emacs-framebuffer

commit 961196e1d461190f2e237c65dc34e78ee063ffce
parent e99f1fc059555a07291c6b437f3feb0c39ad404c
Author: Tomas Hlavaty <tom@logand.com>
Date:   Sat, 17 Oct 2020 19:56:42 +0200

handle remote files

local files:

- some are directly displayed using w3mimgdisplay

- some need conversions which are cached, based on sha256sum of the
  file content

remote files:

- always cached, based on the sha256sum of the file name because this
  needs to be fast without remote access

Diffstat:
M
emacs-framebuffer.el
 | 
49
++++++++++++++++++++++++++++++++++++++-----------

1 file changed, 38 insertions(+), 11 deletions(-)
diff --git a/emacs-framebuffer.el b/emacs-framebuffer.el
@@ -122,11 +122,40 @@
                  (cons (read (match-string 1)) (read (match-string 2))))
                (cons framebuffer-default-width framebuffer-default-height))))))
 
+(defun framebuffer-local-cache-directory ()
+  (let ((z (or framebuffer-cache-directory
+	       (let ((default-directory "/"))
+		 (temporary-file-directory)))))
+    (if (file-remote-p z)
+	(error "framebuffer-cache-directory is remote %s" z)
+      z)))
+
+(defun framebuffer-local-cache-file (name extension)
+  (concat (framebuffer-local-cache-directory) "/" name "." extension))
+
 (defun framebuffer-file-hash (file)
   (with-temp-buffer
-    (call-process "sha256sum" nil t nil (expand-file-name file))
+    (if (file-remote-p file)
+	(let ((f (framebuffer-local-cache-file "emacs-framebuffer" "tmp")))
+	  (with-temp-file f
+	    (insert (expand-file-name file)))
+	  (call-process "sha256sum" nil t nil (expand-file-name f)))
+      (call-process "sha256sum" nil t nil (expand-file-name file)))
     (buffer-substring (point-min) (+ (point-min) 64))))
 
+(defun framebuffer-file-readable-p (file)
+  (when (file-readable-p file)
+    file))
+
+(defun framebuffer-cache-remote (file)
+  (if (file-remote-p file)
+      (let ((z (framebuffer-local-cache-file (framebuffer-file-hash file)
+					     (file-name-extension file))))
+	(unless (file-readable-p z)
+	  (copy-file file z))
+        z)
+    file))
+
 (defun framebuffer-cache-abiword (format ifile ofile)
   (case format
     ((abw odt rtf doc docx)
@@ -134,20 +163,17 @@
        (call-process "abiword" nil nil nil
                      "-t" (expand-file-name ofile)
                      (expand-file-name ifile)))
-     (when (file-readable-p ofile)
-       ofile))))
+     ofile)))
 
 (defun framebuffer-cache-to-pdf (format file)
   (framebuffer-cache-abiword
    format
    file
-   (concat (or framebuffer-cache-directory (temporary-file-directory))
-           "/"
-           (framebuffer-file-hash file) ".pdf")))
+   (framebuffer-local-cache-file (framebuffer-file-hash file) "pdf")))
 
 (defun framebuffer-cache-pdf-to-png (file page)
   (let* ((page (format "%s" (or page 1)))
-         (output (concat (or framebuffer-cache-directory (temporary-file-directory))
+         (output (concat (framebuffer-local-cache-directory)
                          "/"
                          (framebuffer-file-hash file) "-" page))
          (ofile (concat output ".png")))
@@ -156,10 +182,7 @@
     ofile))
 
 (defun framebuffer-cache-svg-to-png (file)
-  (let ((ofile (concat (or framebuffer-cache-directory (temporary-file-directory))
-                       "/"
-                       (framebuffer-file-hash file)
-                       ".png")))
+  (let ((ofile (framebuffer-local-cache-file (framebuffer-file-hash file) "png")))
     (unless (file-readable-p ofile)
       (call-process "convert" nil nil nil (expand-file-name file) ofile))
     ofile))
@@ -185,6 +208,7 @@
       "w3mimgdisplay"))
 
 (defun framebuffer-draw (x y w h sx sy sw sh file)
+  (setq file (framebuffer-cache-remote file))
   (let ((format (framebuffer-file-format file)))
     (case format
       (svg
@@ -256,6 +280,7 @@
       (cons (read (match-string 1)) (read (match-string 2))))))
 
 (defun framebuffer-image-size (file)
+  (setq file (framebuffer-cache-remote file))
   (with-temp-buffer
     (set-buffer-multibyte nil)
     (insert-file-contents-literally file)
@@ -406,6 +431,7 @@
 
 (defun framebuffer-image-file (file)
   (interactive "fFile: ")
+  (setq file (framebuffer-cache-remote file))
   (destructuring-bind (w &rest h) (framebuffer-image-size file)
     (destructuring-bind (fw &rest fh) (framebuffer-size)
       (let* ((scale (min (/ fw 1.0 w) (/ fh 1.0 h)))
@@ -497,6 +523,7 @@
           z)))))
 
 (defun framebuffer-image-npages (file)
+  (setq file (framebuffer-cache-remote file))
   (let ((format (framebuffer-file-format file)))
     (case format
       (pdf