Staging
v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 73acad1fa2634cb4ec77d8c98bdcd1a8b9c031ed authored by Giampaolo RodolĂ on 10 February 2011, 18:42:36 UTC
get rid of asyncore.dispatcher's debug attribute, which is no longer used (assuming it ever was).
get rid of asyncore.dispatcher's debug attribute, which is no longer used (assuming it ever was).
Tip revision: 73acad1
xdrlib.py
"""Implements (a subset of) Sun XDR -- eXternal Data Representation.
See: RFC 1014
"""
import struct
from io import BytesIO
from functools import wraps
__all__ = ["Error", "Packer", "Unpacker", "ConversionError"]
# exceptions
class Error(Exception):
"""Exception class for this module. Use:
except xdrlib.Error as var:
# var has the Error instance for the exception
Public ivars:
msg -- contains the message
"""
def __init__(self, msg):
self.msg = msg
def __repr__(self):
return repr(self.msg)
def __str__(self):
return str(self.msg)
class ConversionError(Error):
pass
def raise_conversion_error(function):
""" Wrap any raised struct.errors in a ConversionError. """
@wraps(function)
def result(self, value):
try:
return function(self, value)
except struct.error as e:
raise ConversionError(e.args[0]) from None
return result
class Packer:
"""Pack various data representations into a buffer."""
def __init__(self):
self.reset()
def reset(self):
self.__buf = BytesIO()
def get_buffer(self):
return self.__buf.getvalue()
# backwards compatibility
get_buf = get_buffer
@raise_conversion_error
def pack_uint(self, x):
self.__buf.write(struct.pack('>L', x))
@raise_conversion_error
def pack_int(self, x):
self.__buf.write(struct.pack('>l', x))
pack_enum = pack_int
def pack_bool(self, x):
if x: self.__buf.write(b'\0\0\0\1')
else: self.__buf.write(b'\0\0\0\0')
def pack_uhyper(self, x):
try:
self.pack_uint(x>>32 & 0xffffffff)
except (TypeError, struct.error) as e:
raise ConversionError(e.args[0]) from None
try:
self.pack_uint(x & 0xffffffff)
except (TypeError, struct.error) as e:
raise ConversionError(e.args[0]) from None
pack_hyper = pack_uhyper
@raise_conversion_error
def pack_float(self, x):
self.__buf.write(struct.pack('>f', x))
@raise_conversion_error
def pack_double(self, x):
self.__buf.write(struct.pack('>d', x))
def pack_fstring(self, n, s):
if n < 0:
raise ValueError('fstring size must be nonnegative')
data = s[:n]
n = ((n+3)//4)*4
data = data + (n - len(data)) * b'\0'
self.__buf.write(data)
pack_fopaque = pack_fstring
def pack_string(self, s):
n = len(s)
self.pack_uint(n)
self.pack_fstring(n, s)
pack_opaque = pack_string
pack_bytes = pack_string
def pack_list(self, list, pack_item):
for item in list:
self.pack_uint(1)
pack_item(item)
self.pack_uint(0)
def pack_farray(self, n, list, pack_item):
if len(list) != n:
raise ValueError('wrong array size')
for item in list:
pack_item(item)
def pack_array(self, list, pack_item):
n = len(list)
self.pack_uint(n)
self.pack_farray(n, list, pack_item)
class Unpacker:
"""Unpacks various data representations from the given buffer."""
def __init__(self, data):
self.reset(data)
def reset(self, data):
self.__buf = data
self.__pos = 0
def get_position(self):
return self.__pos
def set_position(self, position):
self.__pos = position
def get_buffer(self):
return self.__buf
def done(self):
if self.__pos < len(self.__buf):
raise Error('unextracted data remains')
def unpack_uint(self):
i = self.__pos
self.__pos = j = i+4
data = self.__buf[i:j]
if len(data) < 4:
raise EOFError
return struct.unpack('>L', data)[0]
def unpack_int(self):
i = self.__pos
self.__pos = j = i+4
data = self.__buf[i:j]
if len(data) < 4:
raise EOFError
return struct.unpack('>l', data)[0]
unpack_enum = unpack_int
def unpack_bool(self):
return bool(self.unpack_int())
def unpack_uhyper(self):
hi = self.unpack_uint()
lo = self.unpack_uint()
return int(hi)<<32 | lo
def unpack_hyper(self):
x = self.unpack_uhyper()
if x >= 0x8000000000000000:
x = x - 0x10000000000000000
return x
def unpack_float(self):
i = self.__pos
self.__pos = j = i+4
data = self.__buf[i:j]
if len(data) < 4:
raise EOFError
return struct.unpack('>f', data)[0]
def unpack_double(self):
i = self.__pos
self.__pos = j = i+8
data = self.__buf[i:j]
if len(data) < 8:
raise EOFError
return struct.unpack('>d', data)[0]
def unpack_fstring(self, n):
if n < 0:
raise ValueError('fstring size must be nonnegative')
i = self.__pos
j = i + (n+3)//4*4
if j > len(self.__buf):
raise EOFError
self.__pos = j
return self.__buf[i:i+n]
unpack_fopaque = unpack_fstring
def unpack_string(self):
n = self.unpack_uint()
return self.unpack_fstring(n)
unpack_opaque = unpack_string
unpack_bytes = unpack_string
def unpack_list(self, unpack_item):
list = []
while 1:
x = self.unpack_uint()
if x == 0: break
if x != 1:
raise ConversionError('0 or 1 expected, got %r' % (x,))
item = unpack_item()
list.append(item)
return list
def unpack_farray(self, n, unpack_item):
list = []
for i in range(n):
list.append(unpack_item())
return list
def unpack_array(self, unpack_item):
n = self.unpack_uint()
return self.unpack_farray(n, unpack_item)