-# Written by Petru Paler
-# see LICENSE.txt for license information
-from types import IntType, LongType, StringType, ListType, TupleType, DictType
-from re import compile
-from cStringIO import StringIO
+"""Functions for bencoding and bdecoding data.
-int_filter = compile('(0|-?[1-9][0-9]*)e')
+@type decode_func: C{dictionary} of C{function}
+@var decode_func: a dictionary of function calls to be made, based on data,
+ the keys are the first character of the data and the value is the
+ function to use to decode that data
+@type bencached_marker: C{list}
+@var bencached_marker: mutable type to ensure class origination
+@type encode_func: C{dictionary} of C{function}
+@var encode_func: a dictionary of function calls to be made, based on data,
+ the keys are the type of the data and the value is the
+ function to use to encode that data
+@type BencachedType: C{type}
+@var BencachedType: the L{Bencached} type
+"""
-def decode_int(x, f):
- m = int_filter.match(x, f)
- if m is None:
- raise ValueError
- return (long(m.group(1)), m.end())
+from types import IntType, LongType, StringType, ListType, TupleType, DictType, BooleanType
+try:
+ from types import UnicodeType
+except ImportError:
+ UnicodeType = None
+from datetime import datetime
+import time
+
+from twisted.python import log
+from twisted.trial import unittest
-string_filter = compile('(0|[1-9][0-9]*):')
+class BencodeError(ValueError):
+ pass
+def decode_int(x, f):
+ """Bdecode an integer.
+
+ @type x: C{string}
+ @param x: the data to decode
+ @type f: C{int}
+ @param f: the offset in the data to start at
+ @rtype: C{int}, C{int}
+ @return: the bdecoded integer, and the offset to read next
+ @raise BencodeError: if the data is improperly encoded
+
+ """
+
+ f += 1
+ newf = x.index('e', f)
+ try:
+ n = int(x[f:newf])
+ except:
+ n = long(x[f:newf])
+ if x[f] == '-':
+ if x[f + 1] == '0':
+ raise BencodeError, "integer has a leading zero after a negative sign"
+ elif x[f] == '0' and newf != f+1:
+ raise BencodeError, "integer has a leading zero"
+ return (n, newf+1)
+
def decode_string(x, f):
- m = string_filter.match(x, f)
- if m is None:
- raise ValueError
- l = int(m.group(1))
- s = m.end()
- return (x[s:s+l], s + l)
+ """Bdecode a string.
+
+ @type x: C{string}
+ @param x: the data to decode
+ @type f: C{int}
+ @param f: the offset in the data to start at
+ @rtype: C{string}, C{int}
+ @return: the bdecoded string, and the offset to read next
+ @raise BencodeError: if the data is improperly encoded
+
+ """
+
+ colon = x.index(':', f)
+ try:
+ n = int(x[f:colon])
+ except (OverflowError, ValueError):
+ n = long(x[f:colon])
+ if x[f] == '0' and colon != f+1:
+ raise BencodeError, "string length has a leading zero"
+ colon += 1
+ return (x[colon:colon+n], colon+n)
+
+def decode_unicode(x, f):
+ """Bdecode a unicode string.
+
+ @type x: C{string}
+ @param x: the data to decode
+ @type f: C{int}
+ @param f: the offset in the data to start at
+ @rtype: C{int}, C{int}
+ @return: the bdecoded unicode string, and the offset to read next
+
+ """
+
+ s, f = decode_string(x, f+1)
+ return (s.decode('UTF-8'),f)
+def decode_datetime(x, f):
+ """Bdecode a datetime value.
+
+ @type x: C{string}
+ @param x: the data to decode
+ @type f: C{int}
+ @param f: the offset in the data to start at
+ @rtype: C{datetime.datetime}, C{int}
+ @return: the bdecoded integer, and the offset to read next
+ @raise BencodeError: if the data is improperly encoded
+
+ """
+
+ f += 1
+ newf = x.index('e', f)
+ try:
+ date = datetime(*(time.strptime(x[f:newf], '%Y-%m-%dT%H:%M:%S')[0:6]))
+ except:
+ raise BencodeError, "datetime value could not be decoded: %s" % x[f:newf]
+ return (date, newf+1)
+
def decode_list(x, f):
- r = []
+ """Bdecode a list.
