def unpack(fmt, s):
tfmt, fmt = __get_type(fmt)
if not fmt:
return ()
if tfmt != '.':
raise ValueError('Only variable-length encoding is currently supported')
result = []
for offset, havesize, size, f in __unpack_iter_fmt(fmt):
if f == 'x':
if not havesize:
size = 1
s = s[size:]
# Note: no value, don't increment i
elif f in 'SsUu':
if not havesize:
if f == 's':
size = 1
elif f == 'S':
size = s.find('\0')
elif f == 'u' and offset == len(fmt) - 1:
size = len(s)
else:
# Note: 'U' is used internally, and may be exposed to us.
# It indicates that the size is always stored unless there
# is a size in the format.
size, s = unpack_int(s)
result.append(s[:size])
if f == 'S' and not havesize:
size += 1
s = s[size:]
elif f in 't':
# bit type, size is number of bits
if not havesize:
size = 1
result.append(ord(s[0:1]))
s = s[1:]
elif f in 'Bb':
# byte type
if not havesize:
size = 1
for i in xrange(size):
v = ord(s[0:1])
if f != 'B':
v -= 0x80
result.append(v)
s = s[1:]
else:
# integral type
if not havesize:
size = 1
for j in xrange(size):
v, s = unpack_int(s)
result.append(v)
return result
def unpack(fmt, s):
tfmt, fmt = __get_type(fmt)
if not fmt:
return ()
if tfmt != '.':
raise ValueError(
'Only variable-length encoding is currently supported')
result = []
havesize = size = 0
for offset, f in enumerate(fmt):
if f.isdigit():
size = (size * 10) + int(f)
havesize = 1
continue
elif f == 'x':
if not havesize:
size = 1
s = s[size:]
# Note: no value, don't increment i
elif f in 'Ssu':
if not havesize:
if f == 's':
size = 1
elif f == 'S':
size = s.find('\0')
elif f == 'u':
if offset == len(fmt) - 1:
size = len(s)
else:
size, s = unpack_int(s)
result.append(s[:size])
if f == 'S' and not havesize:
size += 1
s = s[size:]
elif f in 't':
# bit type, size is number of bits
if not havesize:
size = 1
result.append(ord(s[0:1]))
s = s[1:]
else:
# integral type
if not havesize:
size = 1
for j in xrange(size):
v, s = unpack_int(s)
result.append(v)
havesize = size = 0
return result
def unpack(fmt, s):
tfmt, fmt = __get_type(fmt)
if not fmt:
return ()
if tfmt != '.':
raise ValueError('Only variable-length encoding is currently supported')
result = []
havesize = size = 0
for offset, f in enumerate(fmt):
if f.isdigit():
size = (size * 10) + int(f)
havesize = 1
continue
elif f == 'x':
if not havesize:
size = 1
s = s[size:]
# Note: no value, don't increment i
elif f in 'Ssu':
if not havesize:
if f == 's':
size = 1
elif f == 'S':
size = s.find('\0')
elif f == 'u':
if offset == len(fmt) - 1:
size = len(s)
else:
size, s = unpack_int(s)
result.append(s[:size])
if f == 'S' and not havesize:
size += 1
s = s[size:]
elif f in 't':
# bit type, size is number of bits
if not havesize:
size = 1
result.append(ord(s[0:1]))
s = s[1:]
else:
# integral type
if not havesize:
size = 1
for j in xrange(size):
v, s = unpack_int(s)
result.append(v)
havesize = size = 0
return result
