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Editing: utf_16.py
""" Python 'utf-16' Codec Written by Marc-Andre Lemburg (mal@lemburg.com). (c) Copyright CNRI, All Rights Reserved. NO WARRANTY. """ import codecs, sys ### Codec APIs encode = codecs.utf_16_encode def decode(input, errors='strict'): return codecs.utf_16_decode(input, errors, True) class IncrementalEncoder(codecs.IncrementalEncoder): def __init__(self, errors='strict'): codecs.IncrementalEncoder.__init__(self, errors) self.encoder = None def encode(self, input, final=False): if self.encoder is None: result = codecs.utf_16_encode(input, self.errors)[0] if sys.byteorder == 'little': self.encoder = codecs.utf_16_le_encode else: self.encoder = codecs.utf_16_be_encode return result return self.encoder(input, self.errors)[0] def reset(self): codecs.IncrementalEncoder.reset(self) self.encoder = None def getstate(self): # state info we return to the caller: # 0: stream is in natural order for this platform # 2: endianness hasn't been determined yet # (we're never writing in unnatural order) return (2 if self.encoder is None else 0) def setstate(self, state): if state: self.encoder = None else: if sys.byteorder == 'little': self.encoder = codecs.utf_16_le_encode else: self.encoder = codecs.utf_16_be_encode class IncrementalDecoder(codecs.BufferedIncrementalDecoder): def __init__(self, errors='strict'): codecs.BufferedIncrementalDecoder.__init__(self, errors) self.decoder = None def _buffer_decode(self, input, errors, final): if self.decoder is None: (output, consumed, byteorder) = \ codecs.utf_16_ex_decode(input, errors, 0, final) if byteorder == -1: self.decoder = codecs.utf_16_le_decode elif byteorder == 1: self.decoder = codecs.utf_16_be_decode elif consumed >= 2: raise UnicodeError("UTF-16 stream does not start with BOM") return (output, consumed) return self.decoder(input, self.errors, final) def reset(self): codecs.BufferedIncrementalDecoder.reset(self) self.decoder = None def getstate(self): # additional state info from the base class must be None here, # as it isn't passed along to the caller state = codecs.BufferedIncrementalDecoder.getstate(self)[0] # additional state info we pass to the caller: # 0: stream is in natural order for this platform # 1: stream is in unnatural order # 2: endianness hasn't been determined yet if self.decoder is None: return (state, 2) addstate = int((sys.byteorder == "big") != (self.decoder is codecs.utf_16_be_decode)) return (state, addstate) def setstate(self, state): # state[1] will be ignored by BufferedIncrementalDecoder.setstate() codecs.BufferedIncrementalDecoder.setstate(self, state) state = state[1] if state == 0: self.decoder = (codecs.utf_16_be_decode if sys.byteorder == "big" else codecs.utf_16_le_decode) elif state == 1: self.decoder = (codecs.utf_16_le_decode if sys.byteorder == "big" else codecs.utf_16_be_decode) else: self.decoder = None class StreamWriter(codecs.StreamWriter): def __init__(self, stream, errors='strict'): codecs.StreamWriter.__init__(self, stream, errors) self.encoder = None def reset(self): codecs.StreamWriter.reset(self) self.encoder = None def encode(self, input, errors='strict'): if self.encoder is None: result = codecs.utf_16_encode(input, errors) if sys.byteorder == 'little': self.encoder = codecs.utf_16_le_encode else: self.encoder = codecs.utf_16_be_encode return result else: return self.encoder(input, errors) class StreamReader(codecs.StreamReader): def reset(self): codecs.StreamReader.reset(self) try: del self.decode except AttributeError: pass def decode(self, input, errors='strict'): (object, consumed, byteorder) = \ codecs.utf_16_ex_decode(input, errors, 0, False) if byteorder == -1: self.decode = codecs.utf_16_le_decode elif byteorder == 1: self.decode = codecs.utf_16_be_decode elif consumed>=2: raise UnicodeError("UTF-16 stream does not start with BOM") return (object, consumed) ### encodings module API def getregentry(): return codecs.CodecInfo( name='utf-16', encode=encode, decode=decode, incrementalencoder=IncrementalEncoder, incrementaldecoder=IncrementalDecoder, streamreader=StreamReader, streamwriter=StreamWriter, )
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