+
+ @type x: C{string}
+ @param x: the data to decode
+ @type f: C{int}
+ @param f: the offset in the data to start at
+ @rtype: C{list}, C{int}
+ @return: the bdecoded list, and the offset to read next
+
+ """
+
+ r, f = [], f+1
while x[f] != 'e':
- v, f = bdecode_rec(x, f)
+ v, f = decode_func[x[f]](x, f)
r.append(v)
return (r, f + 1)
def decode_dict(x, f):
- r = {}
+ """Bdecode a dictionary.
+
+ @type x: C{string}
+ @param x: the data to decode
+ @type f: C{int}
+ @param f: the offset in the data to start at
+ @rtype: C{dictionary}, C{int}
+ @return: the bdecoded dictionary, and the offset to read next
+ @raise BencodeError: if the data is improperly encoded
+
+ """
+
+ r, f = {}, f+1
lastkey = None
while x[f] != 'e':
k, f = decode_string(x, f)
- if lastkey is not None and lastkey >= k:
- raise ValueError
+ if lastkey >= k:
+ raise BencodeError, "dictionary keys must be in sorted order"
lastkey = k
- v, f = bdecode_rec(x, f)
- r[k] = v
+ r[k], f = decode_func[x[f]](x, f)
return (r, f + 1)
-def bdecode_rec(x, f):
- t = x[f]
- if t == 'i':
- return decode_int(x, f + 1)
- elif t == 'l':
- return decode_list(x, f + 1)
- elif t == 'd':
- return decode_dict(x, f + 1)
- else:
- return decode_string(x, f)
-
-def bdecode(x):
+decode_func = {}
+decode_func['l'] = decode_list
+decode_func['d'] = decode_dict
+decode_func['i'] = decode_int
+decode_func['0'] = decode_string
+decode_func['1'] = decode_string
+decode_func['2'] = decode_string
+decode_func['3'] = decode_string
+decode_func['4'] = decode_string
+decode_func['5'] = decode_string
+decode_func['6'] = decode_string
+decode_func['7'] = decode_string
+decode_func['8'] = decode_string
+decode_func['9'] = decode_string
+decode_func['u'] = decode_unicode
+decode_func['t'] = decode_datetime
+
+def bdecode(x, sloppy = 0):
+ """Bdecode a string of data.
+
+ @type x: C{string}
+ @param x: the data to decode
+ @type sloppy: C{boolean}
+ @param sloppy: whether to allow errors in the decoding
+ @rtype: unknown
+ @return: the bdecoded data
+ @raise BencodeError: if the data is improperly encoded
+
+ """
+
try:
- r, l = bdecode_rec(x, 0)
- except IndexError:
- raise ValueError
- if l != len(x):
- raise ValueError
+ r, l = decode_func[x[0]](x, 0)
+# except (IndexError, KeyError):
+ except (IndexError, KeyError, ValueError):
+ raise BencodeError, "bad bencoded data"
+ if not sloppy and l != len(x):
+ raise BencodeError, "bad bencoded data, all could not be decoded"
return r
-def test_bdecode():
- try:
- bdecode('0:0:')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('ie')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('i341foo382e')
- assert 0
- except ValueError:
- pass
- assert bdecode('i4e') == 4L
- assert bdecode('i0e') == 0L
- assert bdecode('i123456789e') == 123456789L
- assert bdecode('i-10e') == -10L
- try:
- bdecode('i-0e')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('i123')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('i6easd')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('35208734823ljdahflajhdf')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('2:abfdjslhfld')
- assert 0
- except ValueError:
- pass
- assert bdecode('0:') == ''
- assert bdecode('3:abc') == 'abc'
- assert bdecode('10:1234567890') == '1234567890'
- try:
- bdecode('02:xy')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('l')
- assert 0
- except ValueError:
- pass
- assert bdecode('le') == []
- try:
- bdecode('leanfdldjfh')
- assert 0
- except ValueError:
- pass
- assert bdecode('l0:0:0:e') == ['', '', '']
- try:
- bdecode('relwjhrlewjh')
- assert 0
- except ValueError:
- pass
- assert bdecode('li1ei2ei3ee') == [1, 2, 3]
- assert bdecode('l3:asd2:xye') == ['asd', 'xy']
