patch 9.1.1672: completion: cannot add timeouts for 'cpt' sources

Problem:  completion: cannot add timeouts for 'cpt' sources
          (Evgeni Chasnovski)
Solution: Add the 'autocompletetimeout' and 'completetimeout' options
          (Girish Palya)

fixes: #17908
closes: #17967

Signed-off-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/insexpand.c

@@ -203,6 +203,9 @@ static buf_T	  *compl_curr_buf = NULL;  // buf where completion is active
 // if the current source exceeds its timeout, it is interrupted and the next
 // begins with half the time. A small minimum timeout ensures every source
 // gets at least a brief chance.
+// Special case: when 'complete' contains "F" or "o" (function sources), a
+// longer fixed timeout is used (COMPL_FUNC_TIMEOUT_MS or
+// COMPL_FUNC_TIMEOUT_NON_KW_MS). - girish
 static int	  compl_autocomplete = FALSE;	    // whether autocompletion is active
 static int	  compl_timeout_ms = COMPL_INITIAL_TIMEOUT_MS;
 static int	  compl_time_slice_expired = FALSE; // time budget exceeded for current source
@@ -216,6 +219,10 @@ static int	  compl_from_nonkeyword = FALSE;    // completion started from non-ke
 	    compl_timeout_ms /= 2; \
     } while (0)
 
+// Timeout values for F{func}, F and o values in 'complete'
+#define COMPL_FUNC_TIMEOUT_MS		300
+#define COMPL_FUNC_TIMEOUT_NON_KW_MS	1000
+
 // List of flags for method of completion.
 static int	  compl_cont_status = 0;
 # define CONT_ADDING	1	// "normal" or "adding" expansion
@@ -5393,7 +5400,7 @@ prepare_cpt_compl_funcs(void)
 compl_source_start_timer(int source_idx UNUSED)
 {
 #ifdef ELAPSED_FUNC
-    if (compl_autocomplete && cpt_sources_array != NULL)
+    if (compl_autocomplete || p_cto > 0)
     {
 	ELAPSED_INIT(cpt_sources_array[source_idx].compl_start_tv);
 	compl_time_slice_expired = FALSE;
@@ -5418,8 +5425,6 @@ advance_cpt_sources_index_safe(void)
     return FAIL;
 }
 
-#define COMPL_FUNC_TIMEOUT_MS		300
-#define COMPL_FUNC_TIMEOUT_NON_KW_MS	1000
 /*
  * Get the next expansion(s), using "compl_pattern".
  * The search starts at position "ini" in curbuf and in the direction
@@ -5439,6 +5444,8 @@ ins_compl_get_exp(pos_T *ini)
     int		type = ctrl_x_mode;
     int		may_advance_cpt_idx = FALSE;
     pos_T	start_pos = *ini;
+    int		normal_mode_strict = FALSE;
+    long	compl_timeout_save = 0;
 
     if (!compl_started)
     {
@@ -5476,15 +5483,18 @@ ins_compl_get_exp(pos_T *ini)
     st.cur_match_pos = (compl_dir_forward())
 				    ? &st.last_match_pos : &st.first_match_pos;
 
-    if (cpt_sources_array != NULL && ctrl_x_mode_normal()
-	    && !ctrl_x_mode_line_or_eval()
-	    && !(compl_cont_status & CONT_LOCAL))
+    normal_mode_strict = ctrl_x_mode_normal() && !ctrl_x_mode_line_or_eval()
+	&& !(compl_cont_status & CONT_LOCAL) && cpt_sources_array != NULL;
+    if (normal_mode_strict)
     {
 	cpt_sources_index = 0;
-	if (compl_autocomplete)
+	if (compl_autocomplete || p_cto > 0)
 	{
 	    compl_source_start_timer(0);
-	    compl_timeout_ms = COMPL_INITIAL_TIMEOUT_MS;
+	    compl_time_slice_expired = FALSE;
+	    compl_timeout_ms = compl_autocomplete
+		? MAX(COMPL_INITIAL_TIMEOUT_MS, p_act)
+		: p_cto;
 	}
     }
 
@@ -5517,14 +5527,18 @@ ins_compl_get_exp(pos_T *ini)
 	    }
 	}
 
-	if (compl_autocomplete && type == CTRL_X_FUNCTION)
+	if (normal_mode_strict && type == CTRL_X_FUNCTION
+		&& (compl_autocomplete || p_cto > 0))
+	{
 	    // LSP servers may sporadically take >1s to respond (e.g., while
 	    // loading modules), but other sources might already have matches.
 	    // To show results quickly use a short timeout for keyword
 	    // completion. Allow longer timeout for non-keyword completion
 	    // where only function based sources (e.g. LSP) are active.
+	    compl_timeout_save = compl_timeout_ms;
 	    compl_timeout_ms = compl_from_nonkeyword
 		? COMPL_FUNC_TIMEOUT_NON_KW_MS : COMPL_FUNC_TIMEOUT_MS;
+	}
 
