Unicode. Why did it have to be Unicode?

Thursday, May 30, 2024

Well, I have my answer. I first found a smaller request that exhibits the behavior as to not generate half a million lines of output:

Lines of code executed for a small request
gopher	2549
gemini	564

Good. Two and a half thousand lines of code is tractable. Now, just to show how easy it is to profile Lua code, here's the code I'm using for my gopher server:

local profile = {}

local function doprofile()
  local info = debug.getinfo(2)
  local name = info.name or "..."
  local file = info.source or "@"
  local key  = string.format("%s$%s(%d)",file,name,info.currentline)
  if not profile[key] then
    profile[key] = 1
  else
    profile[key] = profile[key] + 1
  end
end

For each line of code executed, we get the filename, the function name and the line of code that's executing, turn that into a key, and use that to count the number of times that line of code is executed. Easy. And then some code to dump the results:

local function cleanup()
  local results = {}
  for name,value in pairs(profile) do
    results[#results + 1] = { file = name , count = value }
  end
  
  table.sort(results,function(a,b)
    if a.count > b.count then
      return true
    elseif a.count < b.count then
      return false
    else
      return a.file < b.file
    end
  end)
  
  local f = io.open("/tmp/dump.txt","w")
  for i = 1 , #results do
    f:write(string.format("%6d %s\n",results[i].count,results[i].file))
  end
  f:close()  
end

We sort the results based on line count, then alphabetically by key. And like before:

local function main(iostream)
  debug.sethook(doprofile,'line')

  -- The rest of the main code

  debug.sethook()
  cleanup()
end

I make the request and get some results:

   215 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(202)
   211 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(203)
   211 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(204)
   211 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(268)
   210 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(282)
   210 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(283)
   169 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(219)
   169 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(224)
   169 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(239)
   169 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(240)
    42 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(205)
    42 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(206)
    42 @/usr/local/share/lua/5.4/org/conman/string.lua$wrapt(207)
    17 @port70.lua$...(272)
    17 @port70.lua$...(273)
     9 @/usr/local/share/lua/5.4/org/conman/net/ios.lua$write(547)
...

Oh.

Yeah.

That.

Obvious in hindsight.

I completely forgot about that.

Okay. The function in question, wrapt(), wraps text and it's a rather heavy function due to Unicode (and I'm not even following the full specification there). This is the major difference between the gopher and Gemini servers—I don't wrap text for Gemini (the clients handle that). I guess I'll have to drop down to C if I want to speed this up.

Sigh.

The Boston Diaries

Thursday, May 30, 2024

Unicode. Why did it have to be Unicode?

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