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, see
  29 ;; <http://www.gnu.org/licenses/>.
  30
  31 ;; http://www.fsf.org/copyleft/gpl.html
  32
  33
  34 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  35 ;;
  36 ;;; Commentary:
  37 ;;
  38 ;; Here is an Emacs implementation of incremental git-blame.  When you
  39 ;; turn it on while viewing a file, the editor buffer will be updated by
  40 ;; setting the background of individual lines to a color that reflects
  41 ;; which commit it comes from.  And when you move around the buffer, a
  42 ;; one-line summary will be shown in the echo area.
  43
  44 ;;; Installation:
  45 ;;
  46 ;; To use this package, put it somewhere in `load-path' (or add
  47 ;; directory with git-blame.el to `load-path'), and add the following
  48 ;; line to your .emacs:
  49 ;;
  50 ;;    (require 'git-blame)
  51 ;;
  52 ;; If you do not want to load this package before it is necessary, you
  53 ;; can make use of the `autoload' feature, e.g. by adding to your .emacs
  54 ;; the following lines
  55 ;;
  56 ;;    (autoload 'git-blame-mode "git-blame"
  57 ;;              "Minor mode for incremental blame for Git." t)
  58 ;;
  59 ;; Then first use of `M-x git-blame-mode' would load the package.
  60
  61 ;;; Compatibility:
  62 ;;
  63 ;; It requires GNU Emacs 21 or later and Git 1.5.0 and up
  64 ;;
  65 ;; If you'are using Emacs 20, try 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 (eval-when-compile (require 'cl))                             ; to use `push', `pop'
  81 (require 'format-spec)
  82
  83 (defface git-blame-prefix-face
  84   '((((background dark)) (:foreground "gray"
  85                           :background "black"))
  86     (((background light)) (:foreground "gray"
  87                            :background "white"))
  88     (t (:weight bold)))
  89   "The face used for the hash prefix."
  90   :group 'git-blame)
  91
  92 (defgroup git-blame nil
  93   "A minor mode showing Git blame information."
  94   :group 'git
  95   :link '(function-link git-blame-mode))
  96
  97
  98 (defcustom git-blame-use-colors t
  99   "Use colors to indicate commits in `git-blame-mode'."
 100   :type 'boolean
 101   :group 'git-blame)
 102
 103 (defcustom git-blame-prefix-format
 104   "%h %20A:"
 105   "The format of the prefix added to each line in `git-blame'
 106 mode. The format is passed to `format-spec' with the following format keys:
 107
 108   %h - the abbreviated hash
 109   %H - the full hash
 110   %a - the author name
 111   %A - the author email
 112   %c - the committer name
 113   %C - the committer email
 114   %s - the commit summary
 115 "
 116   :group 'git-blame)
 117
 118 (defcustom git-blame-mouseover-format
 119   "%h %a %A: %s"
 120   "The format of the description shown when pointing at a line in
 121 `git-blame' mode. The format string is passed to `format-spec'
 122 with the following format keys:
 123
 124   %h - the abbreviated hash
 125   %H - the full hash
 126   %a - the author name
 127   %A - the author email
 128   %c - the committer name
 129   %C - the committer email
 130   %s - the commit summary
 131 "
 132   :group 'git-blame)
 133
 134
 135 (defun git-blame-color-scale (&rest elements)
 136   "Given a list, returns a list of triples formed with each
 137 elements of the list.
 138
 139 a b => bbb bba bab baa abb aba aaa aab"
 140   (let (result)
 141     (dolist (a elements)
 142       (dolist (b elements)
 143         (dolist (c elements)
 144           (setq result (cons (format "#%s%s%s" a b c) result)))))
 145     result))
 146
 147 ;; (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c") =>
 148 ;; ("#3c3c3c" "#3c3c14" "#3c3c34" "#3c3c2c" "#3c3c1c" "#3c3c24"
 149 ;; "#3c3c04" "#3c3c0c" "#3c143c" "#3c1414" "#3c1434" "#3c142c" ...)
 150
 151 (defmacro git-blame-random-pop (l)
 152   "Select a random element from L and returns it. Also remove
 153 selected element from l."
 154   ;; only works on lists with unique elements
 155   `(let ((e (elt ,l (random (length ,l)))))
 156      (setq ,l (remove e ,l))
 157      e))
 158
 159 (defvar git-blame-log-oneline-format
 160   "format:[%cr] %cn: %s"
 161   "*Formatting option used for describing current line in the minibuffer.