 	// get the next set of completion matches
 	found_new_match = get_next_completion_match(type, &st, &start_pos);
@@ -5567,9 +5581,10 @@ ins_compl_get_exp(pos_T *ini)
 	    compl_started = FALSE;
 	}
 
-	// Reset the timeout after collecting matches from function source
-	if (compl_autocomplete && type == CTRL_X_FUNCTION)
-	    compl_timeout_ms = COMPL_INITIAL_TIMEOUT_MS;
+	// Restore the timeout after collecting matches from function source
+	if (normal_mode_strict && type == CTRL_X_FUNCTION
+		&& (compl_autocomplete || p_cto > 0))
+	    compl_timeout_ms = compl_timeout_save;
 
 	// For `^P` completion, reset `compl_curr_match` to the head to avoid
 	// mixing matches from different sources.
@@ -6136,9 +6151,6 @@ ins_compl_next(
 check_elapsed_time(void)
 {
 #ifdef ELAPSED_FUNC
-    if (cpt_sources_array == NULL || cpt_sources_index < 0)
-	return;
-
     elapsed_T	*start_tv
 	= &cpt_sources_array[cpt_sources_index].compl_start_tv;
     long	elapsed_ms = ELAPSED_FUNC(*start_tv);
@@ -6211,8 +6223,14 @@ ins_compl_check_keys(int frequency, int in_compl_func)
 	    }
 	}
     }
-    else if (compl_autocomplete)
-	check_elapsed_time();
+    else
+    {
+	int normal_mode_strict = ctrl_x_mode_normal()
+	    && !ctrl_x_mode_line_or_eval() && !(compl_cont_status & CONT_LOCAL)
+	    && cpt_sources_array != NULL && cpt_sources_index >= 0;
+	if (normal_mode_strict && (compl_autocomplete || p_cto > 0))
+	    check_elapsed_time();
+    }
 
     if (compl_pending != 0 && !got_int && !(cot_flags & COT_NOINSERT)
 	    && !compl_autocomplete)

src/option.h

@@ -513,6 +513,7 @@ EXTERN long	p_ch;		// 'cmdheight'
 EXTERN char_u	*p_cms;		// 'commentstring'
 #endif
 EXTERN char_u	*p_cpt;		// 'complete'
+EXTERN long	p_cto;		// 'completetimeout'
 #if defined(FEAT_GUI_DIALOG) || defined(FEAT_CON_DIALOG)
 EXTERN int	p_confirm;	// 'confirm'
 #endif
@@ -524,6 +525,7 @@ EXTERN unsigned cia_flags;	// order flags of 'completeitemalign'
 EXTERN char_u	*p_cot;		// 'completeopt'
 EXTERN unsigned	cot_flags;	// flags from 'completeopt'
 EXTERN int	p_ac;		// 'autocomplete'
+EXTERN long	p_act;		// 'autocompletetimeout'
 EXTERN long	p_acl;		// 'autocompletedelay'
 // Keep in sync with p_cot_values in optionstr.c
 #define COT_MENU	0x001

src/optiondefs.h

@@ -395,6 +395,9 @@ static struct vimoption options[] =
     {"autocompletedelay", "acl", P_NUM|P_VI_DEF,
 			    (char_u *)&p_acl, PV_NONE, NULL, NULL,
 			    {(char_u *)0L, (char_u *)0L} SCTX_INIT},
+    {"autocompletetimeout", "act", P_NUM|P_VI_DEF,
+			    (char_u *)&p_act, PV_NONE, NULL, NULL,
+			    {(char_u *)80L, (char_u *)0L} SCTX_INIT},
 #endif
     {"autoindent",  "ai",   P_BOOL|P_VI_DEF,
 			    (char_u *)&p_ai, PV_AI, NULL, NULL,
@@ -723,6 +726,9 @@ static struct vimoption options[] =
 			    {(char_u *)0L, (char_u *)0L}
 #endif
 			    SCTX_INIT},
+    {"completetimeout", "cto", P_NUM|P_VI_DEF,
+			    (char_u *)&p_cto, PV_NONE, NULL, NULL,
+			    {(char_u *)0L, (char_u *)0L} SCTX_INIT},
     {"concealcursor","cocu", P_STRING|P_ALLOCED|P_RWIN|P_VI_DEF|P_FLAGLIST,
 #ifdef FEAT_CONCEAL
 			    (char_u *)VAR_WIN, PV_COCU, did_set_concealcursor, expand_set_concealcursor,

src/po/vim.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Vim\n"
 "Report-Msgid-Bugs-To: vim-dev@vim.org\n"
-"POT-Creation-Date: 2025-08-18 21:30+0200\n"
+"POT-Creation-Date: 2025-08-23 16:16+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -9952,6 +9952,12 @@ msgstr ""
 msgid "automatic completion in insert mode"
 msgstr ""
 
