Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 1 | """Implements (a subset of) Sun XDR -- eXternal Data Representation. |
| 2 | |
| 3 | See: RFC 1014 |
| 4 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 5 | """ |
| 6 | |
| 7 | import struct |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 8 | |
Skip Montanaro | 40fc160 | 2001-03-01 04:27:19 +0000 | [diff] [blame] | 9 | __all__ = ["Error", "Packer", "Unpacker", "ConversionError"] |
| 10 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 11 | # exceptions |
| 12 | class Error: |
| 13 | """Exception class for this module. Use: |
| 14 | |
| 15 | except xdrlib.Error, var: |
| 16 | # var has the Error instance for the exception |
| 17 | |
| 18 | Public ivars: |
| 19 | msg -- contains the message |
| 20 | |
| 21 | """ |
| 22 | def __init__(self, msg): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 23 | self.msg = msg |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 24 | def __repr__(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 25 | return repr(self.msg) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 26 | def __str__(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 27 | return str(self.msg) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 28 | |
| 29 | |
| 30 | class ConversionError(Error): |
| 31 | pass |
| 32 | |
| 33 | |
Tim Peters | e119006 | 2001-01-15 03:34:38 +0000 | [diff] [blame] | 34 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 35 | class Packer: |
| 36 | """Pack various data representations into a buffer.""" |
| 37 | |
| 38 | def __init__(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 39 | self.reset() |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 40 | |
| 41 | def reset(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 42 | self.__buf = '' |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 43 | |
| 44 | def get_buffer(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 45 | return self.__buf |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 46 | # backwards compatibility |
| 47 | get_buf = get_buffer |
| 48 | |
| 49 | def pack_uint(self, x): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 50 | self.__buf = self.__buf + struct.pack('>L', x) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 51 | |
| 52 | pack_int = pack_uint |
| 53 | pack_enum = pack_int |
| 54 | |
| 55 | def pack_bool(self, x): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 56 | if x: self.__buf = self.__buf + '\0\0\0\1' |
| 57 | else: self.__buf = self.__buf + '\0\0\0\0' |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 58 | |
| 59 | def pack_uhyper(self, x): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 60 | self.pack_uint(x>>32 & 0xffffffffL) |
| 61 | self.pack_uint(x & 0xffffffffL) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 62 | |
| 63 | pack_hyper = pack_uhyper |
| 64 | |
| 65 | def pack_float(self, x): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 66 | try: self.__buf = self.__buf + struct.pack('>f', x) |
| 67 | except struct.error, msg: |
| 68 | raise ConversionError, msg |
Guido van Rossum | 6083f0e | 1997-01-02 22:52:15 +0000 | [diff] [blame] | 69 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 70 | def pack_double(self, x): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 71 | try: self.__buf = self.__buf + struct.pack('>d', x) |
| 72 | except struct.error, msg: |
| 73 | raise ConversionError, msg |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 74 | |
| 75 | def pack_fstring(self, n, s): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 76 | if n < 0: |
| 77 | raise ValueError, 'fstring size must be nonnegative' |
| 78 | n = ((n+3)/4)*4 |
| 79 | data = s[:n] |
| 80 | data = data + (n - len(data)) * '\0' |
| 81 | self.__buf = self.__buf + data |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 82 | |
| 83 | pack_fopaque = pack_fstring |
| 84 | |
| 85 | def pack_string(self, s): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 86 | n = len(s) |
| 87 | self.pack_uint(n) |
| 88 | self.pack_fstring(n, s) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 89 | |
| 90 | pack_opaque = pack_string |
| 91 | pack_bytes = pack_string |
| 92 | |
| 93 | def pack_list(self, list, pack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 94 | for item in list: |
| 95 | self.pack_uint(1) |
| 96 | pack_item(item) |
