summaryrefslogtreecommitdiffstats
path: root/Objects/stringlib
diff options
context:
space:
mode:
Diffstat (limited to 'Objects/stringlib')
-rw-r--r--Objects/stringlib/README.txt34
-rw-r--r--Objects/stringlib/count.h34
-rw-r--r--Objects/stringlib/fastsearch.h104
-rw-r--r--Objects/stringlib/find.h112
-rw-r--r--Objects/stringlib/partition.h111
5 files changed, 395 insertions, 0 deletions
diff --git a/Objects/stringlib/README.txt b/Objects/stringlib/README.txt
new file mode 100644
index 0000000..82a8774
--- /dev/null
+++ b/Objects/stringlib/README.txt
@@ -0,0 +1,34 @@
+bits shared by the stringobject and unicodeobject implementations (and
+possibly other modules, in a not too distant future).
+
+the stuff in here is included into relevant places; see the individual
+source files for details.
+
+--------------------------------------------------------------------
+the following defines used by the different modules:
+
+STRINGLIB_CHAR
+
+ the type used to hold a character (char or Py_UNICODE)
+
+STRINGLIB_EMPTY
+
+ a PyObject representing the empty string
+
+int STRINGLIB_CMP(STRINGLIB_CHAR*, STRINGLIB_CHAR*, Py_ssize_t)
+
+ compares two strings. returns 0 if they match, and non-zero if not.
+
+Py_ssize_t STRINGLIB_LEN(PyObject*)
+
+ returns the length of the given string object (which must be of the
+ right type)
+
+PyObject* STRINGLIB_NEW(STRINGLIB_CHAR*, Py_ssize_t)
+
+ creates a new string object
+
+STRINGLIB_CHAR* STRINGLIB_STR(PyObject*)
+
+ returns the pointer to the character data for the given string
+ object (which must be of the right type)
diff --git a/Objects/stringlib/count.h b/Objects/stringlib/count.h
new file mode 100644
index 0000000..0bd02b5
--- /dev/null
+++ b/Objects/stringlib/count.h
@@ -0,0 +1,34 @@
+/* stringlib: count implementation */
+
+#ifndef STRINGLIB_COUNT_H
+#define STRINGLIB_COUNT_H
+
+#ifndef STRINGLIB_FASTSEARCH_H
+#error must include "stringlib/fastsearch.h" before including this module
+#endif
+
+Py_LOCAL_INLINE(Py_ssize_t)
+stringlib_count(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
+ const STRINGLIB_CHAR* sub, Py_ssize_t sub_len)
+{
+ Py_ssize_t count;
+
+ if (sub_len == 0)
+ return str_len + 1;
+
+ count = fastsearch(str, str_len, sub, sub_len, FAST_COUNT);
+
+ if (count < 0)
+ count = 0; /* no match */
+
+ return count;
+}
+
+#endif
+
+/*
+Local variables:
+c-basic-offset: 4
+indent-tabs-mode: nil
+End:
+*/
diff --git a/Objects/stringlib/fastsearch.h b/Objects/stringlib/fastsearch.h
new file mode 100644
index 0000000..8f79c36
--- /dev/null
+++ b/Objects/stringlib/fastsearch.h
@@ -0,0 +1,104 @@
+/* stringlib: fastsearch implementation */
+
+#ifndef STRINGLIB_FASTSEARCH_H
+#define STRINGLIB_FASTSEARCH_H
+
+/* fast search/count implementation, based on a mix between boyer-
+ moore and horspool, with a few more bells and whistles on the top.
