feat!: ✨ remove needless loads,dont write if no update

autoload/bm.vim

@@ -103,6 +103,7 @@ function! bm#prev(file, current_line_nr)
 endfunction
 
 function! bm#del_bookmark_at_line(file, line_nr)
+  let g:bm_file_version = g:bm_file_version - 1
   let bookmark = bm#get_bookmark_by_line(a:file, a:line_nr)
   unlet g:line_map[a:file][a:line_nr]
   unlet g:sign_map[a:file][bookmark['sign_idx']]
@@ -162,7 +163,7 @@ endfunction
 
 function! bm#serialize()
   let sign_index = "let l:bm_sign_index = ". g:bm_sign_index
-  let file_version = "let l:bm_file_version = 1"
+  let file_version = "let l:bm_file_version = " . (g:bm_file_version == g:bm_sign_index ? 1 : 0)
   let sessions  = "let l:bm_sessions = {'default': {"
   for file in bm#all_files()
     let sessions .= "'". file ."': ["
@@ -186,8 +187,9 @@ endfunction
 function! bm#deserialize(data)
     exec join(a:data, " | ")
     let g:bm_sign_index = l:bm_sign_index
+    let g:bm_file_version = l:bm_sign_index
     let ses = l:bm_sessions["default"]
-    let g:bm_sessions = ses 
+    " let g:bm_sessions = ses 
     let result = []
     for file in keys(ses)
       for bm in ses[file]

plugin/bookmark.vim

@@ -35,7 +35,7 @@ call s:set('g:bookmark_disable_ctrlp',        0 )
 call s:set('g:bookmark_display_annotation',   0 )
 
 function! s:init(file)
-  if g:bookmark_auto_save ==# 1 || g:bookmark_manage_per_buffer ==# 1
+  if g:bookmark_auto_save ==# 1 && g:bookmark_manage_per_buffer ==# 1
     augroup bm_vim_enter
       autocmd!
       autocmd BufEnter * call s:set_up_auto_save(expand('<afile>:p'))
@@ -211,7 +211,10 @@ function! BookmarkSave(target_file, silent)
   call s:refresh_line_numbers()
   if (bm#total_count() > 0 || (!g:bookmark_save_per_working_dir && !g:bookmark_manage_per_buffer))
     let serialized_bookmarks = bm#serialize()
-    call writefile(serialized_bookmarks, a:target_file)
+    let file_version = "let l:bm_file_version = 0"
+    if file_version ==# serialized_bookmarks[1]
+      call writefile(serialized_bookmarks, a:target_file)
+    endif
     if (!a:silent)
       echo "All bookmarks saved"
     endif