| 97 | self.pack_uint(0) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 98 | |
| 99 | def pack_farray(self, n, list, pack_item): |
Fred Drake | 8152d32 | 2000-12-12 23:20:45 +0000 | [diff] [blame] | 100 | if len(list) != n: |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 101 | raise ValueError, 'wrong array size' |
| 102 | for item in list: |
| 103 | pack_item(item) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 104 | |
| 105 | def pack_array(self, list, pack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 106 | n = len(list) |
| 107 | self.pack_uint(n) |
| 108 | self.pack_farray(n, list, pack_item) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 109 | |
| 110 | |
Tim Peters | e119006 | 2001-01-15 03:34:38 +0000 | [diff] [blame] | 111 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 112 | class Unpacker: |
| 113 | """Unpacks various data representations from the given buffer.""" |
| 114 | |
| 115 | def __init__(self, data): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 116 | self.reset(data) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 117 | |
| 118 | def reset(self, data): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 119 | self.__buf = data |
| 120 | self.__pos = 0 |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 121 | |
| 122 | def get_position(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 123 | return self.__pos |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 124 | |
| 125 | def set_position(self, position): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 126 | self.__pos = position |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 127 | |
Barry Warsaw | 75eccc5 | 1996-12-04 22:04:39 +0000 | [diff] [blame] | 128 | def get_buffer(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 129 | return self.__buf |
Barry Warsaw | 75eccc5 | 1996-12-04 22:04:39 +0000 | [diff] [blame] | 130 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 131 | def done(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 132 | if self.__pos < len(self.__buf): |
| 133 | raise Error('unextracted data remains') |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 134 | |
| 135 | def unpack_uint(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 136 | i = self.__pos |
| 137 | self.__pos = j = i+4 |
| 138 | data = self.__buf[i:j] |
| 139 | if len(data) < 4: |
| 140 | raise EOFError |
| 141 | x = struct.unpack('>L', data)[0] |
| 142 | try: |
| 143 | return int(x) |
| 144 | except OverflowError: |
| 145 | return x |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 146 | |
| 147 | def unpack_int(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 148 | i = self.__pos |
| 149 | self.__pos = j = i+4 |
| 150 | data = self.__buf[i:j] |
| 151 | if len(data) < 4: |
| 152 | raise EOFError |
| 153 | return struct.unpack('>l', data)[0] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 154 | |
| 155 | unpack_enum = unpack_int |
| 156 | unpack_bool = unpack_int |
| 157 | |
| 158 | def unpack_uhyper(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 159 | hi = self.unpack_uint() |
| 160 | lo = self.unpack_uint() |
| 161 | return long(hi)<<32 | lo |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 162 | |
| 163 | def unpack_hyper(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 164 | x = self.unpack_uhyper() |
| 165 | if x >= 0x8000000000000000L: |
| 166 | x = x - 0x10000000000000000L |
| 167 | return x |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 168 | |
| 169 | def unpack_float(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 170 | i = self.__pos |
| 171 | self.__pos = j = i+4 |
| 172 | data = self.__buf[i:j] |
| 173 | if len(data) < 4: |
| 174 | raise EOFError |
| 175 | return struct.unpack('>f', data)[0] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 176 | |
Guido van Rossum | 6083f0e | 1997-01-02 22:52:15 +0000 | [diff] [blame] | 177 | def unpack_double(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 178 | i = self.__pos |
| 179 | self.__pos = j = i+8 |
| 180 | data = self.__buf[i:j] |
| 181 | if len(data) < 8: |
| 182 | raise EOFError |
| 183 | return struct.unpack('>d', data)[0] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 184 | |
| 185 | def unpack_fstring(self, n): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 186 | if n < 0: |
| 187 | raise ValueError, 'fstring size must be nonnegative' |
| 188 | i = self.__pos |
| 189 | j = i + (n+3)/4*4 |