+ for some more background, see: http://effbot.org/stringlib */
+
+/* note: fastsearch may access s[n], which isn't a problem when using
+ Python's ordinary string types, but may cause problems if you're
+ using this code in other contexts. also, the count mode returns -1
+ if there cannot possible be a match in the target string, and 0 if
+ it has actually checked for matches, but didn't find any. callers
+ beware! */
+
+#define FAST_COUNT 0
+#define FAST_SEARCH 1
+
+Py_LOCAL_INLINE(Py_ssize_t)
+fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
+ const STRINGLIB_CHAR* p, Py_ssize_t m,
+ int mode)
+{
+ long mask;
+ Py_ssize_t skip, count = 0;
+ Py_ssize_t i, j, mlast, w;
+
+ w = n - m;
+
+ if (w < 0)
+ return -1;
+
+ /* look for special cases */
+ if (m <= 1) {
+ if (m <= 0)
+ return -1;
+ /* use special case for 1-character strings */
+ if (mode == FAST_COUNT) {
+ for (i = 0; i < n; i++)
+ if (s[i] == p[0])
+ count++;
+ return count;
+ } else {
+ for (i = 0; i < n; i++)
+ if (s[i] == p[0])
+ return i;
+ }
+ return -1;
+ }
+
+ mlast = m - 1;
+
+ /* create compressed boyer-moore delta 1 table */
+ skip = mlast - 1;
+ /* process pattern[:-1] */
+ for (mask = i = 0; i < mlast; i++) {
+ mask |= (1 << (p[i] & 0x1F));
+ if (p[i] == p[mlast])
+ skip = mlast - i - 1;
+ }
+ /* process pattern[-1] outside the loop */
+ mask |= (1 << (p[mlast] & 0x1F));
+
+ for (i = 0; i <= w; i++) {
+ /* note: using mlast in the skip path slows things down on x86 */
+ if (s[i+m-1] == p[m-1]) {
+ /* candidate match */
+ for (j = 0; j < mlast; j++)
+ if (s[i+j] != p[j])
+ break;
+ if (j == mlast) {
+ /* got a match! */
+ if (mode != FAST_COUNT)
+ return i;
+ count++;
+ i = i + mlast;
+ continue;
+ }
+ /* miss: check if next character is part of pattern */
+ if (!(mask & (1 << (s[i+m] & 0x1F))))
+ i = i + m;
+ else
+ i = i + skip;
+ } else {
+ /* skip: check if next character is part of pattern */
+ if (!(mask & (1 << (s[i+m] & 0x1F))))
+ i = i + m;
+ }
+ }
+
+ if (mode != FAST_COUNT)
+ return -1;
+ return count;
+}
+
+#endif
+
+/*
+Local variables:
+c-basic-offset: 4
+indent-tabs-mode: nil
+End:
+*/
diff --git a/Objects/stringlib/find.h b/Objects/stringlib/find.h
new file mode 100644
index 0000000..4cea2db
--- /dev/null
+++ b/Objects/stringlib/find.h
@@ -0,0 +1,112 @@
+/* stringlib: find/index implementation */
+
+#ifndef STRINGLIB_FIND_H
+#define STRINGLIB_FIND_H
+
+#ifndef STRINGLIB_FASTSEARCH_H
+#error must include "stringlib/fastsearch.h" before including this module
+#endif
+
+Py_LOCAL_INLINE(Py_ssize_t)
+stringlib_find(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
+ const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
+ Py_ssize_t offset)
+{
+ Py_ssize_t pos;
+
+ if (sub_len == 0)
+ return offset;
+
+ pos = fastsearch(str, str_len, sub, sub_len, FAST_SEARCH);
+
+ if (pos >= 0)
+ pos += offset;
+
+ return pos;
+}
+
+Py_LOCAL_INLINE(Py_ssize_t)
+stringlib_rfind(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
+ const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
+ Py_ssize_t offset)
+{
+ Py_ssize_t pos;
+
+ /* XXX - create reversefastsearch helper! */
+ if (sub_len == 0)
+ pos = str_len + offset;
+ else {
+ Py_ssize_t j;
+ pos = -1;
+ for (j = str_len - sub_len; j >= 0; --j)
+ if (STRINGLIB_CMP(str+j, sub, sub_len) == 0) {
+ pos = j + offset;
+ break;
+ }
+ }
+
+ return pos;
+}
+
+Py_LOCAL_INLINE(Py_ssize_t)
+stringlib_find_slice(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
+ const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
+ Py_ssize_t start, Py_ssize_t end)
+{
+ if (start < 0)
+ start += str_len;
+ if (start < 0)
+ start = 0;
+ if (end > str_len)
+ end = str_len;
