* wl-summary.el (wl-summary-sync-force-update): Added argument no-check.
[elisp/wanderlust.git] / wl / wl-message.el
index 8d52d2c..2e8747f 100644 (file)
@@ -1,6 +1,6 @@
 ;;; wl-message.el -- Message displaying modules for Wanderlust.
 
-;; Copyright 1998,1999,2000 Yuuichi Teranishi <teranisi@gohome.org>
+;; Copyright (C) 1998,1999,2000 Yuuichi Teranishi <teranisi@gohome.org>
 
 ;; Author: Yuuichi Teranishi <teranisi@gohome.org>
 ;; Keywords: mail, net news
 
 (require 'wl-vars)
 (require 'wl-highlight)
+(require 'elmo)
+(require 'elmo-mime) ; XXX should modify for tm.
 
 (eval-when-compile
   (if wl-use-semi
       (progn
        (require 'wl-mime)
-       (require 'mime-view)
-       (require 'mmelmo-imap4))
+       (require 'mime-view))
     (require 'tm-wl))
   (defalias-maybe 'event-window 'ignore)
   (defalias-maybe 'posn-window 'ignore)
   (defalias-maybe 'event-start 'ignore)
   (defalias-maybe 'mime-open-entity 'ignore))
 
-(defvar wl-original-buf-name "*Message*")
-(defvar wl-message-buf-name "Message")
+(defconst wl-message-buffer-prefetch-idle-time
+  (if (featurep 'lisp-float-type) (/ (float 1) (float 5)) 1))
+(defvar wl-message-buffer-prefetch-get-next-function
+  'wl-summary-default-get-next-msg)
+
+(defvar wl-message-buffer-prefetch-folder-type-list t)
+
+(defvar wl-message-buffer-prefetch-debug
+  t)
+
+(defvar wl-message-buffer nil) ; message buffer.
+
 (defvar wl-message-buffer-cur-summary-buffer nil)
 (defvar wl-message-buffer-cur-folder nil)
 (defvar wl-message-buffer-cur-number nil)
-
-(defvar wl-original-buffer-cur-folder nil)
-(defvar wl-original-buffer-cur-number nil)
-(defvar wl-original-buffer-cur-msgdb  nil)
-
-(defvar mmelmo-imap4-skipped-parts)
+(defvar wl-message-buffer-cur-flag nil)
+(defvar wl-message-buffer-cur-summary-buffer nil)
+(defvar wl-message-buffer-original-buffer nil) ; original buffer.
 
 (make-variable-buffer-local 'wl-message-buffer-cur-folder)
 (make-variable-buffer-local 'wl-message-buffer-cur-number)
-
-(require 'product)
-(product-provide (provide 'wl-message) (require 'wl-version))
+(make-variable-buffer-local 'wl-message-buffer-cur-flag)
+(make-variable-buffer-local 'wl-message-buffer-cur-summary-buffer)
+(make-variable-buffer-local 'wl-message-buffer-original-buffer)
 
 (defvar wl-fixed-window-configuration nil)
 
