contrib/emacs/git-blame.el

   1 ;;; git-blame.el --- Minor mode for incremental blame for Git  -*- coding: utf-8 -*-
   2 ;;
   3 ;; Copyright (C) 2007  David Kågedal
   4 ;;
   5 ;; Authors:    David Kågedal <davidk@lysator.liu.se>
   6 ;; Created:    31 Jan 2007
   7 ;; Message-ID: <87iren2vqx.fsf@morpheus.local>
   8 ;; License:    GPL
   9 ;; Keywords:   git, version control, release management
  10 ;;
  11 ;; Compatibility: Emacs21
  12
  13
  14 ;; This file is *NOT* part of GNU Emacs.
  15 ;; This file is distributed under the same terms as GNU Emacs.
  16
  17 ;; This program is free software; you can redistribute it and/or
  18 ;; modify it under the terms of the GNU General Public License as
  19 ;; published by the Free Software Foundation; either version 2 of
  20 ;; the License, or (at your option) any later version.
  21
  22 ;; This program is distributed in the hope that it will be
  23 ;; useful, but WITHOUT ANY WARRANTY; without even the implied
  24 ;; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  25 ;; PURPOSE.  See the GNU General Public License for more details.
  26
  27 ;; You should have received a copy of the GNU General Public
  28 ;; License along with this program; if not, write to the Free
  29 ;; Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  30 ;; MA 02111-1307 USA
  31
  32 ;; http://www.fsf.org/copyleft/gpl.html
  33
  34
  35 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  36 ;;
  37 ;;; Commentary:
  38 ;;
  39 ;; Here is an Emacs implementation of incremental git-blame.  When you
  40 ;; turn it on while viewing a file, the editor buffer will be updated by
  41 ;; setting the background of individual lines to a color that reflects
  42 ;; which commit it comes from.  And when you move around the buffer, a
  43 ;; one-line summary will be shown in the echo area.
  44
  45 ;;; Installation:
  46 ;;
  47 ;; To use this package, put it somewhere in `load-path' (or add
  48 ;; directory with git-blame.el to `load-path'), and add the following
  49 ;; line to your .emacs:
  50 ;;
  51 ;;    (require 'git-blame)
  52 ;;
  53 ;; If you do not want to load this package before it is necessary, you
  54 ;; can make use of the `autoload' feature, e.g. by adding to your .emacs
  55 ;; the following lines
  56 ;;
  57 ;;    (autoload 'git-blame-mode "git-blame"
  58 ;;              "Minor mode for incremental blame for Git." t)
  59 ;;
  60 ;; Then first use of `M-x git-blame-mode' would load the package.
  61
  62 ;;; Compatibility:
  63 ;;
  64 ;; It requires GNU Emacs 21.  If you'are using Emacs 20, try
  65 ;; changing this:
  66 ;;
  67 ;;            (overlay-put ovl 'face (list :background
  68 ;;                                         (cdr (assq 'color (cddddr info)))))
  69 ;;
  70 ;; to
  71 ;;
  72 ;;            (overlay-put ovl 'face (cons 'background-color
  73 ;;                                         (cdr (assq 'color (cddddr info)))))
  74
  75
  76 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  77 ;;
  78 ;;; Code:
  79
  80 (require 'cl)                         ; to use `push', `pop'
  81
  82 (defun color-scale (l)
  83   (let* ((colors ())
  84          r g b)
  85     (setq r l)
  86     (while r
  87       (setq g l)
  88       (while g
  89         (setq b l)
  90         (while b
  91           (push (concat "#" (car r) (car g) (car b)) colors)
  92           (pop b))
  93         (pop g))
  94       (pop r))
  95     colors))
  96
  97 (defvar git-blame-dark-colors
  98   (color-scale '("0c" "04" "24" "1c" "2c" "34" "14" "3c")))
  99
 100 (defvar git-blame-light-colors
 101   (color-scale '("c4" "d4" "cc" "dc" "f4" "e4" "fc" "ec")))
 102
 103 (defvar git-blame-ancient-color "dark green")
 104
 105 (defvar git-blame-autoupdate t
 106   "*Automatically update the blame display while editing")
 107
 108 (defvar git-blame-proc nil
 109   "The running git-blame process")
 110 (make-variable-buffer-local 'git-blame-proc)
 111
 112 (defvar git-blame-overlays nil
 113   "The git-blame overlays used in the current buffer.")