+ if (end < 0)
+ end += str_len;
+ if (end < 0)
+ end = 0;
+
+ return stringlib_find(
+ str + start, end - start,
+ sub, sub_len, start
+ );
+}
+
+Py_LOCAL_INLINE(Py_ssize_t)
+stringlib_rfind_slice(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
+ const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
+ Py_ssize_t start, Py_ssize_t end)
+{
+ if (start < 0)
+ start += str_len;
+ if (start < 0)
+ start = 0;
+ if (end > str_len)
+ end = str_len;
+ if (end < 0)
+ end += str_len;
+ if (end < 0)
+ end = 0;
+
+ return stringlib_rfind(str + start, end - start, sub, sub_len, start);
+}
+
+#ifdef STRINGLIB_STR
+
+Py_LOCAL_INLINE(int)
+stringlib_contains_obj(PyObject* str, PyObject* sub)
+{
+ return stringlib_find(
+ STRINGLIB_STR(str), STRINGLIB_LEN(str),
+ STRINGLIB_STR(sub), STRINGLIB_LEN(sub), 0
+ ) != -1;
+}
+
+#endif /* STRINGLIB_STR */
+
+#endif /* STRINGLIB_FIND_H */
+
+/*
+Local variables:
+c-basic-offset: 4
+indent-tabs-mode: nil
+End:
+*/
diff --git a/Objects/stringlib/partition.h b/Objects/stringlib/partition.h
new file mode 100644
index 0000000..1486347
--- /dev/null
+++ b/Objects/stringlib/partition.h
@@ -0,0 +1,111 @@
+/* stringlib: partition implementation */
+
+#ifndef STRINGLIB_PARTITION_H
+#define STRINGLIB_PARTITION_H
+
+#ifndef STRINGLIB_FASTSEARCH_H
+#error must include "stringlib/fastsearch.h" before including this module
+#endif
+
+Py_LOCAL_INLINE(PyObject*)
+stringlib_partition(
+ PyObject* str_obj, const STRINGLIB_CHAR* str, Py_ssize_t str_len,
+ PyObject* sep_obj, const STRINGLIB_CHAR* sep, Py_ssize_t sep_len
+ )
+{
+ PyObject* out;
+ Py_ssize_t pos;
+
+ if (sep_len == 0) {
+ PyErr_SetString(PyExc_ValueError, "empty separator");
+ return NULL;
+ }
+
+ out = PyTuple_New(3);
+ if (!out)
+ return NULL;
+
+ pos = fastsearch(str, str_len, sep, sep_len, FAST_SEARCH);
+
+ if (pos < 0) {
+ Py_INCREF(str_obj);
+ PyTuple_SET_ITEM(out, 0, (PyObject*) str_obj);
+ Py_INCREF(STRINGLIB_EMPTY);
+ PyTuple_SET_ITEM(out, 1, (PyObject*) STRINGLIB_EMPTY);
+ Py_INCREF(STRINGLIB_EMPTY);
+ PyTuple_SET_ITEM(out, 2, (PyObject*) STRINGLIB_EMPTY);
+ return out;
+ }
+
+ PyTuple_SET_ITEM(out, 0, STRINGLIB_NEW(str, pos));
+ Py_INCREF(sep_obj);
+ PyTuple_SET_ITEM(out, 1, sep_obj);
+ pos += sep_len;
+ PyTuple_SET_ITEM(out, 2, STRINGLIB_NEW(str + pos, str_len - pos));
+
+ if (PyErr_Occurred()) {
+ Py_DECREF(out);
+ return NULL;
+ }
+
+ return out;
+}
+
+Py_LOCAL_INLINE(PyObject*)
+stringlib_rpartition(
+ PyObject* str_obj, const STRINGLIB_CHAR* str, Py_ssize_t str_len,
+ PyObject* sep_obj, const STRINGLIB_CHAR* sep, Py_ssize_t sep_len
+ )
+{
+ PyObject* out;
+ Py_ssize_t pos, j;
+
+ if (sep_len == 0) {
+ PyErr_SetString(PyExc_ValueError, "empty separator");
+ return NULL;
+ }
+
+ out = PyTuple_New(3);
+ if (!out)
+ return NULL;
+
+ /* XXX - create reversefastsearch helper! */
+ pos = -1;
+ for (j = str_len - sep_len; j >= 0; --j)
+ if (STRINGLIB_CMP(str+j, sep, sep_len) == 0) {
+ pos = j;
+ break;
+ }
+
+ if (pos < 0) {
+ Py_INCREF(str_obj);
+ PyTuple_SET_ITEM(out, 0, (PyObject*) str_obj);
+ Py_INCREF(STRINGLIB_EMPTY);
+ PyTuple_SET_ITEM(out, 1, (PyObject*) STRINGLIB_EMPTY);
+ Py_INCREF(STRINGLIB_EMPTY);
+ PyTuple_SET_ITEM(out, 2, (PyObject*) STRINGLIB_EMPTY);
+ return out;
+ }
+
+ PyTuple_SET_ITEM(out, 0, STRINGLIB_NEW(str, pos));
+ Py_INCREF(sep_obj);
+ PyTuple_SET_ITEM(out, 1, sep_obj);
+ pos += sep_len;
+ PyTuple_SET_ITEM(out, 2, STRINGLIB_NEW(str + pos, str_len - pos));
+
+ if (PyErr_Occurred()) {
+ Py_DECREF(out);
+ return NULL;
+ }
+
+ return out;
+}
+
+#endif
+
+/*
+Local variables:
+c-basic-offset: 4
+indent-tabs-mode: nil
+End:
+*/
generated by cgit v0.12 at 2025-02-13 13:08:57 (GMT)