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>

5 files changed, 130 insertions, 33 deletions

diff --git a/Makefile b/Makefile
index ccc7582..ea4d818 100644
--- a/Makefile
+++ b/Makefile
@@ -1,79 +1,80 @@
 CGIT_VERSION = 0.3
 
 prefix = /var/www/htdocs/cgit
 
 SHA1_HEADER = <openssl/sha.h>
 
 CACHE_ROOT = /var/cache/cgit
 EXTLIBS = git/libgit.a git/xdiff/lib.a -lz -lcrypto
 OBJECTS = shared.o cache.o parsing.o html.o ui-shared.o ui-repolist.o \
         ui-summary.o ui-log.o ui-view.o ui-tree.o ui-commit.o ui-diff.o \
         ui-snapshot.o ui-blob.o
 
 CFLAGS += -Wall
 
 ifdef DEBUG
         CFLAGS += -g
 endif
 
 CFLAGS += -Igit -DSHA1_HEADER='$(SHA1_HEADER)'
 
 
 #
 # If make is run on a nongit platform, we need to get the git sources as a tarball.
 # But there is currently no recent enough tarball available on kernel.org, so download
 # a zipfile from hjemli.net instead
 #
 GITVER = $(shell git version 2>/dev/null || echo nogit)
 ifeq ($(GITVER),nogit)
 GITURL = http://hjemli.net/git/git/snapshot/?id=v1.5.2-rc2
 INITGIT = test -e git/git.c || (curl "$(GITURL)" > tmp.zip && unzip tmp.zip)
 else
 INITGIT = ./submodules.sh -i
 endif
 
 
 #
 # basic build rules
 #
 all: cgit
 
 cgit: cgit.c cgit.h $(OBJECTS)
         $(CC) $(CFLAGS) -DCGIT_VERSION='"$(CGIT_VERSION)"' cgit.c -o cgit \
                 $(OBJECTS) $(EXTLIBS)
 
 $(OBJECTS): cgit.h git/libgit.a
 
 git/libgit.a:
         $(INITGIT)
         $(MAKE) -C git
 
 #
 # phony targets
 #
 install: all clean-cache
         mkdir -p $(prefix)
         install cgit $(prefix)/cgit.cgi
         install cgit.css $(prefix)/cgit.css
+        install add.png del.png $(prefix)/
 
 clean-cgit:
         rm -f cgit *.o
 
 distclean-cgit: clean-cgit
         git clean -d -x
 
 clean-sub:
         $(MAKE) -C git clean
 
 distclean-sub: clean-sub
         $(shell cd git && git clean -d -x)
 
 clean-cache:
         rm -rf $(CACHE_ROOT)/*
 
 clean: clean-cgit clean-sub
 
 distclean: distclean-cgit distclean-sub
 
 .PHONY: all install clean clean-cgit clean-sub clean-cache \
         distclean distclean-cgit distclean-sub
diff --git a/add.png b/add.png
new file mode 100644
index 0000000..c550388
--- a/dev/null
+++ b/add.png
diff --git a/cgit.css b/cgit.css
index cded981..b736b19 100644
--- a/cgit.css
+++ b/cgit.css
@@ -1,296 +1,322 @@
 body {
         font-family: arial;
         font-size: 11pt;
         background: white;
 }
 
 body, table {
         padding: 0em;
         margin: 0em;
 }
 
 table {
       border-collapse: collapse;
 }
 
 h2 {
         font-size: 120%;
         font-weight: bold;
         margin-top: 0em;
         margin-bottom: 0.25em;
 }
 
 h3 {
         margin-top: 0em;
         font-size: 100%;
         font-weight: normal;
 }
 
+h4 {
+        margin-top: 1.5em;
+        margin-bottom: 0.1em;
+        font-size: 100%;
+        font-weight: bold;
+}
+
 a {
         color: blue;
         text-decoration: none;
 }
 
 a:hover {
         text-decoration: underline;
 }
 
 table.list {
         border: none;
         border-collapse: collapse;
 }
 
 table.list tr {
         background: white;
 }
 
 table.list tr:hover {
         background: #eee;
 }
 
 table.list tr.nohover:hover {
         background: white;
 }
 
 table.list th {
         font-weight: normal;
         border-bottom: solid 1px #777;
         padding: 0.1em 0.5em 0.1em 0.5em;
         vertical-align: baseline;
 }
 
 table.list td {
         border: none;
         padding: 0.1em 0.5em 0.1em 0.5em;
 }
 
 img {
         border: none;
 }
 
 table#layout {
         width: 100%;
         border-collapse: collapse;
         margin: 0px;
 }
 