+(defvar wl-message-buffer-cache-size 10) ; At least 1.
+
+;;; Message buffer cache.
+
+(defvar wl-message-buffer-cache nil
+  "Message cache.  (old ... new) order alist.
+With association ((\"folder\" message \"message-id\") . cache-buffer).")
+
+(defmacro wl-message-buffer-cache-buffer-get (entry)
+  (` (cdr (, entry))))
+
+(defmacro wl-message-buffer-cache-folder-get (entry)
+  (` (car (car (, entry)))))
+
+(defmacro wl-message-buffer-cache-message-get (entry)
+  (` (cdr (car (, entry)))))
+
+(defmacro wl-message-buffer-cache-entry-make (key buf)
+  (` (cons (, key) (, buf))))
+
+(defmacro wl-message-buffer-cache-hit (key)
+  "Return value assosiated with key."
+  (` (wl-message-buffer-cache-buffer-get
+      (assoc (, key) wl-message-buffer-cache))))
+
+(defun wl-message-buffer-cache-sort (entry)
+  "Move ENTRY to the top of `wl-message-buffer-cache'."
+  (setq wl-message-buffer-cache
+       (cons entry (delete entry wl-message-buffer-cache))))
+;  (let* ((pointer (cons nil wl-message-buffer-cache))
+;       (top pointer))
+;    (while (cdr pointer)
+;      (if (equal (car (cdr pointer)) entry)
+;        (setcdr pointer (cdr (cdr pointer)))
+;      (setq pointer (cdr pointer))))
+;    (setcdr pointer (list entry))
+;    (setq wl-message-buffer-cache (cdr top))))
+
+(defconst wl-message-buffer-cache-name    " *WL:Message*")
+(defconst wl-original-message-buffer-name " *Original*")
+
+(defun wl-original-message-mode ()
+  "A major mode for original message buffer."
+  (setq major-mode 'wl-original-message-mode)
+  (setq buffer-read-only t)
+  (elmo-set-buffer-multibyte nil)
+  (setq mode-name "Wanderlust original message"))
+
+(defun wl-original-message-buffer-get (name)
+  "Get original message buffer for NAME.
+If original message buffer already exists, it is re-used."
+  (let* ((name (concat wl-original-message-buffer-name name))
+        (buffer (get-buffer name)))
+    (unless (and buffer (buffer-live-p buffer))
+      (with-current-buffer (setq buffer (get-buffer-create name))
+       (wl-original-message-mode)))
+    buffer))
+
+(defun wl-message-buffer-create ()
+  "Create a new message buffer."
+  (let* ((buffer (generate-new-buffer wl-message-buffer-cache-name))
+        (name (buffer-name buffer)))
+    (with-current-buffer buffer
+      (setq wl-message-buffer-original-buffer
+           (wl-original-message-buffer-get name)))
+    buffer))
+
+(defun wl-message-buffer-cache-add (key)
+  "Add (KEY . buf) to the top of `wl-message-buffer-cache'.
+Return its cache buffer."
+  (let ((len (length wl-message-buffer-cache))
+       (buf nil))
+    (if (< len wl-message-buffer-cache-size)
+       (setq buf (wl-message-buffer-create))
+      (setq buf (wl-message-buffer-cache-buffer-get
+                (nth (1- len) wl-message-buffer-cache)))
+      (setcdr (nthcdr (- len 2) wl-message-buffer-cache) nil))
+    (setq wl-message-buffer-cache
+         (cons (wl-message-buffer-cache-entry-make key buf)
+               wl-message-buffer-cache))
+    buf))
+
+(defun wl-message-buffer-cache-delete (&optional key)
+  "Delete the most recent cache entry"
+  (if key
+      (setq wl-message-buffer-cache
+           (delq (assoc key wl-message-buffer-cache)
+                 wl-message-buffer-cache))
+    (let ((buf (wl-message-buffer-cache-buffer-get
+               (car wl-message-buffer-cache))))
+      (setq wl-message-buffer-cache
+           (nconc (cdr wl-message-buffer-cache)
+                  (list (wl-message-buffer-cache-entry-make nil buf)))))))
+
+(defun wl-message-buffer-cache-clean-up ()
+  "A function to flush all decoded messages in cache list."
+  (interactive)
+  (if (and (eq major-mode 'wl-summary-mode)
+          wl-message-buffer
+          (get-buffer-window wl-message-buffer))
+      (delete-window (get-buffer-window wl-message-buffer)))
+  (wl-kill-buffers (regexp-quote wl-message-buffer-cache-name))
+  (setq wl-message-buffer-cache nil))
+
+;;; Message buffer handling from summary buffer.
+
 (defun wl-message-buffer-window ()
-  (let* ((mes-buf (concat "^" (default-value 'wl-message-buf-name)))
-        (start-win (selected-window))
+  "Get message buffer window if any."
+  (let* ((start-win (selected-window))
         (cur-win start-win))
     (catch 'found
       (while (progn
               (setq cur-win (next-window cur-win))
-              (if (string-match mes-buf (buffer-name (window-buffer cur-win)))
-                  (throw 'found cur-win))
+              (with-current-buffer (window-buffer cur-win)
+                (if (or (eq major-mode 'wl-message-mode)
+                        (eq major-mode 'mime-view-mode))
+                    (throw 'found cur-win)))
               (not (eq cur-win start-win)))))))
 
-(defun wl-select-buffer (buffer)
-  (let ((gbw (or (get-buffer-window buffer)
-                (wl-message-buffer-window)))
+(defun wl-message-select-buffer (buffer)
+  "Select BUFFER as a message buffer."
+  (let ((window (get-buffer-window buffer))
        (sum (car wl-message-window-size))
        (mes (cdr wl-message-window-size))
        whi)
-    (when (and gbw
-              (not (eq (save-excursion (set-buffer (window-buffer gbw))
+    (when (and window
+              (not (eq (save-excursion (set-buffer (window-buffer window))
                                        wl-message-buffer-cur-summary-buffer)
                        (current-buffer))))
-      (delete-window gbw)
+      (delete-window window)
       (run-hooks 'wl-message-window-deleted-hook)
-      (setq gbw nil))
-    (if gbw
-       (select-window gbw)
-;      (if (or (null mes)
-;            wl-stay-folder-window)
-;        (delete-other-windows))
+      (setq window nil))
+    (if window
+       (select-window window)
       (when wl-fixed-window-configuration
         (delete-other-windows)
         (and wl-stay-folder-window
              (wl-summary-toggle-disp-folder)))
-      (setq whi (1- (window-height)))
-      (if mes
-         (progn
-           (let ((total (+ sum mes)))
-             (setq sum (max window-min-height (/ (* whi sum) total)))
-             (setq mes (max window-min-height (/ (* whi mes) total))))
-            (if (< whi (+ sum mes))
-                (enlarge-window (- (+ sum mes) whi)))))
-      (split-window (get-buffer-window (current-buffer)) sum)
-      (other-window 1))
+      ;; There's no buffer window. Search for message window and snatch it.
+      (if (setq window (wl-message-buffer-window))
+         (select-window window)
+       (setq whi (1- (window-height)))
+       (if mes
+           (progn
+             (let ((total (+ sum mes)))
+               (setq sum (max window-min-height (/ (* whi sum) total)))
+               (setq mes (max window-min-height (/ (* whi mes) total))))
+             (if (< whi (+ sum mes))
+                 (enlarge-window (- (+ sum mes) whi)))))
+       (split-window (get-buffer-window (current-buffer)) sum)
+       (other-window 1)))
     (switch-to-buffer buffer)))
 
