;; Copyright (C) 2006, 2012, 2013 Free Software Foundation, Inc.
-;; Version: 0.6
+;; Version: 1.1
;; Keywords: large files, utilities
+;; Maintainer: Andrey Kotlarski <m00naticus@gmail.com>
;; Authors: 2006 Mathias Dahl <mathias.dahl@gmail.com>
;; 2012 Sam Steingold <sds@gnu.org>
;; 2013 Andrey Kotlarski <m00naticus@gmail.com>
+;; URL: https://github.com/m00natic/vlfi
;; This file is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;;; Commentary:
;; This package provides the M-x vlf command, which visits part of a
-;; large file in a read-only buffer without visiting the entire file.
+;; large file without loading the entire file.
;; The buffer uses VLF mode, which defines several commands for
-;; moving around, searching and editing selected chunk of file.
+;; moving around, searching and editing selected part of file.
;; This package was inspired by a snippet posted by Kevin Rodgers,
;; showing how to use `insert-file-contents' to extract part of a
"Defines how large each batch of file data is (in bytes)."
:type 'integer
:group 'vlf)
+(put 'vlf-batch-size 'permanent-local t)
;;; Keep track of file position.
(defvar vlf-start-pos 0
"Absolute position of the visible chunk start.")
-(defvar vlf-end-pos vlf-batch-size
- "Absolute position of the visible chunk end.")
+(put 'vlf-start-pos 'permanent-local t)
+
+(defvar vlf-end-pos 0 "Absolute position of the visible chunk end.")
+(put 'vlf-end-pos 'permanent-local t)
+
(defvar vlf-file-size 0 "Total size of presented file.")
+(put 'vlf-file-size 'permanent-local t)
(defvar vlf-mode-map
- (let ((map (make-sparse-keymap)))
- (define-key map [M-next] 'vlf-next-batch)
- (define-key map [M-prior] 'vlf-prev-batch)
+ (let ((map-prefix (make-sparse-keymap))
+ (map (make-sparse-keymap)))
+ (define-key map [next] 'vlf-next-batch)
+ (define-key map [prior] 'vlf-prev-batch)
+ (define-key map "n" 'vlf-next-batch-from-point)
(define-key map "+" 'vlf-change-batch-size)
(define-key map "-"
(lambda () "Decrease vlf batch size by factor of 2."
(vlf-change-batch-size t)))
(define-key map "s" 'vlf-re-search-forward)
(define-key map "r" 'vlf-re-search-backward)
+ (define-key map "o" 'vlf-occur)
(define-key map "[" 'vlf-beginning-of-file)
(define-key map "]" 'vlf-end-of-file)
- (define-key map "e" 'vlf-edit-mode)
(define-key map "j" 'vlf-jump-to-chunk)
- map)
+ (define-key map "l" 'vlf-goto-line)
+ (define-key map "g" 'vlf-refresh)
+ (define-key map-prefix "\C-c\C-v" map)
+ map-prefix)
"Keymap for `vlf-mode'.")
-(define-derived-mode vlf-mode special-mode "VLF"
+(define-minor-mode vlf-mode
"Mode to browse large files in."
- (setq buffer-read-only t)
- (set-buffer-modified-p nil)
- (buffer-disable-undo)
- (add-hook 'write-contents-functions 'vlf-write)
- (setq revert-buffer-function 'vlf-revert)
- (make-local-variable 'vlf-batch-size)
- (put 'vlf-batch-size 'permanent-local t)
- (make-local-variable 'vlf-start-pos)
- (put 'vlf-start-pos 'permanent-local t)
- (make-local-variable 'vlf-end-pos)
- (put 'vlf-end-pos 'permanent-local t)
- (make-local-variable 'vlf-file-size)
- (put 'vlf-file-size 'permanent-local t))
+ :lighter " VLF"
+ :group 'vlf
+ :keymap vlf-mode-map
+ (if vlf-mode
+ (progn
+ (set (make-local-variable 'require-final-newline) nil)
+ (add-hook 'write-file-functions 'vlf-write nil t)
+ (set (make-local-variable 'revert-buffer-function)
+ 'vlf-revert)
+ (make-local-variable 'vlf-batch-size)
+ (set (make-local-variable 'vlf-start-pos) -1)
+ (make-local-variable 'vlf-end-pos)
+ (set (make-local-variable 'vlf-file-size)
+ (vlf-get-file-size buffer-file-name))
+ (let* ((pos (position-bytes (point)))
+ (start (* (/ pos vlf-batch-size) vlf-batch-size)))
+ (goto-char (byte-to-position (- pos start)))
+ (vlf-move-to-batch start)))
+ (kill-local-variable 'revert-buffer-function)
+ (when (or (not large-file-warning-threshold)
+ (< vlf-file-size large-file-warning-threshold)
+ (y-or-n-p (format "Load whole file (%s)? "
+ (file-size-human-readable
+ vlf-file-size))))
+ (kill-local-variable 'require-final-newline)
+ (remove-hook 'write-file-functions 'vlf-write t)
+ (let ((pos (+ vlf-start-pos (position-bytes (point)))))
+ (vlf-with-undo-disabled
+ (insert-file-contents buffer-file-name t nil nil t))
+ (goto-char (byte-to-position pos)))
+ (rename-buffer (file-name-nondirectory buffer-file-name) t))))
;;;###autoload
-(defun vlf (file &optional from-end)
- "View Large FILE. With FROM-END prefix, view from the back.
-Batches of the file data from FILE will be displayed in a read-only
-buffer. You can customize number of bytes displayed by customizing
+(defun vlf (file)
+ "View Large FILE in batches.
+You can customize number of bytes displayed by customizing
`vlf-batch-size'."
- (interactive "fFile to open: \nP")
+ (interactive "fFile to open: ")
(with-current-buffer (generate-new-buffer "*vlf*")
- (setq buffer-file-name file
- vlf-file-size (nth 7 (file-attributes file)))
- (vlf-insert-file from-end)
- (vlf-mode)
+ (set-visited-file-name file)
+ (set-buffer-modified-p nil)
+ (vlf-mode 1)
(switch-to-buffer (current-buffer))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; integration with other packages
;;;###autoload
-(defun dired-vlf (from-end)
- "In Dired, visit the file on this line in VLF mode.
-With FROM-END prefix, view from the back."
- (interactive "P")
- (vlf (dired-get-file-for-visit) from-end))
+(defun dired-vlf ()
+ "In Dired, visit the file on this line in VLF mode."