+msgid "initial decay timeout for 'autocomplete' algorithm"
+msgstr ""
+
+msgid "initial decay timeout for CTRL-N and CTRL-P completion"
+msgstr ""
+
 msgid "delay in msec before menu appears after typing"
 msgstr ""
 

src/proto/diff.pro

@@ -22,8 +22,10 @@ int diffopt_horizontal(void);
 int diffopt_hiddenoff(void);
 int diffopt_closeoff(void);
 void diff_update_line(linenr_T lnum);
+#ifdef FEAT_DIFF
 int diff_change_parse(diffline_T *diffline, diffline_change_T *change, int *change_start, int *change_end);
 int diff_find_change(win_T *wp, linenr_T lnum, diffline_T *diffline);
+#endif
 int diff_infold(win_T *wp, linenr_T lnum);
 void nv_diffgetput(int put, long count);
 void ex_diffgetput(exarg_T *eap);

src/testdir/test_ins_complete.vim

@@ -5460,6 +5460,68 @@ func Test_omni_start_invalid_col()
   set omnifunc& complete&
 endfunc
 
+func Test_completetimeout_autocompletetimeout()
+  func OmniFunc(findstart, base)
+    if a:findstart
+      return 1
+    else
+      return ['fooOmni']
+    endif
+  endfunc
+
+  set omnifunc=OmniFunc
+  call test_override("char_avail", 1)
+  inoremap <F2> <Cmd>let b:matches = complete_info(["matches"]).matches<CR>
+
+  call setline(1, ['foobar', 'foobarbaz'])
+  new
+  call setline(1, ['foo', 'foobaz', ''])
+  set complete=.,o,w
+  call feedkeys("G", 'xt!')
+
+  set autocomplete
+  for tt in [1, 80, 1000, -1, 0]
+    exec $'set autocompletetimeout={tt}'
+    call feedkeys("\<Esc>Sf\<F2>\<Esc>0", 'xt!')
+    call assert_equal(['foobaz', 'foo', 'fooOmni', 'foobar', 'foobarbaz'], b:matches->mapnew('v:val.word'))
+  endfor
+  set autocomplete&
+
+  for tt in [80, 1000, -1, 0]
+    exec $'set completetimeout={tt}'
+    call feedkeys("\<Esc>Sf\<C-N>\<F2>\<Esc>0", 'xt!')
+    call assert_equal(['foo', 'foobaz', 'fooOmni', 'foobar', 'foobarbaz'], b:matches->mapnew('v:val.word'))
+  endfor
+
+  " Clock does not have fine granularity, so checking 'elapsed time' is only
+  " approximate. We can only test that some type of timeout is enforced.
+  call feedkeys("\<Esc>", 'xt!')
+  call setline(1, map(range(60000), '"foo" . v:val'))
+  set completetimeout=1
+  call feedkeys("Gof\<C-N>\<F2>\<Esc>0", 'xt!')
+  let match_count = len(b:matches->mapnew('v:val.word'))
+  call assert_true(match_count < 2000)
+
+  set completetimeout=1000
+  call feedkeys("\<Esc>Sf\<C-N>\<F2>\<Esc>0", 'xt!')
+  let match_count = len(b:matches->mapnew('v:val.word'))
+  call assert_true(match_count > 2000)
+
+  set autocomplete
+  set autocompletetimeout=81
+  call feedkeys("\<Esc>Sf\<F2>\<Esc>0", 'xt!')
+  let match_count = len(b:matches->mapnew('v:val.word'))
+  call assert_true(match_count < 50000)
+
+  call feedkeys("\<Esc>", 'xt!')
+  set complete& omnifunc& autocomplete& autocompletetimeout& completetimeout&
+  bwipe!
+  %d
+  call test_override("char_avail", 0)
+  iunmap <F2>
+  delfunc OmniFunc
+endfunc
+
 func Test_autocompletedelay()
   CheckScreendump
 

src/version.c

@@ -724,6 +724,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1672,
 /**/
     1671,
 /**/