-;;
-;; called by wl-summary-mode buffer
-;;
-(defvar wl-message-func-called-hook nil)
-
-(defun wl-message-scroll-down (amount)
-  (let ((view-message-buffer (get-buffer-create wl-message-buf-name))
-       (cur-buf (current-buffer)))
-    (wl-select-buffer view-message-buffer)
-    (if (bobp)
-       ()
-      (scroll-down))
-    (select-window (get-buffer-window cur-buf))))
-
-(defun wl-message-scroll-up (amount)
-  (let ((view-message-buffer (get-buffer-create wl-message-buf-name))
-       (cur-buf (current-buffer)))
-    (wl-select-buffer view-message-buffer)
-    (save-excursion
-      (save-restriction
-       (widen)
-       (forward-page 1)
-       (if (pos-visible-in-window-p (point))
-           (wl-message-narrow-to-page 1))))            ;Go to next page.
-    (if (eobp)
-       ()
-      (scroll-up))
-    (select-window (get-buffer-window cur-buf))))
-  
+(defun wl-message-narrow-to-page (&optional arg)
+  "Narrow to page.
+If ARG is specified, narrow to ARGth page."
+  (interactive "P")
+  (setq arg (if arg (prefix-numeric-value arg) 0))
+  (save-excursion
+    (condition-case ()
+        (forward-page -1)               ; Beginning of current page.
+      (beginning-of-buffer
+       (goto-char (point-min))))
+    (forward-char 1)  ; for compatibility with emacs-19.28 and emacs-19.29
+    (widen)
+    (cond
+     ((> arg 0) (forward-page arg))
+     ((< arg 0) (forward-page (1- arg))))
+    (forward-page)
+    (if wl-break-pages
+       (narrow-to-region (point)
+                         (progn
+                           (forward-page -1)
+                           (if (and (eolp) (not (bobp)))
+                               (forward-line))
+                           (point))))))
+
+(defun wl-message-prev-page (&optional lines)
+  "Scroll down current message by LINES.
+Returns non-nil if top of message."
+  (interactive)
+  (if (buffer-live-p wl-message-buffer)
+      (let ((cur-buf (current-buffer))
+           top)
+       (wl-message-select-buffer wl-message-buffer)
+       (move-to-window-line 0)
+       (if (and wl-break-pages
+                (bobp)
+                (not (save-restriction (widen) (bobp))))
+           (progn
+             (wl-message-narrow-to-page -1)
+             (goto-char (point-max))
+             (recenter))
+         (if (not (bobp))
+             (condition-case nil
+                 (scroll-down lines)
+               (error))
+           (setq top t)))
+       (select-window (get-buffer-window cur-buf))
+       top)))
+
+(defun wl-message-next-page (&optional lines)
+  "Scroll up current message by LINES.
+Returns non-nil if bottom of message."
+  (interactive)
+  (if (buffer-live-p wl-message-buffer)
+      (let ((cur-buf (current-buffer))
+           bottom)
+       (wl-message-select-buffer wl-message-buffer)
+       (move-to-window-line -1)
+       (if (save-excursion
+             (end-of-line)
+             (and (pos-visible-in-window-p)
+                  (eobp)))
+           (if (or (null wl-break-pages)
+                   (save-excursion
+                     (save-restriction
+                       (widen) (forward-line) (eobp))))
+               (setq bottom t)
+             (wl-message-narrow-to-page 1)
+             (setq bottom nil))
+         (condition-case ()
+             (static-if (boundp 'window-pixel-scroll-increment)
+                 ;; XEmacs 21.2.20 and later.
+                 (let (window-pixel-scroll-increment)
+                   (scroll-up lines))
+               (scroll-up lines))            
+           (end-of-buffer
+            (goto-char (point-max))))
+         (setq bottom nil))
+       (select-window (get-buffer-window cur-buf))
+       bottom)))
+
+
 (defun wl-message-follow-current-entity (buffer)
-  "Follow to current message"
+  "Follow to current message."
   (wl-draft-reply (wl-message-get-original-buffer)
-                 'to-all wl-message-buffer-cur-summary-buffer)
+                 nil wl-message-buffer-cur-summary-buffer) ; reply to all
   (let ((mail-reply-buffer buffer))
     (wl-draft-yank-from-mail-reply-buffer nil)))
 
-(defun wl-message-original-mode ()
-  (setq major-mode 'wl-message-original-mode)
-  (setq mode-name "Original")
-  (setq buffer-read-only t)
-  (if (fboundp 'set-buffer-file-coding-system)
-      (set-buffer-file-coding-system wl-cs-noconv)))
+;; 
 
