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 ;;  1) Load into emacs: M-x load-file RET git-blame.el RET
  48 ;;  2) Open a git-controlled file
  49 ;;  3) Blame: M-x git-blame-mode
  50
  51 ;;; Compatibility:
  52 ;;
  53 ;; It requires GNU Emacs 21.  If you'are using Emacs 20, try
  54 ;; changing this:
  55 ;;
  56 ;;            (overlay-put ovl 'face (list :background
  57 ;;                                         (cdr (assq 'color (cddddr info)))))
  58 ;;
  59 ;; to
  60 ;;
  61 ;;            (overlay-put ovl 'face (cons 'background-color
  62 ;;                                         (cdr (assq 'color (cddddr info)))))
  63
  64
  65 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  66 ;;
  67 ;;; Code:
  68
  69 (require 'cl)                         ; to use `push', `pop'
  70
  71 (defun color-scale (l)
  72   (let* ((colors ())
  73          r g b)
  74     (setq r l)
  75     (while r
  76       (setq g l)
  77       (while g
  78         (setq b l)
  79         (while b
  80           (push (concat "#" (car r) (car g) (car b)) colors)
  81           (pop b))
  82         (pop g))
  83       (pop r))
  84     colors))
  85
  86 (defvar git-blame-dark-colors
  87   (color-scale '("00" "04" "08" "0c"
  88                  "10" "14" "18" "1c"
  89                  "20" "24" "28" "2c"
  90                  "30" "34" "38" "3c")))
  91
  92 (defvar git-blame-light-colors
  93   (color-scale '("c0" "c4" "c8" "cc"
  94                  "d0" "d4" "d8" "dc"
  95                  "e0" "e4" "e8" "ec"
  96                  "f0" "f4" "f8" "fc")))
  97
  98 (defvar git-blame-ancient-color "dark green")
  99
 100 (defvar git-blame-overlays nil)
 101 (defvar git-blame-cache nil)
 102
 103 (defvar git-blame-mode nil)
 104 (make-variable-buffer-local 'git-blame-mode)
 105 (push (list 'git-blame-mode " blame") minor-mode-alist)
 106
 107 (defun git-blame-mode (&optional arg)
 108   (interactive "P")
 109   (if arg
 110       (setq git-blame-mode (eq arg 1))
 111     (setq git-blame-mode (not git-blame-mode)))
 112   (make-local-variable 'git-blame-overlays)
 113   (make-local-variable 'git-blame-colors)
 114   (make-local-variable 'git-blame-cache)
 115   (let ((bgmode (cdr (assoc 'background-mode (frame-parameters)))))
 116     (if (eq bgmode 'dark)
 117         (setq git-blame-colors git-blame-dark-colors)
 118       (setq git-blame-colors git-blame-light-colors)))
 119   (if git-blame-mode
 120       (git-blame-run)
 121     (git-blame-cleanup)))
 122
 123 (defun git-blame-run ()
 124   (let* ((display-buf (current-buffer))
 125          (blame-buf (get-buffer-create
 126                      (concat " git blame for " (buffer-name))))
 127          (proc (start-process "git-blame" blame-buf
 128                              "git" "blame" "--incremental"
 129                              (file-name-nondirectory buffer-file-name))))
 130     (mapcar 'delete-overlay git-blame-overlays)
 131     (setq git-blame-overlays nil)
 132     (setq git-blame-cache (make-hash-table :test 'equal))
 133     (with-current-buffer blame-buf
 134       (erase-buffer)
 135       (make-local-variable 'git-blame-file)
 136       (make-local-variable 'git-blame-current)
 137       (setq git-blame-file display-buf)
 138       (setq git-blame-current nil))
 139     (set-process-filter proc 'git-blame-filter)
 140     (set-process-sentinel proc 'git-blame-sentinel)))
 141
 142 (defun git-blame-cleanup ()
 143   "Remove all blame properties"
 144     (mapcar 'delete-overlay git-blame-overlays)
 145     (setq git-blame-overlays nil)
 146     (let ((modified (buffer-modified-p)))
 147       (remove-text-properties (point-min) (point-max) '(point-entered nil))
 148       (set-buffer-modified-p modified)))
 149
 150 (defun git-blame-sentinel (proc status)
 151   ;;(kill-buffer (process-buffer proc))
 152   (message "git blame finished"))
 153
 154 (defvar in-blame-filter nil)
 155
