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 (require 'format-spec)
  83
  84 (defface git-blame-prefix-face
  85   '((((background dark)) (:foreground "gray"
  86                           :background "black"))
  87     (((background light)) (:foreground "gray"
  88                            :background "white"))
  89     (t (:weight bold)))
  90   "The face used for the hash prefix."
  91   :group 'git-blame)
  92
  93 (defgroup git-blame nil
  94   "A minor mode showing Git blame information."
  95   :group 'git
  96   :link '(function-link git-blame-mode))
  97
  98
  99 (defcustom git-blame-use-colors t
 100   "Use colors to indicate commits in `git-blame-mode'."
 101   :type 'boolean
 102   :group 'git-blame)
 103
 104 (defcustom git-blame-prefix-format
 105   "%h %20A:"
 106   "The format of the prefix added to each line in `git-blame'
 107 mode. The format is passed to `format-spec' with the following format keys:
 108
 109   %h - the abbreviated hash
 110   %H - the full hash
 111   %a - the author name
 112   %A - the author email
 113   %c - the committer name
 114   %C - the committer email
 115   %s - the commit summary
 116 "
 117   :group 'git-blame)
 118
 119 (defcustom git-blame-mouseover-format
 120   "%h %a %A: %s"
 121   "The format of the description shown when pointing at a line in
 122 `git-blame' mode. The format string is passed to `format-spec'
 123 with the following format keys:
 124
 125   %h - the abbreviated hash
 126   %H - the full hash
 127   %a - the author name
 128   %A - the author email
 129   %c - the committer name
 130   %C - the committer email
 131   %s - the commit summary
 132 "
 133   :group 'git-blame)
 134
 135
 136 (defun git-blame-color-scale (&rest elements)
 137   "Given a list, returns a list of triples formed with each
 138 elements of the list.
 139
 140 a b => bbb bba bab baa abb aba aaa aab"
 141   (let (result)
 142     (dolist (a elements)
 143       (dolist (b elements)
 144         (dolist (c elements)
 145           (setq result (cons (format "#%s%s%s" a b c) result)))))
 146     result))
 147
 148 ;; (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c") =>
 149 ;; ("#3c3c3c" "#3c3c14" "#3c3c34" "#3c3c2c" "#3c3c1c" "#3c3c24"
 150 ;; "#3c3c04" "#3c3c0c" "#3c143c" "#3c1414" "#3c1434" "#3c142c" ...)
 151
 152 (defmacro git-blame-random-pop (l)
 153   "Select a random element from L and returns it. Also remove
 154 selected element from l."
 155   ;; only works on lists with unique elements
 156   `(let ((e (elt ,l (random (length ,l)))))
 157      (setq ,l (remove e ,l))
 158      e))
 159
 160 (defvar git-blame-log-oneline-format
 161   "format:[%cr] %cn: %s"
 162   "*Formatting option used for describing current line in the minibuffer.
 163
 164 This option is used to pass to git log --pretty= command-line option,
 165 and describe which commit the current line was made.")
 166
 167 (defvar git-blame-dark-colors
 168   (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c")
 169   "*List of colors (format #RGB) to use in a dark environment.
 170
 171 To check out the list, evaluate (list-colors-display git-blame-dark-colors).")
 172
 173 (defvar git-blame-light-colors
 174   (git-blame-color-scale "c4" "d4" "cc" "dc" "f4" "e4" "fc" "ec")
 175   "*List of colors (format #RGB) to use in a light environment.
 176
 177 To check out the list, evaluate (list-colors-display git-blame-light-colors).")
 178
 179 (defvar git-blame-colors '()
 180   "Colors used by git-blame. The list is built once when activating git-blame
 181 minor mode.")
 182
 183 (defvar git-blame-ancient-color "dark green"
 184   "*Color to be used for ancient commit.")
 185
 186 (defvar git-blame-autoupdate t
 187   "*Automatically update the blame display while editing")
 188
 189 (defvar git-blame-proc nil
 190   "The running git-blame process")
 191 (make-variable-buffer-local 'git-blame-proc)
 192
 193 (defvar git-blame-overlays nil
 194   "The git-blame overlays used in the current buffer.")
