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rewrote the pattern.sub and pattern.subn methods in C

Browse source 
removed (conceptually flawed) getliteral helper; the new sub/subn code
uses a faster code path for literal replacement strings, but doesn't
(yet) look for literal patterns.

added STATE_OFFSET macro, and use it to convert state.start/ptr to
char indexes
This commit is contained in:
Fredrik Lundh 2001-10-21 16:47:57 +00:00
parent 5b68ce3122
commit bec95b9d88
2 changed files with 344 additions and 143 deletions
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42
Lib/sre.py
View file

@ -104,7 +104,7 @@
"U", "IGNORECASE", "LOCALE", "MULTILINE", "DOTALL", "VERBOSE",
"UNICODE", "error" ]
__version__ = "2.2.0"
__version__ = "2.2.1"
# this module works under 1.5.2 and later. don't use string methods
import string
@ -244,26 +244,33 @@ def _expand(pattern, match, template):
template = sre_parse.parse_template(template, pattern)
return sre_parse.expand_template(template, match)
def _sub(pattern, template, text, count=0):
# internal: pattern.sub implementation hook
return _subn(pattern, template, text, count, 1)[0]
def _subn(pattern, template, text, count=0, sub=0):
# internal: pattern.subn implementation hook
def _subx(pattern, template):
# internal: pattern.sub/subn implementation helper
if callable(template):
filter = template
else:
template = _compile_repl(template, pattern)
literals = template[1]
if sub and not count:
literal = pattern._getliteral()
if literal and "\\" in literal:
literal = None # may contain untranslated escapes
if literal is not None and len(literals) == 1 and literals[0]:
# shortcut: both pattern and string are literals
return string.replace(text, pattern.pattern, literals[0]), 0
def filter(match, template=template):
return sre_parse.expand_template(template, match)
if not template[0] and len(template[1]) == 1:
# literal replacement
filter = template[1][0]
else:
def filter(match, template=template):
return sre_parse.expand_template(template, match)
return filter
def _sub(pattern, template, text, count=0):
# internal: pattern.sub implementation hook
# FIXME: not used in SRE 2.2.1 and later; will be removed soon
return _subn(pattern, template, text, count)[0]
def _subn(pattern, template, text, count=0):
# internal: pattern.subn implementation hook
# FIXME: not used in SRE 2.2.1 and later; will be removed soon
filter = _subx(pattern, template)
if not callable(filter):
# literal replacement
def filter(match, literal=filter):
return literal
n = i = 0
s = []
append = s.append
@ -286,6 +293,7 @@ def filter(match, template=template):
def _split(pattern, text, maxsplit=0):
# internal: pattern.split implementation hook
# FIXME: not used in SRE 2.2.1 and later; will be removed soon
n = i = 0
s = []
append = s.append

445
Modules/_sre.c
View file

@ -31,9 +31,9 @@
* 2001-04-28 fl added __copy__ methods (work in progress)
* 2001-05-14 fl fixes for 1.5.2
* 2001-07-01 fl added BIGCHARSET support (from Martin von Loewis)
* 2001-09-18 fl added _getliteral helper
* 2001-10-18 fl fixed group reset issue (from Matthew Mueller)
* 2001-10-20 fl added split primitive; reenable unicode for 1.6/2.0/2.1
* 2001-10-21 fl added sub/subn primitive
*
* Copyright (c) 1997-2001 by Secret Labs AB. All rights reserved.
