Add graphical diffstat to commit view

The diffstat is calculated against the leftmost parent of the commit. This
gives nice information for "normal" merges while octopus merges are less
than optimal, so the diffstat isn't calculated for those merges.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 101 insertions, 31 deletions

diff --git a/ui-commit.c b/ui-commit.c
index f1a22d3..ce33cf9 100644
--- a/ui-commit.c
+++ b/ui-commit.c
@@ -1,158 +1,228 @@
 /* ui-commit.c: generate commit view
  *
  * Copyright (C) 2006 Lars Hjemli
  *
  * Licensed under GNU General Public License v2
  *   (see COPYING for full license text)
  */
 
 #include "cgit.h"
 
-int files = 0;
+int files = 0, slots = 0;
+int total_adds = 0, total_rems = 0, max_changes = 0;
+int lines_added, lines_removed;
 
-void print_filepair(struct diff_filepair *pair)
+struct fileinfo {
+	char status;
+	unsigned char old_sha1[20];
+	unsigned char new_sha1[20];
+	unsigned short old_mode;
+	unsigned short new_mode;
+	char *old_path;
+	char *new_path;
+	unsigned int added;
+	unsigned int removed;
+} *items;
+
+
+void print_fileinfo(struct fileinfo *info)
 {
-	char *query;
+	char *query, *query2;
 	char *class;
+	double width;
 
-	switch (pair->status) {
+	switch (info->status) {
 	case DIFF_STATUS_ADDED:
 		class = "add";
 		break;
 	case DIFF_STATUS_COPIED:
 		class = "cpy";
 		break;
 	case DIFF_STATUS_DELETED:
 		class = "del";
 		break;
 	case DIFF_STATUS_MODIFIED:
 		class = "upd";
 		break;
 	case DIFF_STATUS_RENAMED:
 		class = "mov";
 		break;
 	case DIFF_STATUS_TYPE_CHANGED:
 		class = "typ";
 		break;
 	case DIFF_STATUS_UNKNOWN:
 		class = "unk";
 		break;
 	case DIFF_STATUS_UNMERGED:
 		class = "stg";
 		break;
 	default:
-		die("bug: unhandled diff status %c", pair->status);
+		die("bug: unhandled diff status %c", info->status);
 	}
 
 	html("<tr>");
 	htmlf("<td class='mode'>");
-	if (is_null_sha1(pair->two->sha1)) {
-		html_filemode(pair->one->mode);
+	if (is_null_sha1(info->new_sha1)) {
+		html_filemode(info->old_mode);
 	} else {
-		html_filemode(pair->two->mode);
+		html_filemode(info->new_mode);
 	}
 
-	if (pair->one->mode != pair->two->mode &&
-	    !is_null_sha1(pair->one->sha1) &&
-	    !is_null_sha1(pair->two->sha1)) {
+	if (info->old_mode != info->new_mode &&
+	    !is_null_sha1(info->old_sha1) &&
+	    !is_null_sha1(info->new_sha1)) {
 		html("<span class='modechange'>[");
-		html_filemode(pair->one->mode);
+		html_filemode(info->old_mode);
 		html("]</span>");
 	}
 	htmlf("</td><td class='%s'>", class);
-	query = fmt("id=%s&id2=%s", sha1_to_hex(pair->one->sha1),
-		    sha1_to_hex(pair->two->sha1));
+	query = fmt("id=%s&id2=%s", sha1_to_hex(info->old_sha1),
+		    sha1_to_hex(info->new_sha1));
 	html_link_open(cgit_pageurl(cgit_query_repo, "diff", query),
 		       NULL, NULL);
-	if (pair->status == DIFF_STATUS_COPIED ||
-	    pair->status == DIFF_STATUS_RENAMED) {
-		html_txt(pair->two->path);
-		htmlf("</a> (%s from ", pair->status == DIFF_STATUS_COPIED ?
+	if (info->status == DIFF_STATUS_COPIED ||
+	    info->status == DIFF_STATUS_RENAMED) {
+		html_txt(info->new_path);
+		htmlf("</a> (%s from ", info->status == DIFF_STATUS_COPIED ?
 		      "copied" : "renamed");
-		query = fmt("id=%s", sha1_to_hex(pair->one->sha1));
-		html_link_open(cgit_pageurl(cgit_query_repo, "view", query),
+		query2 = fmt("id=%s", sha1_to_hex(info->old_sha1));
+		html_link_open(cgit_pageurl(cgit_query_repo, "view", query2),
 			       NULL, NULL);
-		html_txt(pair->one->path);
+		html_txt(info->old_path);
 		html("</a>)");
 	} else {
-		html_txt(pair->two->path);
+		html_txt(info->new_path);
 		html("</a>");
 	}
-	html("<td>");
+	html("</td><td class='right'>");
+	htmlf("%d", info->added + info->removed);
 
-	//TODO: diffstat graph
+	html("</td><td class='graph'>");
+	width = (info->added + info->removed) * 100.0 / max_changes;
+	if (width < 0.1)
+		width = 0.1;
+	html_link_open(cgit_pageurl(cgit_query_repo, "diff", query),
+		       NULL, NULL);
+	htmlf("<img src='/cgit/add.png' style='width: %.1f%%;'/>",
+	      info->added * width / (info->added + info->removed));
+	htmlf("<img src='/cgit/del.png' style='width: %.1f%%;'/>",
+	      info->removed * width / (info->added + info->removed));
+	html("</a></td></tr>\n");
+}
 
