[elpa] externals/topspace e046ab3a50 157/181: Internal refactoring and performance optimizations

[ELPA Syncer]

branch: externals/topspace
commit e046ab3a50a460c7c1fd4905321aaaf91777d40d
Author: Trevor Pogue <poguete@mcmaster.ca>
Commit: Trevor Pogue <poguete@mcmaster.ca>

    Internal refactoring and performance optimizations
    
    - `topspace--count-pixel-height` was causing large performance overhead 
when opening large buffers, this is now resolved
    - `topspace--count-pixel-height` performance was increased by about 50% 
overall
---
 README.md             |  4 ++--
 test/test-helper.el   |  2 +-
 test/topspace-test.el | 13 +++++++------
 topspace.el           | 49 ++++++++++++++++++++++++++++---------------------
 4 files changed, 38 insertions(+), 30 deletions(-)

diff --git a/README.md b/README.md
index 71a34001a0..a9b9d4706d 100644
--- a/README.md
+++ b/README.md
@@ -183,7 +183,7 @@ Valid top space line heights are:
 (defun topspace-set-height (&optional total-lines)
   "Set and redraw the top space overlay to have a target height of TOTAL-LINES.
 This sets the top space height for the current buffer in the selected window.
-Int or float values are accepted for TOTAL-LINES, and the value is
+Integer or float values are accepted for TOTAL-LINES, and the value is
 considered to be in units of `default-line-height'.
 
 If argument TOTAL-LINES is not provided, the top space height will be set to
@@ -198,7 +198,7 @@ Valid top space line heights are:
 - only positive when `window-start' equals 1,
   `topspace-active' returns non-nil, and `topspace-mode' is enabled,
 - not larger than `topspace--window-height' minus `topspace--context-lines'."
-  (interactive "p")
+  (interactive "P")
 ...
 
 ;;;###autoload
diff --git a/test/test-helper.el b/test/test-helper.el
index e59761bf66..a0fdb3abe2 100644
--- a/test/test-helper.el
+++ b/test/test-helper.el
@@ -9,7 +9,7 @@
 (when (require 'undercover nil t)
   (setq undercover-force-coverage t)
   (undercover "*.el"
-              ;; (:report-file "coverage/.resultset.json")
+              (:report-file "coverage/.resultset.json")
               ;; (:report-format 'simplecov)
               ;; (:report-format 'text)
               ))
diff --git a/test/topspace-test.el b/test/topspace-test.el
index 00c41d0fae..c8fe4dc48a 100644
--- a/test/topspace-test.el
+++ b/test/topspace-test.el
@@ -201,16 +201,17 @@ by default"
   ;;               (line-number-at-pos (point-max)))))
 
   (it "can count lines if start is larger than end"
-      (set-window-start (selected-window) 100)
-      (expect (round (topspace--count-lines (point-max) (point-min)))
-              :to-equal
-              (line-number-at-pos (point-max)))
+      (set-window-start (selected-window) 300)
+      (expect (round (topspace--count-lines 401 201))
+              :to-equal 4)
+      (expect (round (topspace--count-lines 201 401))
+              :to-equal 4)
       (set-window-start (selected-window) 1))
 
   (it "can count lines if window-absolute-pixel-position returns nil"
-      (expect (round (topspace--count-lines (point-min) (point-max)))
+      (expect (round (round (topspace--count-lines 201 401)))
               :to-equal
-              (line-number-at-pos (point-max)))))
+              4)))
 
  (describe
   "topspace--correct-height"
diff --git a/topspace.el b/topspace.el
index 895859e4c8..33da8e8815 100644
--- a/topspace.el
+++ b/topspace.el
@@ -253,7 +253,7 @@ Valid top space line heights are:
 (defun topspace-set-height (&optional total-lines)
   "Set and redraw the top space overlay to have a target height of TOTAL-LINES.
 This sets the top space height for the current buffer in the selected window.
-Int or float values are accepted for TOTAL-LINES, and the value is
+Integer or float values are accepted for TOTAL-LINES, and the value is
 considered to be in units of `default-line-height'.
 
