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, Emacs22 and EmacsCVS
  12 ;;                Git 1.5 and up
  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 or later and Git 1.5.0 and up
  65 ;;
  66 ;; If you'are using Emacs 20, try changing this:
  67 ;;
  68 ;;            (overlay-put ovl 'face (list :background
  69 ;;                                         (cdr (assq 'color (cddddr info)))))
  70 ;;
  71 ;; to
  72 ;;
  73 ;;            (overlay-put ovl 'face (cons 'background-color
  74 ;;                                         (cdr (assq 'color (cddddr info)))))
  75
  76
  77 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  78 ;;
  79 ;;; Code:
  80
  81 (eval-when-compile (require 'cl))                             ; to use `push', `pop'
  82
  83
  84 (defun git-blame-color-scale (&rest elements)
  85   "Given a list, returns a list of triples formed with each
  86 elements of the list.
  87
  88 a b => bbb bba bab baa abb aba aaa aab"
  89   (let (result)
  90     (dolist (a elements)
  91       (dolist (b elements)
  92         (dolist (c elements)
  93           (setq result (cons (format "#%s%s%s" a b c) result)))))
  94     result))
  95
  96 ;; (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c") =>
  97 ;; ("#3c3c3c" "#3c3c14" "#3c3c34" "#3c3c2c" "#3c3c1c" "#3c3c24"
  98 ;; "#3c3c04" "#3c3c0c" "#3c143c" "#3c1414" "#3c1434" "#3c142c" ...)
  99
 100 (defmacro git-blame-random-pop (l)
 101   "Select a random element from L and returns it. Also remove
 102 selected element from l."
 103   ;; only works on lists with unique elements
 104   `(let ((e (elt ,l (random (length ,l)))))
 105      (setq ,l (remove e ,l))
 106      e))
 107
 108 (defvar git-blame-dark-colors
 109   (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c")
 110   "*List of colors (format #RGB) to use in a dark environment.
 111
 112 To check out the list, evaluate (list-colors-display git-blame-dark-colors).")
 113
 114 (defvar git-blame-light-colors
 115   (git-blame-color-scale "c4" "d4" "cc" "dc" "f4" "e4" "fc" "ec")
 116   "*List of colors (format #RGB) to use in a light environment.
 117
 118 To check out the list, evaluate (list-colors-display git-blame-light-colors).")
 119
 120 (defvar git-blame-colors '()
 121   "Colors used by git-blame. The list is built once when activating git-blame
 122 minor mode.")
 123
 124 (defvar git-blame-ancient-color "dark green"
 125   "*Color to be used for ancient commit.")
 126
 127 (defvar git-blame-autoupdate t
 128   "*Automatically update the blame display while editing")
 129
 130 (defvar git-blame-proc nil
 131   "The running git-blame process")
 132 (make-variable-buffer-local 'git-blame-proc)
 133
 134 (defvar git-blame-overlays nil
 135   "The git-blame overlays used in the current buffer.")
 136 (make-variable-buffer-local 'git-blame-overlays)
 137
 138 (defvar git-blame-cache nil
 139   "A cache of git-blame information for the current buffer")
 140 (make-variable-buffer-local 'git-blame-cache)
 141
 142 (defvar git-blame-idle-timer nil
 143   "An idle timer that updates the blame")
 144 (make-variable-buffer-local 'git-blame-cache)
 145
 146 (defvar git-blame-update-queue nil
 147   "A queue of update requests")
 148 (make-variable-buffer-local 'git-blame-update-queue)
 149
 150 ;; FIXME: docstrings
 151 (defvar git-blame-file nil)
 152 (defvar git-blame-current nil)
 153
 154 (defvar git-blame-mode nil)
 155 (make-variable-buffer-local 'git-blame-mode)
 156
 157 (defvar git-blame-mode-line-string " blame"
 158   "String to display on the mode line when git-blame is active.")
 159
 160 (or (assq 'git-blame-mode minor-mode-alist)
 161     (setq minor-mode-alist
 162           (cons '(git-blame-mode git-blame-mode-line-string) minor-mode-alist)))
 163
 164 ;;;###autoload
 165 (defun git-blame-mode (&optional arg)
 166   "Toggle minor mode for displaying Git blame
 167
 168 With prefix ARG, turn the mode on if ARG is positive."
 169   (interactive "P")
 170   (cond
 171    ((null arg)
 172     (if git-blame-mode (git-blame-mode-off) (git-blame-mode-on)))
 173    ((> (prefix-numeric-value arg) 0) (git-blame-mode-on))
 174    (t (git-blame-mode-off))))
 175
 176 (defun git-blame-mode-on ()
 177   "Turn on git-blame mode.
 178
 179 See also function `git-blame-mode'."
 180   (make-local-variable 'git-blame-colors)
 181   (if git-blame-autoupdate
 182       (add-hook 'after-change-functions 'git-blame-after-change nil t)
 183     (remove-hook 'after-change-functions 'git-blame-after-change t))
 184   (git-blame-cleanup)
 185   (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
 186     (if (eq bgmode 'dark)
 187         (setq git-blame-colors git-blame-dark-colors)
 188       (setq git-blame-colors git-blame-light-colors)))
 189   (setq git-blame-cache (make-hash-table :test 'equal))
 190   (setq git-blame-mode t)
 191   (git-blame-run))
 192
 193 (defun git-blame-mode-off ()
 194   "Turn off git-blame mode.