-	html("</td></tr>\n");
+void cgit_count_diff_lines(char *line, int len)
+{
+	if (line && (len > 0)) {
+		if (line[0] == '+')
+			lines_added++;
+		else if (line[0] == '-')
+			lines_removed++;
+	}
+}
+
+void inspect_filepair(struct diff_filepair *pair)
+{
 	files++;
+	lines_added = 0;
+	lines_removed = 0;
+	cgit_diff_files(pair->one->sha1, pair->two->sha1, cgit_count_diff_lines);
+	if (files >= slots) {
+		if (slots == 0)
+			slots = 4;
+		else
+			slots = slots * 2;
+		items = xrealloc(items, slots * sizeof(struct fileinfo));
+	}
+	items[files-1].status = pair->status;
+	hashcpy(items[files-1].old_sha1, pair->one->sha1);
+	hashcpy(items[files-1].new_sha1, pair->two->sha1);
+	items[files-1].old_mode = pair->one->mode;
+	items[files-1].new_mode = pair->two->mode;
+	items[files-1].old_path = xstrdup(pair->one->path);
+	items[files-1].new_path = xstrdup(pair->two->path);
+	items[files-1].added = lines_added;
+	items[files-1].removed = lines_removed;
+	if (lines_added + lines_removed > max_changes)
+		max_changes = lines_added + lines_removed;
+	total_adds += lines_added;
+	total_rems += lines_removed;
 }
 
+
 void cgit_print_commit(const char *hex)
 {
 	struct commit *commit;
 	struct commitinfo *info;
 	struct commit_list *p;
 	unsigned char sha1[20];
 	char *query;
 	char *filename;
+	int i;
 
 	if (get_sha1(hex, sha1)) {
 		cgit_print_error(fmt("Bad object id: %s", hex));
 		return;
 	}
 	commit = lookup_commit_reference(sha1);
 	if (!commit) {
 		cgit_print_error(fmt("Bad commit reference: %s", hex));
 		return;
 	}
 	info = cgit_parse_commit(commit);
 
 	html("<table class='commit-info'>\n");
 	html("<tr><th>author</th><td>");
 	html_txt(info->author);
 	html(" ");
 	html_txt(info->author_email);
 	html("</td><td class='right'>");
 	cgit_print_date(info->author_date);
 	html("</td></tr>\n");
 	html("<tr><th>committer</th><td>");
 	html_txt(info->committer);
 	html(" ");
 	html_txt(info->committer_email);
 	html("</td><td class='right'>");
 	cgit_print_date(info->committer_date);
 	html("</td></tr>\n");
 	html("<tr><th>tree</th><td colspan='2' class='sha1'><a href='");
 	query = fmt("id=%s", sha1_to_hex(commit->tree->object.sha1));
 	html_attr(cgit_pageurl(cgit_query_repo, "tree", query));
 	htmlf("'>%s</a></td></tr>\n", sha1_to_hex(commit->tree->object.sha1));
       	for (p = commit->parents; p ; p = p->next) {
 		html("<tr><th>parent</th>"
 		     "<td colspan='2' class='sha1'>"
 		     "<a href='");
 		query = fmt("id=%s", sha1_to_hex(p->item->object.sha1));
 		html_attr(cgit_pageurl(cgit_query_repo, "commit", query));
 		htmlf("'>%s</a></td></tr>\n",
 		      sha1_to_hex(p->item->object.sha1));
 	}
 	if (cgit_repo->snapshots) {
 		htmlf("<tr><th>download</th><td colspan='2' class='sha1'><a href='");
 		filename = fmt("%s-%s.zip", cgit_query_repo, hex);
 		html_attr(cgit_pageurl(cgit_query_repo, "snapshot",
 				       fmt("id=%s&name=%s", hex, filename)));
 		htmlf("'>%s</a></td></tr>", filename);
 	}
 	html("</table>\n");
 	html("<div class='commit-subject'>");
 	html_txt(info->subject);
 	html("</div>");
 	html("<div class='commit-msg'>");
 	html_txt(info->msg);
 	html("</div>");
-	html("<table class='diffstat'>");
-	html("<tr><th colspan='3'>Affected files</tr>\n");
-	cgit_diff_commit(commit, print_filepair);
-	htmlf("<tr><td colspan='3' class='summary'>"
-	      "%d file%s changed</td></tr>\n", files, files > 1 ? "s" : "");
-	html("</table>");
+	if (!(commit->parents && commit->parents->next && commit->parents->next->next)) {
+		html("<table class='diffstat'>");
+		max_changes = 0;
+		cgit_diff_commit(commit, inspect_filepair);
+		for(i = 0; i<files; i++)
+			print_fileinfo(&items[i]);
+		html("</table>");
+		html("<div class='diffstat-summary'>");
+		htmlf("%d files changed, %d insertions, %d deletions\n",
+		      files, total_adds, total_rems);
+		html("</div>");
+	}
 	cgit_free_commitinfo(info);
 }