pyalot

from struct import unpack
from zlib import decompress

class BufferStream:
    def __init__(self, data):
        self.pos = 0
        self.data = data

    def get(self, amount):
        result = self.data[self.pos:self.pos+amount]

pyalot

decodingTable = new Uint8Array(256)
for c, i in 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
    decodingTable[c.charCodeAt(0)] = i

base64decode = (string) ->
    last = string[string.length-2...string.length]
    if last == '=='
        remainder = 2
    else if last[1] == '='
        remainder = 1