init.lua: create & expand M.dir: only once

1 files changed, 12 insertions, 2 deletions

diff --git a/init.lua b/init.lua
index c9ac004..2481a14 100644
--- a/init.lua
+++ b/init.lua
@@ -14,6 +14,7 @@
 -- If not, see <https://www.gnu.org/licenses/>.
 local M = {}
 M.directory = '${XDG_STATE_HOME:-${HOME}/.local/state}/vis/locks'
+M.directory_expanded = false
 
 -- Helper to execute a command and capture its output
 local function capture_cmd(cmd)
@@ -27,10 +28,16 @@ local function capture_cmd(cmd)
   return s
 end
 
+local function get_lock_dir()
+  if not M.directory_expanded then
+    M.directory = capture_cmd('printf %s "' .. M.directory .. '"')
+  end
+  return M.directory
+end
+
 local function lock_file_path(path)
   local filename = path:gsub('/', '%%')
-  assert(os.execute('mkdir -p "' .. M.directory .. '"'))
-  return capture_cmd('printf %s "' .. M.directory .. '/' .. filename .. '.lock"')
+  return get_lock_dir() .. '/' .. filename .. '.lock'
 end
 
 -- determine vis' pid
@@ -81,6 +88,9 @@ local function create_lock_file(lfile_path)
   end
 
   -- create the lock file with our pid
+  if not io.open(lfile_path, 'w') then
+    assert(os.execute('mkdir -p "' .. get_lock_dir() .. '"'))
+  end
   lock_file = assert(io.open(lfile_path, 'w'))
   lock_file:write(vis_pid)
   lock_file:close()