aboutsummaryrefslogtreecommitdiff
blob: b74e57ad913b11109f32f7a183e932836a784696 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
/* bytes to hex implementation */

#include "Python.h"

#include "pystrhex.h"

static PyObject *_Py_strhex_impl(const char* argbuf, const Py_ssize_t arglen,
                                 const PyObject* sep, int bytes_per_sep_group,
                                 const int return_bytes)
{
    assert(arglen >= 0);

    Py_UCS1 sep_char = 0;
    if (sep) {
        Py_ssize_t seplen = PyObject_Length((PyObject*)sep);
        if (seplen < 0) {
            return NULL;
        }
        if (seplen != 1) {
            PyErr_SetString(PyExc_ValueError, "sep must be length 1.");
            return NULL;
        }
        if (PyUnicode_Check(sep)) {
            if (PyUnicode_READY(sep))
                return NULL;
            if (PyUnicode_KIND(sep) != PyUnicode_1BYTE_KIND) {
                PyErr_SetString(PyExc_ValueError, "sep must be ASCII.");
                return NULL;
            }
            sep_char = PyUnicode_READ_CHAR(sep, 0);
        }
        else if (PyBytes_Check(sep)) {
            sep_char = PyBytes_AS_STRING(sep)[0];
        }
        else {
            PyErr_SetString(PyExc_TypeError, "sep must be str or bytes.");
            return NULL;
        }
        if (sep_char > 127 && !return_bytes) {
            PyErr_SetString(PyExc_ValueError, "sep must be ASCII.");
            return NULL;
        }
    }
    else {
        bytes_per_sep_group = 0;
    }

    unsigned int abs_bytes_per_sep = abs(bytes_per_sep_group);
    Py_ssize_t resultlen = 0;
    if (bytes_per_sep_group && arglen > 0) {
        /* How many sep characters we'll be inserting. */
        resultlen = (arglen - 1) / abs_bytes_per_sep;
    }
    /* Bounds checking for our Py_ssize_t indices. */
    if (arglen >= PY_SSIZE_T_MAX / 2 - resultlen) {
        return PyErr_NoMemory();
    }
    resultlen += arglen * 2;

    if ((size_t)abs_bytes_per_sep >= (size_t)arglen) {
        bytes_per_sep_group = 0;
        abs_bytes_per_sep = 0;
    }

    PyObject *retval;
    Py_UCS1 *retbuf;
    if (return_bytes) {
        /* If _PyBytes_FromSize() were public we could avoid malloc+copy. */
        retval = PyBytes_FromStringAndSize(NULL, resultlen);
        if (!retval) {
            return NULL;
        }
        retbuf = (Py_UCS1 *)PyBytes_AS_STRING(retval);
    }
    else {
        retval = PyUnicode_New(resultlen, 127);
        if (!retval) {
            return NULL;
        }
        retbuf = PyUnicode_1BYTE_DATA(retval);
    }

    /* Hexlify */
    Py_ssize_t i, j;
    unsigned char c;

    if (bytes_per_sep_group == 0) {
        for (i = j = 0; i < arglen; ++i) {
            assert((j + 1) < resultlen);
            c = argbuf[i];
            retbuf[j++] = Py_hexdigits[c >> 4];
            retbuf[j++] = Py_hexdigits[c & 0x0f];
        }
        assert(j == resultlen);
    }
    else {
        /* The number of complete chunk+sep periods */
        Py_ssize_t chunks = (arglen - 1) / abs_bytes_per_sep;
        Py_ssize_t chunk;
        unsigned int k;

        if (bytes_per_sep_group < 0) {
            i = j = 0;
            for (chunk = 0; chunk < chunks; chunk++) {
                for (k = 0; k < abs_bytes_per_sep; k++) {
                    c = argbuf[i++];
                    retbuf[j++] = Py_hexdigits[c >> 4];
                    retbuf[j++] = Py_hexdigits[c & 0x0f];
                }
                retbuf[j++] = sep_char;
            }
            while (i < arglen) {
                c = argbuf[i++];
                retbuf[j++] = Py_hexdigits[c >> 4];
                retbuf[j++] = Py_hexdigits[c & 0x0f];
            }
            assert(j == resultlen);
        }
        else {
            i = arglen - 1;
            j = resultlen - 1;
            for (chunk = 0; chunk < chunks; chunk++) {
                for (k = 0; k < abs_bytes_per_sep; k++) {
                    c = argbuf[i--];
                    retbuf[j--] = Py_hexdigits[c & 0x0f];
                    retbuf[j--] = Py_hexdigits[c >> 4];
                }
                retbuf[j--] = sep_char;
            }
            while (i >= 0) {
                c = argbuf[i--];
                retbuf[j--] = Py_hexdigits[c & 0x0f];
                retbuf[j--] = Py_hexdigits[c >> 4];
            }
            assert(j == -1);
        }
    }

#ifdef Py_DEBUG
    if (!return_bytes) {
        assert(_PyUnicode_CheckConsistency(retval, 1));
    }
#endif

    return retval;
}

PyObject * _Py_strhex(const char* argbuf, const Py_ssize_t arglen)
{
    return _Py_strhex_impl(argbuf, arglen, NULL, 0, 0);
}

/* Same as above but returns a bytes() instead of str() to avoid the
 * need to decode the str() when bytes are needed. */
PyObject * _Py_strhex_bytes(const char* argbuf, const Py_ssize_t arglen)
{
    return _Py_strhex_impl(argbuf, arglen, NULL, 0, 1);
}

/* These variants include support for a separator between every N bytes: */

PyObject * _Py_strhex_with_sep(const char* argbuf, const Py_ssize_t arglen, const PyObject* sep, const int bytes_per_group)
{
    return _Py_strhex_impl(argbuf, arglen, sep, bytes_per_group, 0);
}

/* Same as above but returns a bytes() instead of str() to avoid the
 * need to decode the str() when bytes are needed. */
PyObject * _Py_strhex_bytes_with_sep(const char* argbuf, const Py_ssize_t arglen, const PyObject* sep, const int bytes_per_group)
{
    return _Py_strhex_impl(argbuf, arglen, sep, bytes_per_group, 1);
}