class Reader(object):
'''
Structure stream reader.
'''
def __init__(self, string = None, file = None):
'''
Wrap a string or file stream in a structure reader.
Either string or file must be given.
'''
if string is not None:
self.stream = StringIO(string)
elif file is not None:
self.stream = file
else:
raise "string or file must be non-None"
# Bit reader buffer
self.bitter = BitReader(self.readByte)
def read(self, size):
'''
read(size) -> string
Read bytes into a raw string.
'''
return self.stream.read(size)
def readStruct(self, format):
'''
readStruct(format) -> tuple
Read a structure from the stream.
Raises FormatError() if bytes were unavailable.
'''
size = struct.calcsize(format)
bytes = self.read(size)
if len(bytes) != size:
raise FormatError()
return struct.unpack(format, bytes)
def readString(self):
'''
readString() -> string
Read a UTF8-encoded string from the stream.
Raises FormatError() if bytes were unavailable.
'''
size = self.readStruct("!I")[0]
bytes = self.read(size)
if len(bytes) != size:
raise FormatError()
return bytes.decode("utf-8")
def readByte(self):
'''
readByte() -> int
Read a single byte.
'''
return ord(self.read(1))
def readBits(self, bits):
'''
Read bits (see ppk.bitio.BitReader).
'''
return self.bitter(bits)
def skipBits(self):
'''
Skip buffered bits (see ppk.bitio.BitReader).
'''
self.bitter.skip()
