < 256)
return get_latin1_char(u[0]);
- for (i = 0; i < size; i++) {
- if (u[i] > max_char) {
- max_char = u[i];
- if (max_char >= 0x10000)
- break;
- }
- }
+ max_char = ucs4lib_find_max_char(u, u + size);
res = PyUnicode_New(size, max_char);
if (!res)
return NULL;
@@ -1794,7 +1826,7 @@
{
PyObject *unicode, *copy;
Py_UCS4 max_char;
- Py_ssize_t i, len;
+ Py_ssize_t len;
unsigned int kind;
assert(p_unicode != NULL);
@@ -1807,37 +1839,23 @@
kind = PyUnicode_KIND(unicode);
if (kind == PyUnicode_1BYTE_KIND) {
const Py_UCS1 *u = PyUnicode_1BYTE_DATA(unicode);
- for (i = 0; i < len; i++) {
- if (u[i] & 0x80)
- return;
- }
- max_char = 127;
+ max_char = ucs1lib_find_max_char(u, u + len);
+ if (max_char >= 128)
+ return;
}
else if (kind == PyUnicode_2BYTE_KIND) {
const Py_UCS2 *u = PyUnicode_2BYTE_DATA(unicode);
- max_char = 0;
- for (i = 0; i < len; i++) {
- if (u[i] > max_char) {
- max_char = u[i];
- if (max_char >= 256)
- return;
- }
- }
+ max_char = ucs2lib_find_max_char(u, u + len);
+ if (max_char >= 256)
+ return;
}
else {
- const Py_UCS4 *u;
+ const Py_UCS4 *u = PyUnicode_4BYTE_DATA(unicode);
assert(kind == PyUnicode_4BYTE_KIND);
- u = PyUnicode_4BYTE_DATA(unicode);
- max_char = 0;
- for (i = 0; i < len; i++) {
- if (u[i] > max_char) {
- max_char = u[i];
- if (max_char >= 0x10000)
- return;
- }
- }
- }
- assert(max_char < PyUnicode_MAX_CHAR_VALUE(unicode));
+ max_char = ucs4lib_find_max_char(u, u + len);
+ if (max_char >= 0x10000)
+ return;
+ }
copy = PyUnicode_New(len, max_char);
copy_characters(copy, 0, unicode, 0, len);
Py_DECREF(unicode);
@@ -8508,42 +8526,6 @@
/* --- Helpers ------------------------------------------------------------ */
-#include "stringlib/asciilib.h"
-#include "stringlib/fastsearch.h"
-#include "stringlib/partition.h"
-#include "stringlib/split.h"
-#include "stringlib/count.h"
-#include "stringlib/find.h"
-#include "stringlib/localeutil.h"
-#include "stringlib/undef.h"
-
-#include "stringlib/ucs1lib.h"
-#include "stringlib/fastsearch.h"
-#include "stringlib/partition.h"
-#include "stringlib/split.h"
-#include "stringlib/count.h"
-#include "stringlib/find.h"
-#include "stringlib/localeutil.h"
-#include "stringlib/undef.h"
-
-#include "stringlib/ucs2lib.h"
-#include "stringlib/fastsearch.h"
-#include "stringlib/partition.h"
-#include "stringlib/split.h"
-#include "stringlib/count.h"
-#include "stringlib/find.h"
-#include "stringlib/localeutil.h"
-#include "stringlib/undef.h"
-
-#include "stringlib/ucs4lib.h"
-#include "stringlib/fastsearch.h"
-#include "stringlib/partition.h"
-#include "stringlib/split.h"
-#include "stringlib/count.h"
-#include "stringlib/find.h"
-#include "stringlib/localeutil.h"
-#include "stringlib/undef.h"
-
static Py_ssize_t
any_find_slice(int direction, PyObject* s1, PyObject* s2,
Py_ssize_t start,
--
Repository URL: http://hg.python.org/cpython
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