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 |
Martin v. Löwis | c47016e | 2001-08-16 17:06:44 +0000 | [diff] [blame] | 8 | try: |
| 9 | from cStringIO import StringIO as _StringIO |
| 10 | except ImportError: |
| 11 | from StringIO import StringIO as _StringIO |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 12 | from functools import wraps |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 13 | |
Skip Montanaro | 40fc160 | 2001-03-01 04:27:19 +0000 | [diff] [blame] | 14 | __all__ = ["Error", "Packer", "Unpacker", "ConversionError"] |
| 15 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 16 | # exceptions |
Neal Norwitz | f74e46c | 2002-03-31 13:59:18 +0000 | [diff] [blame] | 17 | class Error(Exception): |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 18 | """Exception class for this module. Use: |
| 19 | |
| 20 | except xdrlib.Error, var: |
| 21 | # var has the Error instance for the exception |
| 22 | |
| 23 | Public ivars: |
| 24 | msg -- contains the message |
| 25 | |
| 26 | """ |
| 27 | def __init__(self, msg): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 28 | self.msg = msg |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 29 | def __repr__(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 30 | return repr(self.msg) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 31 | def __str__(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 32 | return str(self.msg) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 33 | |
| 34 | |
| 35 | class ConversionError(Error): |
| 36 | pass |
| 37 | |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 38 | def raise_conversion_error(function): |
| 39 | """ Wrap any raised struct.errors in a ConversionError. """ |
| 40 | |
| 41 | @wraps(function) |
| 42 | def result(self, value): |
| 43 | try: |
| 44 | return function(self, value) |
| 45 | except struct.error as e: |
| 46 | raise ConversionError(e.args[0]) |
| 47 | return result |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 48 | |
Tim Peters | e119006 | 2001-01-15 03:34:38 +0000 | [diff] [blame] | 49 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 50 | class Packer: |
| 51 | """Pack various data representations into a buffer.""" |
| 52 | |
| 53 | def __init__(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 54 | self.reset() |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 55 | |
| 56 | def reset(self): |
Martin v. Löwis | c47016e | 2001-08-16 17:06:44 +0000 | [diff] [blame] | 57 | self.__buf = _StringIO() |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 58 | |
| 59 | def get_buffer(self): |
Martin v. Löwis | c47016e | 2001-08-16 17:06:44 +0000 | [diff] [blame] | 60 | return self.__buf.getvalue() |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 61 | # backwards compatibility |
| 62 | get_buf = get_buffer |
| 63 | |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 64 | @raise_conversion_error |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 65 | def pack_uint(self, x): |
Martin v. Löwis | c47016e | 2001-08-16 17:06:44 +0000 | [diff] [blame] | 66 | self.__buf.write(struct.pack('>L', x)) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 67 | |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 68 | @raise_conversion_error |
Mark Dickinson | d687be0 | 2011-03-27 16:15:24 +0100 | [diff] [blame] | 69 | def pack_int(self, x): |
| 70 | self.__buf.write(struct.pack('>l', x)) |
| 71 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 72 | pack_enum = pack_int |
| 73 | |
| 74 | def pack_bool(self, x): |
Martin v. Löwis | c47016e | 2001-08-16 17:06:44 +0000 | [diff] [blame] | 75 | if x: self.__buf.write('\0\0\0\1') |
| 76 | else: self.__buf.write('\0\0\0\0') |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 77 | |
| 78 | def pack_uhyper(self, x): |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 79 | try: |
| 80 | self.pack_uint(x>>32 & 0xffffffffL) |
| 81 | except (TypeError, struct.error) as e: |
| 82 | raise ConversionError(e.args[0]) |
| 83 | try: |
| 84 | self.pack_uint(x & 0xffffffffL) |
| 85 | except (TypeError, struct.error) as e: |
| 86 | raise ConversionError(e.args[0]) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 87 | |
| 88 | pack_hyper = pack_uhyper |
| 89 | |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 90 | @raise_conversion_error |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 91 | def pack_float(self, x): |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 92 | self.__buf.write(struct.pack('>f', x)) |
Guido van Rossum | 6083f0e | 1997-01-02 22:52:15 +0000 | [diff] [blame] | 93 | |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 94 | @raise_conversion_error |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 95 | def pack_double(self, x): |
Petri Lehtinen | f85a856 | 2014-10-10 21:11:34 +0300 | [diff] [blame] | 96 | self.__buf.write(struct.pack('>d', x)) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 97 | |
| 98 | def pack_fstring(self, n, s): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 99 | if n < 0: |
| 100 | raise ValueError, 'fstring size must be nonnegative' |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 101 | data = s[:n] |
Georg Brandl | b921a84 | 2006-03-28 10:07:46 +0000 | [diff] [blame] | 102 | n = ((n+3)//4)*4 |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 103 | data = data + (n - len(data)) * '\0' |
Martin v. Löwis | c47016e | 2001-08-16 17:06:44 +0000 | [diff] [blame] | 104 | self.__buf.write(data) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 105 | |
| 106 | pack_fopaque = pack_fstring |
| 107 | |
| 108 | def pack_string(self, s): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 109 | n = len(s) |
| 110 | self.pack_uint(n) |
| 111 | self.pack_fstring(n, s) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 112 | |
| 113 | pack_opaque = pack_string |
| 114 | pack_bytes = pack_string |
| 115 | |
| 116 | def pack_list(self, list, pack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 117 | for item in list: |
| 118 | self.pack_uint(1) |
| 119 | pack_item(item) |
| 120 | self.pack_uint(0) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 121 | |
| 122 | def pack_farray(self, n, list, pack_item): |