*
@ -49,7 +49,7 @@
#ifndef SRE_RECURSIVE
static char copyright[] =
" SRE 2.2.0 Copyright (c) 1997-2001 by Secret Labs AB ";
" SRE 2.2.1 Copyright (c) 1997-2001 by Secret Labs AB ";
#include "Python.h"
#include "structmember.h" /* offsetof */
@ -76,8 +76,9 @@ static char copyright[] =
/* -------------------------------------------------------------------- */
/* optional features */
/* test: define to use sre._split helper instead of C code */
/* test: define to use sre.py helpers instead of C code */
#undef USE_PYTHON_SPLIT
#undef USE_PYTHON_SUB
/* prevent run-away recursion (bad patterns on long strings) */
@ -1493,6 +1494,10 @@ state_fini(SRE_STATE* state)
mark_fini(state);
}
/* calculate offset from start of string */
#define STATE_OFFSET(state, member)\
(((char*)(member) - (char*)(state)->beginning) / (state)->charsize)
LOCAL(PyObject*)
state_getslice(SRE_STATE* state, int index, PyObject* string, int empty)
{
@ -1509,10 +1514,8 @@ state_getslice(SRE_STATE* state, int index, PyObject* string, int empty)
return Py_None;
}
} else {
i = ((char*)state->mark[index] - (char*)state->beginning) /
state->charsize;
j = ((char*)state->mark[index+1] - (char*)state->beginning) /
state->charsize;
i = STATE_OFFSET(state, state->mark[index]);
j = STATE_OFFSET(state, state->mark[index+1]);
}
return PySequence_GetSlice(string, i, j);
@ -1721,6 +1724,8 @@ call(char* module, char* function, PyObject* args)
PyObject* func;
PyObject* result;
if (!args)
return NULL;
name = PyString_FromString(module);
if (!name)
return NULL;
@ -1758,6 +1763,60 @@ deepcopy(PyObject** object, PyObject* memo)
}
#endif
static PyObject*
join(PyObject* list, PyObject* pattern)
{
/* join list elements */
PyObject* joiner;
#if PY_VERSION_HEX >= 0x01060000
PyObject* function;
PyObject* args;
#endif
PyObject* result;
switch (PyList_GET_SIZE(list)) {
case 0:
Py_DECREF(list);
return PyString_FromString("");
case 1:
result = PyList_GET_ITEM(list, 0);
Py_INCREF(result);
Py_DECREF(list);
return result;
}
/* two or more elements: slice out a suitable separator from the
first member, and use that to join the entire list */
joiner = PySequence_GetSlice(pattern, 0, 0);
if (!joiner)
return NULL;
#if PY_VERSION_HEX >= 0x01060000
function = PyObject_GetAttrString(joiner, "join");
if (!function) {
Py_DECREF(joiner);
return NULL;
}
args = PyTuple_New(1);
PyTuple_SET_ITEM(args, 0, list);
result = PyObject_CallObject(function, args);
Py_DECREF(args); /* also removes list */
Py_DECREF(function);
#else
result = call(
"string", "join",
Py_BuildValue("OO", list, joiner)
);
#endif
Py_DECREF(joiner);
return result;
}
#ifdef USE_PYTHON_SUB
static PyObject*
pattern_sub(PatternObject* self, PyObject* args, PyObject* kw)
{
@ -1775,7 +1834,9 @@ pattern_sub(PatternObject* self, PyObject* args, PyObject* kw)
Py_BuildValue("OOOO", self, template, string, count)
);
}
#endif
#ifdef USE_PYTHON_SUB
static PyObject*
pattern_subn(PatternObject* self, PyObject* args, PyObject* kw)
{
@ -1793,6 +1854,7 @@ pattern_subn(PatternObject* self, PyObject* args, PyObject* kw)
Py_BuildValue("OOOO", self, template, string, count)
);
}
#endif
#if defined(USE_PYTHON_SPLIT)
static PyObject*
@ -1851,59 +1913,52 @@ pattern_findall(PatternObject* self, PyObject* args, PyObject* kw)
#endif
}
if (status > 0) {
/* don't bother to build a match object */
switch (self->groups) {
case 0:
b = ((char*) state.start - (char*) state.beginning) /
state.charsize;
e = ((char*) state.ptr - (char*) state.beginning) /
state.charsize;
item = PySequence_GetSlice(string, b, e);
if (!item)
goto error;
break;
case 1:
item = state_getslice(&state, 1, string, 1);
if (!item)
goto error;
break;
default:
item = PyTuple_New(self->groups);
if (!item)
goto error;
for (i = 0; i < self->groups; i++) {
PyObject* o = state_getslice(&state, i+1, string, 1);
