1 /* stringlib: find/index implementation */
2 
3 #ifndef STRINGLIB_FASTSEARCH_H
4 #error must include "stringlib/fastsearch.h" before including this module
5 #endif
6 
7 Py_LOCAL_INLINE(Py_ssize_t)
STRINGLIB(find)8 STRINGLIB(find)(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
9                const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
10                Py_ssize_t offset)
11 {
12     Py_ssize_t pos;
13 
14     assert(str_len >= 0);
15     if (sub_len == 0)
16         return offset;
17 
18     pos = FASTSEARCH(str, str_len, sub, sub_len, -1, FAST_SEARCH);
19 
20     if (pos >= 0)
21         pos += offset;
22 
23     return pos;
24 }
25 
26 Py_LOCAL_INLINE(Py_ssize_t)
STRINGLIB(rfind)27 STRINGLIB(rfind)(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
28                 const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
29                 Py_ssize_t offset)
30 {
31     Py_ssize_t pos;
32 
33     assert(str_len >= 0);
34     if (sub_len == 0)
35         return str_len + offset;
36 
37     pos = FASTSEARCH(str, str_len, sub, sub_len, -1, FAST_RSEARCH);
38 
39     if (pos >= 0)
40         pos += offset;
41 
42     return pos;
43 }
44 
45 Py_LOCAL_INLINE(Py_ssize_t)
STRINGLIB(find_slice)46 STRINGLIB(find_slice)(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
47                      const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
48                      Py_ssize_t start, Py_ssize_t end)
49 {
50     return STRINGLIB(find)(str + start, end - start, sub, sub_len, start);
51 }
52 
53 Py_LOCAL_INLINE(Py_ssize_t)
STRINGLIB(rfind_slice)54 STRINGLIB(rfind_slice)(const STRINGLIB_CHAR* str, Py_ssize_t str_len,
55                       const STRINGLIB_CHAR* sub, Py_ssize_t sub_len,
56                       Py_ssize_t start, Py_ssize_t end)
57 {
58     return STRINGLIB(rfind)(str + start, end - start, sub, sub_len, start);
59 }
60 
61 #ifdef STRINGLIB_WANT_CONTAINS_OBJ
62 
63 Py_LOCAL_INLINE(int)
STRINGLIB(contains_obj)64 STRINGLIB(contains_obj)(PyObject* str, PyObject* sub)
65 {
66     return STRINGLIB(find)(
67         STRINGLIB_STR(str), STRINGLIB_LEN(str),
68         STRINGLIB_STR(sub), STRINGLIB_LEN(sub), 0
69         ) != -1;
70 }
71 
72 #endif /* STRINGLIB_WANT_CONTAINS_OBJ */
73 
74 /*
75 This function is a helper for the "find" family (find, rfind, index,
76 rindex) and for count, startswith and endswith, because they all have
77 the same behaviour for the arguments.
78 
79 It does not touch the variables received until it knows everything
80 is ok.
81 */
82 
83 #define FORMAT_BUFFER_SIZE 50
84 
85 Py_LOCAL_INLINE(int)
STRINGLIB(parse_args_finds)86 STRINGLIB(parse_args_finds)(const char * function_name, PyObject *args,
87                            PyObject **subobj,
88                            Py_ssize_t *start, Py_ssize_t *end)
89 {
90     PyObject *tmp_subobj;
91     Py_ssize_t tmp_start = 0;
92     Py_ssize_t tmp_end = PY_SSIZE_T_MAX;
93     PyObject *obj_start=Py_None, *obj_end=Py_None;
94     char format[FORMAT_BUFFER_SIZE] = "O|OO:";
95     size_t len = strlen(format);
96 
97     strncpy(format + len, function_name, FORMAT_BUFFER_SIZE - len - 1);
98     format[FORMAT_BUFFER_SIZE - 1] = '\0';
99 
100     if (!PyArg_ParseTuple(args, format, &tmp_subobj, &obj_start, &obj_end))
101         return 0;
102 
103     /* To support None in "start" and "end" arguments, meaning
104        the same as if they were not passed.
105     */
106     if (obj_start != Py_None)
107         if (!_PyEval_SliceIndex(obj_start, &tmp_start))
108             return 0;
109     if (obj_end != Py_None)
110         if (!_PyEval_SliceIndex(obj_end, &tmp_end))
111             return 0;
112 
113     *start = tmp_start;
114     *end = tmp_end;
115     *subobj = tmp_subobj;
116     return 1;
117 }
118 
119 #undef FORMAT_BUFFER_SIZE
120