 195 (make-variable-buffer-local 'git-blame-overlays)
 196
 197 (defvar git-blame-cache nil
 198   "A cache of git-blame information for the current buffer")
 199 (make-variable-buffer-local 'git-blame-cache)
 200
 201 (defvar git-blame-idle-timer nil
 202   "An idle timer that updates the blame")
 203 (make-variable-buffer-local 'git-blame-cache)
 204
 205 (defvar git-blame-update-queue nil
 206   "A queue of update requests")
 207 (make-variable-buffer-local 'git-blame-update-queue)
 208
 209 ;; FIXME: docstrings
 210 (defvar git-blame-file nil)
 211 (defvar git-blame-current nil)
 212
 213 (defvar git-blame-mode nil)
 214 (make-variable-buffer-local 'git-blame-mode)
 215
 216 (defvar git-blame-mode-line-string " blame"
 217   "String to display on the mode line when git-blame is active.")
 218
 219 (or (assq 'git-blame-mode minor-mode-alist)
 220     (setq minor-mode-alist
 221           (cons '(git-blame-mode git-blame-mode-line-string) minor-mode-alist)))
 222
 223 ;;;###autoload
 224 (defun git-blame-mode (&optional arg)
 225   "Toggle minor mode for displaying Git blame
 226
 227 With prefix ARG, turn the mode on if ARG is positive."
 228   (interactive "P")
 229   (cond
 230    ((null arg)
 231     (if git-blame-mode (git-blame-mode-off) (git-blame-mode-on)))
 232    ((> (prefix-numeric-value arg) 0) (git-blame-mode-on))
 233    (t (git-blame-mode-off))))
 234
 235 (defun git-blame-mode-on ()
 236   "Turn on git-blame mode.
 237
 238 See also function `git-blame-mode'."
 239   (make-local-variable 'git-blame-colors)
 240   (if git-blame-autoupdate
 241       (add-hook 'after-change-functions 'git-blame-after-change nil t)
 242     (remove-hook 'after-change-functions 'git-blame-after-change t))
 243   (git-blame-cleanup)
 244   (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
 245     (if (eq bgmode 'dark)
 246         (setq git-blame-colors git-blame-dark-colors)
 247       (setq git-blame-colors git-blame-light-colors)))
 248   (setq git-blame-cache (make-hash-table :test 'equal))
 249   (setq git-blame-mode t)
 250   (git-blame-run))
 251
 252 (defun git-blame-mode-off ()
 253   "Turn off git-blame mode.
 254
 255 See also function `git-blame-mode'."
 256   (git-blame-cleanup)
 257   (if git-blame-idle-timer (cancel-timer git-blame-idle-timer))
 258   (setq git-blame-mode nil))
 259
 260 ;;;###autoload
 261 (defun git-reblame ()
 262   "Recalculate all blame information in the current buffer"
 263   (interactive)
 264   (unless git-blame-mode
 265     (error "Git-blame is not active"))
 266
 267   (git-blame-cleanup)
 268   (git-blame-run))
 269
 270 (defun git-blame-run (&optional startline endline)
 271   (if git-blame-proc
 272       ;; Should maybe queue up a new run here
 273       (message "Already running git blame")
 274     (let ((display-buf (current-buffer))
 275           (blame-buf (get-buffer-create
 276                       (concat " git blame for " (buffer-name))))
 277           (args '("--incremental" "--contents" "-")))
 278       (if startline
 279           (setq args (append args
 280                              (list "-L" (format "%d,%d" startline endline)))))
 281       (setq args (append args
 282                          (list (file-name-nondirectory buffer-file-name))))
 283       (setq git-blame-proc
 284             (apply 'start-process
 285                    "git-blame" blame-buf
 286                    "git" "blame"
 287                    args))
 288       (with-current-buffer blame-buf
 289         (erase-buffer)
 290         (make-local-variable 'git-blame-file)
 291         (make-local-variable 'git-blame-current)
 292         (setq git-blame-file display-buf)
 293         (setq git-blame-current nil))
 294       (set-process-filter git-blame-proc 'git-blame-filter)
 295       (set-process-sentinel git-blame-proc 'git-blame-sentinel)
 296       (process-send-region git-blame-proc (point-min) (point-max))
 297       (process-send-eof git-blame-proc))))
 298
 299 (defun remove-git-blame-text-properties (start end)
 300   (let ((modified (buffer-modified-p))
