cgit/ui-diff.c
John Keeping 30304d8156 log: allow users to follow a file
Teach the "log" UI to behave in the same way as "git log --follow", when
given a suitable instruction by the user.  The default behaviour remains
to show the log without following renames, but the follow behaviour can
be activated by following a link in the page header.

Follow is not the default because outputting merges in follow mode is
tricky ("git log --follow" will not show merges).  We also disable the
graph in follow mode because the commit graph is not simplified so we
end up with frequent gaps in the graph and many lines that do not
connect with any commits we're actually showing.

We also teach the "diff" and "commit" UIs to respect the follow flag on
URLs, causing the single-file version of these UIs to detect renames.
This feature is needed only for commits that rename the path we're
interested in.

For commits before the file has been renamed (i.e. that appear later in
the log list) we change the file path in the links from the log to point
to the old name; this means that links to commits always limit by the
path known to that commit.  If we didn't do this we would need to walk
down the log diff'ing every commit whenever we want to show a commit.
The drawback is that the "Log" link in the top bar of such a page links
to the log limited by the old name, so it will only show pre-rename
commits.  I consider this a reasonable trade-off since the "Back" button
still works and the log matches the path displayed in the top bar.

Since following renames requires running diff on every commit we
consider, I've added a knob to the configuration file to globally
enable/disable this feature.  Note that we may consider a large number
of commits the revision walking machinery no longer performs any path
limitation so we have to examine every commit until we find a page full
of commits that affect the target path or something related to it.

Suggested-by: René Neumann <necoro@necoro.eu>
Signed-off-by: John Keeping <john@keeping.me.uk>
2015-08-12 16:57:46 +02:00

