Profile.lua

profile.lua is a small, non-intrusive module for finding bottlenecks in your Lua code. The profiler is used by making minimal changes to your existing code. Basically, you require the profile.lua file and specify when to start or stop collecting data. Once you are done profiling, a report is generated, describing:

which functions were called most frequently and
how much time was spent executing each function

Documentation

The full documentation is available at: https://2dengine.com/?p=profile

Compatibility

The profiler has been tested with both LuaJIT 2.0.5 and Lua 5.3 although there are no guarantees regarding its accuracy. Use at your own discretion! LuaJIT optimizations must be off when using the profiler and coroutines are unsupported.

API

profile.report(rows)

Generates a report and returns it as a string. "rows" limits the number of rows in the report.

profile.start()

Starts collecting data.

profile.stop()

Stops collecting data. For optimal accuracy, this function should be called from code that is NOT being profiled.

profile.reset()

Resets all collected data.

profile.setclock(func)

Defines a custom clock function that must return a number.

Examples

Basic

local profile = require("profile")
profile.start()
-- execute code that will be profiled
profile.stop()
-- report for the top 10 functions, sorted by execution time
print(profile.report(10))

Love2D

-- setup
function love.load()
  love.profiler = require('profile') 
  love.profiler.start()
end

-- generates a report every 100 frames
love.frame = 0
function love.update(dt)
  love.frame = love.frame + 1
  if love.frame%100 == 0 then
    love.report = love.profiler.report(20)
    love.profiler.reset()
  end
end

-- prints the report
function love.draw()
  love.graphics.print(love.report or "Please wait...")
end

Reports

The default report is in plain text:

 +-----+----------------------------------+----------+--------------------------+----------------------------------+
 | #   | Function                         | Calls    | Time                     | Code                             |
 +-----+----------------------------------+----------+--------------------------+----------------------------------+
 | 1   | update                           | 1        | 9.0023296745494          | main.lua:23                      |
 | 2   | f                                | 1        | 9.0022503120126          | main.lua:12                      |
 | 3   | g                                | 8        | 8.0016986143455          | main.lua:5                       |
 | 4   | [string "boot.lua"]:185          | 3        | 2.4960798327811e-005     | [string "boot.lua"]:185          |
 | 5   | [string "boot.lua"]:134          | 2        | 1.7920567188412e-005     | [string "boot.lua"]:134          |
 | 6   | [string "boot.lua"]:188          | 1        | 1.6000514733605e-005     | [string "boot.lua"]:188          |
 | 7   | [string "boot.lua"]:182          | 1        | 1.2160395272076e-005     | [string "boot.lua"]:182          |
 | 8   | [string "boot.lua"]:131          | 1        | 1.0240328265354e-005     | [string "boot.lua"]:131          |
 | 9   | load                             | 0        | 0                        | main.lua:17                      |
 +-----+----------------------------------+----------+--------------------------+----------------------------------+

It's easy to generate any type of report that you want, for example CSV:

print('Position,Function name,Number of calls,Time,Source,')
for t in ipairs(profiler.query(10)) do
  print(table.concat(t, ",")..",")
end

Credits

0x25a0 grump Roland Yonaba

Intrets/profile.lua