prerelease basic profiler for lua, depends on batteries and uses lg as an alias for love.graphics - will be included in ferris at some point

license.txt

Copyright 2023 Max Cahill

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not
   claim that you wrote the original software. If you use this software
   in a product, an acknowledgment in the product documentation would be
   appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
   misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.

profiler.lua

--measuring the time and memory allocated by a stretch of code

local profiler = class({
	name = "profiler"
})

function profiler:new()
	self._stack = {}
	self._result = {}
end

function profiler:push(name)
	if #self._stack == 0 then
		--pushing a new frame
		table.clear(self._result)
	end
	local block = {
		name = name,
		time = love.timer.getTime(),
		memory = (collectgarbage("count") * 1024),
		depth = #self._stack + 1,
	}
	table.insert(self._result, block)
	table.insert(self._stack, block)
end

function profiler:pop(name)
	local block = table.pop(self._stack)
	assert:equal(name, block.name, "profiler block names should match")
	block.time = (love.timer.getTime() - block.time) * 1000
	block.memory = (collectgarbage("count") * 1024) - block.memory
end

function profiler:wrap_system(name, system)
	if system.update then
		system.update = self:wrap_function(name .. "_update", system.update)
	end
	if system.draw then
		system.draw = self:wrap_function(name .. "_draw", system.draw)
	end
	return system
end

function profiler:wrap_function(name, f)
	return function(...)
		self:push(name)
		local result = {f(...)} --capture
		self:pop(name)
		return unpack(result)
	end
end

function profiler:result()
	return table.copy(self._result)
end

function profiler:print_result()
	lg.push()
	local f = lg.getFont()
	local line_height = f:getHeight() * f:getLineHeight()
	for _, v in ipairs(self:result()) do
		lg.setColor(0, 0, 0)
		lg.rectangle("fill", -5, 0, 355, line_height)
		lg.setColor(1, 1, 1)
		lg.push()
		lg.translate(v.depth * 10, 0)
		lg.print(v.name, 0, 0)
		lg.print(("%05.2fms"):format(v.time), 150, 0)
		lg.print(("%04.2fmb"):format(v.memory / 1024 / 1024), 250, 0)
		lg.pop()
		lg.translate(0, line_height)
	end
	lg.pop()
end

return profiler

usage.lua

profiler = require("src.profiler")() --wherever you put it; global so that you can push/pop more frames "wherever"

--either put it in your main loop, or dos omething like this

function love.update(dt)
	profiler:push("frame")
	profiler:push("update")
  
	--do all your update stuff here
  
	profiler:pop("update")
end

function love.draw(t)
	profiler:push("draw")
	
	--draw everything
	
	profiler:pop("draw")
	profiler:pop("frame")
	--draw the profiler on top if you're pressing `
	if input.keyboard:pressed("`") then
		lg.push()
		lg.origin()
		lg.translate(10, 10)
		--set whatever font here
		profiler:print_result()
		lg.pop()
	end
end