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-proc nil
 106   "The running git-blame process")
 107 (make-variable-buffer-local 'git-blame-proc)
 108
 109 (defvar git-blame-overlays nil
 110   "The git-blame overlays used in the current buffer.")
 111 (make-variable-buffer-local 'git-blame-overlays)
 112
 113 (defvar git-blame-cache nil
 114   "A cache of git-blame information for the current buffer")
 115 (make-variable-buffer-local 'git-blame-cache)
 116
 117 (defvar git-blame-mode nil)
 118 (make-variable-buffer-local 'git-blame-mode)
 119 (unless (assq 'git-blame-mode minor-mode-alist)
 120   (setq minor-mode-alist
 121         (cons (list 'git-blame-mode " blame")
 122               minor-mode-alist)))
 123
 124 ;;;###autoload
 125 (defun git-blame-mode (&optional arg)
 126   (interactive "P")
 127   (if arg
 128       (setq git-blame-mode (eq arg 1))
 129     (setq git-blame-mode (not git-blame-mode)))
 130   (make-local-variable 'git-blame-colors)
 131   (git-blame-cleanup)
 132   (if git-blame-mode
 133       (progn
 134         (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
 135           (if (eq bgmode 'dark)
 136               (setq git-blame-colors git-blame-dark-colors)
 137             (setq git-blame-colors git-blame-light-colors)))
 138         (setq git-blame-cache (make-hash-table :test 'equal))
 139         (git-blame-run))))
 140
 141 ;;;###autoload
 142 (defun git-reblame ()
 143   "Recalculate all blame information in the current buffer"
 144   (unless git-blame-mode
 145     (error "git-blame is not active"))
 146   (interactive)
 147   (git-blame-cleanup)
 148   (git-blame-run))
 149
 150 (defun git-blame-run ()
 151   (if git-blame-proc
 152       ;; Should maybe queue up a new run here
 153       (message "Already running git blame")
 154     (let ((display-buf (current-buffer))
 155           (blame-buf (get-buffer-create
 156                       (concat " git blame for " (buffer-name)))))
 157       (setq git-blame-proc
 158             (start-process "git-blame" blame-buf
 159                            "git" "blame"
 160                            "--incremental" "--contents" "-"
 161                            (file-name-nondirectory buffer-file-name)))
 162       (with-current-buffer blame-buf
 163         (erase-buffer)
 164         (make-local-variable 'git-blame-file)
 165         (make-local-variable 'git-blame-current)
 166         (setq git-blame-file display-buf)
 167         (setq git-blame-current nil))
 168       (set-process-filter git-blame-proc 'git-blame-filter)
 169       (set-process-sentinel git-blame-proc 'git-blame-sentinel)
 170       (process-send-region git-blame-proc (point-min) (point-max))
 171       (process-send-eof git-blame-proc))))
 172
 173 (defun git-blame-cleanup ()
 174   "Remove all blame properties"
 175     (mapcar 'delete-overlay git-blame-overlays)
 176     (setq git-blame-overlays nil)
 177     (let ((modified (buffer-modified-p)))
 178       (remove-text-properties (point-min) (point-max) '(point-entered nil))
 179       (set-buffer-modified-p modified)))
 180
 181 (defun git-blame-sentinel (proc status)
 182   (with-current-buffer (process-buffer proc)
 183     (with-current-buffer git-blame-file
 184       (setq git-blame-proc nil)))
 185   ;;(kill-buffer (process-buffer proc))
 186   (message "git blame finished"))
 187
 188 (defvar in-blame-filter nil)
 189
 190 (defun git-blame-filter (proc str)
 191   (save-excursion
 192     (set-buffer (process-buffer proc))
 193     (goto-char (process-mark proc))
 194     (insert-before-markers str)
 195     (goto-char 0)
 196     (unless in-blame-filter
 197       (let ((more t)
 198             (in-blame-filter t))
 199         (while more
 200           (setq more (git-blame-parse)))))))
 201
 202 (defun git-blame-parse ()
 203   (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
 204          (let ((hash (match-string 1))
 205                (src-line (string-to-number (match-string 2)))