Fred Drake | 8152d32 | 2000-12-12 23:20:45 +0000 | [diff] [blame] | 123 | if len(list) != n: |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 124 | raise ValueError, 'wrong array size' |
| 125 | for item in list: |
| 126 | pack_item(item) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 127 | |
| 128 | def pack_array(self, list, pack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 129 | n = len(list) |
| 130 | self.pack_uint(n) |
| 131 | self.pack_farray(n, list, pack_item) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 132 | |
| 133 | |
Tim Peters | e119006 | 2001-01-15 03:34:38 +0000 | [diff] [blame] | 134 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 135 | class Unpacker: |
| 136 | """Unpacks various data representations from the given buffer.""" |
| 137 | |
| 138 | def __init__(self, data): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 139 | self.reset(data) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 140 | |
| 141 | def reset(self, data): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 142 | self.__buf = data |
| 143 | self.__pos = 0 |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 144 | |
| 145 | def get_position(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 146 | return self.__pos |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 147 | |
| 148 | def set_position(self, position): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 149 | self.__pos = position |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 150 | |
Barry Warsaw | 75eccc5 | 1996-12-04 22:04:39 +0000 | [diff] [blame] | 151 | def get_buffer(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 152 | return self.__buf |
Barry Warsaw | 75eccc5 | 1996-12-04 22:04:39 +0000 | [diff] [blame] | 153 | |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 154 | def done(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 155 | if self.__pos < len(self.__buf): |
| 156 | raise Error('unextracted data remains') |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 157 | |
| 158 | def unpack_uint(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 159 | i = self.__pos |
| 160 | self.__pos = j = i+4 |
| 161 | data = self.__buf[i:j] |
| 162 | if len(data) < 4: |
| 163 | raise EOFError |
| 164 | x = struct.unpack('>L', data)[0] |
| 165 | try: |
| 166 | return int(x) |
| 167 | except OverflowError: |
| 168 | return x |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 169 | |
| 170 | def unpack_int(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 171 | i = self.__pos |
| 172 | self.__pos = j = i+4 |
| 173 | data = self.__buf[i:j] |
| 174 | if len(data) < 4: |
| 175 | raise EOFError |
| 176 | return struct.unpack('>l', data)[0] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 177 | |
| 178 | unpack_enum = unpack_int |
Martin v. Löwis | c2a0ac2 | 2005-02-24 20:22:10 +0000 | [diff] [blame] | 179 | |
| 180 | def unpack_bool(self): |
| 181 | return bool(self.unpack_int()) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 182 | |
| 183 | def unpack_uhyper(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 184 | hi = self.unpack_uint() |
| 185 | lo = self.unpack_uint() |
| 186 | return long(hi)<<32 | lo |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 187 | |
| 188 | def unpack_hyper(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 189 | x = self.unpack_uhyper() |
| 190 | if x >= 0x8000000000000000L: |
| 191 | x = x - 0x10000000000000000L |
| 192 | return x |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 193 | |
| 194 | def unpack_float(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 195 | i = self.__pos |
| 196 | self.__pos = j = i+4 |
| 197 | data = self.__buf[i:j] |
| 198 | if len(data) < 4: |
| 199 | raise EOFError |
| 200 | return struct.unpack('>f', data)[0] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 201 | |
Guido van Rossum | 6083f0e | 1997-01-02 22:52:15 +0000 | [diff] [blame] | 202 | def unpack_double(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 203 | i = self.__pos |
| 204 | self.__pos = j = i+8 |
| 205 | data = self.__buf[i:j] |
| 206 | if len(data) < 8: |
| 207 | raise EOFError |
| 208 | return struct.unpack('>d', data)[0] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 209 | |
| 210 | def unpack_fstring(self, n): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 211 | if n < 0: |
| 212 | raise ValueError, 'fstring size must be nonnegative' |
| 213 | i = self.__pos |
Georg Brandl | b921a84 | 2006-03-28 10:07:46 +0000 | [diff] [blame] | 214 | j = i + (n+3)//4*4 |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 215 | if j > len(self.__buf): |
| 216 | raise EOFError |
| 217 | self.__pos = j |
| 218 | return self.__buf[i:i+n] |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 219 | |
| 220 | unpack_fopaque = unpack_fstring |
| 221 | |
| 222 | def unpack_string(self): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 223 | n = self.unpack_uint() |
| 224 | return self.unpack_fstring(n) |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 225 | |
| 226 | unpack_opaque = unpack_string |
| 227 | unpack_bytes = unpack_string |
| 228 | |
| 229 | def unpack_list(self, unpack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 230 | list = [] |
| 231 | while 1: |
| 232 | x = self.unpack_uint() |
| 233 | if x == 0: break |
Fred Drake | 8152d32 | 2000-12-12 23:20:45 +0000 | [diff] [blame] | 234 | if x != 1: |
Walter Dörwald | 70a6b49 | 2004-02-12 17:35:32 +0000 | [diff] [blame] | 235 | raise ConversionError, '0 or 1 expected, got %r' % (x,) |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 236 | item = unpack_item() |
| 237 | list.append(item) |
| 238 | return list |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 239 | |
| 240 | def unpack_farray(self, n, unpack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 241 | list = [] |
| 242 | for i in range(n): |
| 243 | list.append(unpack_item()) |
| 244 | return list |
Guido van Rossum | 731630b | 1996-08-19 22:26:43 +0000 | [diff] [blame] | 245 | |
| 246 | def unpack_array(self, unpack_item): |
Guido van Rossum | 45e2fbc | 1998-03-26 21:13:24 +0000 | [diff] [blame] | 247 | n = self.unpack_uint() |
| 248 | return self.unpack_farray(n, unpack_item) |