 114 (make-variable-buffer-local 'git-blame-overlays)
 115
 116 (defvar git-blame-cache nil
 117   "A cache of git-blame information for the current buffer")
 118 (make-variable-buffer-local 'git-blame-cache)
 119
 120 (defvar git-blame-idle-timer nil
 121   "An idle timer that updates the blame")
 122 (make-variable-buffer-local 'git-blame-cache)
 123
 124 (defvar git-blame-update-queue nil
 125   "A queue of update requests")
 126 (make-variable-buffer-local 'git-blame-update-queue)
 127
 128 (defvar git-blame-mode nil)
 129 (make-variable-buffer-local 'git-blame-mode)
 130 (unless (assq 'git-blame-mode minor-mode-alist)
 131   (setq minor-mode-alist
 132         (cons (list 'git-blame-mode " blame")
 133               minor-mode-alist)))
 134
 135 ;;;###autoload
 136 (defun git-blame-mode (&optional arg)
 137   "Minor mode for displaying Git blame"
 138   (interactive "P")
 139   (if arg
 140       (setq git-blame-mode (eq arg 1))
 141     (setq git-blame-mode (not git-blame-mode)))
 142   (make-local-variable 'git-blame-colors)
 143   (if git-blame-autoupdate
 144       (add-hook 'after-change-functions 'git-blame-after-change nil t)
 145     (remove-hook 'after-change-functions 'git-blame-after-change t))
 146   (git-blame-cleanup)
 147   (if git-blame-mode
 148       (progn
 149         (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
 150           (if (eq bgmode 'dark)
 151               (setq git-blame-colors git-blame-dark-colors)
 152             (setq git-blame-colors git-blame-light-colors)))
 153         (setq git-blame-cache (make-hash-table :test 'equal))
 154         (git-blame-run))
 155     (cancel-timer git-blame-idle-timer)))
 156
 157 ;;;###autoload
 158 (defun git-reblame ()
 159   "Recalculate all blame information in the current buffer"
 160   (unless git-blame-mode
 161     (error "git-blame is not active"))
 162   (interactive)
 163   (git-blame-cleanup)
 164   (git-blame-run))
 165
 166 (defun git-blame-run (&optional startline endline)
 167   (if git-blame-proc
 168       ;; Should maybe queue up a new run here
 169       (message "Already running git blame")
 170     (let ((display-buf (current-buffer))
 171           (blame-buf (get-buffer-create
 172                       (concat " git blame for " (buffer-name))))
 173           (args '("--incremental" "--contents" "-")))
 174       (if startline
 175           (setq args (append args
 176                              (list "-L" (format "%d,%d" startline endline)))))
 177       (setq args (append args
 178                          (list (file-name-nondirectory buffer-file-name))))
 179       (setq git-blame-proc
 180             (apply 'start-process
 181                    "git-blame" blame-buf
 182                    "git" "blame"
 183                    args))
 184       (with-current-buffer blame-buf
 185         (erase-buffer)
 186         (make-local-variable 'git-blame-file)
 187         (make-local-variable 'git-blame-current)
 188         (setq git-blame-file display-buf)
 189         (setq git-blame-current nil))
 190       (set-process-filter git-blame-proc 'git-blame-filter)
 191       (set-process-sentinel git-blame-proc 'git-blame-sentinel)
 192       (process-send-region git-blame-proc (point-min) (point-max))
 193       (process-send-eof git-blame-proc))))
 194
 195 (defun remove-git-blame-text-properties (start end)
 196   (let ((modified (buffer-modified-p))
 197         (inhibit-read-only t))
 198     (remove-text-properties start end '(point-entered nil))
 199     (set-buffer-modified-p modified)))
 200
 201 (defun git-blame-cleanup ()
 202   "Remove all blame properties"
 203     (mapcar 'delete-overlay git-blame-overlays)
 204     (setq git-blame-overlays nil)
