7 class EarlyEnd(Exception):
10 class LateEnd(Exception):
13 def read((data, pos), length):
14 data2 = data[pos:pos + length]
15 if len(data2) != length:
17 return data2, (data, pos + length)
19 def size((data, pos)):
20 return len(data) - pos
25 # the same data can have only one unpacked representation, but multiple packed binary representations
28 rval = getattr(self, '_hash', None)
31 rval = self._hash = hash((type(self), frozenset(self.__dict__.items())))
37 def __eq__(self, other):
38 return type(other) is type(self) and other.__dict__ == self.__dict__
40 def __ne__(self, other):
41 return not (self == other)
43 def _unpack(self, data):
44 obj, (data2, pos) = self.read((data, 0))
54 f = self.write(None, obj)
64 def unpack(self, data):
65 obj = self._unpack(data)
68 data2 = self._pack(obj)
70 if self._unpack(data2) != obj:
71 raise AssertionError()
76 data = self._pack(obj)
79 if self._unpack(data) != obj:
80 raise AssertionError((self._unpack(data), obj))
85 def hash160(self, obj):
86 return IntType(160).unpack(hashlib.new('ripemd160', hashlib.sha256(self.pack(obj)).digest()).digest())
88 def hash256(self, obj):
89 return IntType(256).unpack(hashlib.sha256(hashlib.sha256(self.pack(obj)).digest()).digest())
91 def scrypt(self, obj):
93 return IntType(256).unpack(ltc_scrypt.getPoWHash(self.pack(obj)))
95 class VarIntType(Type):
96 # redundancy doesn't matter here because bitcoin and p2pool both reencode before hashing
98 data, file = read(file, 1)
103 desc, length = '<H', 2
105 desc, length = '<I', 4
107 desc, length = '<Q', 8
109 raise AssertionError()
110 data, file = read(file, length)
111 return struct.unpack(desc, data)[0], file
113 def write(self, file, item):
115 file = file, struct.pack('<B', item)
117 file = file, struct.pack('<BH', 0xfd, item)
118 elif item <= 0xffffffff:
119 file = file, struct.pack('<BI', 0xfe, item)
120 elif item <= 0xffffffffffffffff:
121 file = file, struct.pack('<BQ', 0xff, item)
123 raise ValueError('int too large for varint')
126 class VarStrType(Type):
127 _inner_size = VarIntType()
129 def read(self, file):
130 length, file = self._inner_size.read(file)
131 return read(file, length)
133 def write(self, file, item):
134 return self._inner_size.write(file, len(item)), item
136 class PassthruType(Type):
137 def read(self, file):
138 return read(file, size(file))
140 def write(self, file, item):
143 class EnumType(Type):
144 def __init__(self, inner, values):
149 for k, v in values.iteritems():
151 raise ValueError('duplicate value in values')
155 def read(self, file):
156 data, file = self.inner.read(file)
157 if data not in self.keys:
158 raise ValueError('enum data (%r) not in values (%r)' % (data, self.values))
159 return self.keys[data], file
161 def write(self, file, item):
162 if item not in self.values:
163 raise ValueError('enum item (%r) not in values (%r)' % (item, self.values))
164 return self.inner.write(file, self.values[item])
166 class ListType(Type):
167 _inner_size = VarIntType()
169 def __init__(self, type):
172 def read(self, file):
173 length, file = self._inner_size.read(file)
175 for i in xrange(length):
176 item, file = self.type.read(file)
180 def write(self, file, item):
181 file = self._inner_size.write(file, len(item))
183 file = self.type.write(file, subitem)
186 class StructType(Type):
187 __slots__ = 'desc length'.split(' ')
189 def __init__(self, desc):
191 self.length = struct.calcsize(self.desc)
193 def read(self, file):
194 data, file = read(file, self.length)
195 return struct.unpack(self.desc, data)[0], file
197 def write(self, file, item):
198 return file, struct.pack(self.desc, item)
201 __slots__ = 'bytes step format_str max'.split(' ')
203 def __new__(cls, bits, endianness='little'):
205 assert endianness in ['little', 'big']
206 if bits in [8, 16, 32, 64]:
207 return StructType(('<' if endianness == 'little' else '>') + {8: 'B', 16: 'H', 32: 'I', 64: 'Q'}[bits])
209 return Type.__new__(cls, bits, endianness)
211 def __init__(self, bits, endianness='little'):
213 assert endianness in ['little', 'big']
215 self.step = -1 if endianness == 'little' else 1
216 self.format_str = '%%0%ix' % (2*self.bytes)
219 def read(self, file, b2a_hex=binascii.b2a_hex):
220 data, file = read(file, self.bytes)
221 return int(b2a_hex(data[::self.step]), 16), file
223 def write(self, file, item, a2b_hex=binascii.a2b_hex):
224 if not 0 <= item < self.max:
225 raise ValueError('invalid int value - %r' % (item,))
226 return file, a2b_hex(self.format_str % (item,))[::self.step]
228 class IPV6AddressType(Type):
229 def read(self, file):
230 data, file = read(file, 16)
231 if data[:12] != '00000000000000000000ffff'.decode('hex'):
232 raise ValueError('ipv6 addresses not supported yet')
233 return '.'.join(str(ord(x)) for x in data[12:]), file
235 def write(self, file, item):
236 bits = map(int, item.split('.'))
238 raise ValueError('invalid address: %r' % (bits,))
239 data = '00000000000000000000ffff'.decode('hex') + ''.join(chr(x) for x in bits)
240 assert len(data) == 16, len(data)
245 def get_record(fields):
246 fields = tuple(sorted(fields))
249 if fields not in _record_types:
250 class _Record(object):
253 return repr(dict(self))
254 def __getitem__(self, key):
255 return getattr(self, key)
256 def __setitem__(self, key, value):
257 setattr(self, key, value)
259 # for field in self.__slots__:
260 # yield field, getattr(self, field)
262 return self.__slots__
263 def __eq__(self, other):
264 if isinstance(other, dict):
265 return dict(self) == other
266 elif isinstance(other, _Record):
267 return all(self[k] == other[k] for k in self.keys())
269 def __ne__(self, other):
270 return not (self == other)
271 _record_types[fields] = _Record
272 return _record_types[fields]()
274 class ComposedType(Type):
275 def __init__(self, fields):
276 self.fields = tuple(fields)
278 def read(self, file):
279 item = get_record(k for k, v in self.fields)
280 for key, type_ in self.fields:
281 item[key], file = type_.read(file)
284 def write(self, file, item):
285 for key, type_ in self.fields:
286 file = type_.write(file, item[key])
289 class PossiblyNoneType(Type):
290 def __init__(self, none_value, inner):
291 self.none_value = none_value
294 def read(self, file):
295 value, file = self.inner.read(file)
296 return None if value == self.none_value else value, file
298 def write(self, file, item):
299 if item == self.none_value:
300 raise ValueError('none_value used')
301 return self.inner.write(file, self.none_value if item is None else item)