 td#header, td#logo {
         color: #666;
         background-color: #ddd;
         border-bottom: solid 1px #000;
 }
 
 td#header {
         font-size: 150%;
         font-weight: bold;
         padding: 0.2em 0.5em;
         vertical-align: text-bottom;
 }
 
 td#logo {
         text-align: right;
         vertical-align: middle;
         padding-right: 0.5em;
 }
 
 td#crumb, td#search {
         color: #ccc;
         border-top: solid 3px #555;
         background-color: #666;
         border-bottom: solid 1px #333;
         padding: 2px 1em;
 }
 
 td#crumb {
         font-weight: bold;
 }
 
 td#crumb a {
         color: #ccc;
 }
 
 td#crumb a:hover {
         color: #eee;
 }
 
 td#search {
         text-align: right;
         vertical-align: center;
         padding-right: 0.5em;
 }
 
 td#search form {
         margin: 0px;
         padding: 0px;
 }
 
 td#search input {
         font-size: 9pt;
         padding: 0px;
         width: 10em;
         border: solid 1px #333;
         color: #333;
         background-color: #fff;
 }
 
 td#summary {
         vertical-align: top;
         padding-bottom: 1em;
 }
 
 td#archivelist {
         padding-bottom: 1em;
 }
 
 td#archivelist table {
         float: right;
         border-collapse: collapse;
         border: solid 1px #777;
 }
 
 td#archivelist table th {
         background-color: #ccc;
 }
 
 td#content {
         padding: 1em 0.5em;
 }
 
 div#blob {
         border: solid 1px black;
 }
 
 div.error {
         color: red;
         font-weight: bold;
         margin: 1em 2em;
 }
 
 td.ls-blob, td.ls-dir, td.ls-mod {
         font-family: monospace;
 }
 
 div.ls-dir a {
         font-weight: bold;
 }
 
 th.filesize, td.filesize {
         text-align: right;
 }
 
 td.filesize {
         font-family: monospace;
 }
 
 td.filemode {
         font-family: monospace;
 }
 
 td.blob {
         white-space: pre;
         font-family: monospace;
         background-color: white;
 }
 
 table.nowrap td {
         white-space: nowrap;
 }
 
 table.commit-info {
         border-collapse: collapse;
         margin-top: 1.5em;
 }
 
 table.commit-info th {
         text-align: left;
         font-weight: normal;
         padding: 0.1em 1em 0.1em 0.1em;
 }
 
 table.commit-info td {
         font-weight: normal;
         padding: 0.1em 1em 0.1em 0.1em;
 }
 
 div.commit-subject {
         font-weight: bold;
         font-size: 125%;
         margin: 1.5em 0em 0.5em 0em;
         padding: 0em;
 }
 
 div.commit-msg {
         white-space: pre;
         font-family: monospace;
 }
 
 table.diffstat {
         border-collapse: collapse;
         margin-top: 1.5em;
+        width: 100%;
+        border: solid 1px #aaa;
+}
+
+table.diffstat tr:hover {
+        background-color: #eee;
 }
 
 table.diffstat th {
         font-weight: normal;
         text-align: left;
         text-decoration: underline;
         padding: 0.1em 1em 0.1em 0.1em;
         font-size: 100%;
 }
 
 table.diffstat td {
-        padding: 0.1em 1em 0.1em 0.1em;
+        padding: 0.2em 0.2em 0.1em 0.1em;
         font-size: 100%;
+        border: none;
+        border-top: solid 1px #aaa;
+        border-bottom: solid 1px #aaa;
 }
 
 table.diffstat td span.modechange {
         padding-left: 1em;
         color: red;
 }
 
 table.diffstat td.add a {
         color: green;
 }
 
 table.diffstat td.del a {
         color: red;
 }
 
 table.diffstat td.upd a {
         color: blue;
 }
 
-table.diffstat td.summary {
+table.diffstat td.graph {
+        width: 75%;
+        vertical-align: center;
+}
+
+table.diffstat td.graph img {
+        border: none;
+        height: 11pt;
+}
+
+div.diffstat-summary {
         color: #888;
         padding-top: 0.5em;
 }
 
 table.diff td {
         border: solid 1px black;
         font-family: monospace;
         white-space: pre;
 }
 
 table.diff td div.hunk {
         background: #ccc;
 }
 
 table.diff td div.add {
         color: green;
 }
 
 table.diff td div.del {
         color: red;
 }
 
 .sha1 {
         font-family: courier;
         font-size: 90%;
 }
 
 .left {
         text-align: left;
 }
 
 .right {
         text-align: right;
 }
diff --git a/del.png b/del.png
new file mode 100644
index 0000000..5c73e82
--- a/dev/null
+++ b/del.png
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);
 }