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Issue #13155: Optimize finding the optimal character width of an unicode string

This commit is contained in:
Antoine Pitrou 2011-10-13 00:02:27 +02:00
parent 49a0a21f37
commit dd4e2f0153
3 changed files with 206 additions and 87 deletions
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1
Makefile.pre.in
View File

@ -631,6 +631,7 @@ BYTESTR_DEPS = \
$(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 \

136
Objects/stringlib/find_max_char.h Normal file
View File

@ -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 */

156
Objects/unicodeobject.c
View File

@ -259,6 +259,15 @@ static void copy_characters(
static int unicode_is_singleton(PyObject *unicode);
#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,
@ -468,6 +477,48 @@ make_bloom_mask(int kind, void* ptr, Py_ssize_t len)
(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 @@ _PyUnicode_FromUCS1(const unsigned char* u, Py_ssize_t size)
{
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 @@ _PyUnicode_FromUCS2(const Py_UCS2 *u, Py_ssize_t size)
{
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 @@ _PyUnicode_FromUCS4(const Py_UCS4 *u, Py_ssize_t size)
{
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 @@ unicode_adjust_maxchar(PyObject **p_unicode)
{
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 @@ unicode_adjust_maxchar(PyObject **p_unicode)
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;
}
}
max_char = ucs4lib_find_max_char(u, u + len);
if (max_char >= 0x10000)
return;
}
assert(max_char < PyUnicode_MAX_CHAR_VALUE(unicode));
copy = PyUnicode_New(len, max_char);
copy_characters(copy, 0, unicode, 0, len);
Py_DECREF(unicode);
@ -8508,42 +8526,6 @@ PyUnicode_EncodeDecimal(Py_UNICODE *s,
/* --- 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,