 195
 196 See also function `git-blame-mode'."
 197   (git-blame-cleanup)
 198   (if git-blame-idle-timer (cancel-timer git-blame-idle-timer))
 199   (setq git-blame-mode nil))
 200
 201 ;;;###autoload
 202 (defun git-reblame ()
 203   "Recalculate all blame information in the current buffer"
 204   (interactive)
 205   (unless git-blame-mode
 206     (error "Git-blame is not active"))
 207
 208   (git-blame-cleanup)
 209   (git-blame-run))
 210
 211 (defun git-blame-run (&optional startline endline)
 212   (if git-blame-proc
 213       ;; Should maybe queue up a new run here
 214       (message "Already running git blame")
 215     (let ((display-buf (current-buffer))
 216           (blame-buf (get-buffer-create
 217                       (concat " git blame for " (buffer-name))))
 218           (args '("--incremental" "--contents" "-")))
 219       (if startline
 220           (setq args (append args
 221                              (list "-L" (format "%d,%d" startline endline)))))
 222       (setq args (append args
 223                          (list (file-name-nondirectory buffer-file-name))))
 224       (setq git-blame-proc
 225             (apply 'start-process
 226                    "git-blame" blame-buf
 227                    "git" "blame"
 228                    args))
 229       (with-current-buffer blame-buf
 230         (erase-buffer)
 231         (make-local-variable 'git-blame-file)
 232         (make-local-variable 'git-blame-current)
 233         (setq git-blame-file display-buf)
 234         (setq git-blame-current nil))
 235       (set-process-filter git-blame-proc 'git-blame-filter)
 236       (set-process-sentinel git-blame-proc 'git-blame-sentinel)
 237       (process-send-region git-blame-proc (point-min) (point-max))
 238       (process-send-eof git-blame-proc))))
 239
 240 (defun remove-git-blame-text-properties (start end)
 241   (let ((modified (buffer-modified-p))
 242         (inhibit-read-only t))
 243     (remove-text-properties start end '(point-entered nil))
 244     (set-buffer-modified-p modified)))
 245
 246 (defun git-blame-cleanup ()
 247   "Remove all blame properties"
 248     (mapcar 'delete-overlay git-blame-overlays)
 249     (setq git-blame-overlays nil)
 250     (remove-git-blame-text-properties (point-min) (point-max)))
 251
 252 (defun git-blame-update-region (start end)
 253   "Rerun blame to get updates between START and END"
 254   (let ((overlays (overlays-in start end)))
 255     (while overlays
 256       (let ((overlay (pop overlays)))
 257         (if (< (overlay-start overlay) start)
 258             (setq start (overlay-start overlay)))
 259         (if (> (overlay-end overlay) end)
 260             (setq end (overlay-end overlay)))
 261         (setq git-blame-overlays (delete overlay git-blame-overlays))
 262         (delete-overlay overlay))))
 263   (remove-git-blame-text-properties start end)
 264   ;; We can be sure that start and end are at line breaks
 265   (git-blame-run (1+ (count-lines (point-min) start))
 266                  (count-lines (point-min) end)))
 267
 268 (defun git-blame-sentinel (proc status)
 269   (with-current-buffer (process-buffer proc)
 270     (with-current-buffer git-blame-file
 271       (setq git-blame-proc nil)
 272       (if git-blame-update-queue
 273           (git-blame-delayed-update))))
 274   ;;(kill-buffer (process-buffer proc))
 275   ;;(message "git blame finished")
 276   )
 277
 278 (defvar in-blame-filter nil)
 279
 280 (defun git-blame-filter (proc str)
 281   (save-excursion
 282     (set-buffer (process-buffer proc))
 283     (goto-char (process-mark proc))
 284     (insert-before-markers str)
 285     (goto-char 0)
 286     (unless in-blame-filter
 287       (let ((more t)
 288             (in-blame-filter t))
 289         (while more
 290           (setq more (git-blame-parse)))))))
 291
 292 (defun git-blame-parse ()
 293   (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
 294          (let ((hash (match-string 1))
 295                (src-line (string-to-number (match-string 2)))
 296                (res-line (string-to-number (match-string 3)))
 297                (num-lines (string-to-number (match-string 4))))
 298            (setq git-blame-current
 299                  (if (string= hash "0000000000000000000000000000000000000000")
 300                      nil
 301                    (git-blame-new-commit
 302                     hash src-line res-line num-lines))))
 303          (delete-region (point) (match-end 0))
 304          t)
 305         ((looking-at "filename \\(.+\\)\n")
 306          (let ((filename (match-string 1)))
 307            (git-blame-add-info "filename" filename))
 308          (delete-region (point) (match-end 0))
 309          t)
 310         ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
 311          (let ((key (match-string 1))
 312                (value (match-string 2)))
 313            (git-blame-add-info key value))
