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 '("00" "04" "08" "0c"
  99                  "10" "14" "18" "1c"
 100                  "20" "24" "28" "2c"
 101                  "30" "34" "38" "3c")))
 102
 103 (defvar git-blame-light-colors
 104   (color-scale '("c0" "c4" "c8" "cc"
 105                  "d0" "d4" "d8" "dc"
 106                  "e0" "e4" "e8" "ec"
 107                  "f0" "f4" "f8" "fc")))
 108
 109 (defvar git-blame-ancient-color "dark green")
 110
 111 (defvar git-blame-overlays nil)
 112 (defvar git-blame-cache nil)
 113
 114 (defvar git-blame-mode nil)
 115 (make-variable-buffer-local 'git-blame-mode)
 116 (unless (assq 'git-blame-mode minor-mode-alist)
 117   (setq minor-mode-alist
 118         (cons (list 'git-blame-mode " blame")
 119               minor-mode-alist)))
 120
 121 ;;;###autoload
 122 (defun git-blame-mode (&optional arg)
 123   (interactive "P")
 124   (if arg
 125       (setq git-blame-mode (eq arg 1))
 126     (setq git-blame-mode (not git-blame-mode)))
 127   (make-local-variable 'git-blame-overlays)
 128   (make-local-variable 'git-blame-colors)
 129   (make-local-variable 'git-blame-cache)
 130   (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
 131     (if (eq bgmode 'dark)
 132         (setq git-blame-colors git-blame-dark-colors)
 133       (setq git-blame-colors git-blame-light-colors)))
 134   (if git-blame-mode
 135       (git-blame-run)
 136     (git-blame-cleanup)))
 137
 138 (defun git-blame-run ()
 139   (let* ((display-buf (current-buffer))
 140          (blame-buf (get-buffer-create
 141                      (concat " git blame for " (buffer-name))))
 142          (proc (start-process "git-blame" blame-buf
 143                              "git" "blame" "--incremental"
 144                              (file-name-nondirectory buffer-file-name))))
 145     (mapcar 'delete-overlay git-blame-overlays)
 146     (setq git-blame-overlays nil)
 147     (setq git-blame-cache (make-hash-table :test 'equal))
 148     (with-current-buffer blame-buf
 149       (erase-buffer)
 150       (make-local-variable 'git-blame-file)
 151       (make-local-variable 'git-blame-current)
 152       (setq git-blame-file display-buf)
 153       (setq git-blame-current nil))
 154     (set-process-filter proc 'git-blame-filter)
 155     (set-process-sentinel proc 'git-blame-sentinel)))
 156
 157 (defun git-blame-cleanup ()
 158   "Remove all blame properties"
 159     (mapcar 'delete-overlay git-blame-overlays)
 160     (setq git-blame-overlays nil)
 161     (let ((modified (buffer-modified-p)))
 162       (remove-text-properties (point-min) (point-max) '(point-entered nil))
 163       (set-buffer-modified-p modified)))
 164
 165 (defun git-blame-sentinel (proc status)
 166   ;;(kill-buffer (process-buffer proc))
 167   (message "git blame finished"))
 168
 169 (defvar in-blame-filter nil)
 170
 171 (defun git-blame-filter (proc str)
 172   (save-excursion
 173     (set-buffer (process-buffer proc))
 174     (goto-char (process-mark proc))
 175     (insert-before-markers str)
 176     (goto-char 0)
 177     (unless in-blame-filter
 178       (let ((more t)
 179             (in-blame-filter t))
 180         (while more
 181           (setq more (git-blame-parse)))))))
 182
 183 (defun git-blame-parse ()
 184   (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
 185          (let ((hash (match-string 1))
 186                (src-line (string-to-number (match-string 2)))
 187                (res-line (string-to-number (match-string 3)))
 188                (num-lines (string-to-number (match-string 4))))
 189            (setq git-blame-current
 190                  (if (string= hash "0000000000000000000000000000000000000000")
 191                      nil
 192                    (git-blame-new-commit
 193                     hash src-line res-line num-lines))))
 194          (delete-region (point) (match-end 0))
 195          t)
 196         ((looking-at "filename \\(.+\\)\n")
 197          (let ((filename (match-string 1)))
 198            (git-blame-add-info "filename" filename))
 199          (delete-region (point) (match-end 0))
 200          t)
 201         ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
 202          (let ((key (match-string 1))
 203                (value (match-string 2)))
 204            (git-blame-add-info key value))
 205          (delete-region (point) (match-end 0))
 206          t)
 207         ((looking-at "boundary\n")
 208          (setq git-blame-current nil)
 209          (delete-region (point) (match-end 0))
 210          t)
 211         (t
 212          nil)))
 213
 214
 215 (defun git-blame-new-commit (hash src-line res-line num-lines)
 216   (save-excursion
 217     (set-buffer git-blame-file)
 218     (let ((info (gethash hash git-blame-cache))
 219           (inhibit-point-motion-hooks t))
 220       (when (not info)
 221         (let ((color (pop git-blame-colors)))
 222           (unless color
 223             (setq color git-blame-ancient-color))
 224           (setq info (list hash src-line res-line num-lines
 225                            (git-describe-commit hash)
 226                            (cons 'color color))))
 227         (puthash hash info git-blame-cache))
 228       (goto-line res-line)
 229       (while (> num-lines 0)
 230         (if (get-text-property (point) 'git-blame)
 231             (forward-line)
 232           (let* ((start (point))
 233                  (end (progn (forward-line 1) (point)))
 234                  (ovl (make-overlay start end)))
 235             (push ovl git-blame-overlays)
 236             (overlay-put ovl 'git-blame info)
 237             (overlay-put ovl 'help-echo hash)
 238             (overlay-put ovl 'face (list :background
 239                                          (cdr (assq 'color (nthcdr 5 info)))))
 240             ;; the point-entered property doesn't seem to work in overlays
 241             ;;(overlay-put ovl 'point-entered
 242             ;;             `(lambda (x y) (git-blame-identify ,hash)))
 243             (let ((modified (buffer-modified-p)))
 244               (put-text-property (if (= start 1) start (1- start)) (1- end)
 245                                  'point-entered
 246                                  `(lambda (x y) (git-blame-identify ,hash)))
 247               (set-buffer-modified-p modified))))
 248         (setq num-lines (1- num-lines))))))
 249
 250 (defun git-blame-add-info (key value)
 251   (if git-blame-current
 252       (nconc git-blame-current (list (cons (intern key) value)))))
 253
 254 (defun git-blame-current-commit ()
 255   (let ((info (get-char-property (point) 'git-blame)))
 256     (if info
 257         (car info)
 258       (error "No commit info"))))
 259
 260 (defun git-describe-commit (hash)
 261   (with-temp-buffer
 262     (call-process "git" nil t nil
 263                   "log" "-1" "--pretty=oneline"
 264                   hash)
 265     (buffer-substring (point-min) (1- (point-max)))))
 266
 267 (defvar git-blame-last-identification nil)
 268 (make-variable-buffer-local 'git-blame-last-identification)
 269 (defun git-blame-identify (&optional hash)
 270   (interactive)
 271   (let ((info (gethash (or hash (git-blame-current-commit)) git-blame-cache)))
 272     (when (and info (not (eq info git-blame-last-identification)))
 273       (message "%s" (nth 4 info))
 274       (setq git-blame-last-identification info))))
 275
 276 (provide 'git-blame)
 277
 278 ;;; git-blame.el ends here