 205     (remove-git-blame-text-properties (point-min) (point-max)))
 206
 207 (defun git-blame-update-region (start end)
 208   "Rerun blame to get updates between START and END"
 209   (let ((overlays (overlays-in start end)))
 210     (while overlays
 211       (let ((overlay (pop overlays)))
 212         (if (< (overlay-start overlay) start)
 213             (setq start (overlay-start overlay)))
 214         (if (> (overlay-end overlay) end)
 215             (setq end (overlay-end overlay)))
 216         (setq git-blame-overlays (delete overlay git-blame-overlays))
 217         (delete-overlay overlay))))
 218   (remove-git-blame-text-properties start end)
 219   ;; We can be sure that start and end are at line breaks
 220   (git-blame-run (1+ (count-lines (point-min) start))
 221                  (count-lines (point-min) end)))
 222
 223 (defun git-blame-sentinel (proc status)
 224   (with-current-buffer (process-buffer proc)
 225     (with-current-buffer git-blame-file
 226       (setq git-blame-proc nil)
 227       (if git-blame-update-queue
 228           (git-blame-delayed-update))))
 229   ;;(kill-buffer (process-buffer proc))
 230   ;;(message "git blame finished")
 231   )
 232
 233 (defvar in-blame-filter nil)
 234
 235 (defun git-blame-filter (proc str)
 236   (save-excursion
 237     (set-buffer (process-buffer proc))
 238     (goto-char (process-mark proc))
 239     (insert-before-markers str)
 240     (goto-char 0)
 241     (unless in-blame-filter
 242       (let ((more t)
 243             (in-blame-filter t))
 244         (while more
 245           (setq more (git-blame-parse)))))))
 246
 247 (defun git-blame-parse ()
 248   (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
 249          (let ((hash (match-string 1))
 250                (src-line (string-to-number (match-string 2)))
 251                (res-line (string-to-number (match-string 3)))
 252                (num-lines (string-to-number (match-string 4))))
 253            (setq git-blame-current
 254                  (if (string= hash "0000000000000000000000000000000000000000")
 255                      nil
 256                    (git-blame-new-commit
 257                     hash src-line res-line num-lines))))
 258          (delete-region (point) (match-end 0))
 259          t)
 260         ((looking-at "filename \\(.+\\)\n")
 261          (let ((filename (match-string 1)))
 262            (git-blame-add-info "filename" filename))
 263          (delete-region (point) (match-end 0))
 264          t)
 265         ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
 266          (let ((key (match-string 1))
 267                (value (match-string 2)))
 268            (git-blame-add-info key value))
 269          (delete-region (point) (match-end 0))
 270          t)
 271         ((looking-at "boundary\n")
 272          (setq git-blame-current nil)
 273          (delete-region (point) (match-end 0))
 274          t)
 275         (t
 276          nil)))
 277
 278
 279 (defun git-blame-new-commit (hash src-line res-line num-lines)
 280   (save-excursion
 281     (set-buffer git-blame-file)
 282     (let ((info (gethash hash git-blame-cache))
 283           (inhibit-point-motion-hooks t)
 284           (inhibit-modification-hooks t))
 285       (when (not info)
 286         (let ((color (pop git-blame-colors)))
 287           (unless color
 288             (setq color git-blame-ancient-color))
 289           (setq info (list hash src-line res-line num-lines
 290                            (git-describe-commit hash)
 291                            (cons 'color color))))
 292         (puthash hash info git-blame-cache))
 293       (goto-line res-line)
 294       (while (> num-lines 0)
 295         (if (get-text-property (point) 'git-blame)