 314          (delete-region (point) (match-end 0))
 315          t)
 316         ((looking-at "boundary\n")
 317          (setq git-blame-current nil)
 318          (delete-region (point) (match-end 0))
 319          t)
 320         (t
 321          nil)))
 322
 323 (defun git-blame-new-commit (hash src-line res-line num-lines)
 324   (save-excursion
 325     (set-buffer git-blame-file)
 326     (let ((info (gethash hash git-blame-cache))
 327           (inhibit-point-motion-hooks t)
 328           (inhibit-modification-hooks t))
 329       (when (not info)
 330         ;; Assign a random color to each new commit info
 331         ;; Take care not to select the same color multiple times
 332         (let ((color (if git-blame-colors
 333                          (git-blame-random-pop git-blame-colors)
 334                        git-blame-ancient-color)))
 335           (setq info (list hash src-line res-line num-lines
 336                            (git-describe-commit hash)
 337                            (cons 'color color))))
 338         (puthash hash info git-blame-cache))
 339       (goto-line res-line)
 340       (while (> num-lines 0)
 341         (if (get-text-property (point) 'git-blame)
 342             (forward-line)
 343           (let* ((start (point))
 344                  (end (progn (forward-line 1) (point)))
 345                  (ovl (make-overlay start end)))
 346             (push ovl git-blame-overlays)
 347             (overlay-put ovl 'git-blame info)
 348             (overlay-put ovl 'help-echo hash)
 349             (overlay-put ovl 'face (list :background
 350                                          (cdr (assq 'color (nthcdr 5 info)))))
 351             ;; the point-entered property doesn't seem to work in overlays
 352             ;;(overlay-put ovl 'point-entered
 353             ;;             `(lambda (x y) (git-blame-identify ,hash)))
 354             (let ((modified (buffer-modified-p)))
 355               (put-text-property (if (= start 1) start (1- start)) (1- end)
 356                                  'point-entered
 357                                  `(lambda (x y) (git-blame-identify ,hash)))
 358               (set-buffer-modified-p modified))))
 359         (setq num-lines (1- num-lines))))))
 360
 361 (defun git-blame-add-info (key value)
 362   (if git-blame-current
 363       (nconc git-blame-current (list (cons (intern key) value)))))
 364
 365 (defun git-blame-current-commit ()
 366   (let ((info (get-char-property (point) 'git-blame)))
 367     (if info
 368         (car info)
 369       (error "No commit info"))))
 370
 371 (defun git-describe-commit (hash)
 372   (with-temp-buffer
 373     (call-process "git" nil t nil
 374                   "log" "-1" "--pretty=oneline"
 375                   hash)
 376     (buffer-substring (point-min) (1- (point-max)))))
 377
 378 (defvar git-blame-last-identification nil)
 379 (make-variable-buffer-local 'git-blame-last-identification)
 380 (defun git-blame-identify (&optional hash)
 381   (interactive)
 382   (let ((info (gethash (or hash (git-blame-current-commit)) git-blame-cache)))
 383     (when (and info (not (eq info git-blame-last-identification)))
 384       (message "%s" (nth 4 info))
 385       (setq git-blame-last-identification info))))
 386
 387 ;; (defun git-blame-after-save ()
 388 ;;   (when git-blame-mode
 389 ;;     (git-blame-cleanup)
 390 ;;     (git-blame-run)))
 391 ;; (add-hook 'after-save-hook 'git-blame-after-save)
 392
 393 (defun git-blame-after-change (start end length)
 394   (when git-blame-mode
 395     (git-blame-enq-update start end)))
 396
 397 (defvar git-blame-last-update nil)
 398 (make-variable-buffer-local 'git-blame-last-update)
 399 (defun git-blame-enq-update (start end)
 400   "Mark the region between START and END as needing blame update"
 401   ;; Try to be smart and avoid multiple callouts for sequential
 402   ;; editing
 403   (cond ((and git-blame-last-update
 404               (= start (cdr git-blame-last-update)))
 405          (setcdr git-blame-last-update end))
 406         ((and git-blame-last-update
 407               (= end (car git-blame-last-update)))
 408          (setcar git-blame-last-update start))
 409         (t
 410          (setq git-blame-last-update (cons start end))
 411          (setq git-blame-update-queue (nconc git-blame-update-queue
 412                                              (list git-blame-last-update)))))
 413   (unless (or git-blame-proc git-blame-idle-timer)
 414     (setq git-blame-idle-timer
 415           (run-with-idle-timer 0.5 nil 'git-blame-delayed-update))))
 416
 417 (defun git-blame-delayed-update ()
 418   (setq git-blame-idle-timer nil)
 419   (if git-blame-update-queue
 420       (let ((first (pop git-blame-update-queue))
 421             (inhibit-point-motion-hooks t))
 422         (git-blame-update-region (car first) (cdr first)))))
 423
 424 (provide 'git-blame)
 425
 426 ;;; git-blame.el ends here