summaryrefslogtreecommitdiff
path: root/sleekxmpp/util/misc_ops.py
blob: 18c919a857478326ac0614ed0fddfa908a677ef2 (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
import sys
import hashlib


def unicode(text):
    if sys.version_info < (3, 0):
        if isinstance(text, str):
            text = text.decode('utf-8')
        import __builtin__
        return __builtin__.unicode(text)
    elif not isinstance(text, str):
        return text.decode('utf-8')
    else:
        return text


def bytes(text):
    """
    Convert Unicode text to UTF-8 encoded bytes.

    Since Python 2.6+ and Python 3+ have similar but incompatible
    signatures, this function unifies the two to keep code sane.

    :param text: Unicode text to convert to bytes
    :rtype: bytes (Python3), str (Python2.6+)
    """
    if text is None:
        return b''

    if sys.version_info < (3, 0):
        import __builtin__
        return __builtin__.bytes(text)
    else:
        import builtins
        if isinstance(text, builtins.bytes):
            # We already have bytes, so do nothing
            return text
        if isinstance(text, list):
            # Convert a list of integers to bytes
            return builtins.bytes(text)
        else:
            # Convert UTF-8 text to bytes
            return builtins.bytes(text, encoding='utf-8')


def quote(text):
    """
    Enclose in quotes and escape internal slashes and double quotes.

    :param text: A Unicode or byte string.
    """
    text = bytes(text)
    return b'"' + text.replace(b'\\', b'\\\\').replace(b'"', b'\\"') + b'"'


def num_to_bytes(num):
    """
    Convert an integer into a four byte sequence.

    :param integer num: An integer to convert to its byte representation.
    """
    bval = b''
    bval += bytes(chr(0xFF & (num >> 24)))
    bval += bytes(chr(0xFF & (num >> 16)))
    bval += bytes(chr(0xFF & (num >> 8)))
    bval += bytes(chr(0xFF & (num >> 0)))
    return bval


def bytes_to_num(bval):
    """
    Convert a four byte sequence to an integer.

    :param bytes bval: A four byte sequence to turn into an integer.
    """
    num = 0
    num += ord(bval[0] << 24)
    num += ord(bval[1] << 16)
    num += ord(bval[2] << 8)
    num += ord(bval[3])
    return num


def XOR(x, y):
    """
    Return the results of an XOR operation on two equal length byte strings.

    :param bytes x: A byte string
    :param bytes y: A byte string
    :rtype: bytes
    """
    result = b''
    for a, b in zip(x, y):
        if sys.version_info < (3, 0):
            result += chr((ord(a) ^ ord(b)))
        else:
            result += bytes([a ^ b])
    return result


def hash(name):
    """
    Return a hash function implementing the given algorithm.

    :param name: The name of the hashing algorithm to use.
    :type name: string

    :rtype: function
    """
    name = name.lower()
    if name.startswith('sha-'):
        name = 'sha' + name[4:]
    if name in dir(hashlib):
        return getattr(hashlib, name)
    return None


def hashes():
    """
    Return a list of available hashing algorithms.

    :rtype: list of strings
    """
    t = []
    if 'md5' in dir(hashlib):
        t = ['MD5']
    if 'md2' in dir(hashlib):
        t += ['MD2']
    hashes = ['SHA-' + h[3:] for h in dir(hashlib) if h.startswith('sha')]
    return t + hashes


def setdefaultencoding(encoding):
    """
    Set the current default string encoding used by the Unicode implementation.

    Actually calls sys.setdefaultencoding under the hood - see the docs for that
    for more details.  This method exists only as a way to call find/call it
    even after it has been 'deleted' when the site module is executed.

    :param string encoding: An encoding name, compatible with sys.setdefaultencoding
    """
    func = getattr(sys, 'setdefaultencoding', None)
    if func is None:
        import gc
        import types
        for obj in gc.get_objects():
            if (isinstance(obj, types.BuiltinFunctionType)
                    and obj.__name__ == 'setdefaultencoding'):
                func = obj
                break
        if func is None:
            raise RuntimeError("Could not find setdefaultencoding")
        sys.setdefaultencoding = func
    return func(encoding)


def safedict(data):
    if sys.version_info < (2, 7):
        safe = {}
        for key in data:
            safe[key.encode('utf8')] = data[key]
        return safe
    else:
        return data