 (defun wl-message-mode ()
+  "A major mode for message displaying."
   (interactive)
   (setq major-mode 'wl-message-mode)
   (setq buffer-read-only t)
   (setq mode-name "Message"))
 
-(defun wl-message-get-buffer-create ()
-  (let ((buf-name wl-message-buf-name))
-    (or (get-buffer buf-name)
-       (save-excursion
-         (set-buffer (get-buffer-create buf-name))
-         (wl-message-mode)
-         (run-hooks 'wl-message-buffer-created-hook)
-         (get-buffer buf-name)))))
-
-(defun wl-message-original-get-buffer-create ()
-  (or (get-buffer wl-original-buf-name)
-      (save-excursion
-       (set-buffer (get-buffer-create wl-original-buf-name))
-       (wl-message-original-mode)
-       (get-buffer wl-original-buf-name))))
-  
 (defun wl-message-exit ()
+  "Move to summary buffer."
   (interactive)
   (let (summary-buf summary-win)
     (if (setq summary-buf wl-message-buffer-cur-summary-buffer)
        (if (setq summary-win (get-buffer-window summary-buf))
            (select-window summary-win)
          (switch-to-buffer summary-buf)
-         (wl-select-buffer wl-message-buf-name)
+         (wl-message-select-buffer wl-message-buffer)
          (select-window (get-buffer-window summary-buf))))
     (run-hooks 'wl-message-exit-hook)))
 
-(defun wl-message-decode (outbuf inbuf flag)
-  (cond
-   ((eq flag 'all-header)
-    (save-excursion
-      (set-buffer inbuf)
-      (let ((buffer-read-only nil))
-       (decode-mime-charset-region (point-min)
-                                   (save-excursion
-                                     (goto-char (point-min))
-                                     (re-search-forward "^$" nil t)
-                                     (point))
-                                   wl-mime-charset)))
-    (wl-message-decode-with-all-header outbuf inbuf))
-   ((eq flag 'no-mime)
-    (save-excursion
-      (set-buffer inbuf)
-      (let ((buffer-read-only nil))
-       (save-excursion
-         (set-buffer outbuf)
-         (elmo-set-buffer-multibyte nil))
-       (copy-to-buffer outbuf (point-min) (point-max))
-       (set-buffer outbuf)
-       (local-set-key "q" 'wl-message-exit)
-       (local-set-key "p" 'wl-message-exit)
-       (local-set-key "n" 'wl-message-exit)
-       (elmo-set-buffer-multibyte default-enable-multibyte-characters)
-       ;;(decode-mime-charset-region (point-min) (point-max) wl-mime-charset)
-       ;; we can call decode-coding-region() directly, because multibyte flag is t.
-       (decode-coding-region (point-min) (point-max) wl-cs-autoconv)
-       (wl-highlight-message (point-min)
-                             (save-excursion
-                               (goto-char (point-min))
-                               (re-search-forward "^$" nil t)) nil))))
-   (t                                  ; normal
-    (save-excursion
-      (set-buffer inbuf)
-      (let ((buffer-read-only nil))
-       (decode-mime-charset-region (point-min)
-                                   (save-excursion
-                                     (goto-char (point-min))
-                                     (re-search-forward "^$" nil t)
-                                     (point))
-                                   wl-mime-charset)))
-    (wl-message-decode-mode outbuf inbuf))))
-
-(defun wl-message-prev-page (&optional lines)
-  "Scroll down this message. Returns non-nil if top of message"
-  (interactive)
-  (let ((cur-buf (current-buffer))
-       (view-message-buffer (get-buffer-create wl-message-buf-name))
-       ret-val)
-    (wl-select-buffer view-message-buffer)
-    (move-to-window-line 0)
-    (if (and wl-break-pages
-            (bobp)
-            (not (save-restriction (widen) (bobp))))
-       (progn
-         (wl-message-narrow-to-page -1)
-         (goto-char (point-max))
-         (recenter -1))
-      (if (not (bobp))
-         (scroll-down lines)
-       (setq ret-val t)))
-    (select-window (get-buffer-window cur-buf))
-    ret-val))
-
-(static-if (fboundp 'luna-make-entity)
-    (defsubst wl-message-make-mime-entity (backend number backend folder msgdb)
-      (luna-make-entity (mm-expand-class-name 'elmo)
-                       :location (get-buffer-create
-                                  (concat mmelmo-entity-buffer-name "0"))
-                       :imap (eq backend 'elmo-imap4)
-                       :folder folder
-                       :number number
-                       :msgdb msgdb :size 0))
-  (defsubst wl-message-make-mime-entity (backend number backend folder msgdb)
-    (mime-open-entity backend (list folder number msgdb nil))))
-
-(defun wl-message-next-page (&optional lines)
-  "Scroll up this message. Returns non-nil if bottom of message"
-  (interactive)
-  (let ((cur-buf (current-buffer))
-       (view-message-buffer (get-buffer-create wl-message-buf-name))
-       ret-val)
-    (wl-select-buffer view-message-buffer)
-    (move-to-window-line -1)
-    (if (save-excursion
-         (end-of-line)
-         (and (pos-visible-in-window-p)
-              (eobp)))
-       (if (or (null wl-break-pages)
-               (save-excursion
-                 (save-restriction
-                   (widen) (forward-line) (eobp))))
-           (setq ret-val t)
-         (wl-message-narrow-to-page 1)
-         (setq ret-val nil))
-      (condition-case ()
-         (scroll-up lines)
-       (end-of-buffer
-        (goto-char (point-max))))
-      (setq ret-val nil))
-    (select-window (get-buffer-window cur-buf))
-    ret-val
-    ))
-
-(defun wl-message-narrow-to-page (&optional arg)
-  (interactive "P")
-  (setq arg (if arg (prefix-numeric-value arg) 0))
-  (save-excursion
-    (condition-case ()
-        (forward-page -1)               ; Beginning of current page.
-      (beginning-of-buffer
-       (goto-char (point-min))))
-    (forward-char 1)  ; for compatibility with emacs-19.28 and emacs-19.29
-    (widen)
-    (cond
-     ((> arg 0)        (forward-page arg))
-     ((< arg 0) (forward-page (1- arg))))
-    (forward-page)
-    (if wl-break-pages
-       (narrow-to-region (point)
-                         (progn
-                           (forward-page -1)
-                           (if (and (eolp) (not (bobp)))
-                               (forward-line))
-                           (point)))) ))
-
 (defun wl-message-toggle-disp-summary ()
   (interactive)
   (let ((summary-buf (get-buffer wl-message-buffer-cur-summary-buffer))
        (if (setq summary-win (get-buffer-window summary-buf))
            (delete-window summary-win)
          (switch-to-buffer summary-buf)
-         (wl-select-buffer wl-message-buf-name))
+         (wl-message-select-buffer wl-message-buffer))
       (wl-summary-goto-folder-subr wl-message-buffer-cur-folder 'no-sync
                                   nil nil t)
                                        ; no summary-buf
       (let ((sum-buf (current-buffer)))
-       (wl-select-buffer wl-message-buf-name)
+       (wl-message-select-buffer wl-message-buffer)
        (setq wl-message-buffer-cur-summary-buffer sum-buf)))))
 
