bongo: Add cache

* common.el (durand-take): Declare as pure and side-effect free.

* durand-bongo.el (bongo-sub-redisplay): Do nothing when not playing,
  to avoid clearing the subtitles buffer when stopped.

(durand-bongo-time-process): A helper to replace nil values by 0 in
the return value of `parse-time-string'.

(bongo-sub-status-string): Use a cache to avoid searching for the
subtitle every second.

1 files changed, 103 insertions, 91 deletions

diff --git a/durand-bongo.el b/durand-bongo.el
index a93053a..a3c9ba5 100644
--- a/durand-bongo.el
+++ b/durand-bongo.el
@@ -897,13 +897,14 @@ is the value of PLAYER's `time-update-delay-after-seek' property."
 (defun bongo-sub-redisplay ()
   "Update the Bongo Subtitle buffer to reflect the current time."
   (interactive)
-  (unless bongo-sub-redisplaying
-    (let ((bongo-sub-redisplaying t)
+  (cond
+   ((or bongo-sub-redisplaying (not (bongo-playing-p))))
+   ((let ((bongo-sub-redisplaying t)
           (sub (or (bongo-sub-status-string (window-width)) "")))
       (let ((inhibit-read-only t))
         (set-buffer durand-bongo-sub-buffer)
         (delete-region (point-min) (point-max))
-        (insert sub)))))
+        (insert sub))))))
 
 ;;;; Display string
 
@@ -947,97 +948,108 @@ TIME must be a list of two to four elements."
          (cond ((/= ele 0) ele)))
        (list tu tp))))))
 
