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Diffstat (limited to 'serial/tools/hexlify_codec.py')
-rw-r--r-- | serial/tools/hexlify_codec.py | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/serial/tools/hexlify_codec.py b/serial/tools/hexlify_codec.py new file mode 100644 index 0000000..bd8f6b0 --- /dev/null +++ b/serial/tools/hexlify_codec.py @@ -0,0 +1,126 @@ +#! python +# +# This is a codec to create and decode hexdumps with spaces between characters. used by miniterm. +# +# This file is part of pySerial. https://github.com/pyserial/pyserial +# (C) 2015-2016 Chris Liechti <cliechti@gmx.net> +# +# SPDX-License-Identifier: BSD-3-Clause +"""\ +Python 'hex' Codec - 2-digit hex with spaces content transfer encoding. + +Encode and decode may be a bit missleading at first sight... + +The textual representation is a hex dump: e.g. "40 41" +The "encoded" data of this is the binary form, e.g. b"@A" + +Therefore decoding is binary to text and thus converting binary data to hex dump. + +""" + +from __future__ import absolute_import + +import codecs +import serial + + +try: + unicode +except (NameError, AttributeError): + unicode = str # for Python 3, pylint: disable=redefined-builtin,invalid-name + + +HEXDIGITS = '0123456789ABCDEF' + + +# Codec APIs + +def hex_encode(data, errors='strict'): + """'40 41 42' -> b'@ab'""" + return (serial.to_bytes([int(h, 16) for h in data.split()]), len(data)) + + +def hex_decode(data, errors='strict'): + """b'@ab' -> '40 41 42'""" + return (unicode(''.join('{:02X} '.format(ord(b)) for b in serial.iterbytes(data))), len(data)) + + +class Codec(codecs.Codec): + def encode(self, data, errors='strict'): + """'40 41 42' -> b'@ab'""" + return serial.to_bytes([int(h, 16) for h in data.split()]) + + def decode(self, data, errors='strict'): + """b'@ab' -> '40 41 42'""" + return unicode(''.join('{:02X} '.format(ord(b)) for b in serial.iterbytes(data))) + + +class IncrementalEncoder(codecs.IncrementalEncoder): + """Incremental hex encoder""" + + def __init__(self, errors='strict'): + self.errors = errors + self.state = 0 + + def reset(self): + self.state = 0 + + def getstate(self): + return self.state + + def setstate(self, state): + self.state = state + + def encode(self, data, final=False): + """\ + Incremental encode, keep track of digits and emit a byte when a pair + of hex digits is found. The space is optional unless the error + handling is defined to be 'strict'. + """ + state = self.state + encoded = [] + for c in data.upper(): + if c in HEXDIGITS: + z = HEXDIGITS.index(c) + if state: + encoded.append(z + (state & 0xf0)) + state = 0 + else: + state = 0x100 + (z << 4) + elif c == ' ': # allow spaces to separate values + if state and self.errors == 'strict': + raise UnicodeError('odd number of hex digits') + state = 0 + else: + if self.errors == 'strict': + raise UnicodeError('non-hex digit found: {!r}'.format(c)) + self.state = state + return serial.to_bytes(encoded) + + +class IncrementalDecoder(codecs.IncrementalDecoder): + """Incremental decoder""" + def decode(self, data, final=False): + return unicode(''.join('{:02X} '.format(ord(b)) for b in serial.iterbytes(data))) + + +class StreamWriter(Codec, codecs.StreamWriter): + """Combination of hexlify codec and StreamWriter""" + + +class StreamReader(Codec, codecs.StreamReader): + """Combination of hexlify codec and StreamReader""" + + +def getregentry(): + """encodings module API""" + return codecs.CodecInfo( + name='hexlify', + encode=hex_encode, + decode=hex_decode, + incrementalencoder=IncrementalEncoder, + incrementaldecoder=IncrementalDecoder, + streamwriter=StreamWriter, + streamreader=StreamReader, + #~ _is_text_encoding=True, + ) |