-(defun wl-message-normal-get-original-buffer ()
-  (let ((ret-val (get-buffer wl-original-buf-name)))
-    (if (not ret-val)
-       (save-excursion
-         (set-buffer (setq ret-val
-                           (get-buffer-create wl-original-buf-name)))
-         (wl-message-original-mode)))
-    ret-val))
-
-
-(if wl-use-semi
-    (defalias 'wl-message-get-original-buffer
-      'mmelmo-get-original-buffer)
-  (defalias 'wl-message-get-original-buffer
-    'wl-message-normal-get-original-buffer))
-
-(defvar wl-message-redisplay-func 'wl-normal-message-redisplay)
-(defvar wl-message-cache-used nil) ;whether cache is used or not.
-
-(defun wl-message-redisplay (folder number flag msgdb &optional force-reload)
-  (let ((default-mime-charset wl-mime-charset)
-       (buffer-read-only nil))
-    (setq wl-message-cache-used nil)
-    (if wl-message-redisplay-func
-       (funcall wl-message-redisplay-func
-                folder number flag msgdb force-reload))))
-
-;; nil means don't fetch all.
-(defun wl-message-decide-backend (folder number message-id size)
-  (let ((dont-do-that (and
-                      (not (setq wl-message-cache-used
-                                 (or
-                                  (elmo-buffer-cache-hit
-                                   (list folder number message-id))
-                                  (elmo-cache-exists-p message-id
-                                                       folder number))))
-                      (integerp size)
-                      (not (elmo-local-file-p folder number))
-                      wl-fetch-confirm-threshold
-                      (>= size wl-fetch-confirm-threshold)
-                      (not (y-or-n-p
-                            (format "Fetch entire message? (%dbytes)"
-                                    size))))))
-    (message "")
-    (cond ((and dont-do-that
-               (eq (elmo-folder-number-get-type folder number) 'imap4)
-               (not (and (elmo-use-cache-p folder number)
-                         (elmo-cache-exists-p message-id folder number))))
-          'elmo-imap4)
-         (t (if (not dont-do-that) 'elmo)))))
-
-(defmacro wl-message-original-buffer-folder ()
-  wl-original-buffer-cur-folder)
-
-(defmacro wl-message-original-buffer-number ()
-  wl-original-buffer-cur-number)
-
-(defun wl-message-set-original-buffer-information (folder number)
-  (when (or (not (string= folder (or wl-original-buffer-cur-folder "")))
-           (not (eq number (or wl-original-buffer-cur-number 0))))
-    (setq wl-original-buffer-cur-folder folder)
-    (setq wl-original-buffer-cur-number number)))
-
-;; Works on FLIM-1.9.0/SEMI-1.8.2 or later (maybe).
-(defun wl-mmelmo-message-redisplay (folder number flag msgdb
-                                          &optional force-reload)
-  (let* ((cur-buf (current-buffer))
-        (view-message-buffer (wl-message-get-buffer-create))
-        (message-id (cdr (assq number
-                               (elmo-msgdb-get-number-alist msgdb))))
-        (size (elmo-msgdb-overview-entity-get-size
-               (elmo-msgdb-overview-get-entity number msgdb)))
-        (backend (wl-message-decide-backend folder number message-id size))
-        cur-entity ret-val header-end real-fld-num summary-win)
-    (require 'mmelmo)
-    (wl-select-buffer view-message-buffer)
-    (set-buffer view-message-buffer)
-    (unwind-protect
-       (progn
-         (setq wl-message-buffer-cur-summary-buffer cur-buf)
-         (setq wl-message-buffer-cur-folder folder)
-         (setq wl-message-buffer-cur-number number)
-         (setq buffer-read-only nil)
-         (erase-buffer)
-         (if backend
-             (let (mime-display-header-hook ;; bind to nil...
-                   (wl-message-ignored-field-list
-                    (if (eq flag 'all-header)
-                        nil
-                      wl-message-ignored-field-list))
-                   (mmelmo-force-reload force-reload)
-                   (mmelmo-imap4-threshold wl-fetch-confirm-threshold))
-               (setq real-fld-num (elmo-get-real-folder-number
-                                   folder number))
-               (setq cur-entity
-                     (wl-message-make-mime-entity
-                      backend
-                      (if (eq backend 'elmo-imap4)
-                          (cdr real-fld-num)
-                        number)
-                      backend
-                      (if (eq backend 'elmo-imap4)
-                          (car real-fld-num)
-                        folder)
-                      msgdb))
-               (setq mmelmo-imap4-skipped-parts nil)
-               ;;; mime-display-message sets buffer-read-only variable as t.
