mirror of https://github.com/python/cpython
142 lines
2.8 KiB
Python
142 lines
2.8 KiB
Python
# Implement (a subset of) Sun XDR -- RFC1014.
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import struct
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class Packer:
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def init(self):
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self.reset()
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return self
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def reset(self):
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self.buf = ''
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def get_buf(self):
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return self.buf
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def pack_uint(self, x):
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self.buf = self.buf + \
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(chr(int(x>>24 & 0xff)) + chr(int(x>>16 & 0xff)) + \
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chr(int(x>>8 & 0xff)) + chr(int(x & 0xff)))
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if struct.pack('i', 1) == '\0\0\0\1':
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def pack_uint(self, x):
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self.buf = self.buf + struct.pack('i', x)
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pack_int = pack_uint
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pack_enum = pack_int
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def pack_bool(self, x):
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if x: self.buf = self.buf + '\0\0\0\1'
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else: self.buf = self.buf + '\0\0\0\0'
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def pack_uhyper(self, x):
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self.pack_uint(x>>32 & 0xffffffff)
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self.pack_uint(x & 0xffffffff)
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pack_hyper = pack_uhyper
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def pack_fstring(self, n, s):
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if n < 0:
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raise ValueError, 'fstring size must be nonnegative'
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n = ((n+3)/4)*4
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data = s[:n]
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data = data + (n - len(data)) * '\0'
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self.buf = self.buf + data
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pack_fopaque = pack_fstring
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def pack_string(self, s):
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n = len(s)
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self.pack_uint(n)
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self.pack_fstring(n, s)
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pack_opaque = pack_string
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def pack_list(self, list, pack_item):
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for item in list:
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self.pack_uint(1)
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pack_item(list)
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self.pack_uint(0)
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class Unpacker:
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def init(self, data):
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self.reset(data)
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return self
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def reset(self, data):
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self.buf = data
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self.pos = 0
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def done(self):
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if self.pos < len(self.buf):
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raise RuntimeError, 'unextracted data remains'
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def unpack_uint(self):
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i = self.pos
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self.pos = j = i+4
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data = self.buf[i:j]
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x = long(ord(data[0]))<<24 | ord(data[1])<<16 | \
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ord(data[2])<<8 | ord(data[3])
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# Return a Python long only if the value is not representable
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# as a nonnegative Python int
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if x < 0x80000000L: x = int(x)
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return x
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if struct.unpack('i', '\0\0\0\1') == 1:
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def unpack_uint(self):
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i = self.pos
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self.pos = j = i+4
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return struct.unpack('i', self.buf[i:j])
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def unpack_int(self):
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x = self.unpack_uint()
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if x >= 0x80000000L: x = x - 0x100000000L
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return int(x)
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unpack_enum = unpack_int
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unpack_bool = unpack_int
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def unpack_uhyper(self):
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hi = self.unpack_uint()
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lo = self.unpack_uint()
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return long(hi)<<32 | lo
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def unpack_hyper(self):
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x = self.unpack_uhyper()
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if x >= 0x8000000000000000L: x = x - 0x10000000000000000L
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return x
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def unpack_fstring(self, n):
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if n < 0:
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raise ValueError, 'fstring size must be nonnegative'
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i = self.pos
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j = i + (n+3)/4*4
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if j > len(self.buf):
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raise RuntimeError, 'buffer overrun'
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self.pos = j
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return self.buf[i:i+n]
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unpack_fopaque = unpack_fstring
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def unpack_string(self):
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n = self.unpack_uint()
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return self.unpack_fstring(n)
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unpack_opaque = unpack_string
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def unpack_list(self, unpack_item):
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list = []
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while 1:
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x = self.unpack_uint()
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if not x: break
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if x <> 1:
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raise RuntimeError, \
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'0 or 1 expected, got ' + `x`
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list.append(unpack_item())
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return list
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