97 lines
3.0 KiB
Lua
97 lines
3.0 KiB
Lua
-- Minified CRC32 blob - MIT license - from here: https://raw.githubusercontent.com/davidm/lua-digest-crc32lua/master/lmod/digest/crc32lua.lua
|
|
do
|
|
local type=type;local require=require;local setmetatable=setmetatable;local a=bit.bxor;local b=bit.bnot;local c=bit.band;local d=bit.brshift;local e=0xEDB88320;local function f(g)local h={}local i=setmetatable({},h)function h:__index(j)local k=g(j)i[j]=k;return k end;return i end;local l=f(function(m)local n=m;for o=1,8 do local p=c(n,1)n=d(n,1)if p==1 then n=a(n,e)end end;return n end)local function q(r,n)n=b(n or 0)local s=d(n,8)local t=l[a(n%256,r)]return b(a(s,t))end;local function u(v,n)n=n or 0;for m=1,#v do n=q(v:byte(m),n)end;return n end;function crc32(v,n)if type(v)=='string'then return u(v,n)else return q(v,n)end end
|
|
end
|
|
|
|
local function get_byte(num, byte)
|
|
return bit.band(bit.brshift(num, byte * 8), 0xFF)
|
|
end
|
|
|
|
local function from_bytes(b)
|
|
local n = 0
|
|
for ix, byte in pairs(b) do
|
|
n = bit.bor(n, bit.blshift(byte, (ix - 1) * 8))
|
|
end
|
|
return n
|
|
end
|
|
|
|
local side = settings.get "bundlenet.side" or "back"
|
|
|
|
local function send_raw(str)
|
|
local i = 1
|
|
for i = 1, math.ceil(#str / 2) do
|
|
local first = str:byte(i * 2 - 1)
|
|
local second = str:byte(i * 2) or 0
|
|
local u16 = first * 256 + second
|
|
rs.setBundledOutput(side, u16)
|
|
sleep(0.1)
|
|
end
|
|
rs.setBundledOutput(side, 0)
|
|
end
|
|
|
|
local function receive_raw(length)
|
|
local str = ""
|
|
local count = 0
|
|
os.pullEvent "redstone"
|
|
while true do
|
|
local u16 = rs.getBundledInput(side)
|
|
local first = string.char(math.floor(u16 / 256))
|
|
if not length and first == "\0" then break
|
|
else
|
|
count = count + 1
|
|
str = str .. first
|
|
if count == length then break end
|
|
local second = string.char(u16 % 256)
|
|
if not length and second == "\0" then break
|
|
else
|
|
count = count + 1
|
|
str = str .. second
|
|
if count == length then break end
|
|
end
|
|
end
|
|
sleep(0.1)
|
|
end
|
|
return str
|
|
end
|
|
|
|
local function u32_to_string(u32)
|
|
return string.char(get_byte(u32, 0), get_byte(u32, 1), get_byte(u32, 2), get_byte(u32, 3))
|
|
end
|
|
|
|
local function string_to_u32(str)
|
|
return from_bytes{str:byte(1), str:byte(2), str:byte(3), str:byte(4)}
|
|
end
|
|
|
|
local function send(data)
|
|
local length = u32_to_string(#data)
|
|
local checksum = u32_to_string(crc32(data))
|
|
print("len", length, "checksum", checksum)
|
|
send_raw(length)
|
|
send_raw(checksum)
|
|
send_raw(data)
|
|
end
|
|
|
|
local function receive()
|
|
local length = receive_raw(4)
|
|
sleep(0.1)
|
|
local checksum = receive_raw(4)
|
|
print("len", length, "checksum", checksum, "l", string_to_u32(length), "c", string_to_u32(checksum))
|
|
sleep(0.1)
|
|
local data = receive_raw(string_to_u32(length))
|
|
if crc32(data) ~= string_to_u32(checksum) then return false, "checksum mismatch", data end
|
|
return true, data
|
|
end
|
|
|
|
local option = ...
|
|
|
|
if option == "send" then
|
|
write "Send: "
|
|
local text = read()
|
|
send(text)
|
|
elseif option == "raw_receive" then
|
|
print(receive_raw())
|
|
elseif option == "receive" then
|
|
print(receive())
|
|
end
|
|
|
|
return { send = send, receive = receive } |