 162
 163 This option is used to pass to git log --pretty= command-line option,
 164 and describe which commit the current line was made.")
 165
 166 (defvar git-blame-dark-colors
 167   (git-blame-color-scale "0c" "04" "24" "1c" "2c" "34" "14" "3c")
 168   "*List of colors (format #RGB) to use in a dark environment.
 169
 170 To check out the list, evaluate (list-colors-display git-blame-dark-colors).")
 171
 172 (defvar git-blame-light-colors
 173   (git-blame-color-scale "c4" "d4" "cc" "dc" "f4" "e4" "fc" "ec")
 174   "*List of colors (format #RGB) to use in a light environment.
 175
 176 To check out the list, evaluate (list-colors-display git-blame-light-colors).")
 177
 178 (defvar git-blame-colors '()
 179   "Colors used by git-blame. The list is built once when activating git-blame
 180 minor mode.")
 181
 182 (defvar git-blame-ancient-color "dark green"
 183   "*Color to be used for ancient commit.")
 184
 185 (defvar git-blame-autoupdate t
 186   "*Automatically update the blame display while editing")
 187
 188 (defvar git-blame-proc nil
 189   "The running git-blame process")
 190 (make-variable-buffer-local 'git-blame-proc)
 191
 192 (defvar git-blame-overlays nil
 193   "The git-blame overlays used in the current buffer.")
 194 (make-variable-buffer-local 'git-blame-overlays)
 195
 196 (defvar git-blame-cache nil
 197   "A cache of git-blame information for the current buffer")
 198 (make-variable-buffer-local 'git-blame-cache)
 199
 200 (defvar git-blame-idle-timer nil
 201   "An idle timer that updates the blame")
 202 (make-variable-buffer-local 'git-blame-cache)
 203
 204 (defvar git-blame-update-queue nil
 205   "A queue of update requests")
 206 (make-variable-buffer-local 'git-blame-update-queue)
 207
 208 ;; FIXME: docstrings
 209 (defvar git-blame-file nil)
 210 (defvar git-blame-current nil)
 211
 212 (defvar git-blame-mode nil)
 213 (make-variable-buffer-local 'git-blame-mode)
 214
 215 (defvar git-blame-mode-line-string " blame"
 216   "String to display on the mode line when git-blame is active.")
 217
 218 (or (assq 'git-blame-mode minor-mode-alist)
 219     (setq minor-mode-alist
 220           (cons '(git-blame-mode git-blame-mode-line-string) minor-mode-alist)))
 221
 222 ;;;###autoload
 223 (defun git-blame-mode (&optional arg)
 224   "Toggle minor mode for displaying Git blame
 225
 226 With prefix ARG, turn the mode on if ARG is positive."
 227   (interactive "P")
 228   (cond
 229    ((null arg)
 230     (if git-blame-mode (git-blame-mode-off) (git-blame-mode-on)))
 231    ((> (prefix-numeric-value arg) 0) (git-blame-mode-on))
 232    (t (git-blame-mode-off))))
 233
 234 (defun git-blame-mode-on ()
 235   "Turn on git-blame mode.
 236
 237 See also function `git-blame-mode'."
 238   (make-local-variable 'git-blame-colors)
 239   (if git-blame-autoupdate
 240       (add-hook 'after-change-functions 'git-blame-after-change nil t)
 241     (remove-hook 'after-change-functions 'git-blame-after-change t))
 242   (git-blame-cleanup)
 243   (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
 244     (if (eq bgmode 'dark)
 245         (setq git-blame-colors git-blame-dark-colors)
 246       (setq git-blame-colors git-blame-light-colors)))
 247   (setq git-blame-cache (make-hash-table :test 'equal))
 248   (setq git-blame-mode t)
 249   (git-blame-run))
 250
 251 (defun git-blame-mode-off ()
 252   "Turn off git-blame mode.
