Show More
@@ -0,0 +1,132 b'' | |||
|
1 | /* | |
|
2 | base85 codec | |
|
3 | ||
|
4 | Copyright 2006 Brendan Cully <brendan@kublai.com> | |
|
5 | ||
|
6 | This software may be used and distributed according to the terms of | |
|
7 | the GNU General Public License, incorporated herein by reference. | |
|
8 | ||
|
9 | Largely based on git's implementation | |
|
10 | */ | |
|
11 | ||
|
12 | #include <Python.h> | |
|
13 | ||
|
14 | static const char b85chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" | |
|
15 | "abcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~"; | |
|
16 | static char b85dec[256]; | |
|
17 | ||
|
18 | static void | |
|
19 | b85prep(void) | |
|
20 | { | |
|
21 | int i; | |
|
22 | ||
|
23 | memset(b85dec, 0, sizeof(b85dec)); | |
|
24 | for (i = 0; i < sizeof(b85chars); i++) | |
|
25 | b85dec[(int)(b85chars[i])] = i + 1; | |
|
26 | } | |
|
27 | ||
|
28 | static PyObject * | |
|
29 | b85encode(PyObject *self, PyObject *args) | |
|
30 | { | |
|
31 | const unsigned char *text; | |
|
32 | PyObject *out; | |
|
33 | char *dst; | |
|
34 | int len, olen, i; | |
|
35 | unsigned int acc, val, ch; | |
|
36 | ||
|
37 | if (!PyArg_ParseTuple(args, "s#", &text, &len)) | |
|
38 | return NULL; | |
|
39 | ||
|
40 | olen = (len + 3) / 4 * 5; | |
|
41 | if (!(out = PyString_FromStringAndSize(NULL, olen))) | |
|
42 | return NULL; | |
|
43 | ||
|
44 | dst = PyString_AS_STRING(out); | |
|
45 | ||
|
46 | while (len) | |
|
47 | { | |
|
48 | acc = 0; | |
|
49 | for (i = 24; i >= 0; i -= 8) { | |
|
50 | ch = *text++; | |
|
51 | acc |= ch << i; | |
|
52 | if (--len == 0) | |
|
53 | break; | |
|
54 | } | |
|
55 | for (i = 4; i >= 0; i--) { | |
|
56 | val = acc % 85; | |
|
57 | acc /= 85; | |
|
58 | dst[i] = b85chars[val]; | |
|
59 | } | |
|
60 | dst += 5; | |
|
61 | } | |
|
62 | ||
|
63 | return out; | |
|
64 | } | |
|
65 | ||
|
66 | static PyObject * | |
|
67 | b85decode(PyObject *self, PyObject *args) | |
|
68 | { | |
|
69 | PyObject *out; | |
|
70 | const char *text; | |
|
71 | char *dst; | |
|
72 | int len, i, j, olen, c; | |
|
73 | unsigned int acc; | |
|
74 | ||
|
75 | if (!PyArg_ParseTuple(args, "s#", &text, &len)) | |
|
76 | return NULL; | |
|
77 | ||
|
78 | olen = (len + 4) / 5 * 4; | |
|
79 | if (!(out = PyString_FromStringAndSize(NULL, olen))) | |
|
80 | return NULL; | |
|
81 | ||
|
82 | dst = PyString_AS_STRING(out); | |
|
83 | ||
|
84 | for (i = 1; len; i++) | |
|
85 | { | |
|
86 | acc = 0; | |
|
87 | for (j = 0; j < 4 && --len; j++) | |
|
88 | { | |
|
89 | c = b85dec[(int)*text++] - 1; | |
|
90 | if (c < 0) | |
|
91 | return PyErr_Format(PyExc_ValueError, "Bad base85 character at position %d", i); | |
|
92 | acc = acc * 85 + c; | |
|
93 | } | |
|
94 | if (len--) | |
|
95 | { | |
|
96 | c = b85dec[(int)*text++] - 1; | |
|
97 | if (c < 0) | |
|
98 | return PyErr_Format(PyExc_ValueError, "Bad base85 character at position %d", i); | |
|
99 | } | |
|
100 | else | |
|
101 | c = 0; | |
|
102 | /* overflow detection: 0xffffffff == "|NsC0", | |
|
103 | * "|NsC" == 0x03030303 */ | |
|
104 | if (acc > 0x03030303 || (acc *= 85) > 0xffffffff - c) | |
|
105 | return PyErr_Format(PyExc_ValueError, "Bad base85 sequence at position %d", i); | |
|
106 | ||
|
107 | acc += c; | |
|
108 | ||
|
109 | for (j = 0; j < 4; j++) | |
|
110 | { | |
|
111 | acc = (acc << 8) | (acc >> 24); | |
|
112 | *dst++ = (char)acc; | |
|
113 | } | |
|
114 | } | |
|
115 | ||
|
116 | return out; | |
|
117 | } | |
|
118 | ||
|
119 | static char base85_doc[] = "Base85 Data Encoding"; | |
|
120 | ||
|
121 | static PyMethodDef methods[] = { | |
|
122 | {"b85encode", b85encode, METH_VARARGS, "encode text in base85\n"}, | |
|
123 | {"b85decode", b85decode, METH_VARARGS, "decode base85 text\n"}, | |
|
124 | {NULL, NULL} | |
|
125 | }; | |
|
126 | ||
|
127 | PyMODINIT_FUNC initbase85(void) | |
|
128 | { | |
|
129 | Py_InitModule3("base85", methods, base85_doc); | |
|
130 | ||
|
131 | b85prep(); | |
|
132 | } |
@@ -89,7 +89,8 b" setup(name='mercurial'," | |||
|
89 | 89 | license='GNU GPL', |
|
90 | 90 | packages=['mercurial', 'mercurial.hgweb', 'hgext'], |
|
91 | 91 | ext_modules=[Extension('mercurial.mpatch', ['mercurial/mpatch.c']), |
|
92 |
Extension('mercurial.bdiff', ['mercurial/bdiff.c']) |
|
|
92 | Extension('mercurial.bdiff', ['mercurial/bdiff.c']), | |
|
93 | Extension('mercurial.base85', ['mercurial/base85.c'])], | |
|
93 | 94 | data_files=[(os.path.join('mercurial', root), |
|
94 | 95 | [os.path.join(root, file_) for file_ in files]) |
|
95 | 96 | for root, dirs, files in os.walk('templates')], |
General Comments 0
You need to be logged in to leave comments.
Login now