+ (interactive)
+ (vlf (dired-get-file-for-visit)))
;;;###autoload
(eval-after-load "dired"
'(define-key dired-mode-map "V" 'dired-vlf))
;;;###autoload
-(defun vlf-if-file-too-large (size op-type &optional filename)
+(defadvice abort-if-file-too-large (around vlf-if-file-too-large
+ (size op-type
+ &optional filename)
+ compile activate)
"If file SIZE larger than `large-file-warning-threshold', \
-allow user to view file with `vlf', open it normally or abort.
+allow user to view file with `vlf', open it normally, or abort.
OP-TYPE specifies the file operation being performed over FILENAME."
(and large-file-warning-threshold size
(> size large-file-warning-threshold)
'(?o ?O ?v ?V ?a ?A))))
(cond ((memq char '(?o ?O)))
((memq char '(?v ?V))
- (vlf filename nil)
+ (vlf filename)
(error ""))
((memq char '(?a ?A))
(error "Aborted"))))))
-;; hijack `abort-if-file-too-large'
-;;;###autoload
-(fset 'abort-if-file-too-large 'vlf-if-file-too-large)
-;; non recent Emacs
+;; scroll auto batching
+(defadvice scroll-up (around vlf-scroll-up
+ activate compile)
+ "Slide to next batch if at end of buffer in `vlf-mode'."
+ (if (and vlf-mode (pos-visible-in-window-p (point-max)))
+ (progn (vlf-next-batch 1)
+ (goto-char (point-min)))
+ ad-do-it))
+
+(defadvice scroll-down (around vlf-scroll-down
+ activate compile)
+ "Slide to previous batch if at beginning of buffer in `vlf-mode'."
+ (if (and vlf-mode (pos-visible-in-window-p (point-min)))
+ (progn (vlf-prev-batch 1)
+ (goto-char (point-max)))
+ ad-do-it))
+
+;; non-recent Emacs
+;;;###autoload
(unless (fboundp 'file-size-human-readable)
(defun file-size-human-readable (file-size)
"Print FILE-SIZE in MB."
- (format "%.1fMB" (/ file-size 1024.0))))
+ (format "%.1fMB" (/ file-size 1048576.0))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; utilities
Normally, the value is doubled;
with the prefix argument DECREASE it is halved."
(interactive "P")
- (or (assq 'vlf-batch-size (buffer-local-variables))
- (error "%s is not local in this buffer" 'vlf-batch-size))
(setq vlf-batch-size (if decrease
- (/ vlf-batch-size 2)
- (* vlf-batch-size 2)))
+ (/ vlf-batch-size 2)
+ (* vlf-batch-size 2)))
(vlf-move-to-batch vlf-start-pos))
-(defun vlf-format-buffer-name ()
- "Return format for vlf buffer name."
- (format "%s(%s)[%d/%d](%d)"
- (file-name-nondirectory buffer-file-name)
- (file-size-human-readable vlf-file-size)
- (/ vlf-end-pos vlf-batch-size)
- (/ vlf-file-size vlf-batch-size)
- vlf-batch-size))
-
(defun vlf-update-buffer-name ()
"Update the current buffer name."
- (rename-buffer (vlf-format-buffer-name) t))
+ (rename-buffer (format "%s(%d/%d)[%s]"
+ (file-name-nondirectory buffer-file-name)
+ (/ vlf-end-pos vlf-batch-size)
+ (/ vlf-file-size vlf-batch-size)
+ (file-size-human-readable vlf-batch-size))
+ t))
+
+(defun vlf-get-file-size (file)
+ "Get size in bytes of FILE."
+ (nth 7 (file-attributes file)))
+
+(defun vlf-verify-size ()
+ "Update file size information if necessary and visited file time."
+ (unless (verify-visited-file-modtime (current-buffer))
+ (setq vlf-file-size (vlf-get-file-size buffer-file-name))
+ (set-visited-file-modtime)))
(defun vlf-insert-file (&optional from-end)
"Insert first chunk of current file contents in current buffer.
With FROM-END prefix, start from the back."
- (if from-end
- (setq vlf-start-pos (max 0 (- vlf-file-size vlf-batch-size))
- vlf-end-pos vlf-file-size)
- (setq vlf-start-pos 0
- vlf-end-pos (min vlf-batch-size vlf-file-size)))
- (vlf-move-to-chunk vlf-start-pos vlf-end-pos))
+ (let ((start 0)
+ (end vlf-batch-size))
+ (if from-end
+ (setq start (- vlf-file-size vlf-batch-size)
+ end vlf-file-size)
+ (setq end (min vlf-batch-size vlf-file-size)))
+ (vlf-move-to-chunk start end)))
(defun vlf-beginning-of-file ()
"Jump to beginning of file content."
(interactive)
(vlf-insert-file t))
-(defun vlf-revert (&rest args)
- "Revert current chunk. Ignore ARGS."
- (ignore args)
- (vlf-move-to-chunk vlf-start-pos vlf-end-pos))
+(defun vlf-revert (&optional _ignore-auto noconfirm)
+ "Revert current chunk. Ignore _IGNORE-AUTO.
+Ask for confirmation if NOCONFIRM is nil."
+ (if (or noconfirm
+ (yes-or-no-p (format "Revert buffer from file %s? "
+ buffer-file-name)))
+ (vlf-move-to-chunk-2 vlf-start-pos vlf-end-pos)))
(defun vlf-jump-to-chunk (n)
"Go to to chunk N."
(interactive "nGoto to chunk: ")
(vlf-move-to-batch (* (1- n) vlf-batch-size)))
+(defmacro vlf-with-undo-disabled (&rest body)
+ "Execute BODY with temporarily disabled undo."
+ `(let ((undo-enabled (not (eq buffer-undo-list t))))
+ (if undo-enabled
+ (buffer-disable-undo))
+ (unwind-protect (progn ,@body)
+ (if undo-enabled
+ (buffer-enable-undo)))))
+
+(defun vlf-no-modifications ()
+ "Ensure there are no buffer modifications."
+ (if (buffer-modified-p)
+ (error "Save or discard your changes first")
+ t))
+
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; batch movement
When prefix argument is negative
append next APPEND number of batches to the existing buffer."