+(defun durand-bongo-time-process (time)
+  "Replace nil by 0 in time."
+  (declare (pure t) (side-effect-free t))
+  (encode-time
+   (append
+    (mapcar (lambda (element) (or element 0))
+            (durand-take 6 time))
+    (nthcdr 6 time))))
+
 (defun bongo-sub-status-string (width)
   "Return the subtitle filled to WIDTH."
-  (cond
-   ((and (bongo-playing-p)
-         (bongo-player-get bongo-player 'sub-time)
-         (bongo-player-get bongo-player 'sub-file-buffer))
-    (let ((fb (bongo-player-get bongo-player 'sub-file-buffer))
-          (time (bongo-player-get bongo-player 'sub-time))
-          found start start-sub end end-sub)
-      (setq
-       time
-       (let ((fake-time
-              (parse-time-string
-               (format-seconds "%.2h:%.2m:%.2s" time))))
-         (encode-time
-          (append
-           (mapcar (lambda (ele) (or ele 0))
-                   (durand-take 6 fake-time))
-           (nthcdr 6 fake-time)))))
-      (with-current-buffer fb
-        (goto-char (point-min))
-        (save-match-data
-          (while (and
-                  (not found)
-                  (re-search-forward
-                   (rx bol
-                       (group
-                        (1+ digit) ":"
-                        (1+ digit) ":" (1+ digit)
-                        (zero-or-one
-                         "," (1+ digit)))
-                       (zero-or-more " ")
-                       "-->"
-                       (zero-or-more " ")
-                       (group
-                        (1+ digit) ":"
-                        (1+ digit) ":" (1+ digit)
-                        (zero-or-one
-                         "," (1+ digit)))
-                       eol)
-                   nil t))
-            (setq start (match-string 1))
-            (setq end (match-string 2))
-            (cond
-             ((string-match ",\\([[:digit:]]+\\)$" start)
-              (setq start-sub (match-string 1 start))
-              (setq
-               start
-               (durand-convert-sub-second
-                (let ((fake-time (parse-time-string
-                                  (replace-regexp-in-string
-                                   ",.*$" "" start))))
-                  (encode-time
-                   (append
-                    (mapcar (lambda (ele) (or ele 0))
-                            (durand-take 6 fake-time))
-                    (nthcdr 6 fake-time))))
-                (string-to-number start-sub))))
-             ((setq start (parse-time-string start))))
-            (cond
-             ((string-match ",\\([[:digit:]]+\\)$" end)
-              (setq end-sub (match-string 1 end))
-              (setq
-               end
-               (durand-convert-sub-second
-                (let ((fake-time (parse-time-string
-                                  (replace-regexp-in-string
-                                   ",.*$" "" end))))
-                  (encode-time
-                   (append
-                    (mapcar (lambda (ele) (or ele 0))
-                            (durand-take 6 fake-time))
-                    (nthcdr 6 fake-time))))
-                (string-to-number end-sub))))
-             ((setq end (parse-time-string end))))
-            (cond
-             ((and (time-less-p start time)
-                   (time-less-p time end))
-              (setq found t))))
-          (cond
-           (found
+  (with-bongo-playlist-buffer
+    (cond
+     ((and (bongo-playing-p)
+           (bongo-player-get bongo-player 'sub-time)
+           (bongo-player-get bongo-player 'sub-file-buffer))
+      (let ((fb (bongo-player-get bongo-player 'sub-file-buffer))
+            (time (bongo-player-get bongo-player 'sub-time))
+            (bound (bongo-player-get bongo-player 'sub-bound))
+            found start start-sub end end-sub end-pt)
+        (setq
+         time
+         (durand-bongo-time-process
+          (parse-time-string
+           (format-seconds "%.2h:%.2m:%.2s" time))))
+        (cond
+         ((and (consp bound)
+               (time-less-p (car bound) time)
+               (time-less-p time (cadr bound)))
+          (caddr bound))
+         ((with-current-buffer fb
+            (goto-char (point-min))
             (save-match-data
-              (save-excursion
-                (setq
-                 end
-                 (cond
-                  ((re-search-forward (rx bol (zero-or-more space) eol) nil t)
-                   (point))
-                  ((point-max)))))
-              (buffer-substring-no-properties
-               (1+ (point)) end))))))))))
+              (while (and
+                      (not found)
+                      (re-search-forward
+                       (rx bol
+                           (group
+                            (1+ digit) ":"
+                            (1+ digit) ":" (1+ digit)
+                            (zero-or-one
+                             "," (1+ digit)))
+                           (zero-or-more " ")
+                           "-->"
+                           (zero-or-more " ")
+                           (group
+                            (1+ digit) ":"
+                            (1+ digit) ":" (1+ digit)
+                            (zero-or-one
+                             "," (1+ digit)))
+                           eol)
+                       nil t))
+                (setq start (match-string 1))
+                (setq end (match-string 2))
+                (cond
+                 ((string-match ",\\([[:digit:]]+\\)$" start)
+                  (setq start-sub (match-string 1 start))
+                  (setq
+                   start
+                   (durand-convert-sub-second
+                    (durand-bongo-time-process
+                     (parse-time-string
+                      (replace-regexp-in-string
+                       ",.*$" "" start)))
+                    (string-to-number start-sub))))
+                 ((setq start (durand-bongo-time-process
+                               (parse-time-string start)))))
+                (cond
+                 ((string-match ",\\([[:digit:]]+\\)$" end)
+                  (setq end-sub (match-string 1 end))
+                  (setq
+                   end
+                   (durand-convert-sub-second
+                    (durand-bongo-time-process
+                     (parse-time-string
+                      (replace-regexp-in-string
+                       ",.*$" "" end)))
+                    (string-to-number end-sub))))
+                 ((setq end (durand-bongo-time-process
+                             (parse-time-string end)))))
+                (cond
+                 ((and (time-less-p start time)
+                       (time-less-p time end))
+                  (setq found t))))
+              (cond
+               (found
+                (let* ((end-pt
+                        (save-match-data
+                          (save-excursion
+                            (cond
+                             ((re-search-forward
+                               (rx bol (zero-or-more space) eol)
+                               nil t)
+                              (point))
+                             ((point-max))))))
+                       (found
+                        (buffer-substring-no-properties
+                         (point) end-pt)))
+                  (with-bongo-playlist-buffer
+                    (bongo-player-put bongo-player 'sub-bound
+                      (list start end found)))
+                  found))))))))))))
 
 ;; Normally we should do this, but I override the function by my
 ;; custom function, so I can just call this function there.