table_shrinking.lua

table_shrinking.lua

-- memory test

local size = 1000000
local t = {}   -- create a table

local function report(title)
  collectgarbage()
  collectgarbage()
  print(title, collectgarbage("count"))
end


report("start")

for i = 1,size do  -- fill the table with values, causing the c-size structure of the table to expand several times over
  t[i] = {}
end

report("filled")

for i = 1,size do  -- clear individual values from the table. But the table structures itself will not shrink back
  t[i] = nil
end

report("emptied") -- replace the table structure, such that it get's GC'ed and it finally releases its memory

t = {}

report("cleared")