forked from izaya/OC-PsychOS2
54 lines
1.2 KiB
Lua
54 lines
1.2 KiB
Lua
local lz = require "lzss"
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local buffer = require "buffer"
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lz16 = {}
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local function readBuffer(fi)
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local stream = {}
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if fi:read(4) ~= "lz16" then
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return false, "not an lz16 archive"
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end
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function stream.read()
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local len = string.unpack(">I2", fi:read(2) or "\0\0")
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if len < 1 then
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return nil
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end
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coroutine.yield()
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return lz.decompress(fi:read(len))
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end
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function stream.close()
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fi:close()
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end
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return buffer.new("rb",stream)
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end
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local function writeBuffer(fo)
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local stream = {}
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function stream:write(data)
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local cblock = lz.compress(data)
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fo:write(string.pack(">I2", cblock:len()) .. cblock)
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return cblock:len()+2
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end
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function stream.close()
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fo:close()
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end
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fo:write("lz16") -- write header
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return buffer.new("wb",stream)
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end
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function lz16.buffer(stream) -- table -- table -- Wrap a stream to read or write LZ16.
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if stream.mode.w then
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return writeBuffer(stream)
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end
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return readBuffer(stream)
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end
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function lz16.open(fname, mode) -- string string -- table -- Open file *fname* to read or write LZ16-compressed data depending on *mode*
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local f = io.open(fname, mode)
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if not f then return false end
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f.mode.b = true
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return lz16.buffer(f)
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end
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return lz16
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