 301         (inhibit-read-only t))
 302     (remove-text-properties start end '(point-entered nil))
 303     (set-buffer-modified-p modified)))
 304
 305 (defun git-blame-cleanup ()
 306   "Remove all blame properties"
 307     (mapc 'delete-overlay git-blame-overlays)
 308     (setq git-blame-overlays nil)
 309     (remove-git-blame-text-properties (point-min) (point-max)))
 310
 311 (defun git-blame-update-region (start end)
 312   "Rerun blame to get updates between START and END"
 313   (let ((overlays (overlays-in start end)))
 314     (while overlays
 315       (let ((overlay (pop overlays)))
 316         (if (< (overlay-start overlay) start)
 317             (setq start (overlay-start overlay)))
 318         (if (> (overlay-end overlay) end)
 319             (setq end (overlay-end overlay)))
 320         (setq git-blame-overlays (delete overlay git-blame-overlays))
 321         (delete-overlay overlay))))
 322   (remove-git-blame-text-properties start end)
 323   ;; We can be sure that start and end are at line breaks
 324   (git-blame-run (1+ (count-lines (point-min) start))
 325                  (count-lines (point-min) end)))
 326
 327 (defun git-blame-sentinel (proc status)
 328   (with-current-buffer (process-buffer proc)
 329     (with-current-buffer git-blame-file
 330       (setq git-blame-proc nil)
 331       (if git-blame-update-queue
 332           (git-blame-delayed-update))))
 333   ;;(kill-buffer (process-buffer proc))
 334   ;;(message "git blame finished")
 335   )
 336
 337 (defvar in-blame-filter nil)
 338
 339 (defun git-blame-filter (proc str)
 340   (with-current-buffer (process-buffer proc)
 341     (save-excursion
 342       (goto-char (process-mark proc))
 343       (insert-before-markers str)
 344       (goto-char (point-min))
 345       (unless in-blame-filter
 346         (let ((more t)
 347               (in-blame-filter t))
 348           (while more
 349             (setq more (git-blame-parse))))))))
 350
 351 (defun git-blame-parse ()
 352   (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
 353          (let ((hash (match-string 1))
 354                (src-line (string-to-number (match-string 2)))
 355                (res-line (string-to-number (match-string 3)))
 356                (num-lines (string-to-number (match-string 4))))
 357            (delete-region (point) (match-end 0))
 358            (setq git-blame-current (list (git-blame-new-commit hash)
 359                                          src-line res-line num-lines)))
 360          t)
 361         ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
 362          (let ((key (match-string 1))
 363                (value (match-string 2)))
 364            (delete-region (point) (match-end 0))
 365            (git-blame-add-info (car git-blame-current) key value)
 366            (when (string= key "filename")
 367              (git-blame-create-overlay (car git-blame-current)
 368                                        (caddr git-blame-current)
 369                                        (cadddr git-blame-current))
 370              (setq git-blame-current nil)))
 371          t)
 372         (t
 373          nil)))
 374
 375 (defun git-blame-new-commit (hash)
 376   (with-current-buffer git-blame-file
 377     (or (gethash hash git-blame-cache)
 378         ;; Assign a random color to each new commit info
 379         ;; Take care not to select the same color multiple times
 380         (let* ((color (if git-blame-colors
 381                           (git-blame-random-pop git-blame-colors)
 382                         git-blame-ancient-color))
 383                (info `(,hash (color . ,color))))
 384           (puthash hash info git-blame-cache)
 385           info))))
 386
 387 (defun git-blame-create-overlay (info start-line num-lines)
 388   (with-current-buffer git-blame-file
 389     (save-excursion
 390       (let ((inhibit-point-motion-hooks t)
 391             (inhibit-modification-hooks t))
 392         (goto-char (point-min))
 393         (forward-line (1- start-line))
