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questhelperredux/QuestHelper/collect_lzw.lua

337 lignes
9 Kio
Lua
Brut Vue normale Historique

2010-10-24 23:17:33 +02:00
QuestHelper_File["collect_lzw.lua"] = "1.4.0"
QuestHelper_Loadtime["collect_lzw.lua"] = GetTime()
local Merger
local Bitstream
local function cleanup(tab)
for _, v in pairs(tab) do
QuestHelper:ReleaseTable(v)
end
QuestHelper:ReleaseTable(tab)
end
local function QH_LZW_Decompress(input, tokens, outbits, inputstatic)
local d = QuestHelper:CreateTable("lzw")
local i
for i = 0, tokens-1 do
d[i] = QuestHelper:CreateTable("lzw")
d[i][0] = string.char(i)
end
local dsize = tokens + 1 -- we use the "tokens" value as an EOF marker
if inputstatic then
local used = QuestHelper:CreateTable("lzw")
for _, v in ipairs(inputstatic) do
for i = #v, 2, -1 do
local subi = v:sub(1, i)
if not used[subi] then
used[subi] = true
d[bit.mod(dsize, tokens)][math.floor(dsize / tokens)] = subi
dsize = dsize + 1
else
break
end
end
end
QuestHelper:ReleaseTable(used)
end
local bits = 1
local nextbits = 2
while nextbits < dsize do bits = bits + 1; nextbits = nextbits * 2 end
local i = Bitstream.Input(input, outbits)
local rv = {}
local idlect = 0
local tok = i:depend(bits)
if tok == tokens then cleanup(d) return "" end -- Okay. There's nothing. We get it.
Merger.Add(rv, d[bit.mod(tok, tokens)][math.floor(tok / tokens)])
local w = d[bit.mod(tok, tokens)][math.floor(tok / tokens)]
while true do
if idlect == 25 then
QH_Timeslice_Yield()
idlect = 0
else
idlect = idlect + 1
end
dsize = dsize + 1 -- We haven't actually added the next element yet. However, we could in theory include it in the stream, so we need to adjust the number of bits properly.
if dsize > nextbits then
bits = bits + 1
nextbits = nextbits * 2
end
tok = i:depend(bits)
if tok == tokens then break end -- we're done!
local entry
if d[bit.mod(tok, tokens)][math.floor(tok / tokens)] then
entry = d[bit.mod(tok, tokens)][math.floor(tok / tokens)]
elseif tok == dsize - 1 then
entry = w .. w:sub(1, 1)
else
QuestHelper: Assert(false, "faaaail")
end
Merger.Add(rv, entry)
d[bit.mod(dsize - 1, tokens)][math.floor((dsize - 1) / tokens)] = w .. entry:sub(1, 1) -- Naturally, we're writing to one *less* than dsize, since we already incremented.
w = entry
end
cleanup(d)
return Merger.Finish(rv)
end
local function QH_LZW_Compress(input, tokens, outbits, inputstatic)
-- shared init code
local d = {}
local i
for i = 0, tokens-1 do
d[string.char(i)] = {[""] = i}
end
local dsize = tokens + 1 -- we use the "tokens" value as an EOF marker
if inputstatic then
for _, v in ipairs(inputstatic) do
local da = d[v:sub(1, 1)]
for i = #v, 2, -1 do
local b = v:sub(2, i)
if not da[b] then
da[b] = dsize
dsize = dsize + 1
else
break
end
end
end
end
local bits = 1
local nextbits = 2
while nextbits < dsize do bits = bits + 1; nextbits = nextbits * 2 end
local r = Bitstream.Output(outbits)
local idlect = 0
local w = ""
for ci = 1, #input do
if idlect == 100 then
QH_Timeslice_Yield()
idlect = 0
else
idlect = idlect + 1
end
local c = input:sub(ci, ci)
local wcp = w .. c
if d[wcp:sub(1, 1)][wcp:sub(2)] then
w = wcp
else
r:append(d[w:sub(1, 1)][w:sub(2)], bits)
d[wcp:sub(1, 1)][wcp:sub(2)] = dsize
dsize = dsize + 1
if dsize > nextbits then
bits = bits + 1
nextbits = nextbits * 2
end
w = c
end
end
if w ~= "" then
r:append(d[w:sub(1, 1)][w:sub(2)], bits)
dsize = dsize + 1 -- Our decompressor doesn't realize we're ending here, so it will have added a table entry for that last token. Sigh.