(interactive "p")
- (let ((end (+ vlf-end-pos (* vlf-batch-size
- (abs append)))))
- (when (< vlf-file-size end) ; re-check file size
- (setq vlf-file-size (nth 7 (file-attributes buffer-file-name)))
- (cond ((= vlf-end-pos vlf-file-size)
- (error "Already at EOF"))
- ((< vlf-file-size end)
- (setq end vlf-file-size))))
- (let ((inhibit-read-only t)
- (do-append (< append 0))
- (pos (point)))
- (if do-append
- (goto-char (point-max))
- (setq vlf-start-pos (- end vlf-batch-size))
- (erase-buffer))
- (insert-file-contents buffer-file-name nil (if do-append
- vlf-end-pos
- vlf-start-pos)
- end)
- (goto-char pos))
- (setq vlf-end-pos end))
- (set-visited-file-modtime)
- (set-buffer-modified-p nil)
- (vlf-update-buffer-name))
+ (vlf-verify-size)
+ (let* ((end (min (+ vlf-end-pos (* vlf-batch-size
+ (abs append)))
+ vlf-file-size))
+ (start (if (< append 0)
+ vlf-start-pos
+ (- end vlf-batch-size))))
+ (vlf-move-to-chunk start end)))
(defun vlf-prev-batch (prepend)
"Display the previous batch of file data.
(interactive "p")
(if (zerop vlf-start-pos)
(error "Already at BOF"))
- (let ((inhibit-read-only t)
- (start (max 0 (- vlf-start-pos (* vlf-batch-size
+ (let* ((start (max 0 (- vlf-start-pos (* vlf-batch-size
(abs prepend)))))
- (do-prepend (< prepend 0))
- (pos (- (point-max) (point))))
- (if do-prepend
- (goto-char (point-min))
- (setq vlf-end-pos (+ start vlf-batch-size))
- (erase-buffer))
- (insert-file-contents buffer-file-name nil start
- (if do-prepend
- vlf-start-pos
- vlf-end-pos))
- (goto-char (- (point-max) pos))
- (setq vlf-start-pos start))
- (set-visited-file-modtime)
- (set-buffer-modified-p nil)
- (vlf-update-buffer-name))
+ (end (if (< prepend 0)
+ vlf-end-pos
+ (+ start vlf-batch-size))))
+ (vlf-move-to-chunk start end)))
-(defun vlf-move-to-batch (start)
+(defun vlf-move-to-batch (start &optional minimal)
"Move to batch determined by START.
-Adjust according to file start/end and show `vlf-batch-size' bytes."
- (setq vlf-start-pos (max 0 start)
- vlf-end-pos (+ vlf-start-pos vlf-batch-size))
- (if (< vlf-file-size vlf-end-pos) ; re-check file size
- (setq vlf-file-size
- (nth 7 (file-attributes buffer-file-name))
- vlf-end-pos (min vlf-end-pos vlf-file-size)
- vlf-start-pos (max 0 (- vlf-end-pos vlf-batch-size))))
- (let ((inhibit-read-only t)
- (pos (point)))
- (erase-buffer)
- (insert-file-contents buffer-file-name nil
- vlf-start-pos vlf-end-pos)
- (goto-char pos))
- (set-visited-file-modtime)
- (set-buffer-modified-p nil)
- (vlf-update-buffer-name))
+Adjust according to file start/end and show `vlf-batch-size' bytes.
+When given MINIMAL flag, skip non important operations."
+ (vlf-verify-size)
+ (let* ((start (max 0 start))
+ (end (min (+ start vlf-batch-size) vlf-file-size)))
+ (if (= vlf-file-size end) ; re-adjust start
+ (setq start (max 0 (- end vlf-batch-size))))
+ (vlf-move-to-chunk start end minimal)))
+
+(defun vlf-next-batch-from-point ()
+ "Display batch of file data starting from current point."
+ (interactive)
+ (vlf-move-to-batch (+ vlf-start-pos (position-bytes (point)) -1))
+ (goto-char (point-min)))
-(defun vlf-move-to-chunk (start end)
- "Move to chunk determined by START END."
- (if (< vlf-file-size end) ; re-check file size
- (setq vlf-file-size (nth 7
- (file-attributes buffer-file-name))))
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; primitive chunk operations
+
+(defun vlf-move-to-chunk (start end &optional minimal)
+ "Move to chunk determined by START END.
+When given MINIMAL flag, skip non important operations.
+If same as current chunk is requested, do nothing."
+ (unless (and (= start vlf-start-pos)
+ (= end vlf-end-pos))
+ (vlf-verify-size)
+ (if (vlf-move-to-chunk-1 start end)
+ (or minimal (vlf-update-buffer-name)))))
+
+(defun vlf-move-to-chunk-1 (start end)
+ "Move to chunk determined by START END keeping as much edits if any.
+Return t if move hasn't been canceled."
+ (let ((modified (buffer-modified-p))
+ (start (max 0 start))
+ (end (min end vlf-file-size))
+ (edit-end (+ (position-bytes (point-max)) vlf-start-pos)))
+ (cond
+ ((and (= start vlf-start-pos) (= end edit-end))
+ (unless modified
+ (vlf-move-to-chunk-2 start end)
+ t))
+ ((or (<= edit-end start) (<= end vlf-start-pos))
+ (when (or (not modified)
+ (y-or-n-p "Chunk modified, are you sure? ")) ;full chunk renewal
+ (set-buffer-modified-p nil)
+ (vlf-move-to-chunk-2 start end)
+ t))
+ ((or (and (<= start vlf-start-pos) (<= edit-end end))
+ (not modified)
+ (y-or-n-p "Chunk modified, are you sure? "))
+ (let ((pos (+ (position-bytes (point)) vlf-start-pos))
+ (shift-start 0)
+ (shift-end 0)
+ (inhibit-read-only t))
+ (cond ((< end edit-end)
+ (let* ((del-pos (1+ (byte-to-position
+ (- end vlf-start-pos))))
+ (del-len (length (encode-coding-region
+ del-pos (point-max)
+ buffer-file-coding-system
+ t))))
+ (setq end (- vlf-end-pos del-len))
+ (vlf-with-undo-disabled
+ (delete-region del-pos (point-max)))))
+ ((< edit-end end)
+ (let ((edit-end-pos (point-max)))
+ (goto-char edit-end-pos)
+ (vlf-with-undo-disabled
+ (insert-file-contents buffer-file-name nil
+ vlf-end-pos end)
+ (setq shift-end (cdr (vlf-adjust-chunk
+ vlf-end-pos end nil t
+ edit-end-pos)))))))
+ (cond ((< vlf-start-pos start)
+ (let* ((del-pos (1+ (byte-to-position
+ (- start vlf-start-pos))))
+ (del-len (length (encode-coding-region
+ (point-min) del-pos
+ buffer-file-coding-system
+ t))))
+ (setq start (+ vlf-start-pos del-len))
+ (vlf-with-undo-disabled
+ (delete-region (point-min) del-pos))))
+ ((< start vlf-start-pos)
+ (let ((edit-end-pos (point-max)))
+ (goto-char edit-end-pos)
+ (vlf-with-undo-disabled
+ (insert-file-contents buffer-file-name nil
+ start vlf-start-pos)
+ (setq shift-start (car
+ (vlf-adjust-chunk start
+ vlf-start-pos
+ t nil
+ edit-end-pos)))
+ (goto-char (point-min))
+ (insert (delete-and-extract-region edit-end-pos
+ (point-max)))))))
+ (setq vlf-start-pos (- start shift-start)
+ vlf-end-pos (+ end shift-end))
+ (goto-char (or (byte-to-position (- pos vlf-start-pos))
+ (point-max))))
+ (set-buffer-modified-p modified)
+ t))))
+
+(defun vlf-move-to-chunk-2 (start end)
+ "Unconditionally move to chunk determined by START END."
