想了 大约 2个月

我效果非常满意

humbase64.lua

–[[

haffman compressed spical base64 by T.G.(farmer1992@gmail.com)
QQ 22267156
]]

local base64chars = {[0]=’A',[1]=’B',[2]=’C',[3]=’D',[4]=’E',[5]=’F',[6]=’G',[7]=’H',[8]=’I',[9]=’J',[10]=’K',[11]=’L',[12]=’M',[13]=’N',[14]=’O',[15]=’P',[16]=’Q',[17]=’R',[18]=’S',[19]=’T',[20]=’U',[21]=’V',[22]=’W',[23]=’X',[24]=’Y',[25]=’Z',[26]=’a',[27]=’b',[28]=’c',[29]=’d',[30]=’e',[31]=’f',[32]=’g',[33]=’h',[34]=’i',[35]=’j',[36]=’k',[37]=’l',[38]=’m',[39]=’n',[40]=’o',[41]=’p',[42]=’q',[43]=’r',[44]=’s',[45]=’t',[46]=’u',[47]=’v',[48]=’w',[49]=’x',[50]=’y',[51]=’z',[52]=’0′,[53]=’1′,[54]=’2′,[55]=’3′,[56]=’4′,[57]=’5′,[58]=’6′,[59]=’7′,[60]=’8′,[61]=’9′,[62]=’-',[63]=’_'}
local base64bytes = {['-']=”111110″,['_']=”111111″,['0']=”110100″,['1']=”110101″,['2']=”110110″,['3']=”110111″,['4']=”111000″,['5']=”111001″,['6']=”111010″,['7']=”111011″,['8']=”111100″,['9']=”111101″,['A']=”000000″,['a']=”011010″,['B']=”000001″,['b']=”011011″,['C']=”000010″,['c']=”011100″,['D']=”000011″,['d']=”011101″,['E']=”000100″,['e']=”011110″,['F']=”000101″,['f']=”011111″,['G']=”000110″,['g']=”100000″,['H']=”000111″,['h']=”100001″,['I']=”001000″,['i']=”100010″,['J']=”001001″,['j']=”100011″,['K']=”001010″,['k']=”100100″,['L']=”001011″,['l']=”100101″,['M']=”001100″,['m']=”100110″,['N']=”001101″,['n']=”100111″,['O']=”001110″,['o']=”101000″,['P']=”001111″,['p']=”101001″,['Q']=”010000″,['q']=”101010″,['R']=”010001″,['r']=”101011″,['S']=”010010″,['s']=”101100″,['T']=”010011″,['t']=”101101″,['U']=”010100″,['u']=”101110″,['V']=”010101″,['v']=”101111″,['W']=”010110″,['w']=”110000″,['X']=”010111″,['x']=”110001″,['Y']=”011000″,['y']=”110010″,['Z']=”011001″,['z']=”110011″}

local haffman_t={[0]=”00″,[1]=”01″,[2]=”100″,[3]=”101″,[4]=”1100″,[5]=”1101″,[6]=”11100″,[7]=”11101″,[8]=”111100″,[9]=”111101″,[10]=”1111100″,[11]=”1111101″,[12]=”11111100″,[13]=”11111101″,[14]=”111111100″,[15]=”111111101″,}

– enc begin

local function tobase64char(num)
while string.len(num)~=6 do
num=num..”1″
end
return base64chars[(tonumber(num,2))]
end

local function enc(data)

local count_t={[1]={n=”0″,p=0},[2]={n=”1″,p=0},[3]={n=”2″,p=0},[4]={n=”3″,p=0},[5]={n=”4″,p=0},[6]={n=”5″,p=0},[7]={n=”6″,p=0},[8]={n=”7″,p=0},[9]={n=”8″,p=0},[10]={n=”9″,p=0},[11]={n=”a”,p=0},[12]={n=”b”,p=0},[13]={n=”c”,p=0},[14]={n=”d”,p=0},[15]={n=”e”,p=0},[16]={n=”f”,p=0},}
local data_str={}

for i=1,string.len(data) do
n=string.byte(data,i)
a=n%16
b=(n-a)/16

count_t[a+1].p=count_t[a+1].p+1
count_t[b+1].p=count_t[b+1].p+1

data_str[#data_str+1]=b
data_str[#data_str+1]=a
end

table.sort(count_t,function(a,b) return a.p>b.p end)

local out_str={}
local this_haffman_t={}

for i,v in ipairs(count_t) do
this_haffman_t[tonumber(v.n,16)]=haffman_t[i-1]
out_str[#out_str+1]=v.n
end

for i,v in ipairs(data_str) do
data_str[i]=this_haffman_t[v]
end

local bin_str=table.concat(data_str)

for i=1,string.len(bin_str),6 do
local bin6=string.sub(bin_str,i,i+5)
out_str[#out_str+1]=tobase64char(bin6)
end

return table.concat(out_str)
end

– enc end

– dec begin

local function readabit(s)
local i=0
return function()
i=i+1
return string.sub(s,i,i) or “”
end
end

local function getxbit(r,h)
local t=”"
while(r()==”1″) do
t=t..”1″
end

t=t..”0″..r()
return h[t] or “X”
end

local function dec(data)

local this_haffman_t={}

for i=1,16 do
this_haffman_t[haffman_t[i-1]]=(string.sub(data,i,i))
end

local t={}
for i=17,string.len(data) do
t[#t+1]=base64bytes[(string.sub(data,i,i))]
end

local reader=readabit(table.concat(t))

local temp=getxbit(reader,this_haffman_t)

local out_str={}

while temp~=”X” do
out_str[#out_str+1]=string.char(tonumber(temp..getxbit(reader,this_haffman_t),16))
temp=getxbit(reader,this_haffman_t)
end

return table.concat(out_str)
end

HumBase64={
enc=enc,
dec=dec,
}

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