- assert bdecode('ll5:Alice3:Bobeli2ei3eee') == [['Alice', 'Bob'], [2, 3]]
- try:
- bdecode('d')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('defoobar')
- assert 0
- except ValueError:
- pass
- assert bdecode('de') == {}
- assert bdecode('d3:agei25e4:eyes4:bluee') == {'age': 25, 'eyes': 'blue'}
- assert bdecode('d8:spam.mp3d6:author5:Alice6:lengthi100000eee') == {'spam.mp3': {'author': 'Alice', 'length': 100000}}
- try:
- bdecode('d3:fooe')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('di1e0:e')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('d1:b0:1:a0:e')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('d1:a0:1:a0:e')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('i03e')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('l01:ae')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('9999:x')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('l0:')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('d0:0:')
- assert 0
- except ValueError:
- pass
- try:
- bdecode('d0:')
- assert 0
- except ValueError:
- pass
-
-def bencode_rec(x, b):
- t = type(x)
- if t in (IntType, LongType):
- b.write('i%de' % x)
- elif t is StringType:
- b.write('%d:%s' % (len(x), x))
- elif t in (ListType, TupleType):
- b.write('l')
- for e in x:
- bencode_rec(e, b)
- b.write('e')
- elif t is DictType:
- b.write('d')
- keylist = x.keys()
- keylist.sort()
- for k in keylist:
- assert type(k) is StringType
- bencode_rec(k, b)
- bencode_rec(x[k], b)
- b.write('e')
+bencached_marker = []
+
+class Bencached:
+ """Dummy data structure for storing bencoded data in memory.
+
+ @type marker: C{list}
+ @ivar marker: mutable type to make sure the data was encoded by this class
+ @type bencoded: C{string}
+ @ivar bencoded: the bencoded data stored in a string
+
+ """
+
+ def __init__(self, s):
+ """
+
+ @type s: C{string}
+ @param s: the new bencoded data to store
+
+ """
+
+ self.marker = bencached_marker
+ self.bencoded = s
+
+BencachedType = type(Bencached('')) # insufficient, but good as a filter
+
+def encode_bencached(x,r):
+ """Bencode L{Bencached} data.
+
+ @type x: L{Bencached}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ assert x.marker == bencached_marker
+ r.append(x.bencoded)
+
+def encode_int(x,r):
+ """Bencode an integer.
+
+ @type x: C{int}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ r.extend(('i',str(x),'e'))
+
+def encode_bool(x,r):
+ """Bencode a boolean.
+
+ @type x: C{boolean}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ encode_int(int(x),r)
+
+def encode_string(x,r):
+ """Bencode a string.
+
+ @type x: C{string}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ r.extend((str(len(x)),':',x))
+
+def encode_unicode(x,r):
+ """Bencode a unicode string.
+
+ @type x: C{unicode}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ #r.append('u')
+ encode_string(x.encode('UTF-8'),r)
+
+def encode_datetime(x,r):
+ """Bencode a datetime value in UTC.
+
+ If the datetime object has time zone info, it is converted to UTC time.
+ Otherwise it is assumed that the time is already in UTC time.
+ Microseconds are removed.
+
+ @type x: C{datetime.datetime}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ date = x.replace(microsecond = 0)
+ offset = date.utcoffset()
+ if offset is not None:
+ utcdate = date.replace(tzinfo = None) + offset
else:
- assert 0
+ utcdate = date
+ r.extend(('t',utcdate.isoformat(),'e'))
+
+def encode_list(x,r):
+ """Bencode a list.
+
+ @type x: C{list}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ r.append('l')
+ for e in x:
+ encode_func[type(e)](e, r)
+ r.append('e')
+
+def encode_dict(x,r):
+ """Bencode a dictionary.