if dsize > nextbits then
bits = bits + 1
nextbits = nextbits * 2
end
end
r:append(tokens, bits)
local rst = r:finish()
QuestHelper: Assert(QH_LZW_Decompress(rst, tokens, outbits, inputstatic) == input) -- yay
return rst
end
local function mdict(inputdict)
local idc = QuestHelper:CreateTable("lzw mdict")
for i = 1, #inputdict do if math.fmod(i, 100) == 0 then QH_Timeslice_Yield() end idc[inputdict:sub(i, i)] = strchar(i - 1) end
return idc
end
local function dictize(idcl, stt)
local im = QuestHelper:CreateTable("lzw dictize")
for i = 1, #stt do
local subl = idcl[stt:sub(i, i)]
QuestHelper: Assert(subl)
Merger.Add(im, subl)
end
local result = Merger.Finish(im)
QuestHelper:ReleaseTable(im)
return result
end
local function QH_LZW_Prepare(inputdict, inputstatic)
QuestHelper: Assert(inputdict and inputstatic)
local idc = mdict(inputdict)
local inpstat = {}
local ct = 0
for _, v in ipairs(inputstatic) do
ct = ct + 1
if ct == 10 then QH_Timeslice_Yield() ct = 0 end
table.insert(inpstat, dictize(idc, v))
end
return idc, #inputdict, inpstat
end
local function QH_LZW_Compress_Dicts_Prepared(input, idprepped, idpreppedsize, outputdict, isprepped)
input = dictize(idprepped, input)
local bits, dsize = 1, 2
if not outputdict then bits = 8 else while dsize < #outputdict do bits = bits + 1 ; dsize = dsize * 2 end end
QuestHelper: Assert(not outputdict or #outputdict == dsize)
local comp = QH_LZW_Compress(input, idpreppedsize, bits, isprepped)
if outputdict then
local origcomp = comp
local im = {}
for i = 1, #origcomp do Merger.Add(im, outputdict:sub(strbyte(origcomp:sub(i, i)) + 1)) end
comp = Merger.Finish(im)
end
return comp
end
local function QH_LZW_Compress_Dicts(input, inputdict, outputdict, inputstatic)
local inproc = input
local inpstat = inputstatic
if inputdict then
local idc = mdict(inputdict)
inproc = dictize(idc, input)
if inputstatic then
inpstat = {}
for _, v in ipairs(inputstatic) do
table.insert(inpstat, dictize(idc, v))
end
end
QuestHelper:ReleaseTable(idc)
end
local bits, dsize = 1, 2
if not outputdict then bits = 8 else while dsize < #outputdict do bits = bits + 1 ; dsize = dsize * 2 end end
QuestHelper: Assert(not outputdict or #outputdict == dsize)
local comp = QH_LZW_Compress(inproc, inputdict and #inputdict or 256, bits, inpstat)
if outputdict then
local origcomp = comp
local im = {}
for i = 1, #origcomp do Merger.Add(im, outputdict:sub(strbyte(origcomp:sub(i, i)) + 1)) end
comp = Merger.Finish(im)
end
return comp
end
local function QH_LZW_Decompress_Dicts_Prepared(compressed, inputdict, outputdict, ispreppred) -- this is kind of backwards - we assume that "outputdict" is the dictionary that "compressed" is encoded in
QuestHelper: Assert(not outputdict)
QuestHelper: Assert(inputdict)
local decomp = QH_LZW_Decompress(compressed, #inputdict, 8, ispreppred)
local ov = {}
for i = 1, #decomp do
Merger.Add(ov, inputdict:sub(decomp:byte(i) + 1, decomp:byte(i) + 1))
end
return Merger.Finish(ov)
end
local function QH_LZW_Decompress_Dicts(compressed, inputdict, outputdict, inputstatic) -- this is kind of backwards - we assume that "outputdict" is the dictionary that "compressed" is encoded in
QuestHelper: Assert(not outputdict)
QuestHelper: Assert(inputdict)
local inpstat = inputstatic
if inputdict and inputstatic then
local idc = mdict(inputdict)
inpstat = {}
for _, v in ipairs(inputstatic) do
table.insert(inpstat, dictize(idc, v))
end
QuestHelper:ReleaseTable(idc)
end
local decomp = QH_LZW_Decompress(compressed, #inputdict, 8, inpstat)
local ov = {}
for i = 1, #decomp do
Merger.Add(ov, inputdict:sub(decomp:byte(i) + 1, decomp:byte(i) + 1))
end
return Merger.Finish(ov)
end
QH_LZW_Prepare_Arghhacky = QH_LZW_Prepare -- need to rig up a better mechanism for this really
QH_LZW_Decompress_Dicts_Arghhacky = QH_LZW_Decompress_Dicts -- need to rig up a better mechanism for this really
QH_LZW_Decompress_Dicts_Prepared_Arghhacky = QH_LZW_Decompress_Dicts_Prepared -- need to rig up a better mechanism for this really
function QH_Collect_LZW_Init(_, API)
Merger = API.Utility_Merger
QuestHelper: Assert(Merger)
Bitstream = API.Utility_Bitstream
QuestHelper: Assert(Bitstream)
API.Utility_LZW = {Compress = QH_LZW_Compress, Decompress = QH_LZW_Decompress, Compress_Dicts = QH_LZW_Compress_Dicts, Decompress_Dicts = QH_LZW_Decompress_Dicts, Prepare = QH_LZW_Prepare, Compress_Dicts_Prepared = QH_LZW_Compress_Dicts_Prepared, Decompress_Dicts_Prepared = QH_LZW_Decompress_Dicts_Prepared}
end
-- old debug code :)
--[[
print("hello")
QH_LZW_Compress("TOBEORNOTTOBEORTOBEORNOT", 256, 8)
]]
--[[
QuestHelper:TextOut("lulz")
local inq = "ABABABABA"
local alpha = 253
local bits = 7
str = QH_LZW_Compress(inq, alpha, bits)
tvr = ""
for i = 1, #str do
tvr = tvr .. string.format("%d ", strbyte(str, i))
end
QuestHelper:TextOut(tvr)
ret = QH_LZW_Decompress(str, alpha, bits)
QuestHelper:TextOut(ret)
QuestHelper: Assert(inq == ret)
]]