 253
 254 See also function `git-blame-mode'."
 255   (git-blame-cleanup)
 256   (if git-blame-idle-timer (cancel-timer git-blame-idle-timer))
 257   (setq git-blame-mode nil))
 258
 259 ;;;###autoload
 260 (defun git-reblame ()
 261   "Recalculate all blame information in the current buffer"
 262   (interactive)
 263   (unless git-blame-mode
 264     (error "Git-blame is not active"))
 265
 266   (git-blame-cleanup)
 267   (git-blame-run))
 268
 269 (defun git-blame-run (&optional startline endline)
 270   (if git-blame-proc
 271       ;; Should maybe queue up a new run here
 272       (message "Already running git blame")
 273     (let ((display-buf (current-buffer))
 274           (blame-buf (get-buffer-create
 275                       (concat " git blame for " (buffer-name))))
 276           (args '("--incremental" "--contents" "-")))
 277       (if startline
 278           (setq args (append args
 279                              (list "-L" (format "%d,%d" startline endline)))))
 280       (setq args (append args
 281                          (list (file-name-nondirectory buffer-file-name))))
 282       (setq git-blame-proc
 283             (apply 'start-process
 284                    "git-blame" blame-buf
 285                    "git" "blame"
 286                    args))
 287       (with-current-buffer blame-buf
 288         (erase-buffer)
 289         (make-local-variable 'git-blame-file)
 290         (make-local-variable 'git-blame-current)
 291         (setq git-blame-file display-buf)
 292         (setq git-blame-current nil))
 293       (set-process-filter git-blame-proc 'git-blame-filter)
 294       (set-process-sentinel git-blame-proc 'git-blame-sentinel)
 295       (process-send-region git-blame-proc (point-min) (point-max))
 296       (process-send-eof git-blame-proc))))
 297
 298 (defun remove-git-blame-text-properties (start end)
 299   (let ((modified (buffer-modified-p))
 300         (inhibit-read-only t))
 301     (remove-text-properties start end '(point-entered nil))
 302     (set-buffer-modified-p modified)))
 303
 304 (defun git-blame-cleanup ()
 305   "Remove all blame properties"
 306     (mapc 'delete-overlay git-blame-overlays)
 307     (setq git-blame-overlays nil)
 308     (remove-git-blame-text-properties (point-min) (point-max)))
 309
 310 (defun git-blame-update-region (start end)
 311   "Rerun blame to get updates between START and END"
 312   (let ((overlays (overlays-in start end)))
 313     (while overlays
 314       (let ((overlay (pop overlays)))
 315         (if (< (overlay-start overlay) start)
 316             (setq start (overlay-start overlay)))
 317         (if (> (overlay-end overlay) end)
 318             (setq end (overlay-end overlay)))
 319         (setq git-blame-overlays (delete overlay git-blame-overlays))
 320         (delete-overlay overlay))))
 321   (remove-git-blame-text-properties start end)
 322   ;; We can be sure that start and end are at line breaks
 323   (git-blame-run (1+ (count-lines (point-min) start))
 324                  (count-lines (point-min) end)))
 325
 326 (defun git-blame-sentinel (proc status)
 327   (with-current-buffer (process-buffer proc)
 328     (with-current-buffer git-blame-file
 329       (setq git-blame-proc nil)
 330       (if git-blame-update-queue
 331           (git-blame-delayed-update))))
 332   ;;(kill-buffer (process-buffer proc))
 333   ;;(message "git blame finished")
 334   )
 335
 336 (defvar in-blame-filter nil)
 337
 338 (defun git-blame-filter (proc str)
 339   (with-current-buffer (process-buffer proc)
 340     (save-excursion
 341       (goto-char (process-mark proc))
 342       (insert-before-markers str)
 343       (goto-char (point-min))
 344       (unless in-blame-filter
 345         (let ((more t)
 346               (in-blame-filter t))
 347           (while more
 348             (setq more (git-blame-parse))))))))
 349
 350 (defun git-blame-parse ()
 351   (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
 352          (let ((hash (match-string 1))
 353                (src-line (string-to-number (match-string 2)))
 354                (res-line (string-to-number (match-string 3)))
 355                (num-lines (string-to-number (match-string 4))))
 356            (delete-region (point) (match-end 0))
 357            (setq git-blame-current (list (git-blame-new-commit hash)
 358                                          src-line res-line num-lines)))
 359          t)
 360         ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
 361          (let ((key (match-string 1))
 362                (value (match-string 2)))
 363            (delete-region (point) (match-end 0))
 364            (git-blame-add-info (car git-blame-current) key value)
 365            (when (string= key "filename")
 366              (git-blame-create-overlay (car git-blame-current)
 367                                        (caddr git-blame-current)
 368                                        (cadddr git-blame-current))
