feat(profile): added accurate startuptime to ui/stats/docs

Author: folke

README.md

@@ -500,13 +500,25 @@ $ nvim --headless "+Lazy! sync" +qa
 - **plugins**: a list of plugin names to run the operation on
 - **concurrency**: limit the `number` of concurrently running tasks
 
-If you want to display the number of plugins on your dashboard, you can use
-this simple API:
+Stats API (`require("lazy").stats()`):
+
+<!-- stats:start -->
 
 ```lua
-local plugins = require("lazy").stats().count
+{
+  -- startuptime in milliseconds till UIEnter
+  startuptime = 0,
+  -- when true, startuptime is the accurate cputime for the Neovim process. (Linux & Macos)
+  -- this is more accurate than `nvim --startuptime`, and as such will be slightly higher
+  -- when false, startuptime is calculated based on a delta with a timestamp when lazy started.
+  startuptime_cputime = false,
+  count = 0, -- total number of plugins
+  loaded = 0, -- number of loaded plugins
+}
 ```
 
+<!-- stats:end -->
+
 **lazy.nvim** provides a statusline component that you can use to show the number of pending updates.
 Make sure to enable `config.checker.enabled = true` to make this work.
 
@@ -543,6 +555,8 @@ The following user events will be triggered:
 - **LazyLog**: after running log
 - **LazyReload**: triggered by change detection after reloading plugin specs
 - **VeryLazy**: triggered after `LazyDone` and processing `VimEnter` auto commands
+- **LazyVimStarted**: triggered after `UIEnter` when `require("lazy").stats().startuptime` has been calculated.
+  Useful to update the startuptime on your dashboard.
 
 ## 🔒 Lockfile `lazy-lock.json`
 

lua/lazy/core/config.lua

@@ -200,6 +200,12 @@ function M.setup(spec, opts)
   if M.headless then
     require("lazy.view.commands").setup()
   else
+    vim.api.nvim_create_autocmd("UIEnter", {
+      callback = function()
+        require("lazy.stats").on_ui_enter()
+      end,
+    })
+
     vim.api.nvim_create_autocmd("User", {
       pattern = "VeryLazy",
       once = true,

lua/lazy/docs.lua

@@ -126,6 +126,7 @@ function M.update()
   config = config:gsub("%s*debug = false.\n", "\n")
   M.save({
     bootstrap = M.extract("lua/lazy/init.lua", "function M%.bootstrap%(%)\n(.-)\nend"),
+    stats = M.extract("lua/lazy/stats.lua", "\nM%._stats = ({.-\n})"),
     config = config,
     spec = Util.read_file("lua/lazy/example.lua"),
     commands = M.commands(),

lua/lazy/init.lua

@@ -1,9 +1,11 @@
 ---@type LazyCommands
 local M = {}
+M._start = 0
 
 ---@param spec LazySpec Should be a module name to load, or a plugin spec
 ---@param opts? LazyConfig
 function M.setup(spec, opts)
+  M._start = M._start == 0 and vim.loop.hrtime() or M._start
   if vim.g.lazy_did_setup then
     return vim.notify(
       "Re-sourcing your config is not supported with lazy.nvim",
@@ -62,14 +64,7 @@ function M.setup(spec, opts)
 end
 
 function M.stats()
-  local ret = { count = 0, loaded = 0 }
-  for _, plugin in pairs(require("lazy.core.config").plugins) do
-    ret.count = ret.count + 1
-    if plugin._.loaded then
-      ret.loaded = ret.loaded + 1
-    end
-  end
-  return ret
+  return require("lazy.stats").stats()
 end
 
 function M.bootstrap()

lua/lazy/stats.lua

@@ -0,0 +1,56 @@
+local M = {}
+
+---@class LazyStats
+M._stats = {
+  -- startuptime in milliseconds till UIEnter
+  startuptime = 0,
+  -- when true, startuptime is the accurate cputime for the Neovim process. (Linux & Macos)
+  -- this is more accurate than `nvim --startuptime`, and as such will be slightly higher
+  -- when false, startuptime is calculated based on a delta with a timestamp when lazy started.
+  startuptime_cputime = false,
+  count = 0, -- total number of plugins
+  loaded = 0, -- number of loaded plugins
+}
+
+function M.on_ui_enter()
+  if not M.C then
+    pcall(function() end)
+  end
+
+  local ok = pcall(function()
+    local ffi = require("ffi")
+    ffi.cdef([[
+        typedef long time_t;
+        typedef int clockid_t;
+
+        typedef struct timespec {
+          time_t   tv_sec;        /* seconds */
+          long     tv_nsec;       /* nanoseconds */
+        } nanotime;
+        int clock_gettime(clockid_t clk_id, struct timespec *tp);
+      ]])
+    local pnano = assert(ffi.new("nanotime[?]", 1))
+    local CLOCK_PROCESS_CPUTIME_ID = jit.os == "OSX" and 12 or 2
+    ffi.C.clock_gettime(CLOCK_PROCESS_CPUTIME_ID, pnano)
+    M._stats.startuptime = tonumber(pnano[0].tv_sec) / 1e6 + tonumber(pnano[0].tv_nsec) / 1e6
+    M._stats.startuptime_cputime = true
+  end)
+  if not ok then
+    M._stats.startuptime = (vim.loop.hrtime() - require("lazy")._start) / 1e6
+  end
+  vim.cmd([[do User LazyVimStarted]])
+end
+
+function M.stats()
+  M._stats.count = 0
+  M._stats.loaded = 0
+  for _, plugin in pairs(require("lazy.core.config").plugins) do
+    M._stats.count = M._stats.count + 1
+    if plugin._.loaded then
+      M._stats.loaded = M._stats.loaded + 1
+    end
+  end
+  return M._stats
+end
+
+return M

lua/lazy/view/render.lua

@@ -491,6 +491,24 @@ function M:details(plugin)
 end
 
 function M:profile()
+  local stats = require("lazy.stats").stats()
+  local ms = (math.floor(stats.startuptime * 100 + 0.5) / 100)
+  self:append("Startuptime: ", "LazyH2"):append(ms .. "ms", "Number"):nl():nl()
+  if stats.startuptime_cputime then
+    self:append("Based on the actual CPU time of the Neovim process till "):append("UIEnter", "LazySpecial")
+    self:append("."):nl()
+    self:append("This is more accurate than ")
+    self:append("`nvim --startuptime`", "@text.literal.markdown_inline")
+    self:append(".")
+  else
+    self:append("An accurate startuptime based on the actual CPU time of the Neovim process is not available."):nl()
+    self
+      :append("Startuptime is instead based on a delta with a timestamp when lazy started till ")
+      :append("UIEnter", "LazySpecial")
+    self:append(".")
+  end
+  self:nl():nl()
+
   self:append("Profile", "LazyH2"):nl():nl()
   self
     :append("You can press ")
@@ -505,6 +523,8 @@ function M:profile()
 
   self:nl()
 
+  self:nl():nl()
+
   ---@param a LazyProfile
   ---@param b LazyProfile
   local function sort(a, b)