(setq vlf-start-pos (max 0 start)
vlf-end-pos (min end vlf-file-size))
(let ((inhibit-read-only t)
- (pos (point)))
- (erase-buffer)
- (insert-file-contents buffer-file-name nil
- vlf-start-pos vlf-end-pos)
- (goto-char pos))
- (set-visited-file-modtime)
+ (pos (position-bytes (point))))
+ (vlf-with-undo-disabled
+ (erase-buffer)
+ (insert-file-contents buffer-file-name nil
+ vlf-start-pos vlf-end-pos)
+ (let ((shifts (vlf-adjust-chunk vlf-start-pos vlf-end-pos t
+ t)))
+ (setq vlf-start-pos (- vlf-start-pos (car shifts))
+ vlf-end-pos (+ vlf-end-pos (cdr shifts)))
+ (goto-char (or (byte-to-position (+ pos (car shifts)))
+ (point-max))))))
(set-buffer-modified-p nil)
- (vlf-update-buffer-name))
+ (set-visited-file-modtime))
+
+(defun vlf-adjust-chunk (start end &optional adjust-start adjust-end
+ position)
+ "Adjust chunk at absolute START to END till content can be\
+properly decoded. ADJUST-START determines if trying to prepend bytes\
+ to the beginning, ADJUST-END - append to the end.
+Use buffer POSITION as start if given.
+Return number of bytes moved back for proper decoding and number of
+bytes added to the end."
+ (let ((shift-start 0)
+ (shift-end 0))
+ (if adjust-start
+ (let ((position (or position (point-min)))
+ (chunk-size (- end start)))
+ (while (and (not (zerop start))
+ (< shift-start 4)
+ (< 4 (abs (- chunk-size
+ (length (encode-coding-region
+ position (point-max)
+ buffer-file-coding-system
+ t))))))
+ (setq shift-start (1+ shift-start)
+ start (1- start)
+ chunk-size (1+ chunk-size))
+ (delete-region position (point-max))
+ (goto-char position)
+ (insert-file-contents buffer-file-name nil start end))))
+ (if adjust-end
+ (cond ((vlf-partial-decode-shown-p) ;remove raw bytes from end
+ (goto-char (point-max))
+ (while (eq (char-charset (preceding-char)) 'eight-bit)
+ (setq shift-end (1- shift-end))
+ (delete-char -1)))
+ ((< end vlf-file-size) ;add bytes until new character is displayed
+ (let ((position (or position (point-min)))
+ (expected-size (buffer-size)))
+ (while (and (progn
+ (setq shift-end (1+ shift-end)
+ end (1+ end))
+ (delete-region position (point-max))
+ (goto-char position)
+ (insert-file-contents buffer-file-name
+ nil start end)
+ (< end vlf-file-size))
+ (= expected-size (buffer-size))))))))
+ (cons shift-start shift-end)))
+
+(defun vlf-partial-decode-shown-p ()
+ "Determine if partial decode codes are displayed.
+This seems to be the case with GNU/Emacs before 24.4."
+ (cond ((< emacs-major-version 24) t)
+ ((< 24 emacs-major-version) nil)
+ (t ;; TODO: use (< emacs-minor-version 4) after 24.4 release
+ (string-lessp emacs-version "24.3.5"))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; search
-(defun vlf-re-search (regexp count backward)
- "Search for REGEXP COUNT number of times forward or BACKWARD."
- (let* ((match-start-pos (+ vlf-start-pos (point)))
+(defun vlf-re-search (regexp count backward batch-step)
+ "Search for REGEXP COUNT number of times forward or BACKWARD.
+BATCH-STEP is amount of overlap between successive chunks."
+ (if (<= count 0)
+ (error "Count must be positive"))
+ (let* ((case-fold-search t)
+ (match-chunk-start vlf-start-pos)
+ (match-chunk-end vlf-end-pos)
+ (match-start-pos (+ vlf-start-pos (position-bytes (point))))
(match-end-pos match-start-pos)
(to-find count)
- (search-reporter (make-progress-reporter
- (concat "Searching for " regexp)
- (if backward
- (- vlf-file-size vlf-end-pos)
- vlf-start-pos)
- vlf-file-size))
- (batch-step (/ vlf-batch-size 8))) ; amount of chunk overlap
- (unwind-protect
- (catch 'end-of-file
- (if backward
- (while (not (zerop to-find))
- (cond ((re-search-backward regexp nil t)
- (setq to-find (1- to-find)
- match-start-pos (+ vlf-start-pos
- (match-beginning 0))
- match-end-pos (+ vlf-start-pos
- (match-end 0))))
- ((zerop vlf-start-pos)
- (throw 'end-of-file nil))
- (t (let ((batch-move (- vlf-start-pos
- (- vlf-batch-size
- batch-step))))
- (vlf-move-to-batch
- (if (< match-start-pos batch-move)
- (- match-start-pos vlf-batch-size)
- batch-move)))
- (goto-char (if (< match-start-pos
- vlf-end-pos)
- (- match-start-pos
- vlf-start-pos)
- (point-max)))
- (progress-reporter-update search-reporter
- vlf-start-pos))))
- (while (not (zerop to-find))
- (cond ((re-search-forward regexp nil t)
- (setq to-find (1- to-find)
- match-start-pos (+ vlf-start-pos
- (match-beginning 0))
- match-end-pos (+ vlf-start-pos
- (match-end 0))))
- ((= vlf-end-pos vlf-file-size)
- (throw 'end-of-file nil))
- (t (let ((batch-move (- vlf-end-pos batch-step)))
- (vlf-move-to-batch
- (if (< batch-move match-end-pos)
- match-end-pos
- batch-move)))
- (goto-char (if (< vlf-start-pos match-end-pos)
- (- match-end-pos vlf-start-pos)
- (point-min)))
- (progress-reporter-update search-reporter
- vlf-end-pos)))))
- (progress-reporter-done search-reporter))
- (if backward
- (vlf-goto-match match-end-pos match-start-pos
+ (reporter (make-progress-reporter
+ (concat "Searching for " regexp "...")
+ (if backward
+ (- vlf-file-size vlf-end-pos)
+ vlf-start-pos)
+ vlf-file-size)))
+ (vlf-with-undo-disabled
+ (unwind-protect
+ (catch 'end-of-file
+ (if backward
+ (while (not (zerop to-find))
+ (cond ((re-search-backward regexp nil t)
+ (setq to-find (1- to-find)
+ match-chunk-start vlf-start-pos
+ match-chunk-end vlf-end-pos
+ match-start-pos (+ vlf-start-pos
+ (position-bytes
+ (match-beginning 0)))
+ match-end-pos (+ vlf-start-pos
+ (position-bytes
+ (match-end 0)))))
+ ((zerop vlf-start-pos)
+ (throw 'end-of-file nil))
+ (t (let ((batch-move (- vlf-start-pos
+ (- vlf-batch-size
+ batch-step))))
+ (vlf-move-to-batch
+ (if (< match-start-pos batch-move)
+ (- match-start-pos vlf-batch-size)
+ batch-move) t))
+ (goto-char (if (< match-start-pos
+ vlf-end-pos)
+ (or (byte-to-position
+ (- match-start-pos
+ vlf-start-pos))
+ (point-max))
+ (point-max)))
+ (progress-reporter-update
+ reporter (- vlf-file-size
+ vlf-start-pos)))))
+ (while (not (zerop to-find))
+ (cond ((re-search-forward regexp nil t)
+ (setq to-find (1- to-find)
+ match-chunk-start vlf-start-pos
+ match-chunk-end vlf-end-pos
+ match-start-pos (+ vlf-start-pos
+ (position-bytes
+ (match-beginning 0)))
+ match-end-pos (+ vlf-start-pos
+ (position-bytes
+ (match-end 0)))))
+ ((= vlf-end-pos vlf-file-size)
+ (throw 'end-of-file nil))
+ (t (let ((batch-move (- vlf-end-pos batch-step)))
+ (vlf-move-to-batch
+ (if (< batch-move match-end-pos)
+ match-end-pos
+ batch-move) t))
+ (goto-char (if (< vlf-start-pos match-end-pos)
+ (or (byte-to-position
+ (- match-end-pos
+ vlf-start-pos))
+ (point-min))
+ (point-min)))
+ (progress-reporter-update reporter
+ vlf-end-pos)))))
+ (progress-reporter-done reporter))
+ (set-buffer-modified-p nil)
+ (if backward
+ (vlf-goto-match match-chunk-start match-chunk-end
+ match-end-pos match-start-pos
count to-find)
- (vlf-goto-match match-start-pos match-end-pos
- count to-find)))))
-
-(defun vlf-goto-match (match-pos-start match-pos-end count to-find)
- "Move to chunk surrounding MATCH-POS-START and MATCH-POS-END.
+ (vlf-goto-match match-chunk-start match-chunk-end
+ match-start-pos match-end-pos
+ count to-find))))))
+
+(defun vlf-goto-match (match-chunk-start match-chunk-end
+ match-pos-start
+ match-pos-end
+ count to-find)
+ "Move to MATCH-CHUNK-START MATCH-CHUNK-END surrounding \
+MATCH-POS-START and MATCH-POS-END.
According to COUNT and left TO-FIND, show if search has been
successful. Return nil if nothing found."
- (let ((success (zerop to-find)))
- (or success
- (vlf-move-to-batch (- match-pos-start
- (/ vlf-batch-size 2))))
- (let* ((match-end (- match-pos-end vlf-start-pos))
- (overlay (make-overlay (- match-pos-start vlf-start-pos)
- match-end)))
- (overlay-put overlay 'face 'region)
- (or success (goto-char match-end))
- (prog1 (cond (success t)
- ((< to-find count)
- (message "Moved to the %d match which is last"
- (- count to-find))
- t)
- (t (message "Not found")
- nil))
- (sit-for 0.1)
- (delete-overlay overlay)))))
+ (if (= count to-find)
+ (progn (vlf-move-to-chunk match-chunk-start match-chunk-end)
+ (goto-char (or (byte-to-position (- match-pos-start
+ vlf-start-pos))
+ (point-max)))
+ (message "Not found")
+ nil)
+ (let ((success (zerop to-find)))
+ (if success
+ (vlf-update-buffer-name)
+ (vlf-move-to-chunk match-chunk-start match-chunk-end))
+ (let* ((match-end (or (byte-to-position (- match-pos-end
+ vlf-start-pos))
+ (point-max)))
+ (overlay (make-overlay (byte-to-position
+ (- match-pos-start
+ vlf-start-pos))
+ match-end)))
+ (overlay-put overlay 'face 'match)
+ (unless success
+ (goto-char match-end)
+ (message "Moved to the %d match which is last"
+ (- count to-find)))
+ (unwind-protect (sit-for 3)
+ (delete-overlay overlay))
+ t))))
(defun vlf-re-search-forward (regexp count)
"Search forward for REGEXP prefix COUNT number of times.
Search is performed chunk by chunk in `vlf-batch-size' memory."
- (interactive (list (read-regexp "Search whole file"
- (if regexp-history
- (car regexp-history))
- 'regexp-history)
- (or current-prefix-arg 1)))
- (vlf-re-search regexp count nil))
+ (interactive (if (vlf-no-modifications)
+ (list (read-regexp "Search whole file"
+ (if regexp-history
+ (car regexp-history)))
+ (or current-prefix-arg 1))))
+ (vlf-re-search regexp count nil (/ vlf-batch-size 8)))
(defun vlf-re-search-backward (regexp count)
"Search backward for REGEXP prefix COUNT number of times.
Search is performed chunk by chunk in `vlf-batch-size' memory."
- (interactive (list (read-regexp "Search whole file backward"
- (if regexp-history
- (car regexp-history))
- 'regexp-history)
- (or current-prefix-arg 1)))
- (vlf-re-search regexp count t))
+ (interactive (if (vlf-no-modifications)
+ (list (read-regexp "Search whole file backward"
+ (if regexp-history
+ (car regexp-history)))
+ (or current-prefix-arg 1))))
+ (vlf-re-search regexp count t (/ vlf-batch-size 8)))
+
+(defun vlf-goto-line (n)
+ "Go to line N. If N is negative, count from the end of file."
+ (interactive (if (vlf-no-modifications)
+ (list (read-number "Go to line: "))))
+ (let ((start-pos vlf-start-pos)
+ (end-pos vlf-end-pos)
+ (pos (point))
+ (success nil))
+ (unwind-protect
+ (if (< 0 n)
+ (progn (vlf-beginning-of-file)
+ (goto-char (point-min))
+ (setq success (vlf-re-search "[\n\C-m]" (1- n)
+ nil 0)))
+ (vlf-end-of-file)
+ (goto-char (point-max))
+ (setq success (vlf-re-search "[\n\C-m]" (- n) t 0)))
+ (if success
+ (message "Onto line %s" n)
+ (vlf-move-to-chunk start-pos end-pos)
+ (goto-char pos)))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;; editing
+;;; occur
-(defvar vlf-edit-mode-map
+(defvar vlf-occur-mode-map
(let ((map (make-sparse-keymap)))
- (set-keymap-parent map text-mode-map)
- (define-key map "\C-c\C-c" 'vlf-write)
- (define-key map "\C-c\C-q" 'vlf-discard-edit)
+ (define-key map "n" 'vlf-occur-next-match)
+ (define-key map "p" 'vlf-occur-prev-match)
+ (define-key map "\C-m" 'vlf-occur-visit)
+ (define-key map "\M-\r" 'vlf-occur-visit-new-buffer)
+ (define-key map [mouse-1] 'vlf-occur-visit)
+ (define-key map "o" 'vlf-occur-show)
map)
- "Keymap for command `vlf-edit-mode'.")
+ "Keymap for command `vlf-occur-mode'.")
-(define-derived-mode vlf-edit-mode vlf-mode "VLF[edit]"
- "Major mode for editing large file chunks."
- (setq buffer-read-only nil)
- (buffer-enable-undo)
- (message (substitute-command-keys
- "Editing: Type \\[vlf-write] to write chunk \
-or \\[vlf-discard-edit] to discard changes.")))
+(define-derived-mode vlf-occur-mode special-mode "VLF[occur]"
+ "Major mode for showing occur matches of VLF opened files.")
-(defun vlf-discard-edit ()
+(defun vlf-occur-next-match ()
+ "Move cursor to next match."
+ (interactive)
+ (if (eq (get-char-property (point) 'face) 'match)
+ (goto-char (next-single-property-change (point) 'face)))
+ (goto-char (or (text-property-any (point) (point-max) 'face 'match)
+ (text-property-any (point-min) (point)
+ 'face 'match))))
+
+(defun vlf-occur-prev-match ()
+ "Move cursor to previous match."
+ (interactive)
+ (if (eq (get-char-property (point) 'face) 'match)
+ (goto-char (previous-single-property-change (point) 'face)))
+ (while (not (eq (get-char-property (point) 'face) 'match))
+ (goto-char (or (previous-single-property-change (point) 'face)
+ (point-max)))))
+
+(defun vlf-occur-show (&optional event)
+ "Visit current `vlf-occur' link in a vlf buffer but stay in the \
+occur buffer. If original VLF buffer has been killed,
+open new VLF session each time.
+EVENT may hold details of the invocation."
+ (interactive (list last-nonmenu-event))
+ (let ((occur-buffer (if event
+ (window-buffer (posn-window
+ (event-end event)))
+ (current-buffer))))
+ (vlf-occur-visit event)
+ (pop-to-buffer occur-buffer)))
+
+(defun vlf-occur-visit-new-buffer ()
+ "Visit `vlf-occur' link in new vlf buffer."
+ (interactive)
+ (let ((current-prefix-arg t))
+ (vlf-occur-visit)))
+
+(defun vlf-occur-visit (&optional event)
+ "Visit current `vlf-occur' link in a vlf buffer.
+With prefix argument or if original VLF buffer has been killed,
+open new VLF session.
+EVENT may hold details of the invocation."
+ (interactive (list last-nonmenu-event))
+ (when event
+ (set-buffer (window-buffer (posn-window (event-end event))))
+ (goto-char (posn-point (event-end event))))
+ (let* ((pos (point))
+ (pos-relative (- pos (line-beginning-position) 1))
+ (file (get-char-property pos 'file)))
+ (if file
+ (let ((chunk-start (get-char-property pos 'chunk-start))
+ (chunk-end (get-char-property pos 'chunk-end))
+ (vlf-buffer (get-char-property pos 'buffer))
+ (occur-buffer (current-buffer))
+ (match-pos (+ (get-char-property pos 'line-pos)
+ pos-relative)))
+ (cond (current-prefix-arg
+ (setq vlf-buffer (vlf file))
+ (switch-to-buffer occur-buffer))
+ ((not (buffer-live-p vlf-buffer))
+ (or (catch 'found
+ (dolist (buf (buffer-list))
+ (set-buffer buf)
+ (and vlf-mode (equal file buffer-file-name)
+ (setq vlf-buffer buf)
+ (throw 'found t))))
+ (setq vlf-buffer (vlf file)))
+ (switch-to-buffer occur-buffer)))
+ (pop-to-buffer vlf-buffer)
+ (vlf-move-to-chunk chunk-start chunk-end)
+ (goto-char match-pos)))))
+
+(defun vlf-occur (regexp)
+ "Make whole file occur style index for REGEXP.
+Prematurely ending indexing will still show what's found so far."
+ (interactive (list (read-regexp "List lines matching regexp"
+ (if regexp-history
+ (car regexp-history)))))
+ (if (buffer-modified-p) ;use temporary buffer not to interfere with modifications
+ (let ((vlf-buffer (current-buffer))
+ (file buffer-file-name)
+ (batch-size vlf-batch-size))
+ (with-temp-buffer
+ (setq buffer-file-name file)
+ (set-buffer-modified-p nil)
+ (set (make-local-variable 'vlf-batch-size) batch-size)
+ (vlf-mode 1)
+ (goto-char (point-min))
+ (vlf-with-undo-disabled
+ (vlf-build-occur regexp vlf-buffer))))
+ (let ((start-pos vlf-start-pos)
+ (end-pos vlf-end-pos)
+ (pos (point)))
+ (vlf-beginning-of-file)
+ (goto-char (point-min))
+ (vlf-with-undo-disabled
+ (unwind-protect (vlf-build-occur regexp (current-buffer))
+ (vlf-move-to-chunk start-pos end-pos)
+ (goto-char pos))))))
+
+(defun vlf-build-occur (regexp vlf-buffer)
+ "Build occur style index for REGEXP over VLF-BUFFER."
+ (let ((case-fold-search t)
+ (line 1)
+ (last-match-line 0)
+ (last-line-pos (point-min))
+ (file buffer-file-name)
+ (total-matches 0)
+ (match-end-pos (+ vlf-start-pos (position-bytes (point))))
+ (occur-buffer (generate-new-buffer
+ (concat "*VLF-occur " (file-name-nondirectory
+ buffer-file-name)
+ "*")))
+ (line-regexp (concat "\\(?5:[\n\C-m]\\)\\|\\(?10:"
+ regexp "\\)"))
+ (batch-step (/ vlf-batch-size 8))
+ (end-of-file nil)
+ (reporter (make-progress-reporter
+ (concat "Building index for " regexp "...")
+ vlf-start-pos vlf-file-size)))
+ (unwind-protect
+ (progn
+ (while (not end-of-file)
+ (if (re-search-forward line-regexp nil t)
+ (progn
+ (setq match-end-pos (+ vlf-start-pos
+ (position-bytes
+ (match-end 0))))
+ (if (match-string 5)
+ (setq line (1+ line) ; line detected
+ last-line-pos (point))
+ (let* ((chunk-start vlf-start-pos)
+ (chunk-end vlf-end-pos)
+ (line-pos (line-beginning-position))
+ (line-text (buffer-substring
+ line-pos (line-end-position))))
+ (with-current-buffer occur-buffer
+ (unless (= line last-match-line) ;new match line
+ (insert "\n:") ; insert line number
+ (let* ((overlay-pos (1- (point)))
+ (overlay (make-overlay
+ overlay-pos
+ (1+ overlay-pos))))
+ (overlay-put overlay 'before-string
+ (propertize
+ (number-to-string line)
+ 'face 'shadow)))
+ (insert (propertize line-text ; insert line
+ 'file file
+ 'buffer vlf-buffer
+ 'chunk-start chunk-start
+ 'chunk-end chunk-end
+ 'mouse-face '(highlight)
+ 'line-pos line-pos
+ 'help-echo
+ (format "Move to line %d"
+ line))))
+ (setq last-match-line line
+ total-matches (1+ total-matches))
+ (let ((line-start (1+
+ (line-beginning-position)))
+ (match-pos (match-beginning 10)))
+ (add-text-properties ; mark match
+ (+ line-start match-pos (- last-line-pos))
+ (+ line-start (match-end 10)
+ (- last-line-pos))
+ (list 'face 'match
+ 'help-echo
+ (format "Move to match %d"
+ total-matches))))))))
+ (setq end-of-file (= vlf-end-pos vlf-file-size))
+ (unless end-of-file
+ (let ((batch-move (- vlf-end-pos batch-step)))
+ (vlf-move-to-batch (if (< batch-move match-end-pos)
+ match-end-pos
+ batch-move) t))
+ (goto-char (if (< vlf-start-pos match-end-pos)
+ (or (byte-to-position (- match-end-pos
+ vlf-start-pos))
+ (point-min))
+ (point-min)))
+ (setq last-match-line 0
+ last-line-pos (line-beginning-position))
+ (progress-reporter-update reporter vlf-end-pos))))
+ (progress-reporter-done reporter))
+ (set-buffer-modified-p nil)
+ (if (zerop total-matches)
+ (progn (with-current-buffer occur-buffer
+ (set-buffer-modified-p nil))
+ (kill-buffer occur-buffer)
+ (message "No matches for \"%s\"" regexp))
+ (with-current-buffer occur-buffer
+ (goto-char (point-min))
+ (insert (propertize
+ (format "%d matches in %d lines for \"%s\" \
+in file: %s" total-matches line regexp file)
+ 'face 'underline))
+ (set-buffer-modified-p nil)
+ (forward-char 2)
+ (vlf-occur-mode))
+ (display-buffer occur-buffer)))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; editing
+
+(defun vlf-refresh ()
"Discard edit and refresh chunk from file."
(interactive)
- (vlf-move-to-chunk vlf-start-pos vlf-end-pos)
- (vlf-mode)
- (message "Switched to VLF mode."))
+ (set-buffer-modified-p nil)
+ (vlf-move-to-chunk-2 vlf-start-pos vlf-end-pos))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; saving
(defun vlf-write ()
"Write current chunk to file. Always return true to disable save.
-If changing size of chunk shift remaining file content."
+If changing size of chunk, shift remaining file content."
(interactive)
- (when (and (derived-mode-p 'vlf-mode)
- (buffer-modified-p)
- (or (verify-visited-file-modtime)
+ (when (and (buffer-modified-p)
+ (or (verify-visited-file-modtime (current-buffer))
(y-or-n-p "File has changed since visited or saved. \
Save anyway? ")))
- (let ((size-change (- vlf-end-pos vlf-start-pos
+ (let ((pos (point))
+ (size-change (- vlf-end-pos vlf-start-pos
(length (encode-coding-region
(point-min) (point-max)
- buffer-file-coding-system t))))
- (pos (point)))
+ buffer-file-coding-system t)))))
(cond ((zerop size-change)
(write-region nil nil buffer-file-name vlf-start-pos t))
((< 0 size-change)
(vlf-file-shift-back size-change))
(t (vlf-file-shift-forward (- size-change))))
- (goto-char pos))
- (vlf-move-to-chunk vlf-start-pos vlf-end-pos)
- (vlf-mode)
- t))
+ (vlf-move-to-chunk-2 vlf-start-pos vlf-end-pos)
+ (goto-char pos)))
+ t)
(defun vlf-file-shift-back (size-change)
"Shift file contents SIZE-CHANGE bytes back."
- (let ((coding-system buffer-file-coding-system))
- (write-region nil nil buffer-file-name vlf-start-pos t)
- (setq buffer-file-coding-system nil)
- (let ((read-start-pos vlf-end-pos)
- (reporter (make-progress-reporter "Adjusting file content"
- vlf-end-pos
- vlf-file-size)))
- (while (vlf-shift-batch read-start-pos (- read-start-pos
- size-change))
- (setq read-start-pos (+ read-start-pos vlf-batch-size))
- (progress-reporter-update reporter read-start-pos))
- ;; pad end with space
- (erase-buffer)
- (insert-char 32 size-change)
- (write-region nil nil buffer-file-name (- vlf-file-size
- size-change) t)
- (progress-reporter-done reporter))
- (setq buffer-file-coding-system coding-system)))
+ (write-region nil nil buffer-file-name vlf-start-pos t)
+ (let ((read-start-pos vlf-end-pos)
+ (coding-system-for-write 'no-conversion)
+ (reporter (make-progress-reporter "Adjusting file content..."
+ vlf-end-pos
+ vlf-file-size)))
+ (vlf-with-undo-disabled
+ (while (vlf-shift-batch read-start-pos (- read-start-pos
+ size-change))
+ (setq read-start-pos (+ read-start-pos vlf-batch-size))
+ (progress-reporter-update reporter read-start-pos))
+ ;; pad end with space
+ (erase-buffer)
+ (vlf-verify-size)
+ (insert-char 32 size-change))
+ (write-region nil nil buffer-file-name (- vlf-file-size
+ size-change) t)
+ (progress-reporter-done reporter)))
(defun vlf-shift-batch (read-pos write-pos)
"Read `vlf-batch-size' bytes from READ-POS and write them \
back at WRITE-POS. Return nil if EOF is reached, t otherwise."
(erase-buffer)
- (setq vlf-file-size (nth 7 (file-attributes buffer-file-name)))
+ (vlf-verify-size)
(let ((read-end (+ read-pos vlf-batch-size)))
(insert-file-contents-literally buffer-file-name nil
read-pos
(min vlf-file-size read-end))
- (write-region nil nil buffer-file-name write-pos t)
+ (write-region nil nil buffer-file-name write-pos 0)
(< read-end vlf-file-size)))
(defun vlf-file-shift-forward (size-change)
"Shift file contents SIZE-CHANGE bytes forward.
Done by saving content up front and then writing previous batch."
- (let ((vlf-buffer (current-buffer))
- (temp-buffer (generate-new-buffer (concat " "
- (buffer-name))))
- (coding-system buffer-file-coding-system))
- (let ((file buffer-file-name))
- (set-buffer temp-buffer)
- (setq buffer-file-name file))
- (set-buffer vlf-buffer)
- (let ((read-buffer temp-buffer)
- (write-buffer vlf-buffer)
- (size (+ vlf-batch-size size-change))
- (read-pos vlf-end-pos)
- (write-pos vlf-start-pos)
- swap-buffer
- (reporter (make-progress-reporter "Adjusting file content"
- vlf-start-pos
- vlf-file-size)))
- (while (vlf-shift-batches size read-buffer read-pos
- write-buffer write-pos)
- (setq swap-buffer read-buffer
- read-buffer write-buffer
- write-buffer swap-buffer
- write-pos (+ read-pos size-change)
- read-pos (+ read-pos size))
- (progress-reporter-update reporter write-pos))
- (progress-reporter-done reporter))
- (kill-buffer temp-buffer)
- (set-buffer vlf-buffer)
- (setq buffer-file-coding-system coding-system)))
-
-(defun vlf-shift-batches (size read-buffer read-pos
- write-buffer write-pos)
- "Read SIZE bytes in READ-BUFFER starting from READ-POS.
-Then write contents of WRITE-BUFFER to buffer file at WRITE-POS.
+ (let ((read-size (max (/ vlf-batch-size 2) size-change))
+ (read-pos vlf-end-pos)
+ (write-pos vlf-start-pos)
+ (reporter (make-progress-reporter "Adjusting file content..."
+ vlf-start-pos
+ vlf-file-size)))
+ (vlf-with-undo-disabled
+ (when (vlf-shift-batches read-size read-pos write-pos t)
+ (setq write-pos (+ read-pos size-change)
+ read-pos (+ read-pos read-size))
+ (progress-reporter-update reporter write-pos)
+ (let ((coding-system-for-write 'no-conversion))
+ (while (vlf-shift-batches read-size read-pos write-pos nil)
+ (setq write-pos (+ read-pos size-change)
+ read-pos (+ read-pos read-size))
+ (progress-reporter-update reporter write-pos)))))
+ (progress-reporter-done reporter)))
+
+(defun vlf-shift-batches (read-size read-pos write-pos hide-read)
+ "Append READ-SIZE bytes of file starting at READ-POS.
+Then write initial buffer content to file at WRITE-POS.
+If HIDE-READ is non nil, temporarily hide literal read content.
Return nil if EOF is reached, t otherwise."
- (let* ((file-size (nth 7 (file-attributes buffer-file-name)))
- (read-more (< read-pos file-size)))
+ (vlf-verify-size)
+ (let ((read-more (< read-pos vlf-file-size))
+ (start-write-pos (point-min))
+ (end-write-pos (point-max)))
(when read-more
- ;; read
- (set-buffer read-buffer)
- (erase-buffer)
- (setq buffer-file-coding-system nil)
+ (goto-char end-write-pos)
(insert-file-contents-literally buffer-file-name nil read-pos
- (min file-size (+ read-pos
- size))))
+ (min vlf-file-size
+ (+ read-pos read-size))))
;; write
- (set-buffer write-buffer)
- (write-region nil nil buffer-file-name write-pos t)
+ (if hide-read ; hide literal region if user has to choose encoding
+ (narrow-to-region start-write-pos end-write-pos))
+ (write-region start-write-pos end-write-pos
+ buffer-file-name write-pos 0)
+ (delete-region start-write-pos end-write-pos)
+ (if hide-read (widen))
read-more))
(provide 'vlf)