 206                (res-line (string-to-number (match-string 3)))
 207                (num-lines (string-to-number (match-string 4))))
 208            (setq git-blame-current
 209                  (if (string= hash "0000000000000000000000000000000000000000")
 210                      nil
 211                    (git-blame-new-commit
 212                     hash src-line res-line num-lines))))
 213          (delete-region (point) (match-end 0))
 214          t)
 215         ((looking-at "filename \\(.+\\)\n")
 216          (let ((filename (match-string 1)))
 217            (git-blame-add-info "filename" filename))
 218          (delete-region (point) (match-end 0))
 219          t)
 220         ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
 221          (let ((key (match-string 1))
 222                (value (match-string 2)))
 223            (git-blame-add-info key value))
 224          (delete-region (point) (match-end 0))
 225          t)
 226         ((looking-at "boundary\n")
 227          (setq git-blame-current nil)
 228          (delete-region (point) (match-end 0))
 229          t)
 230         (t
 231          nil)))
 232
 233
 234 (defun git-blame-new-commit (hash src-line res-line num-lines)
 235   (save-excursion
 236     (set-buffer git-blame-file)
 237     (let ((info (gethash hash git-blame-cache))
 238           (inhibit-point-motion-hooks t))
 239       (when (not info)
 240         (let ((color (pop git-blame-colors)))
 241           (unless color
 242             (setq color git-blame-ancient-color))
 243           (setq info (list hash src-line res-line num-lines
 244                            (git-describe-commit hash)
 245                            (cons 'color color))))
 246         (puthash hash info git-blame-cache))
 247       (goto-line res-line)
 248       (while (> num-lines 0)
 249         (if (get-text-property (point) 'git-blame)
 250             (forward-line)
 251           (let* ((start (point))
 252                  (end (progn (forward-line 1) (point)))
 253                  (ovl (make-overlay start end)))
 254             (push ovl git-blame-overlays)
 255             (overlay-put ovl 'git-blame info)
 256             (overlay-put ovl 'help-echo hash)
 257             (overlay-put ovl 'face (list :background
 258                                          (cdr (assq 'color (nthcdr 5 info)))))
 259             ;; the point-entered property doesn't seem to work in overlays
 260             ;;(overlay-put ovl 'point-entered
 261             ;;             `(lambda (x y) (git-blame-identify ,hash)))
 262             (let ((modified (buffer-modified-p)))
 263               (put-text-property (if (= start 1) start (1- start)) (1- end)
 264                                  'point-entered
 265                                  `(lambda (x y) (git-blame-identify ,hash)))
 266               (set-buffer-modified-p modified))))
 267         (setq num-lines (1- num-lines))))))
 268
 269 (defun git-blame-add-info (key value)
 270   (if git-blame-current
 271       (nconc git-blame-current (list (cons (intern key) value)))))
 272
 273 (defun git-blame-current-commit ()
 274   (let ((info (get-char-property (point) 'git-blame)))
 275     (if info
 276         (car info)
 277       (error "No commit info"))))
 278
 279 (defun git-describe-commit (hash)
 280   (with-temp-buffer
 281     (call-process "git" nil t nil
 282                   "log" "-1" "--pretty=oneline"
 283                   hash)
 284     (buffer-substring (point-min) (1- (point-max)))))
 285
 286 (defvar git-blame-last-identification nil)
 287 (make-variable-buffer-local 'git-blame-last-identification)
 288 (defun git-blame-identify (&optional hash)
 289   (interactive)
 290   (let ((info (gethash (or hash (git-blame-current-commit)) git-blame-cache)))
 291     (when (and info (not (eq info git-blame-last-identification)))
 292       (message "%s" (nth 4 info))
 293       (setq git-blame-last-identification info))))
 294
 295 (provide 'git-blame)
 296
 297 ;;; git-blame.el ends here