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- local lz = require "lzss"
- local buffer = require "buffer"
-
- lz16 = {}
-
- local function cint(n,l)
- local t={}
- for i = 0, 7 do
- t[i+1] = (n >> (i * 8)) & 0xFF
- end
- return string.reverse(string.char(table.unpack(t)):sub(1,l))
- end
- local function toint(s)
- local n = 0
- local i = 1
- for p in s:gmatch(".") do
- n = n << 8
- n = n | string.byte(p)
- i=i+1
- end
- return n
- end
-
- local function readBuffer(fi)
- local stream = {}
- if fi:read(4) ~= "lz16" then
- return false, "not an lz16 archive"
- end
- function stream.read()
- local len = toint(fi:read(2) or "\0\0")
- if len < 1 then
- return nil
- end
- coroutine.yield()
- return lz.decompress(fi:read(len))
- end
- function stream.close()
- fi:close()
- end
- return buffer.new("rb",stream)
- end
-
- local function writeBuffer(fo)
- local stream = {}
- function stream:write(data)
- local cblock = lz.compress(data)
- fo:write(cint(cblock:len(),2)..cblock)
- return cblock:len()+2
- end
- function stream.close()
- fo:close()
- end
- fo:write("lz16") -- write header
- return buffer.new("wb",stream)
- end
-
- function lz16.buffer(stream) -- table -- table -- Wrap a stream to read or write LZ16.
- if stream.mode.w then
- return writeBuffer(stream)
- end
- return readBuffer(stream)
- end
-
- function lz16.open(fname, mode) -- string string -- table -- Open file *fname* to read or write LZ16-compressed data depending on *mode*
- local f = io.open(fname, mode)
- if not f then return false end
- f.mode.b = true
- return lz16.buffer(f)
- end
-
- return lz16
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