Git Execution Blocks UI Thread

[alex-courtis]

Description

Git operations block the UI thread whilst they are running.

Neovim version

NVIM v0.8.3
Build type: Release
LuaJIT 2.1.0-beta3

Operating system and version

Linux 6.1.9-arch1-1

nvim-tree version

02fdc26

Minimal config

vim.cmd [[set runtimepath=$VIMRUNTIME]]
vim.cmd [[set packpath=/tmp/nvt-min/site]]
local package_root = "/tmp/nvt-min/site/pack"
local install_path = package_root .. "/packer/start/packer.nvim"
local function load_plugins()
  require("packer").startup {
    {
      "wbthomason/packer.nvim",
      "nvim-tree/nvim-tree.lua",
      "nvim-tree/nvim-web-devicons",
      -- ADD PLUGINS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
    },
    config = {
      package_root = package_root,
      compile_path = install_path .. "/plugin/packer_compiled.lua",
      display = { non_interactive = true },
    },
  }
end
if vim.fn.isdirectory(install_path) == 0 then
  print "Installing nvim-tree and dependencies."
  vim.fn.system { "git", "clone", "--depth=1", "https://github.com/wbthomason/packer.nvim", install_path }
end
load_plugins()
require("packer").sync()
vim.cmd [[autocmd User PackerComplete ++once echo "Ready!" | lua setup()]]
vim.opt.termguicolors = true
vim.opt.cursorline = true

-- MODIFY NVIM-TREE SETTINGS THAT ARE _NECESSARY_ FOR REPRODUCING THE ISSUE
_G.setup = function()
  require("nvim-tree").setup {
    git = {
      timeout = 3000,
    },
}
end

Steps to reproduce

Replace git job with "sleep 2"

Expected behavior

No response

Actual behavior

No response

[alex-courtis]

Replace git command with a 2 sec sleep

1974.patch.txt

[alex-courtis]

refresh_node is synchronous and the main codepath for git excecution, usually following debounce: https://github.com/nvim-tree/nvim-tree.lua/blob/master/lua/nvim-tree/explorer/reload.lua#L145

This could be made asynchronous as per #1870 or some simpler means.

[alex-courtis]

Async/await is a possibility however adds complexity and is not yet available in nvim: neovim/neovim#19624

It looks like this one might be the winner: https://github.com/lewis6991/async.nvim It's more straightforward and complete that plenary's.

current control is OK: spawn git process, watcher timer to time out.

Runner.run can invoke a callback on OK/timeout passing raw output as per current return.

load_project_status is invoked only by Explorer:_load which can load the tree in the callback.

reload_project:

• reload
  • reload_explorer can render in the callback using the event_running lock
  • reload_git can do the same
• reload_and_get_git_project
  • refresh_node
    • refresh_nodes_for_path is problematic due to the iteration; it will probably be OK to callback individually
    • watcher can act inside the callback

[alex-courtis]

SIGINT timed out processes.

SIGKILL process that don't interrupt after a further git.timeout

[alex-courtis]

Unfortunately callbacks from git runner are getting too deep into callback hell, specifically Explorer:_load

Alternatives:

• Explorer:_load is synchronous, others are async
• git status is always asynchronously drawn

[alex-courtis]

core.init has too great a fanout to make Explorer:_load async.

[alex-courtis]

Async watcher git execution for files is working. The same can be done for git watcher executions.

The above two are the only reactive git executions; all others are in response to a user action.

That should be sufficient as the perceived delays following user actions are less noticeable.