-               ;;; which makes buffer read-only status confused...
-               (wl-mime-display-message cur-entity view-message-buffer
-                                        nil nil 'mmelmo-original-mode)
-               (if mmelmo-imap4-skipped-parts
-                   (progn
-                     (message "Skipped fetching of %s."
-                              (mapconcat
-                               (lambda (x)
-                                 (format "[%s]" x))
-                               mmelmo-imap4-skipped-parts ","))))
-               (if (and (eq backend 'elmo-imap4)
-                        (null mmelmo-imap4-skipped-parts))
-                   (message "No required part was skipped."))
-               (setq ret-val (not (eq backend 'elmo-imap4))))
-           (message "Skipped fetching.")
-           (setq ret-val nil)))
-      (setq buffer-read-only nil)
-      (wl-message-set-original-buffer-information folder number)
-      (wl-message-overload-functions)
-      ;; highlight body
-      (when wl-highlight-body-too
-       (wl-highlight-body))
-      (condition-case ()
-         (wl-message-narrow-to-page)
-       (error nil));; ignore errors.
-      (setq mode-line-buffer-identification
-           (format "Wanderlust: << %s / %s >>"
-                   (if (memq 'modeline wl-use-folder-petname)
-                       (wl-folder-get-petname folder)
-                     folder) number))
-      (goto-char (point-min))
-      (unwind-protect
-         (save-excursion
-           (run-hooks 'wl-message-redisplay-hook))
-       ;; go back to summary mode
-       (set-buffer-modified-p nil)
-       (setq buffer-read-only t)
-       (set-buffer cur-buf)
-       (setq summary-win (get-buffer-window cur-buf))
-       (if (window-live-p summary-win)
-           (select-window summary-win))))
-    ret-val
-    ))
-
-(defun wl-normal-message-redisplay (folder number flag msgdb
-                                          &optional force-reload)
-  (interactive)
-  (let* ((cur-buf (current-buffer))
-        (original-message-buffer (wl-message-get-original-buffer))
-        (view-message-buffer (wl-message-get-buffer-create))
-        (message-id (cdr (assq number
-                               (elmo-msgdb-get-number-alist msgdb))))
-        (size (elmo-msgdb-overview-entity-get-size
-               (elmo-msgdb-overview-get-entity number msgdb)))
-        header-end ret-val summary-win)
-    (wl-select-buffer view-message-buffer)
+(defun wl-message-get-original-buffer ()
+  "Get original buffer for current message buffer."
+  wl-message-buffer-original-buffer)
+
+(defun wl-message-redisplay (folder number flag &optional force-reload)
+  (let* ((default-mime-charset wl-mime-charset)
+        (buffer-read-only nil)
+        (summary-buf (current-buffer))
+        message-buf
+        strategy entity
+        cache-used
+        header-end real-fld-num summary-win)
+    (setq buffer-read-only nil)
+    (setq cache-used (wl-message-buffer-display
+                     folder number flag force-reload))
+    (setq wl-message-buffer (car cache-used))
+    (setq message-buf wl-message-buffer)
+    (wl-message-select-buffer wl-message-buffer)
+
+    (set-buffer message-buf)
+    (setq buffer-read-only nil)
+    (setq wl-message-buffer-cur-summary-buffer summary-buf)
+    (setq wl-message-buffer-cur-folder (elmo-folder-name-internal folder))
+    (setq wl-message-buffer-cur-number number)
+    (wl-message-overload-functions)
+    (setq mode-line-buffer-identification
+         (format "Wanderlust: << %s / %s >>"
+                 (if (memq 'modeline wl-use-folder-petname)
+                     (wl-folder-get-petname (elmo-folder-name-internal
+                                             folder))
+                   (elmo-folder-name-internal folder)) number))
+    ;; highlight body
+;    (when wl-highlight-body-too
+;      (wl-highlight-body))
+    (condition-case ()
+       (wl-message-narrow-to-page)
+      (error nil)); ignore errors.
+    (setq cache-used (cdr cache-used))
+    (goto-char (point-min))
     (unwind-protect
+       (save-excursion
+         (run-hooks 'wl-message-redisplay-hook))
+      ;; go back to summary mode
+      (set-buffer-modified-p nil)
+      (setq buffer-read-only t)
+      (set-buffer summary-buf)
+      (setq summary-win (get-buffer-window summary-buf))
+      (if (window-live-p summary-win)
+         (select-window summary-win)))
+    cache-used))
+
+;; Use message buffer cache.
+(defun wl-message-buffer-display (folder number flag
+                                        &optional force-reload unread)
+  (let* ((msg-id (elmo-message-field folder number 'message-id))
+        (fname (elmo-folder-name-internal folder))
