On Sat, Jul 3, 2021 at 12:44 AM Xmilia Hermit wrote:
How about:
-- compressor.lua
local num_bits = 64
local function Encode(what)
local tab = {}
for i = 1, num_bits do
if what & (1 << (i - 1)) ~= 0 then
tab[i + 0.5] = true
end
end
for k, v in pairs(tab) do
tab[k] = nil
end
return tab
end
return Encode(...)
-- decompressor.lua
local num_bits = 64
function Decode(tab)
local num = 0
for i = 1, num_bits do
if pcall(next, tab, i + 0.5) then
num = num | (1 << (i - 1))
end
end
return num
end
return Decode(...)
It is simpler, smaller, uses less memory.
Almost solved!
64 is better than 256, but still not good enough
Try to use the same idea to reduce hash part size to 8 hash slots.
And another one using callbacks via __gc metamethod:
-- compressor.lua
local function Encode(what)
local tab = {}
local function gc()
if not tab.pass then
setmetatable({}, {__gc = gc})
else
tab.res = what
end
end
gc()
return tab
end
return Encode(...)
-- decompressor.lua
local function ForceGC()
local gc = false
setmetatable({}, {__gc = function() gc = true end})
local mem = {}
while not gc do
mem = {mem}
end
end
local function Decode(tab)
tab.pass = true
ForceGC()
return tab.res
end
return Decode(...)
Wonderful idea!
