Per-author added lines graph

Old versions of gnuplot produce garbage if the author's name contain
non-ascii, but gnuplot 4.4 seems to handle it just fine.

Signed-off-by: Heikki Hokkanen <hoxu@users.sf.net>

gitstats

 		self.total_lines = total_lines
 
 		# Per-author statistics
+		self.changes_by_date_by_author = {} # stamp -> author -> lines_added
+		                                    # defined for stamp, author only if
+		                                    # author commited at this timestamp.
 		# Similar to the above, but never use --first-parent
 		# (we need to walk through every commits to know who
 		# commited what, not just through mainline)
 							self.authors[author] = { 'lines_added' : 0, 'lines_removed' : 0 }
 						self.authors[author]['lines_added'] = self.authors[author].get('lines_added', 0) + inserted
 						self.authors[author]['lines_removed'] = self.authors[author].get('lines_removed', 0) + deleted
+						if stamp not in self.changes_by_date_by_author:
+							self.changes_by_date_by_author[stamp] = {}
+						self.changes_by_date_by_author[stamp][author] = self.authors[author]['lines_added']
 						files, inserted, deleted = 0, 0, 0
 					except ValueError:
 						print 'Warning: unexpected line "%s"' % line
 			rest = allauthors[conf['max_authors']:]
 			f.write('<p class="moreauthors">These didn\'t make it to the top: %s</p>' % ', '.join(rest))
 
+		f.write(html_header(2, 'Cumulated Added Lines of Code per Author'))
+		f.write('<img src="lines_of_code_by_author.png" alt="Lines of code per Author" />')
+		if len(allauthors) > conf['max_authors']:
+			rest = allauthors[conf['max_authors']:]
+			f.write('<p class="moreauthors">These didn\'t make it to the graph: %s</p>' % ', '.join(rest))
+
+		fg = open(path + '/lines_of_code_by_author.dat', 'w')
+		lines_by_authors = {} # cumulated added lines by
+		# author. to save memory,
+		# changes_by_date_by_author[stamp][author] is defined
+		# only at points where author commits.
+		# lines_by_authors allows us to generate all the
+		# points in the .dat file.
+
+		# Don't rely on getAuthors to give the same order each
+		# time. Be robust and keep the list in a variable.
+		self.authors_to_plot = data.getAuthors(conf['max_authors'])
+		for author in self.authors_to_plot:
+			lines_by_authors[author] = 0
+		for stamp in sorted(data.changes_by_date_by_author.keys()):
+			fg.write('%d' % stamp)
+			for author in self.authors_to_plot:
+				if author in data.changes_by_date_by_author[stamp].keys():
+					lines_by_authors[author] = data.changes_by_date_by_author[stamp][author]
+				fg.write(' %d' % lines_by_authors[author])
+			fg.write('\n');
+		fg.close()
+
 		# Authors :: Author of Month
 		f.write(html_header(2, 'Author of Month'))
 		f.write('<table class="sortable" id="aom">')
 """)
 		f.close()
 
+		# Lines of Code Added per author
+		f = open(path + '/lines_of_code_by_author.plot', 'w')
+		f.write(GNUPLOT_COMMON)
+		f.write(
+"""
+set terminal png transparent size 640,480
+set output 'lines_of_code_by_author.png'
+set key left top
+set xdata time
+set timefmt "%s"
+set format x "%Y-%m-%d"
+set grid y
+set ylabel "Lines"
+set xtics rotate
+set bmargin 6
+plot """
+)
+		i = 1
+		plots = []
+		for a in self.authors_to_plot:
+			i = i + 1
+			plots.append("""'lines_of_code_by_author.dat' using 1:%d title "%s" w lines""" % (i, a.replace("\"", "\\\"")))
+		f.write(", ".join(plots))
+		f.write('\n')
+
+		f.close()
+
 		os.chdir(path)
 		files = glob.glob(path + '/*.plot')
 		for f in files: