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mirror of https://github.com/m00natic/vlfi.git synced 2025-01-18 20:10:47 +00:00

Keep as much editing as possible when moving to intersecting chunk.

This commit is contained in:
Andrey Kotlarski 2013-08-08 12:43:00 +03:00
parent 02a37c4192
commit 0ecb40a5ee

229
vlfi.el
View File

@ -289,149 +289,118 @@ When prefix argument is negative
Adjust according to file start/end and show `vlfi-batch-size' bytes.
When given MINIMAL flag, skip non important operations."
(vlfi-verify-size)
(let ((start (max 0 start))
(end (min (+ vlfi-start-pos vlfi-batch-size)
vlfi-file-size)))
(let* ((start (max 0 start))
(end (min (+ start vlfi-batch-size) vlfi-file-size)))
(if (= vlfi-file-size end) ; re-adjust start
(setq start (max 0 (- end vlfi-batch-size))))
(vlfi-move-to-chunk start end minimal)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; primitive chunk operations
(defun vlfi-move-to-chunk (start end &optional minimal)
"Move to chunk determined by START END.
When given MINIMAL flag, skip non important operations."
(catch 'abort
(let ((changed (not (verify-visited-file-modtime
(current-buffer))))
(modified (buffer-modified-p))
(inhibit-read-only t)
(start (max 0 start))
(end (min end vlfi-file-size)))
(if changed
(setq vlfi-file-size (vlfi-get-file-size buffer-file-name)))
(if (or changed
(<= vlfi-end-pos start)
(<= end vlfi-start-pos))
(progn ; full chunk renewal
(if (and modified
(not (y-or-n-p
"Buffer modified, are you sure? ")))
(throw 'abort nil))
(setq vlfi-start-pos start
vlfi-end-pos end)
(let ((pos (position-bytes (point))))
(erase-buffer)
(insert-file-contents-literally
buffer-file-name nil vlfi-start-pos vlfi-end-pos)
(setq pos (+ pos (vlfi-prepare-chunk)))
(decode-coding-region (point-min) (point-max)
buffer-file-coding-system)
(goto-char (or (byte-to-position pos)
(point-max))))
(set-buffer-modified-p nil))
(if (and modified
(or (< end vlfi-end-pos)
(< 3 (- start vlfi-start-pos)))
(not (y-or-n-p "Buffer modified, are you sure? ")))
(throw 'abort nil))
(let* ((pos (+ (position-bytes (point))
vlfi-start-pos))
(adjust-chunk (< start vlfi-start-pos))
(adjust-encoding (or adjust-chunk
(< vlfi-end-pos end))))
(if adjust-encoding
(encode-coding-region (point-min) (point-max)
buffer-file-coding-system))
(cond ((< end vlfi-end-pos) ; adjust ends
(let ((offset (- end vlfi-start-pos)))
(if adjust-encoding
(progn (delete-region offset (point-max))
(setq vlfi-end-pos end)))
(setq offset (byte-to-position offset))
(delete-region offset (point-max))
(setq vlfi-end-pos (+ vlfi-start-pos
(position-bytes
(1- offset))))))
((< vlfi-end-pos end)
(goto-char (point-max))
(insert-file-contents-literally
buffer-file-name nil vlfi-end-pos end)
(setq vlfi-end-pos end)))
(cond ((< start vlfi-start-pos) ; adjust start
(goto-char (point-min))
(insert-file-contents-literally
buffer-file-name nil start vlfi-start-pos)
(setq vlfi-start-pos start))
((< 3 (- start vlfi-start-pos))
(let ((offset (- start vlfi-start-pos)))
(if adjust-encoding
(progn (delete-region (point-min) offset)
(setq vlfi-start-pos start))
(setq offset (byte-to-position offset))
(setq vlfi-start-pos (+ vlfi-start-pos
(position-bytes
(1+ offset))))
(delete-region (point-min) offset)))
(setq vlfi-start-pos start)))
(when adjust-encoding
(if adjust-chunk
(vlfi-prepare-chunk))
(decode-coding-region (point-min) (point-max)
buffer-file-coding-system))
(or modified (set-buffer-modified-p nil))
(goto-char
(cond ((< pos vlfi-start-pos) (point-min))
((< vlfi-end-pos pos) (point-max))
(t (or (byte-to-position (- pos vlfi-start-pos))
(point-min)))))))
(if changed (set-visited-file-modtime)))
(vlfi-verify-size)
(if (buffer-modified-p)
(and (vlfi-move-to-chunk-2 start end)
(not minimal)
(vlfi-update-buffer-name))
(vlfi-move-to-chunk-1 start end)
(or minimal (vlfi-update-buffer-name))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; encoding
(defun vlfi-move-to-chunk-1 (start end)
"Move to chunk determined by START END."
(setq vlfi-start-pos (max 0 start)
vlfi-end-pos (min end vlfi-file-size))
(let ((inhibit-read-only t)
(pos (position-bytes (point))))
(erase-buffer)
(insert-file-contents buffer-file-name nil
vlfi-start-pos vlfi-end-pos)
(let ((shift (vlfi-adjust-chunk vlfi-start-pos vlfi-end-pos)))
(setq vlfi-start-pos (- vlfi-start-pos shift))
(goto-char (or (byte-to-position (+ pos shift))
(point-max)))))
(set-buffer-modified-p nil)
(set-visited-file-modtime))
(defun vlfi-prepare-chunk ()
"Apply proper decoding and adjust chunk start if needed.
(defun vlfi-move-to-chunk-2 (start end)
"Move to chunk determined by START END.
Return t if move hasn't been canceled."
(let ((start (max 0 start))
(end (min end vlfi-file-size))
(edit-end (+ (position-bytes (point-max)) vlfi-start-pos)))
(cond
((and (= start vlfi-start-pos) (= end edit-end))
nil)
((or (<= edit-end start) (<= end vlfi-start-pos))
(when (y-or-n-p "Buffer modified, are you sure? ") ; full chunk renewal
(vlfi-move-to-chunk-1 start end)
t))
((or (and (<= start vlfi-start-pos) (<= edit-end end))
(y-or-n-p "Buffer modified, are you sure? "))
(let ((pos (+ (position-bytes (point)) vlfi-start-pos))
(shift 0)
(inhibit-read-only t))
(cond ((< end edit-end)
(delete-region (byte-to-position (- end
vlfi-start-pos))
(point-max)))
((< edit-end end)
(let ((edit-end-pos (point-max)))
(goto-char edit-end-pos)
(insert-file-contents buffer-file-name nil
vlfi-end-pos end)
(vlfi-adjust-chunk vlfi-end-pos end edit-end-pos))))
(cond ((< vlfi-start-pos start)
(delete-region (point-min) (byte-to-position
(- start vlfi-start-pos))))
((< start vlfi-start-pos)
(let ((edit-end-pos (point-max)))
(goto-char edit-end-pos)
(insert-file-contents buffer-file-name nil
start vlfi-start-pos)
(setq shift (vlfi-adjust-chunk start vlfi-start-pos
edit-end-pos))
(goto-char (point-min))
(insert (delete-and-extract-region edit-end-pos
(point-max))))))
(setq vlfi-start-pos (- start shift)
vlfi-end-pos end)
(goto-char (or (byte-to-position (- pos vlfi-start-pos))
(point-max))))
(set-visited-file-modtime)
t))))
(defun vlfi-adjust-chunk (start end &optional position)
"Adjust chunk at absolute START till END until content can be \
properly decoded. Use buffer POSITION as start if given.
Set `vlfi-encode-size' to size of buffer when encoded.
Return number of bytes moved back for this to happen."
(let ((status (vlfi-adjust-chunk 'utf-8)))
(unless (car status) ; no success with utf-8, auto-detect
(delete-region (point-min) (+ (point-min) (cdr status)))
(setq vlfi-start-pos (+ vlfi-start-pos (cdr status))
status (vlfi-adjust-chunk)))
(cdr status)))
(defun vlfi-adjust-chunk (&optional encoding)
"Adjust chunk beginning until content can be properly decoded.
Try with explicit ENCODING if given, otherwise auto-detect.
Return cons \(success-status . number-of-bytes-moved-back\)."
(setq buffer-file-coding-system
(or encoding
(detect-coding-region (point-min) (point-max) t)))
(let ((shift 0)
(success nil)
(chunk-size (- vlfi-end-pos vlfi-start-pos)))
(let ((update-encode-size (not position))
(encode-size 0)
(position (or position (point-min)))
(shift 0)
(chunk-size (- end start)))
(while (and (< shift 4)
(not (setq success (vlfi-decode-status chunk-size)))
(not (zerop vlfi-start-pos)))
(goto-char (point-min))
(insert-file-contents-literally ; insert 1 byte
buffer-file-name nil (1- vlfi-start-pos) vlfi-start-pos)
(< 4 (abs (- chunk-size
(setq encode-size
(length (encode-coding-region
position (point-max)
buffer-file-coding-system
t))))))
(not (zerop start)))
(setq shift (1+ shift)
chunk-size (1+ chunk-size)
vlfi-start-pos (1- vlfi-start-pos)
buffer-file-coding-system
(or encoding
(detect-coding-region (point-min) (point-max) t))))
(cons success shift)))
(defun vlfi-decode-status (size)
"Check if decoding followed by encoding results in SIZE bytes."
(< (abs (- size (setq vlfi-encode-size
(length (encode-coding-string
(decode-coding-region
(point-min) (point-max)
buffer-file-coding-system t)
buffer-file-coding-system t)))))
4))
start (1- start)
chunk-size (1+ chunk-size))
(let ((inhibit-read-only t))
(delete-region position (point-max))
(goto-char position)
(insert-file-contents buffer-file-name nil start end)))
(if update-encode-size
(setq vlfi-encode-size encode-size))
shift))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; search