if (!o) {
Py_DECREF(item);
goto error;
}
PyTuple_SET_ITEM(item, i, o);
}
break;
}
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
if (state.ptr == state.start)
state.start = (void*) ((char*) state.ptr + state.charsize);
else
state.start = state.ptr;
} else {
if (status <= 0) {
if (status == 0)
break;
pattern_error(status);
goto error;
}
/* don't bother to build a match object */
switch (self->groups) {
case 0:
b = STATE_OFFSET(&state, state.start);
e = STATE_OFFSET(&state, state.ptr);
item = PySequence_GetSlice(string, b, e);
if (!item)
goto error;
break;
case 1:
item = state_getslice(&state, 1, string, 1);
if (!item)
goto error;
break;
default:
item = PyTuple_New(self->groups);
if (!item)
goto error;
for (i = 0; i < self->groups; i++) {
PyObject* o = state_getslice(&state, i+1, string, 1);
if (!o) {
Py_DECREF(item);
goto error;
}
PyTuple_SET_ITEM(item, i, o);
}
break;
}
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
if (state.ptr == state.start)
state.start = (void*) ((char*) state.ptr + state.charsize);
else
state.start = state.ptr;
}
state_fini(&state);
@ -1925,8 +1980,8 @@ pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
PyObject* item;
int status;
int n;
int i, b, e;
int g;
int i;
void* last;
PyObject* string;
int maxsplit = 0;
@ -1941,9 +1996,10 @@ pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
list = PyList_New(0);
i = n = 0;
n = 0;
last = state.start;
while (maxsplit == 0 || n < maxsplit) {
while (!maxsplit || n < maxsplit) {
state_reset(&state);
@ -1957,58 +2013,54 @@ pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
#endif
}
if (status > 0) {
if (status <= 0) {
if (status == 0)
break;
pattern_error(status);
goto error;
}
if (state.start == state.ptr) {
if (last == state.end)
break;
/* skip one character */
state.start = (void*) ((char*) state.ptr + state.charsize);
continue;
}
if (state.start == state.ptr) {
if (i >= state.endpos)
break;
/* skip one character */
state.start = (void*) ((char*) state.ptr + state.charsize);
continue;
}
/* get segment before this match */
item = PySequence_GetSlice(
string, STATE_OFFSET(&state, last),
STATE_OFFSET(&state, state.start)
);
if (!item)
goto error;
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
b = ((char*) state.start - (char*) state.beginning) /
state.charsize;
e = ((char*) state.ptr - (char*) state.beginning) /
state.charsize;
/* get segment before this match */
item = PySequence_GetSlice(string, i, b);
/* add groups (if any) */
for (i = 0; i < self->groups; i++) {
item = state_getslice(&state, i+1, string, 0);
if (!item)
goto error;
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
for (g = 0; g < self->groups; g++) {
item = state_getslice(&state, g+1, string, 0);
if (!item)
goto error;
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
}
i = e;
n = n + 1;
state.start = state.ptr;
} else {
if (status == 0)
break;
pattern_error(status);
goto error;
}
n = n + 1;
last = state.start = state.ptr;
}
/* get segment following last match */
item = PySequence_GetSlice(string, i, state.endpos);
item = PySequence_GetSlice(
string, STATE_OFFSET(&state, last), state.endpos
);
if (!item)
goto error;
status = PyList_Append(list, item);
@ -2027,6 +2079,174 @@ pattern_split(PatternObject* self, PyObject* args, PyObject* kw)
}
#endif
#if !defined(USE_PYTHON_SUB)
static PyObject*
pattern_subx(PatternObject* self, PyObject* template, PyObject* string,
int count, int subn)
{
SRE_STATE state;
PyObject* list;
PyObject* item;
PyObject* filter;
PyObject* args;
PyObject* match;
int status;
int n;
int i, b, e;
int filter_is_callable;
/* call subx helper to get the filter */
filter = call(
SRE_MODULE, "_subx",
Py_BuildValue("OO", self, template)
);
if (!filter)
return NULL;
filter_is_callable = PyCallable_Check(filter);