+
+ @type x: C{dictionary}
+ @param x: the data to encode
+ @type r: C{list}
+ @param r: the currently bencoded data, to which the bencoding of x
+ will be appended
+
+ """
+
+ r.append('d')
+ ilist = 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 = {}
+encode_func[BencachedType] = encode_bencached
+encode_func[IntType] = encode_int
+encode_func[LongType] = encode_int
+encode_func[StringType] = encode_string
+encode_func[ListType] = encode_list
+encode_func[TupleType] = encode_list
+encode_func[DictType] = encode_dict
+encode_func[BooleanType] = encode_bool
+encode_func[datetime] = encode_datetime
+if UnicodeType:
+ encode_func[UnicodeType] = encode_unicode
+
def bencode(x):
- b = StringIO()
- bencode_rec(x, b)
- return b.getvalue()
-
-def test_bencode():
- assert bencode(4) == 'i4e'
- assert bencode(0) == 'i0e'
- assert bencode(-10) == 'i-10e'
- assert bencode(12345678901234567890L) == 'i12345678901234567890e'
- assert bencode('') == '0:'
- assert bencode('abc') == '3:abc'
- assert bencode('1234567890') == '10:1234567890'
- assert bencode([]) == 'le'
- assert bencode([1, 2, 3]) == 'li1ei2ei3ee'
- assert bencode([['Alice', 'Bob'], [2, 3]]) == 'll5:Alice3:Bobeli2ei3eee'
- assert bencode({}) == 'de'
- assert bencode({'age': 25, 'eyes': 'blue'}) == 'd3:agei25e4:eyes4:bluee'
- assert bencode({'spam.mp3': {'author': 'Alice', 'length': 100000}}) == 'd8:spam.mp3d6:author5:Alice6:lengthi100000eee'
+ """Bencode some data.
+
+ @type x: unknown
+ @param x: the data to encode
+ @rtype: string
+ @return: the bencoded data
+ @raise BencodeError: if the data contains a type that cannot be encoded
+
+ """
+ r = []
try:
- bencode({1: 'foo'})
- assert 0
- except AssertionError:
- pass
+ encode_func[type(x)](x, r)
+ except:
+ raise BencodeError, "failed to bencode the data"
+ return ''.join(r)
+
+class TestBencode(unittest.TestCase):
+ """Test the bencoding and bdecoding of data."""
+
+ timeout = 2
+
+ def test_bdecode_string(self):
+ self.failUnlessRaises(BencodeError, bdecode, '0:0:')
+ self.failUnlessRaises(BencodeError, bdecode, '')
+ self.failUnlessRaises(BencodeError, bdecode, '35208734823ljdahflajhdf')
+ self.failUnlessRaises(BencodeError, bdecode, '2:abfdjslhfld')
+ self.failUnlessEqual(bdecode('0:'), '')
+ self.failUnlessEqual(bdecode('3:abc'), 'abc')
+ self.failUnlessEqual(bdecode('10:1234567890'), '1234567890')
+ self.failUnlessRaises(BencodeError, bdecode, '02:xy')
+ self.failUnlessRaises(BencodeError, bdecode, '9999:x')
+
+ def test_bdecode_int(self):
+ self.failUnlessRaises(BencodeError, bdecode, 'ie')
+ self.failUnlessRaises(BencodeError, bdecode, 'i341foo382e')
+ self.failUnlessEqual(bdecode('i4e'), 4L)
+ self.failUnlessEqual(bdecode('i0e'), 0L)
+ self.failUnlessEqual(bdecode('i123456789e'), 123456789L)
+ self.failUnlessEqual(bdecode('i-10e'), -10L)
+ self.failUnlessRaises(BencodeError, bdecode, 'i-0e')
+ self.failUnlessRaises(BencodeError, bdecode, 'i123')
+ self.failUnlessRaises(BencodeError, bdecode, 'i6easd')
+ self.failUnlessRaises(BencodeError, bdecode, 'i03e')
+
+ def test_bdecode_list(self):
+ self.failUnlessRaises(BencodeError, bdecode, 'l')
+ self.failUnlessEqual(bdecode('le'), [])
+ self.failUnlessRaises(BencodeError, bdecode, 'leanfdldjfh')
+ self.failUnlessEqual(bdecode('l0:0:0:e'), ['', '', ''])
+ self.failUnlessRaises(BencodeError, bdecode, 'relwjhrlewjh')
