+++ /dev/null
-# Base91 encode/decode for Python 2 and Python 3
-#
-# Copyright (c) 2012 Adrien Beraud
-# Copyright (c) 2015 Guillaume Jacquenot
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are met:
-#
-# * Redistributions of source code must retain the above copyright notice,
-# this list of conditions and the following disclaimer.
-# * Redistributions in binary form must reproduce the above copyright notice,
-# this list of conditions and the following disclaimer in the documentation
-# and/or other materials provided with the distribution.
-# * Neither the name of Adrien Beraud, Wisdom Vibes Pte. Ltd., nor the names
-# of its contributors may be used to endorse or promote products derived
-# from this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
-# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
-# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
-# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
-# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-#
-import struct
-
-base91_alphabet = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
- 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
- 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
- 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
- '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '!', '#', '$',
- '%', '&', '(', ')', '*', '+', ',', '.', '/', ':', ';', '<', '=',
- '>', '?', '@', '[', ']', '^', '_', '`', '{', '|', '}', '~', '"']
-
-decode_table = dict((v,k) for k,v in enumerate(base91_alphabet))
-
-def decode(encoded_str):
- ''' Decode Base91 string to a bytearray '''
- v = -1
- b = 0
- n = 0
- out = bytearray()
- for strletter in encoded_str:
- if not strletter in decode_table:
- continue
- c = decode_table[strletter]
- if(v < 0):
- v = c
- else:
- v += c*91
- b |= v << n
- n += 13 if (v & 8191)>88 else 14
- while True:
- out += struct.pack('B', b&255)
- b >>= 8
- n -= 8
- if not n>7:
- break
- v = -1
- if v+1:
- out += struct.pack('B', (b | v << n) & 255 )
- return out
-
-def encode(bindata):
- ''' Encode a bytearray to a Base91 string '''
- b = 0
- n = 0
- out = ''
- for count in range(len(bindata)):
- byte = bindata[count:count+1]
- b |= struct.unpack('B', byte)[0] << n
- n += 8
- if n>13:
- v = b & 8191
- if v > 88:
- b >>= 13
- n -= 13
- else:
- v = b & 16383
- b >>= 14
- n -= 14
- out += base91_alphabet[v % 91] + base91_alphabet[v // 91]
- if n:
- out += base91_alphabet[b % 91]
- if n>7 or b>90:
- out += base91_alphabet[b // 91]
- return out