简易Lua剖析

要跟踪变量,您需要使用debug.getlocal和debug.getupvalue(来自您的代码或来自调试钩子).

要跟踪内存使用情况,您可以使用collectgarbage(count)(可能在collectgarbage(collect)之后),但这只会告诉您使用的总内存.要跟踪单个数据结构,您可能需要遍历全局和局部变量并计算它们占用的空间量.您可以查看this discussion以获取一些指针和实现细节.

像这样的东西将是跟踪函数调用/返回的最简单的分析器(请注意,您不应该信任它生成的绝对数字,只有相对的数字)：

local calls,total,this = {},{},{}
debug.sethook(function(event)
  local i = debug.getinfo(2,"Sln")
  if i.what ~= 'Lua' then return end
  local func = i.name or (i.source..':'..i.linedefined)
  if event == 'call' then
    this[func] = os.clock()
  else
    local time = os.clock() - this[func]
    total[func] = (total[func] or 0) + time
    calls[func] = (calls[func] or 0) + 1
  end
end,"cr")

-- the code to debug starts here
local function DoSomethingMore(x)
  x = x / 2
end

local function DoSomething(x)
  x = x + 1
  if x % 2 then DoSomethingMore(x) end
end

for outer=1,100 do
  for inner=1,1000 do
    DoSomething(inner)
  end
end

-- the code to debug ends here; reset the hook
debug.sethook()

-- print the results
for f,time in pairs(total) do
  print(("Function %s took %.3f seconds after %d calls"):format(f,time,calls[f]))
end