torrent_file/bencode_py3.py - master - ilya.petrash/SimplePyScripts

torrent_file/bencode_py3.py
160 строк3 KB
Ilya Petrash
get_info_from_torrent_file.py -> torrent_file
30 янв 2017, 20:54
30 янв 2017, 20:548f21489
# The contents of this file are subject to the BitTorrent Open Source License
# Version 1.1 (the License).  You may not copy or use this file, in either
# source code or executable form, except in compliance with the License.  You
# may obtain a copy of the License at http://www.bittorrent.com/license/.
#
# Software distributed under the License is distributed on an AS IS basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the License
# for the specific language governing rights and limitations under the
# License.

# Written by Petru Paler


# SOURCE: https://pypi.python.org/pypi/BitTorrent-bencode
# Modify file for using on python 3


class BTFailure(Exception):
    pass


def decode_int(x, f):
    f += 1
    newf = x.index('e', f)
    n = int(x[f:newf])
    if x[f] == '-':
        if x[f + 1] == '0':
            raise ValueError
    elif x[f] == '0' and newf != f+1:
        raise ValueError
    return n, newf+1


def decode_string(x, f):
    colon = x.index(':', f)
    n = int(x[f:colon])
    if x[f] == '0' and colon != f+1:
        raise ValueError
    colon += 1
    return x[colon:colon+n], colon+n


def decode_list(x, f):
    r, f = [], f+1
    while x[f] != 'e':
        v, f = decode_func[x[f]](x, f)
        r.append(v)
    return r, f + 1


def decode_dict(x, f):
    r, f = {}, f+1
    while x[f] != 'e':
        k, f = decode_string(x, f)
        r[k], f = decode_func[x[f]](x, f)
    return r, f + 1


decode_func = {
    'l': decode_list,
    'd': decode_dict,
    'i': decode_int,
    '0': decode_string,
    '1': decode_string,
    '2': decode_string,
    '3': decode_string,
    '4': decode_string,
    '5': decode_string,
    '6': decode_string,
    '7': decode_string,
    '8': decode_string,
    '9': decode_string
}


def bdecode(x):
    try:
        r, l = decode_func[x[0]](x, 0)
    except (IndexError, KeyError, ValueError):
        raise BTFailure("not a valid bencoded string")
    if l != len(x):
        raise BTFailure("invalid bencoded value (data after valid prefix)")
    return r

try:
    from types import StringType, IntType, LongType, DictType, ListType, TupleType
except:
    StringType = str
    IntType = int
    LongType = int
    DictType = dict
    ListType = list
    TupleType = tuple


class Bencached(object):
    __slots__ = ['bencoded']

    def __init__(self, s):
        self.bencoded = s


def encode_bencached(x,r):
    r.append(x.bencoded)


def encode_int(x, r):
    r.extend(('i', str(x), 'e'))


def encode_string(x, r):
    r.extend((str(len(x)), ':', x))


def encode_list(x, r):
    r.append('l')
    for i in x:
        encode_func[type(i)](i, r)
    r.append('e')


def encode_dict(x,r):
    r.append('d')
    ilist = list(x.items())
    ilist.sort()
    for k, v in ilist:
        r.extend((str(len(k)), ':', k))
        encode_func[type(v)](v, r)
    r.append('e')


encode_func = {
    Bencached: encode_bencached,
    IntType: encode_int,
    LongType: encode_int,
    StringType: encode_string,
    ListType: encode_list,
    TupleType: encode_list,
    DictType: encode_dict,
}

try:
    try:
        from types import BooleanType
    except:
        BooleanType = bool

    def encode_bool(x, r):
        encode_int(1 if x else 0, r)

    encode_func[BooleanType] = encode_bool

except:
    pass


def bencode(x):
    r = []
    encode_func[type(x)](x, r)
    return ''.join(r)