| 190 | if j > len(self.__buf): |
| 191 | raise EOFError |
| 192 | self.__pos = j |
| 193 | return self.__buf[i:i+n] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 194 | |
| 195 | unpack_fopaque = unpack_fstring |
| 196 | |
| 197 | def unpack_string(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 198 | n = self.unpack_uint() |
| 199 | return self.unpack_fstring(n) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 200 | |
| 201 | unpack_opaque = unpack_string |
| 202 | unpack_bytes = unpack_string |
| 203 | |
| 204 | def unpack_list(self, unpack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 205 | list = [] |
| 206 | while 1: |
| 207 | x = self.unpack_uint() |
| 208 | if x == 0: break |
Fred Drake | 8152d32 | 2000-12-12 23:20:45 +0000 | [diff] [blame] | 209 | if x != 1: |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 210 | raise ConversionError, '0 or 1 expected, got ' + `x` |
| 211 | item = unpack_item() |
| 212 | list.append(item) |
| 213 | return list |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 214 | |
| 215 | def unpack_farray(self, n, unpack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 216 | list = [] |
| 217 | for i in range(n): |
| 218 | list.append(unpack_item()) |
| 219 | return list |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 220 | |
| 221 | def unpack_array(self, unpack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 222 | n = self.unpack_uint() |
| 223 | return self.unpack_farray(n, unpack_item) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 224 | |
Tim Peters | e119006 | 2001-01-15 03:34:38 +0000 | [diff] [blame] | 225 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 226 | # test suite |
Guido van Rossum | 72fba79 | 1996-08-19 22:49:35 +0000 | [diff] [blame] | 227 | def _test(): |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 228 | p = Packer() |
| 229 | packtest = [ |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 230 | (p.pack_uint, (9,)), |
| 231 | (p.pack_bool, (None,)), |
| 232 | (p.pack_bool, ('hello',)), |
| 233 | (p.pack_uhyper, (45L,)), |
| 234 | (p.pack_float, (1.9,)), |
| 235 | (p.pack_double, (1.9,)), |
| 236 | (p.pack_string, ('hello world',)), |
| 237 | (p.pack_list, (range(5), p.pack_uint)), |
| 238 | (p.pack_array, (['what', 'is', 'hapnin', 'doctor'], p.pack_string)), |
| 239 | ] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 240 | succeedlist = [1] * len(packtest) |
| 241 | count = 0 |
| 242 | for method, args in packtest: |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 243 | print 'pack test', count, |
| 244 | try: |
| 245 | apply(method, args) |
| 246 | print 'succeeded' |
| 247 | except ConversionError, var: |
| 248 | print 'ConversionError:', var.msg |
| 249 | succeedlist[count] = 0 |
| 250 | count = count + 1 |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 251 | data = p.get_buffer() |
| 252 | # now verify |
| 253 | up = Unpacker(data) |
| 254 | unpacktest = [ |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 255 | (up.unpack_uint, (), lambda x: x == 9), |
| 256 | (up.unpack_bool, (), lambda x: not x), |
| 257 | (up.unpack_bool, (), lambda x: x), |
| 258 | (up.unpack_uhyper, (), lambda x: x == 45L), |
| 259 | (up.unpack_float, (), lambda x: 1.89 < x < 1.91), |
| 260 | (up.unpack_double, (), lambda x: 1.89 < x < 1.91), |
| 261 | (up.unpack_string, (), lambda x: x == 'hello world'), |
| 262 | (up.unpack_list, (up.unpack_uint,), lambda x: x == range(5)), |
| 263 | (up.unpack_array, (up.unpack_string,), |
| 264 | lambda x: x == ['what', 'is', 'hapnin', 'doctor']), |
| 265 | ] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 266 | count = 0 |
| 267 | for method, args, pred in unpacktest: |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 268 | print 'unpack test', count, |
| 269 | try: |
| 270 | if succeedlist[count]: |
| 271 | x = apply(method, args) |
| 272 | print pred(x) and 'succeeded' or 'failed', ':', x |
| 273 | else: |
| 274 | print 'skipping' |
| 275 | except ConversionError, var: |
| 276 | print 'ConversionError:', var.msg |
| 277 | count = count + 1 |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 278 | |
Tim Peters | e119006 | 2001-01-15 03:34:38 +0000 | [diff] [blame] | 279 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 280 | if __name__ == '__main__': |
Guido van Rossum | 72fba79 | 1996-08-19 22:49:35 +0000 | [diff] [blame] | 281 | _test() |