 394         (let* ((start (point))
 395                (end (progn (forward-line num-lines) (point)))
 396                (ovl (make-overlay start end))
 397                (hash (car info))
 398                (spec `((?h . ,(substring hash 0 6))
 399                        (?H . ,hash)
 400                        (?a . ,(git-blame-get-info info 'author))
 401                        (?A . ,(git-blame-get-info info 'author-mail))
 402                        (?c . ,(git-blame-get-info info 'committer))
 403                        (?C . ,(git-blame-get-info info 'committer-mail))
 404                        (?s . ,(git-blame-get-info info 'summary)))))
 405           (push ovl git-blame-overlays)
 406           (overlay-put ovl 'git-blame info)
 407           (overlay-put ovl 'help-echo
 408                        (format-spec git-blame-mouseover-format spec))
 409           (if git-blame-use-colors
 410               (overlay-put ovl 'face (list :background
 411                                            (cdr (assq 'color (cdr info))))))
 412           (overlay-put ovl 'line-prefix
 413                        (propertize (format-spec git-blame-prefix-format spec)
 414                                    'face 'git-blame-prefix-face)))))))
 415
 416 (defun git-blame-add-info (info key value)
 417   (nconc info (list (cons (intern key) value))))
 418
 419 (defun git-blame-get-info (info key)
 420   (cdr (assq key (cdr info))))
 421
 422 (defun git-blame-current-commit ()
 423   (let ((info (get-char-property (point) 'git-blame)))
 424     (if info
 425         (car info)
 426       (error "No commit info"))))
 427
 428 (defun git-describe-commit (hash)
 429   (with-temp-buffer
 430     (call-process "git" nil t nil
 431                   "log" "-1"
 432                   (concat "--pretty=" git-blame-log-oneline-format)
 433                   hash)
 434     (buffer-substring (point-min) (point-max))))
 435
 436 (defvar git-blame-last-identification nil)
 437 (make-variable-buffer-local 'git-blame-last-identification)
 438 (defun git-blame-identify (&optional hash)
 439   (interactive)
 440   (let ((info (gethash (or hash (git-blame-current-commit)) git-blame-cache)))
 441     (when (and info (not (eq info git-blame-last-identification)))
 442       (message "%s" (nth 4 info))
 443       (setq git-blame-last-identification info))))
 444
 445 ;; (defun git-blame-after-save ()
 446 ;;   (when git-blame-mode
 447 ;;     (git-blame-cleanup)
 448 ;;     (git-blame-run)))
 449 ;; (add-hook 'after-save-hook 'git-blame-after-save)
 450
 451 (defun git-blame-after-change (start end length)
 452   (when git-blame-mode
 453     (git-blame-enq-update start end)))
 454
 455 (defvar git-blame-last-update nil)
 456 (make-variable-buffer-local 'git-blame-last-update)
 457 (defun git-blame-enq-update (start end)
 458   "Mark the region between START and END as needing blame update"
 459   ;; Try to be smart and avoid multiple callouts for sequential
 460   ;; editing
 461   (cond ((and git-blame-last-update
 462               (= start (cdr git-blame-last-update)))
 463          (setcdr git-blame-last-update end))
 464         ((and git-blame-last-update
 465               (= end (car git-blame-last-update)))
 466          (setcar git-blame-last-update start))
 467         (t
 468          (setq git-blame-last-update (cons start end))
 469          (setq git-blame-update-queue (nconc git-blame-update-queue
 470                                              (list git-blame-last-update)))))
 471   (unless (or git-blame-proc git-blame-idle-timer)
 472     (setq git-blame-idle-timer
 473           (run-with-idle-timer 0.5 nil 'git-blame-delayed-update))))
 474
 475 (defun git-blame-delayed-update ()
 476   (setq git-blame-idle-timer nil)
 477   (if git-blame-update-queue
 478       (let ((first (pop git-blame-update-queue))
 479             (inhibit-point-motion-hooks t))
 480         (git-blame-update-region (car first) (cdr first)))))
 481
 482 (provide 'git-blame)
 483
 484 ;;; git-blame.el ends here