 156 (defun git-blame-filter (proc str)
 157   (save-excursion
 158     (set-buffer (process-buffer proc))
 159     (goto-char (process-mark proc))
 160     (insert-before-markers str)
 161     (goto-char 0)
 162     (unless in-blame-filter
 163       (let ((more t)
 164             (in-blame-filter t))
 165         (while more
 166           (setq more (git-blame-parse)))))))
 167
 168 (defun git-blame-parse ()
 169   (cond ((looking-at "\\([0-9a-f]\\{40\\}\\) \\([0-9]+\\) \\([0-9]+\\) \\([0-9]+\\)\n")
 170          (let ((hash (match-string 1))
 171                (src-line (string-to-number (match-string 2)))
 172                (res-line (string-to-number (match-string 3)))
 173                (num-lines (string-to-number (match-string 4))))
 174            (setq git-blame-current
 175                  (git-blame-new-commit
 176                   hash src-line res-line num-lines)))
 177          (delete-region (point) (match-end 0))
 178          t)
 179         ((looking-at "filename \\(.+\\)\n")
 180          (let ((filename (match-string 1)))
 181            (git-blame-add-info "filename" filename))
 182          (delete-region (point) (match-end 0))
 183          t)
 184         ((looking-at "\\([a-z-]+\\) \\(.+\\)\n")
 185          (let ((key (match-string 1))
 186                (value (match-string 2)))
 187            (git-blame-add-info key value))
 188          (delete-region (point) (match-end 0))
 189          t)
 190         ((looking-at "boundary\n")
 191          (setq git-blame-current nil)
 192          (delete-region (point) (match-end 0))
 193          t)
 194         (t
 195          nil)))
 196
 197
 198 (defun git-blame-new-commit (hash src-line res-line num-lines)
 199   (save-excursion
 200     (set-buffer git-blame-file)
 201     (let ((info (gethash hash git-blame-cache))
 202           (inhibit-point-motion-hooks t))
 203       (when (not info)
 204         (let ((color (pop git-blame-colors)))
 205           (unless color
 206             (setq color git-blame-ancient-color))
 207           (setq info (list hash src-line res-line num-lines
 208                            (cons 'color color))))
 209         (puthash hash info git-blame-cache))
 210       (goto-line res-line)
 211       (while (> num-lines 0)
 212         (if (get-text-property (point) 'git-blame)
 213             (forward-line)
 214           (let* ((start (point))
 215                  (end (progn (forward-line 1) (point)))
 216                  (ovl (make-overlay start end)))
 217             (push ovl git-blame-overlays)
 218             (overlay-put ovl 'git-blame info)
 219             (overlay-put ovl 'help-echo hash)
 220             (overlay-put ovl 'face (list :background
 221                                          (cdr (assq 'color (cddddr info)))))
 222             ;;(overlay-put ovl 'point-entered
 223             ;;             `(lambda (x y) (git-blame-identify ,hash)))
 224             (let ((modified (buffer-modified-p)))
 225               (put-text-property (if (= start 1) start (1- start)) (1- end)
 226                                  'point-entered
 227                                  `(lambda (x y) (git-blame-identify ,hash)))
 228               (set-buffer-modified-p modified))))
 229         (setq num-lines (1- num-lines))))))
 230
 231 (defun git-blame-add-info (key value)
 232   (if git-blame-current
 233       (nconc git-blame-current (list (cons (intern key) value)))))
 234
 235 (defun git-blame-current-commit ()
 236   (let ((info (get-char-property (point) 'git-blame)))
 237     (if info
 238         (car info)
 239       (error "No commit info"))))
 240
 241 (defun git-blame-identify (&optional hash)
 242   (interactive)
 243   (shell-command
 244    (format "git log -1 --pretty=oneline %s" (or hash
 245                                                 (git-blame-current-commit)))))
 246
 247 (provide 'git-blame)
 248
 249 ;;; git-blame.el ends here