+        (hit (wl-message-buffer-cache-hit (list fname number msg-id)))
+        (read nil)
+        cache-used)
+    (when (and hit (not (buffer-live-p hit)))
+      (wl-message-buffer-cache-delete (list fname number msg-id))
+      (setq hit nil))
+    (if hit
        (progn
-         (setq wl-message-buffer-cur-summary-buffer cur-buf)
-         (setq wl-message-buffer-cur-folder folder)
-         (setq wl-message-buffer-cur-number number)
-         (setq buffer-read-only nil)
-         (erase-buffer)
-         (if (or (eq (elmo-folder-number-get-type folder number) 'localdir)
-                 (not (and (integerp size)
-                           wl-fetch-confirm-threshold
-                           (>= size wl-fetch-confirm-threshold)
-                           (not (elmo-cache-exists-p message-id
-                                                     folder number))
-                           (not (y-or-n-p
-                                 (format "Fetch entire message? (%dbytes)"
-                                         size))))))
-             (progn
-               (save-excursion
-                 (set-buffer original-message-buffer)
-                 (let ((buffer-read-only nil))
-                   (elmo-read-msg-with-buffer-cache
-                    folder number original-message-buffer msgdb force-reload)))
-               ;; decode MIME message.
-               (wl-message-decode
-                view-message-buffer
-                original-message-buffer flag)
-               (setq ret-val t))
+         ;; move hit to the top.
+         (wl-message-buffer-cache-sort
+          (wl-message-buffer-cache-entry-make (list fname number msg-id) hit))
+         ;; buffer cache is used.
+         (setq cache-used t)
+         (with-current-buffer hit
+           (unless (eq wl-message-buffer-cur-flag flag)
+             (setq read t))))
+      ;; delete tail and add new to the top.
+      (setq hit (wl-message-buffer-cache-add (list fname number msg-id)))
+      (setq read t))
+    (if (or force-reload read)
+       (condition-case err
            (save-excursion
-             (set-buffer view-message-buffer)
-             (insert "\n\n"))))
-      (setq buffer-read-only nil)
-      (wl-message-set-original-buffer-information folder number)
-      (wl-message-overload-functions)
-      ;; highlight body
-      (and wl-highlight-body-too (wl-highlight-body))
-      (condition-case ()
-         (wl-message-narrow-to-page)
-       (error nil)) ; ignore errors.
-      (setq mode-line-buffer-identification
-           (format "Wanderlust: << %s / %s >>"
-                   (if (memq 'modeline wl-use-folder-petname)
-                       (wl-folder-get-petname folder)
-                     folder)
-                   number))
-      (goto-char (point-min))
-      (unwind-protect
-         (run-hooks 'wl-message-redisplay-hook)
-       ;; go back to summary mode
-       (set-buffer-modified-p nil)
-       (setq buffer-read-only t)
-       (set-buffer cur-buf)
-       (setq summary-win (get-buffer-window cur-buf))
-       (if (window-live-p summary-win)
-           (select-window summary-win)))
-      ret-val
-      )))
+             (set-buffer hit)
+             (setq
+              cache-used
+              (wl-message-display-internal folder number flag
+                                           force-reload unread))
+             (setq wl-message-buffer-cur-flag flag))
+         (quit
+          (wl-message-buffer-cache-delete)
+          (error "Display message %s/%s is quitted" fname number))
+         (error
+          (wl-message-buffer-cache-delete)
+          (signal (car err) (cdr err))
+          nil))) ;; will not be used
+    (cons hit cache-used)))
+
+(defun wl-message-display-internal (folder number flag
+                                          &optional force-reload unread)
+  (let ((elmo-message-ignored-field-list
+        (if (eq flag 'all-header)
+            nil
+          wl-message-ignored-field-list))
+       (elmo-message-visible-field-list wl-message-visible-field-list)
+       (elmo-message-sorted-field-list wl-message-sort-field-list)
+       (elmo-fetch-threshold wl-fetch-confirm-threshold))
+    (prog1 
+       (if (eq flag 'as-is)
+           (let (wl-highlight-x-face-function)
+             (elmo-mime-display-as-is folder number
+                                      (current-buffer)
+                                      (wl-message-get-original-buffer)
+                                      'wl-original-message-mode
+                                      force-reload
+                                      unread))
+         (elmo-mime-message-display folder number
