mirror of
https://github.com/ShadowKatStudios/OC-Minitel.git
synced 2024-11-01 08:10:56 +11:00
64 lines
1.5 KiB
Lua
64 lines
1.5 KiB
Lua
local imt = {}
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imt.ttypes = {}
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imt.ttypes.string=1
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imt.ttypes.number=2
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imt.ftypes = {tostring,tonumber}
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function imt.to16bn(n)
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return string.char(math.floor(n/256))..string.char(math.floor(n%256))
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end
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function imt.from16bn(s)
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return (string.byte(s,1,1)*256)+string.byte(s,2,2)
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end
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function imt.encodePacket(...)
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local tArgs = {...}
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local packet = string.char(#tArgs%256)
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for _,segment in ipairs(tArgs) do
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local segtype = type(segment)
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segment = tostring(segment)
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packet = packet .. imt.to16bn(segment:len()) .. string.char(imt.ttypes[segtype]) .. tostring(segment)
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end
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packet = imt.to16bn(packet:len()) .. packet
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return packet
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end
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function imt.decodePacket(s)
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local function getfirst(n)
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local ns = s:sub(1,n)
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s=s:sub(n+1)
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return ns
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end
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if s:len() < 2 then return false end
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local plen = imt.from16bn(getfirst(2))
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local segments = {}
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if s:len() < plen then return false end
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local nsegments = string.byte(getfirst(1))
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--print(tostring(plen).." bytes, "..tostring(nsegments).." segments")
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for i = 1, nsegments do
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local seglen = imt.from16bn(getfirst(2))
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local segtype = imt.ftypes[string.byte(getfirst(1))]
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local segment = segtype(getfirst(seglen))
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--print(seglen,segtype,segment,type(segment))
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segments[#segments+1] = segment
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end
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return table.unpack(segments)
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end
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function imt.getRemainder(s)
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local function getfirst(n)
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local ns = s:sub(1,n)
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s=s:sub(n+1)
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return ns
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end
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local plen = imt.from16bn(getfirst(2))
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if s:len() > plen then
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getfirst(plen)
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return s
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end
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return nil
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end
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return imt
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