 296             (forward-line)
 297           (let* ((start (point))
 298                  (end (progn (forward-line 1) (point)))
 299                  (ovl (make-overlay start end)))
 300             (push ovl git-blame-overlays)
 301             (overlay-put ovl 'git-blame info)
 302             (overlay-put ovl 'help-echo hash)
 303             (overlay-put ovl 'face (list :background
 304                                          (cdr (assq 'color (nthcdr 5 info)))))
 305             ;; the point-entered property doesn't seem to work in overlays
 306             ;;(overlay-put ovl 'point-entered
 307             ;;             `(lambda (x y) (git-blame-identify ,hash)))
 308             (let ((modified (buffer-modified-p)))
 309               (put-text-property (if (= start 1) start (1- start)) (1- end)
 310                                  'point-entered
 311                                  `(lambda (x y) (git-blame-identify ,hash)))
 312               (set-buffer-modified-p modified))))
 313         (setq num-lines (1- num-lines))))))
 314
 315 (defun git-blame-add-info (key value)
 316   (if git-blame-current
 317       (nconc git-blame-current (list (cons (intern key) value)))))
 318
 319 (defun git-blame-current-commit ()
 320   (let ((info (get-char-property (point) 'git-blame)))
 321     (if info
 322         (car info)
 323       (error "No commit info"))))
 324
 325 (defun git-describe-commit (hash)
 326   (with-temp-buffer
 327     (call-process "git" nil t nil
 328                   "log" "-1" "--pretty=oneline"
 329                   hash)
 330     (buffer-substring (point-min) (1- (point-max)))))
 331
 332 (defvar git-blame-last-identification nil)
 333 (make-variable-buffer-local 'git-blame-last-identification)
 334 (defun git-blame-identify (&optional hash)
 335   (interactive)
 336   (let ((info (gethash (or hash (git-blame-current-commit)) git-blame-cache)))
 337     (when (and info (not (eq info git-blame-last-identification)))
 338       (message "%s" (nth 4 info))
 339       (setq git-blame-last-identification info))))
 340
 341 ;; (defun git-blame-after-save ()
 342 ;;   (when git-blame-mode
 343 ;;     (git-blame-cleanup)
 344 ;;     (git-blame-run)))
 345 ;; (add-hook 'after-save-hook 'git-blame-after-save)
 346
 347 (defun git-blame-after-change (start end length)
 348   (when git-blame-mode
 349     (git-blame-enq-update start end)))
 350
 351 (defvar git-blame-last-update nil)
 352 (make-variable-buffer-local 'git-blame-last-update)
 353 (defun git-blame-enq-update (start end)
 354   "Mark the region between START and END as needing blame update"
 355   ;; Try to be smart and avoid multiple callouts for sequential
 356   ;; editing
 357   (cond ((and git-blame-last-update
 358               (= start (cdr git-blame-last-update)))
 359          (setcdr git-blame-last-update end))
 360         ((and git-blame-last-update
 361               (= end (car git-blame-last-update)))
 362          (setcar git-blame-last-update start))
 363         (t
 364          (setq git-blame-last-update (cons start end))
 365          (setq git-blame-update-queue (nconc git-blame-update-queue
 366                                              (list git-blame-last-update)))))
 367   (unless (or git-blame-proc git-blame-idle-timer)
 368     (setq git-blame-idle-timer
 369           (run-with-idle-timer 0.5 nil 'git-blame-delayed-update))))
 370
 371 (defun git-blame-delayed-update ()
 372   (setq git-blame-idle-timer nil)
 373   (if git-blame-update-queue
 374       (let ((first (pop git-blame-update-queue))
 375             (inhibit-point-motion-hooks t))
 376         (git-blame-update-region (car first) (cdr first)))))
 377
 378 (provide 'git-blame)
 379
 380 ;;; git-blame.el ends here