+ self.failUnlessEqual(bdecode('li1ei2ei3ee'), [1, 2, 3])
+ self.failUnlessEqual(bdecode('l3:asd2:xye'), ['asd', 'xy'])
+ self.failUnlessEqual(bdecode('ll5:Alice3:Bobeli2ei3eee'), [['Alice', 'Bob'], [2, 3]])
+ self.failUnlessRaises(BencodeError, bdecode, 'l01:ae')
+ self.failUnlessRaises(BencodeError, bdecode, 'l0:')
+
+ def test_bdecode_dict(self):
+ self.failUnlessRaises(BencodeError, bdecode, 'd')
+ self.failUnlessRaises(BencodeError, bdecode, 'defoobar')
+ self.failUnlessEqual(bdecode('de'), {})
+ self.failUnlessEqual(bdecode('d3:agei25e4:eyes4:bluee'), {'age': 25, 'eyes': 'blue'})
+ self.failUnlessEqual(bdecode('d8:spam.mp3d6:author5:Alice6:lengthi100000eee'),
+ {'spam.mp3': {'author': 'Alice', 'length': 100000}})
+ self.failUnlessRaises(BencodeError, bdecode, 'd3:fooe')
+ self.failUnlessRaises(BencodeError, bdecode, 'di1e0:e')
+ self.failUnlessRaises(BencodeError, bdecode, 'd1:b0:1:a0:e')
+ self.failUnlessRaises(BencodeError, bdecode, 'd1:a0:1:a0:e')
+ self.failUnlessRaises(BencodeError, bdecode, 'd0:0:')
+ self.failUnlessRaises(BencodeError, bdecode, 'd0:')
+
+ def test_bdecode_unicode(self):
+ self.failUnlessRaises(BencodeError, bdecode, 'u0:0:')
+ self.failUnlessRaises(BencodeError, bdecode, 'u')
+ self.failUnlessRaises(BencodeError, bdecode, 'u35208734823ljdahflajhdf')
+ self.failUnlessRaises(BencodeError, bdecode, 'u2:abfdjslhfld')
+ self.failUnlessEqual(bdecode('u0:'), '')
+ self.failUnlessEqual(bdecode('u3:abc'), 'abc')
+ self.failUnlessEqual(bdecode('u10:1234567890'), '1234567890')
+ self.failUnlessRaises(BencodeError, bdecode, 'u02:xy')
+ self.failUnlessRaises(BencodeError, bdecode, 'u9999:x')
+
+ def test_bencode_int(self):
+ self.failUnlessEqual(bencode(4), 'i4e')
+ self.failUnlessEqual(bencode(0), 'i0e')
+ self.failUnlessEqual(bencode(-10), 'i-10e')
+ self.failUnlessEqual(bencode(12345678901234567890L), 'i12345678901234567890e')
+
+ def test_bencode_string(self):
+ self.failUnlessEqual(bencode(''), '0:')
+ self.failUnlessEqual(bencode('abc'), '3:abc')
+ self.failUnlessEqual(bencode('1234567890'), '10:1234567890')
+
+ def test_bencode_list(self):
+ self.failUnlessEqual(bencode([]), 'le')
+ self.failUnlessEqual(bencode([1, 2, 3]), 'li1ei2ei3ee')
+ self.failUnlessEqual(bencode([['Alice', 'Bob'], [2, 3]]), 'll5:Alice3:Bobeli2ei3eee')
+
+ def test_bencode_dict(self):
+ self.failUnlessEqual(bencode({}), 'de')
+ self.failUnlessEqual(bencode({'age': 25, 'eyes': 'blue'}), 'd3:agei25e4:eyes4:bluee')
+ self.failUnlessEqual(bencode({'spam.mp3': {'author': 'Alice', 'length': 100000}}),
+ 'd8:spam.mp3d6:author5:Alice6:lengthi100000eee')
+ self.failUnlessRaises(BencodeError, bencode, {1: 'foo'})
+
+ def test_bencode_unicode(self):
+ self.failUnlessEqual(bencode(u''), '0:')
+ self.failUnlessEqual(bencode(u'abc'), '3:abc')
+ self.failUnlessEqual(bencode(u'1234567890'), '10:1234567890')
+
+ def test_bool(self):
+ self.failUnless(bdecode(bencode(True)))
+ self.failIf(bdecode(bencode(False)))
+
+ def test_datetime(self):
+ date = datetime.utcnow()
+ self.failUnlessEqual(bdecode(bencode(date)), date.replace(microsecond = 0))
+ if UnicodeType == None:
+ test_bencode_unicode.skip = "Python was not compiled with unicode support"
+ test_bdecode_unicode.skip = "Python was not compiled with unicode support"
projects / quix0rs-apt-p2p.git / blobdiff