+                                    (current-buffer)
+                                    (wl-message-get-original-buffer)
+                                    'wl-original-message-mode
+                                    force-reload
+                                    unread))
+      (setq buffer-read-only t))))
+
+(defsubst wl-message-buffer-prefetch-p (folder &optional number)
+  (cond 
+   ((eq wl-message-buffer-prefetch-folder-type-list t)
+    t)
+   ((and number wl-message-buffer-prefetch-folder-type-list)
+    (memq (elmo-folder-type-internal
+          (elmo-message-folder folder number))
+         wl-message-buffer-prefetch-folder-type-list))
+   (wl-message-buffer-prefetch-folder-type-list
+    (let ((list wl-message-buffer-prefetch-folder-type-list)
+         type)
+      (catch 'done
+       (while (setq type (pop list))
+         (if (elmo-folder-contains-type folder type)
+             (throw 'done t))))))
+   ((consp wl-message-buffer-prefetch-folder-type-list)
+    (wl-string-match-member (elmo-folder-name-internal folder)
+                           wl-message-buffer-prefetch-folder-type-list))
+   (t wl-message-buffer-prefetch-folder-type-list)))
+
+
+(defvar wl-message-buffer-prefetch-timer nil)
+
+(defun wl-message-buffer-prefetch-next (folder number &optional
+                                              summary charset)
+  (if (wl-message-buffer-prefetch-p folder)
+      (with-current-buffer (or summary (get-buffer wl-summary-buffer-name))
+       (let* ((next (funcall wl-message-buffer-prefetch-get-next-function
+                             number)))
+         (when (and next (wl-message-buffer-prefetch-p folder next))
+           (if (not (fboundp 'run-with-idle-timer))
+               (when (sit-for wl-message-buffer-prefetch-idle-time)
+                 (wl-message-buffer-prefetch folder next summary charset))
+             (unless wl-message-buffer-prefetch-timer
+               (setq wl-message-buffer-prefetch-timer
+                     (run-with-idle-timer
+                      wl-message-buffer-prefetch-idle-time
+                      nil
+                      'wl-message-buffer-prefetch
+                      folder next summary charset)))))))))
+
+(defun wl-message-buffer-prefetch (folder number summary charset)
+  (when (buffer-live-p summary)
+    (save-excursion
+      (set-buffer summary)
+      (when (string= (elmo-folder-name-internal folder)
+                    (wl-summary-buffer-folder-name))
+       (let ((message-id (elmo-message-field folder number 'message-id))
+             (wl-mime-charset      charset)
+             (default-mime-charset charset)
+             result time1 time2 sec micro)
+         (if (not (wl-message-buffer-cache-hit (list folder
+                                                     number message-id)))
+             (let* ((size (elmo-message-field folder number 'size)))
+               (when (or (elmo-message-file-p folder number)
+                         (not 
+                          (and (integerp size)
+                               elmo-message-fetch-threshold
+                               (>= size
+                                   elmo-message-fetch-threshold))))
+                 ;;(not (elmo-file-cache-exists-p message-id)))))
+                 (when wl-message-buffer-prefetch-debug
+                   (setq time1 (current-time))
+                   (message "Prefetching %d..." number))
+                 (setq result (wl-message-buffer-display folder number
+                                                         'mime nil 'unread))
+                 (when wl-message-buffer-prefetch-debug
+                   (setq time2 (current-time))
+                   (setq sec  (- (nth 1 time2)(nth 1 time1)))
+                   (setq micro (- (nth 2 time2)(nth 2 time1)))
+                   (setq micro (+ micro (* 1000000 sec)))
+                   (message "Prefetching %d...done(%f msec)."
+                            number
+                            (/ micro 1000.0))))))))))
+  (setq wl-message-buffer-prefetch-timer nil))
 
 (defvar wl-message-button-map (make-sparse-keymap))
 
       (wl-summary-redisplay)))
 
 (defun wl-message-refer-article-or-url (e)
-  "Read article specified by message-id around point. If failed,
-   attempt to execute button-dispatcher."
+  "Read article specified by message-id around point.
+If failed, attempt to execute button-dispatcher."
   (interactive "e")
   (let ((window (get-buffer-window (current-buffer)))
        mouse-window point beg end msg-id)
        (set-buffer buf)
        filename))))
 
-;;; wl-message.el ends here
-
+(require 'product)
+(product-provide (provide 'wl-message) (require 'wl-version))
 
+;;; wl-message.el ends here