string = state_init(&state, self, string, 0, INT_MAX);
if (!string)
return NULL;
list = PyList_New(0);
n = i = 0;
while (!count || n < count) {
state_reset(&state);
state.ptr = state.start;
if (state.charsize == 1) {
status = sre_search(&state, PatternObject_GetCode(self));
} else {
#if defined(HAVE_UNICODE)
status = sre_usearch(&state, PatternObject_GetCode(self));
#endif
}
if (status <= 0) {
if (status == 0)
break;
pattern_error(status);
goto error;
}
b = STATE_OFFSET(&state, state.start);
e = STATE_OFFSET(&state, state.ptr);
if (i < b) {
/* get segment before this match */
item = PySequence_GetSlice(string, i, b);
if (!item)
goto error;
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
} else if (i == b && i == e && n > 0)
/* ignore empty match on latest position */
goto next;
if (filter_is_callable) {
/* filter match */
match = pattern_new_match(self, &state, 1);
if (!match)
goto error;
args = Py_BuildValue("(O)", match);
if (!args) {
Py_DECREF(args);
goto error;
}
item = PyObject_CallObject(filter, args);
Py_DECREF(args);
Py_DECREF(match);
if (!item)
goto error;
} else {
/* filter is literal string */
item = filter;
Py_INCREF(filter);
}
/* add to list */
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
i = e;
n = n + 1;
next:
/* move on */
if (state.ptr == state.start)
state.start = (void*) ((char*) state.ptr + state.charsize);
else
state.start = state.ptr;
}
/* get segment following last match */
item = PySequence_GetSlice(string, i, state.endpos);
if (!item)
goto error;
status = PyList_Append(list, item);
Py_DECREF(item);
if (status < 0)
goto error;
state_fini(&state);
/* convert list to single string */
item = join(list, self->pattern);
if (!item)
return NULL;
if (subn)
return Py_BuildValue("Ni", item, n);
return item;
error:
Py_DECREF(list);
state_fini(&state);
return NULL;
}
static PyObject*
pattern_sub(PatternObject* self, PyObject* args, PyObject* kw)
{
PyObject* template;
PyObject* string;
int count = 0;
static char* kwlist[] = { "repl", "string", "count", NULL };
if (!PyArg_ParseTupleAndKeywords(args, kw, "OO|i:sub", kwlist,
&template, &string, &count))
return NULL;
return pattern_subx(self, template, string, count, 0);
}
static PyObject*
pattern_subn(PatternObject* self, PyObject* args, PyObject* kw)
{
PyObject* template;
PyObject* string;
int count = 0;
static char* kwlist[] = { "repl", "string", "count", NULL };
if (!PyArg_ParseTupleAndKeywords(args, kw, "OO|i:subn", kwlist,
&template, &string, &count))
return NULL;
return pattern_subx(self, template, string, count, 1);
}
#endif
static PyObject*
pattern_copy(PatternObject* self, PyObject* args)
{
@ -2084,32 +2304,6 @@ pattern_deepcopy(PatternObject* self, PyObject* args)
#endif
}
static PyObject*
pattern_getliteral(PatternObject* self, PyObject* args)
{
/* internal: if the pattern is a literal string, return that
string. otherwise, return None */
SRE_CODE* code;
PyObject* literal;
if (!PyArg_ParseTuple(args, ":_getliteral"))
return NULL;
code = PatternObject_GetCode(self);
if (code[0] == SRE_OP_INFO && code[2] & SRE_INFO_LITERAL) {
/* FIXME: extract literal string from code buffer. we can't
use the pattern member, since it may contain untranslated
escape codes (see SF bug 449000) */
literal = Py_None;
} else
literal = Py_None; /* no literal */
Py_INCREF(literal);
return literal;
}
static PyMethodDef pattern_methods[] = {
{"match", (PyCFunction) pattern_match, METH_VARARGS|METH_KEYWORDS},
{"search", (PyCFunction) pattern_search, METH_VARARGS|METH_KEYWORDS},
@ -2120,7 +2314,6 @@ static PyMethodDef pattern_methods[] = {
{"scanner", (PyCFunction) pattern_scanner, METH_VARARGS},
{"__copy__", (PyCFunction) pattern_copy, METH_VARARGS},
{"__deepcopy__", (PyCFunction) pattern_deepcopy, METH_VARARGS},
{"_getliteral", (PyCFunction) pattern_getliteral, METH_VARARGS},
{NULL, NULL}
};