Improves performance when receiving large bursts of data.

5 files changed, 57 insertions, 5 deletions

diff --git a/elisp.c b/elisp.c
index e132262..69599ae 100644
--- a/elisp.c
+++ b/elisp.c
@@ -107,9 +107,11 @@ void delete_lines(emacs_env *env, int linenum, int count, bool del_whole_line) {
 void recenter(emacs_env *env, emacs_value pos) {
   env->funcall(env, Frecenter, 1, (emacs_value[]){pos});
 }
+
 void forward_char(emacs_env *env, emacs_value n) {
   env->funcall(env, Fforward_char, 1, (emacs_value[]){n});
 }
+
 emacs_value buffer_line_number(emacs_env *env) {
   return env->funcall(env, Fbuffer_line_number, 0, (emacs_value[]){});
 }
@@ -143,6 +145,11 @@ emacs_value get_hex_color_bg(emacs_env *env, emacs_value face) {
   return env->funcall(env, Fvterm_face_color_hex, 2,
                       (emacs_value[]){face, Qbackground});
 }
+
 void set_title(emacs_env *env, emacs_value string) {
-   env->funcall(env, Fvterm_set_title, 1, (emacs_value[]){string});
+  env->funcall(env, Fvterm_set_title, 1, (emacs_value[]){string});
+}
+
+void vterm_invalidate(emacs_env *env) {
+  env->funcall(env, Fvterm_invalidate, 0, NULL);
 }
diff --git a/elisp.h b/elisp.h
index c200754..07fc6d5 100644
--- a/elisp.h
+++ b/elisp.h
@@ -40,6 +40,7 @@ emacs_value Fblink_cursor_mode;
 emacs_value Fget_buffer_window;
 emacs_value Fselected_window;
 emacs_value Fvterm_set_title;
+emacs_value Fvterm_invalidate;
 
 // Utils
 void bind_function(emacs_env *env, const char *name, emacs_value Sfun);
@@ -68,6 +69,7 @@ void recenter(emacs_env *env, emacs_value pos);
 void forward_char(emacs_env *env, emacs_value n);
 emacs_value get_buffer_window(emacs_env *env);
 emacs_value selected_window(emacs_env *env);
-void set_title(emacs_env *env, emacs_value string) ;
+void set_title(emacs_env *env, emacs_value string);
+void vterm_invalidate(emacs_env *env);
 
 #endif /* ELISP_H */
diff --git a/vterm-module.c b/vterm-module.c
index e1bbf6d..5f5196f 100644
--- a/vterm-module.c
+++ b/vterm-module.c
@@ -665,12 +665,19 @@ static emacs_value Fvterm_update(emacs_env *env, ptrdiff_t nargs,
 
   // Flush output
   term_flush_output(term, env);
-
-  term_redraw(term, env);
+  if (term->is_invalidated) {
+    vterm_invalidate(env);
+  }
 
   return env->make_integer(env, 0);
 }
 
+static emacs_value Fvterm_redraw(emacs_env *env, ptrdiff_t nargs,
+                                 emacs_value args[], void *data) {
+  Term *term = env->get_user_ptr(env, args[0]);
+  term_redraw(term, env);
+  return env->make_integer(env, 0);
+}
 static emacs_value Fvterm_write_input(emacs_env *env, ptrdiff_t nargs,
                                       emacs_value args[], void *data) {
   Term *term = env->get_user_ptr(env, args[0]);
@@ -749,6 +756,9 @@ int emacs_module_init(struct emacs_runtime *ert) {
 
   Fvterm_set_title =
       env->make_global_ref(env, env->intern(env, "vterm--set-title"));
+  Fvterm_invalidate =
+      env->make_global_ref(env, env->intern(env, "vterm--invalidate"));
+
   // Faces
   Qterm = env->make_global_ref(env, env->intern(env, "vterm"));
   Qterm_color_black =
@@ -778,6 +788,11 @@ int emacs_module_init(struct emacs_runtime *ert) {
                            "Process io and update the screen.", NULL);
   bind_function(env, "vterm--update", fun);
 
+
+  fun =
+      env->make_function(env, 1, 1, Fvterm_redraw, "Redraw the screen.", NULL);
+  bind_function(env, "vterm--redraw", fun);
+
   fun = env->make_function(env, 2, 2, Fvterm_write_input,
                            "Write input to vterm.", NULL);
   bind_function(env, "vterm--write-input", fun);
diff --git a/vterm-module.h b/vterm-module.h
index d985033..bd05dc4 100644
--- a/vterm-module.h
+++ b/vterm-module.h
@@ -87,6 +87,8 @@ static emacs_value Fvterm_new(emacs_env *env, ptrdiff_t nargs,
                               emacs_value args[], void *data);
 static emacs_value Fvterm_update(emacs_env *env, ptrdiff_t nargs,
                                  emacs_value args[], void *data);
+static emacs_value Fvterm_redraw(emacs_env *env, ptrdiff_t nargs,
+                                 emacs_value args[], void *data);
 int emacs_module_init(struct emacs_runtime *ert);
 
 #endif /* VTERM_MODULE_H */
diff --git a/vterm.el b/vterm.el
index 469a12c..8447cb7 100644
--- a/vterm.el
+++ b/vterm.el
@@ -81,6 +81,7 @@ for different shell. "
   :type 'hook
   :group 'vterm)
 
+
 (defface vterm
   '((t :inherit default))
   "Default face to use in Term mode."
@@ -146,7 +147,8 @@ for different shell. "
   (setq-local scroll-margin 0)
 
   (add-hook 'window-size-change-functions #'vterm--window-size-change t t)
-  (let ((process-environment (append '("TERM=xterm") process-environment)))
+  (let ((process-environment (append '("TERM=xterm") process-environment))
+        (process-adaptive-read-buffering nil))
     (setq vterm--process
           (make-process
            :name "vterm"
@@ -225,6 +227,30 @@ for different shell. "
     (dolist (char (string-to-list string))
       (vterm--update vterm--term (char-to-string char) nil nil nil))))
 
+(defvar vterm--redraw-timer nil)
+(make-variable-buffer-local 'vterm--redraw-timer)
+
+(defvar vterm-timer-delay 0.01
+  "Delay for refreshing the terminal buffer after receiving updates from
+libvterm. Improves performance when receiving large bursts of data.
+If nil, never delay")
+
+(defun vterm--invalidate()
+  (if vterm-timer-delay
+      (unless vterm--redraw-timer
+        (setq vterm--redraw-timer
+              (run-with-timer vterm-timer-delay nil
+                              #'vterm--delayed-redraw (current-buffer))))
+    (vterm--delayed-redraw (current-buffer))))
+
+(defun vterm--delayed-redraw(buffer)
+  (with-current-buffer buffer
+    (let ((inhibit-redisplay t)
+          (inhibit-read-only t))
+      (when vterm--term
+        (vterm--redraw vterm--term)))
+    (setq vterm--redraw-timer nil)))
+
 ;;;###autoload
 (defun vterm ()
   "Create a new vterm."