Rev 2231: add bencode utility in file:///home/mbp/bzr/Work/tags/

Martin Pool mbp at sourcefrog.net
Tue Feb 20 04:47:57 GMT 2007


------------------------------------------------------------
revno: 2231
revision-id: mbp at sourcefrog.net-20070220044754-ptovhd212hs4vkkf
parent: mbp at sourcefrog.net-20070212071826-5x37ixz8r6cylk75
committer: Martin Pool <mbp at sourcefrog.net>
branch nick: tags
timestamp: Tue 2007-02-20 15:47:54 +1100
message:
  add bencode utility
added:
  bzrlib/util/bencode.py         bencode.py-20070220044742-sltr28q21w2wzlxi-1
=== added file 'bzrlib/util/bencode.py'
--- a/bzrlib/util/bencode.py	1970-01-01 00:00:00 +0000
+++ b/bzrlib/util/bencode.py	2007-02-20 04:47:54 +0000
@@ -0,0 +1,328 @@
+# bencode structured encoding
+#
+# Written by Petru Paler
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+# 
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+# 
+# The Software is provided "AS IS", without warranty of any kind,
+# express or implied, including but not limited to the warranties of
+# merchantability,  fitness for a particular purpose and
+# noninfringement. In no event shall the  authors or copyright holders
+# be liable for any claim, damages or other liability, whether in an
+# action of contract, tort or otherwise, arising from, out of or in
+# connection with the Software or the use or other dealings in the
+# Software.
+
+def decode_int(x, f):
+    f += 1
+    newf = x.index('e', f)
+    try:
+        n = int(x[f:newf])
+    except (OverflowError, ValueError):
+        n = long(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)
+    try:
+        n = int(x[f:colon])
+    except (OverflowError, ValueError):
+        n = long(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
+    lastkey = None
+    while x[f] != 'e':
+        k, f = decode_string(x, f)
+        if lastkey >= k:
+            raise ValueError
+        lastkey = k
+        r[k], f = decode_func[x[f]](x, f)
+    return (r, f + 1)
+
+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
+
+def bdecode(x):
+    try:
+        r, l = decode_func[x[0]](x, 0)
+    except (IndexError, KeyError):
+        raise ValueError
+    if l != len(x):
+        raise ValueError
+    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
+    try:
+        bdecode('00:')
+        assert 0
+    except ValueError:
+        pass
+    try:
+        bdecode('l-3:e')
+        assert 0
+    except ValueError:
+        pass
+    try:
+        bdecode('i-03e')
+        assert 0
+    except ValueError:
+        pass
+    bdecode('d0:i3ee')
+
+from types import StringType, IntType, LongType, DictType, ListType, TupleType
+
+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 = 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[type(Bencached(0))] = 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
+
+try:
+    from types import BooleanType
+    encode_func[BooleanType] = encode_int
+except ImportError:
+    pass
+
+def bencode(x):
+    r = []
+    encode_func[type(x)](x, r)
+    return ''.join(r)
+
+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'
+    assert bencode(Bencached(bencode(3))) == 'i3e'
+    try:
+        bencode({1: 'foo'})
+    except TypeError:
+        return
+    assert 0
+
+try:
+    import psyco
+    psyco.bind(bdecode)
+    psyco.bind(bencode)
+except ImportError:
+    pass




More information about the bazaar-commits mailing list