 369              (setq git-blame-current nil)))
 370          t)
 371         (t
 372          nil)))
 373
 374 (defun git-blame-new-commit (hash)
 375   (with-current-buffer git-blame-file
 376     (or (gethash hash git-blame-cache)
 377         ;; Assign a random color to each new commit info
 378         ;; Take care not to select the same color multiple times
 379         (let* ((color (if git-blame-colors
 380                           (git-blame-random-pop git-blame-colors)
 381                         git-blame-ancient-color))
 382                (info `(,hash (color . ,color))))
 383           (puthash hash info git-blame-cache)
 384           info))))
 385
 386 (defun git-blame-create-overlay (info start-line num-lines)
 387   (with-current-buffer git-blame-file
 388     (save-excursion
 389       (let ((inhibit-point-motion-hooks t)
 390             (inhibit-modification-hooks t))
 391         (goto-char (point-min))
 392         (forward-line (1- start-line))
 393         (let* ((start (point))
 394                (end (progn (forward-line num-lines) (point)))
 395                (ovl (make-overlay start end))
 396                (hash (car info))
 397                (spec `((?h . ,(substring hash 0 6))
 398                        (?H . ,hash)
 399                        (?a . ,(git-blame-get-info info 'author))
 400                        (?A . ,(git-blame-get-info info 'author-mail))
 401                        (?c . ,(git-blame-get-info info 'committer))
 402                        (?C . ,(git-blame-get-info info 'committer-mail))
 403                        (?s . ,(git-blame-get-info info 'summary)))))
 404           (push ovl git-blame-overlays)
 405           (overlay-put ovl 'git-blame info)
 406           (overlay-put ovl 'help-echo
 407                        (format-spec git-blame-mouseover-format spec))
 408           (if git-blame-use-colors
 409               (overlay-put ovl 'face (list :background
 410                                            (cdr (assq 'color (cdr info))))))
 411           (overlay-put ovl 'line-prefix
 412                        (propertize (format-spec git-blame-prefix-format spec)
 413                                    'face 'git-blame-prefix-face)))))))
 414
 415 (defun git-blame-add-info (info key value)
 416   (nconc info (list (cons (intern key) value))))
 417
 418 (defun git-blame-get-info (info key)
 419   (cdr (assq key (cdr info))))
 420
 421 (defun git-blame-current-commit ()
 422   (let ((info (get-char-property (point) 'git-blame)))
 423     (if info
 424         (car info)
 425       (error "No commit info"))))
 426
 427 (defun git-describe-commit (hash)
 428   (with-temp-buffer
 429     (call-process "git" nil t nil
 430                   "log" "-1"
 431                   (concat "--pretty=" git-blame-log-oneline-format)
 432                   hash)
 433     (buffer-substring (point-min) (point-max))))
 434
 435 (defvar git-blame-last-identification nil)
 436 (make-variable-buffer-local 'git-blame-last-identification)
 437 (defun git-blame-identify (&optional hash)
 438   (interactive)
 439   (let ((info (gethash (or hash (git-blame-current-commit)) git-blame-cache)))
 440     (when (and info (not (eq info git-blame-last-identification)))
 441       (message "%s" (nth 4 info))
 442       (setq git-blame-last-identification info))))
 443
 444 ;; (defun git-blame-after-save ()
 445 ;;   (when git-blame-mode
 446 ;;     (git-blame-cleanup)
 447 ;;     (git-blame-run)))
 448 ;; (add-hook 'after-save-hook 'git-blame-after-save)
 449
 450 (defun git-blame-after-change (start end length)
 451   (when git-blame-mode
 452     (git-blame-enq-update start end)))
 453
 454 (defvar git-blame-last-update nil)
 455 (make-variable-buffer-local 'git-blame-last-update)
 456 (defun git-blame-enq-update (start end)
 457   "Mark the region between START and END as needing blame update"
 458   ;; Try to be smart and avoid multiple callouts for sequential
 459   ;; editing
 460   (cond ((and git-blame-last-update
 461               (= start (cdr git-blame-last-update)))
 462          (setcdr git-blame-last-update end))
 463         ((and git-blame-last-update
 464               (= end (car git-blame-last-update)))
 465          (setcar git-blame-last-update start))
 466         (t
 467          (setq git-blame-last-update (cons start end))
 468          (setq git-blame-update-queue (nconc git-blame-update-queue
 469                                              (list git-blame-last-update)))))
 470   (unless (or git-blame-proc git-blame-idle-timer)
 471     (setq git-blame-idle-timer
 472           (run-with-idle-timer 0.5 nil 'git-blame-delayed-update))))
 473
 474 (defun git-blame-delayed-update ()
 475   (setq git-blame-idle-timer nil)
 476   (if git-blame-update-queue
 477       (let ((first (pop git-blame-update-queue))
 478             (inhibit-point-motion-hooks t))
 479         (git-blame-update-region (car first) (cdr first)))))
 480
 481 (provide 'git-blame)
 482
 483 ;;; git-blame.el ends here