 If argument TOTAL-LINES is not provided, the top space height will be set to
@@ -557,7 +557,8 @@ mode-line in centering."
       (goto-char start)
       (beginning-of-visual-line)
       (while (< (point) end)
-        (setq result (+ result (* (vertical-motion 1) (line-pixel-height))))))
+        (setq result (+ result (line-pixel-height)))
+        (vertical-motion 1)))
     result))
 
 (defun topspace--count-lines-slow (start end)
@@ -575,23 +576,29 @@ If that doesn't work it uses 
`topspace--count-lines-slow'."
   (setq end (min end (point-max)))
   (setq start (max start (point-min)))
   (let ((old-end) (old-start) (swap)
-        (line-height (float (default-line-height))))
-    (when (> start end) (setq swap end) (setq end start) (setq start swap))
-    (setq old-end end) (setq old-start start)
-    (setq end (min end (- (window-end) 1)))
-    (setq start (max start (window-start)))
-    (let ((end-y (window-absolute-pixel-position end))
-          (start-y (window-absolute-pixel-position start)))
-      (+
-       (if (> old-end end) (topspace--count-lines-slow end old-end) 0)
-       (if (< old-start start) (topspace--count-lines-slow old-start start) 0)
-       (condition-case nil
-           ;; first try counting lines by getting the pixel difference
-           ;; between end and start and dividing by `default-line-height'
-           (/ (- (cdr end-y) (cdr start-y)) line-height)
-         ;; if the pixel method above doesn't work do this slower method
-         ;; (it won't work if either START or END are not visible in window)
-         (error (topspace--count-lines-slow start end)))))))
+        (line-height (float (default-line-height)))
+        (window-height (topspace--window-height)))
+    (cond
+     ((> (- (line-number-at-pos end) (line-number-at-pos start))
+         (* 2 window-height))
+      window-height)
+     (t
+      (when (> start end) (setq swap end) (setq end start) (setq start swap))
+      (setq old-end end) (setq old-start start)
+      (setq end (min end (- (window-end) 1)))
+      (setq start (max start (window-start)))
+      (let ((end-y (window-absolute-pixel-position end))
+            (start-y (window-absolute-pixel-position start)))
+        (+
+         (if (> old-end end) (topspace--count-lines-slow end old-end) 0)
+         (if (< old-start start) (topspace--count-lines-slow old-start start) 
0)
+         (condition-case nil
+             ;; first try counting lines by getting the pixel difference
+             ;; between end and start and dividing by `default-line-height'
+             (/ (- (cdr end-y) (cdr start-y)) line-height)
+           ;; if the pixel method above doesn't work do this slower method
+           ;; (it won't work if either START or END are not visible in window)
+           (error (topspace--count-lines-slow start end)))))))))
 
 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; Overlay drawing
@@ -717,13 +724,13 @@ Topspace will not be enabled for:
       (setq topspace--advice-added t)
       (advice-add #'scroll-up :filter-args #'topspace--filter-args-scroll-up)
       (advice-add #'scroll-down :filter-args
-                    #'topspace--filter-args-scroll-down)
+                  #'topspace--filter-args-scroll-down)
       (advice-add #'scroll-up :after #'topspace--after-scroll)
       (advice-add #'scroll-down :after #'topspace--after-scroll)
       (advice-add #'recenter :after #'topspace--after-recenter)
       (when (fboundp 'smooth-scroll-lines-above-point)
         (advice-add #'smooth-scroll-lines-above-point
-                      :override #'topspace--smooth-scroll-lines-above-point)))
+                    :override #'topspace--smooth-scroll-lines-above-point)))
     (dolist (window (get-buffer-window-list))
       (with-selected-window window (topspace-set-height)))))