493 lines
13 KiB
C

/* ui-diff.c: show diff between two blobs
*
* Copyright (C) 2006-2014 cgit Development Team <cgit@lists.zx2c4.com>
*
* Licensed under GNU General Public License v2
* (see COPYING for full license text)
*/
#include "cgit.h"
#include "ui-diff.h"
#include "html.h"
#include "ui-shared.h"
#include "ui-ssdiff.h"
unsigned char old_rev_sha1[20];
unsigned char new_rev_sha1[20];
static int files, slots;
static int total_adds, total_rems, max_changes;
static int lines_added, lines_removed;
static 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;
unsigned long old_size;
unsigned long new_size;
unsigned int binary:1;
} *items;
static int use_ssdiff = 0;
static struct diff_filepair *current_filepair;
static const char *current_prefix;
struct diff_filespec *cgit_get_current_old_file(void)
{
return current_filepair->one;
}
struct diff_filespec *cgit_get_current_new_file(void)
{
return current_filepair->two;
}
static void print_fileinfo(struct fileinfo *info)
{
char *class;
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", info->status);
}
html("<tr>");
htmlf("<td class='mode'>");
if (is_null_sha1(info->new_sha1)) {
cgit_print_filemode(info->old_mode);
} else {
cgit_print_filemode(info->new_mode);
}
if (info->old_mode != info->new_mode &&
!is_null_sha1(info->old_sha1) &&
!is_null_sha1(info->new_sha1)) {
html("<span class='modechange'>[");
cgit_print_filemode(info->old_mode);
html("]</span>");
}
htmlf("</td><td class='%s'>", class);
cgit_diff_link(info->new_path, NULL, NULL, ctx.qry.head, ctx.qry.sha1,
ctx.qry.sha2, info->new_path);
if (info->status == DIFF_STATUS_COPIED || info->status == DIFF_STATUS_RENAMED) {
htmlf(" (%s from ",
info->status == DIFF_STATUS_COPIED ? "copied" : "renamed");
html_txt(info->old_path);
html(")");
}
html("</td><td class='right'>");
if (info->binary) {
htmlf("bin</td><td class='graph'>%ld -> %ld bytes",
info->old_size, info->new_size);
return;
}
htmlf("%d", info->added + info->removed);
html("</td><td class='graph'>");
htmlf("<table summary='file diffstat' width='%d%%'><tr>", (max_changes > 100 ? 100 : max_changes));
htmlf("<td class='add' style='width: %.1f%%;'/>",
info->added * 100.0 / max_changes);
htmlf("<td class='rem' style='width: %.1f%%;'/>",
info->removed * 100.0 / max_changes);
htmlf("<td class='none' style='width: %.1f%%;'/>",
(max_changes - info->removed - info->added) * 100.0 / max_changes);
html("</tr></table></td></tr>\n");
}
static void count_diff_lines(char *line, int len)
{
if (line && (len > 0)) {
if (line[0] == '+')
lines_added++;
else if (line[0] == '-')
lines_removed++;
}
}
static int show_filepair(struct diff_filepair *pair)
{
/* Always show if we have no limiting prefix. */
if (!current_prefix)
return 1;
/* Show if either path in the pair begins with the prefix. */
if (starts_with(pair->one->path, current_prefix) ||
starts_with(pair->two->path, current_prefix))
return 1;
/* Otherwise we don't want to show this filepair. */
return 0;
}
static void inspect_filepair(struct diff_filepair *pair)
{
int binary = 0;
unsigned long old_size = 0;
unsigned long new_size = 0;
if (!show_filepair(pair))
return;
files++;
lines_added = 0;
lines_removed = 0;
cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size, &new_size,
&binary, 0, ctx.qry.ignorews, 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;
items[files-1].old_size = old_size;
items[files-1].new_size = new_size;
items[files-1].binary = binary;
if (lines_added + lines_removed > max_changes)
max_changes = lines_added + lines_removed;
total_adds += lines_added;
total_rems += lines_removed;
}
static void cgit_print_diffstat(const unsigned char *old_sha1,
const unsigned char *new_sha1,
const char *prefix)
{
int i;
html("<div class='diffstat-header'>");
cgit_diff_link("Diffstat", NULL, NULL, ctx.qry.head, ctx.qry.sha1,
ctx.qry.sha2, NULL);
if (prefix) {
html(" (limited to '");
html_txt(prefix);
html("')");
}
html("</div>");
html("<table summary='diffstat' class='diffstat'>");
max_changes = 0;
cgit_diff_tree(old_sha1, new_sha1, inspect_filepair, prefix,
ctx.qry.ignorews);
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",
files, total_adds, total_rems);
html("</div>");
}
/*
* print a single line returned from xdiff
*/
static void print_line(char *line, int len)
{
char *class = "ctx";
char c = line[len-1];
if (line[0] == '+')
class = "add";
else if (line[0] == '-')
class = "del";
else if (line[0] == '@')
class = "hunk";
htmlf("<div class='%s'>", class);
line[len-1] = '\0';
html_txt(line);
html("</div>");
line[len-1] = c;
}
static void header(unsigned char *sha1, char *path1, int mode1,
unsigned char *sha2, char *path2, int mode2)
{
char *abbrev1, *abbrev2;
int subproject;
subproject = (S_ISGITLINK(mode1) || S_ISGITLINK(mode2));
html("<div class='head'>");
html("diff --git a/");
html_txt(path1);
html(" b/");
html_txt(path2);
if (mode1 == 0)
htmlf("<br/>new file mode %.6o", mode2);
if (mode2 == 0)
htmlf("<br/>deleted file mode %.6o", mode1);
if (!subproject) {
abbrev1 = xstrdup(find_unique_abbrev(sha1, DEFAULT_ABBREV));
abbrev2 = xstrdup(find_unique_abbrev(sha2, DEFAULT_ABBREV));
htmlf("<br/>index %s..%s", abbrev1, abbrev2);
free(abbrev1);
free(abbrev2);
if (mode1 != 0 && mode2 != 0) {
htmlf(" %.6o", mode1);
if (mode2 != mode1)
htmlf("..%.6o", mode2);
}
if (is_null_sha1(sha1)) {
path1 = "dev/null";
html("<br/>--- /");
} else
html("<br/>--- a/");
if (mode1 != 0)
cgit_tree_link(path1, NULL, NULL, ctx.qry.head,
sha1_to_hex(old_rev_sha1), path1);
else
html_txt(path1);
if (is_null_sha1(sha2)) {
path2 = "dev/null";
html("<br/>+++ /");
} else
html("<br/>+++ b/");
if (mode2 != 0)
cgit_tree_link(path2, NULL, NULL, ctx.qry.head,
sha1_to_hex(new_rev_sha1), path2);
else
html_txt(path2);
}
html("</div>");
}
static void filepair_cb(struct diff_filepair *pair)
{
unsigned long old_size = 0;
unsigned long new_size = 0;
int binary = 0;
linediff_fn print_line_fn = print_line;
if (!show_filepair(pair))
return;
current_filepair = pair;
if (use_ssdiff) {
cgit_ssdiff_header_begin();
print_line_fn = cgit_ssdiff_line_cb;
}
header(pair->one->sha1, pair->one->path, pair->one->mode,
pair->two->sha1, pair->two->path, pair->two->mode);
if (use_ssdiff)
cgit_ssdiff_header_end();
if (S_ISGITLINK(pair->one->mode) || S_ISGITLINK(pair->two->mode)) {
if (S_ISGITLINK(pair->one->mode))
print_line_fn(fmt("-Subproject %s", sha1_to_hex(pair->one->sha1)), 52);
if (S_ISGITLINK(pair->two->mode))
print_line_fn(fmt("+Subproject %s", sha1_to_hex(pair->two->sha1)), 52);
if (use_ssdiff)
cgit_ssdiff_footer();
return;
}
if (cgit_diff_files(pair->one->sha1, pair->two->sha1, &old_size,
&new_size, &binary, ctx.qry.context,
ctx.qry.ignorews, print_line_fn))
cgit_print_error("Error running diff");
if (binary) {
if (use_ssdiff)
html("<tr><td colspan='4'>Binary files differ</td></tr>");
else
html("Binary files differ");
}
if (use_ssdiff)
cgit_ssdiff_footer();
}
void cgit_print_diff_ctrls(void)
{
int i, curr;
html("<div class='cgit-panel'>");
html("<b>diff options</b>");
html("<form method='get' action='.'>");
cgit_add_hidden_formfields(1, 0, ctx.qry.page);
html("<table>");
html("<tr><td colspan='2'/></tr>");
html("<tr>");
html("<td class='label'>context:</td>");
html("<td class='ctrl'>");
html("<select name='context' onchange='this.form.submit();'>");
curr = ctx.qry.context;
if (!curr)
curr = 3;
for (i = 1; i <= 10; i++)
html_intoption(i, fmt("%d", i), curr);
for (i = 15; i <= 40; i += 5)
html_intoption(i, fmt("%d", i), curr);
html("</select>");
html("</td>");
html("</tr><tr>");
html("<td class='label'>space:</td>");
html("<td class='ctrl'>");
html("<select name='ignorews' onchange='this.form.submit();'>");
html_intoption(0, "include", ctx.qry.ignorews);
html_intoption(1, "ignore", ctx.qry.ignorews);
html("</select>");
html("</td>");
html("</tr><tr>");
html("<td class='label'>mode:</td>");
html("<td class='ctrl'>");
html("<select name='dt' onchange='this.form.submit();'>");
curr = ctx.qry.has_difftype ? ctx.qry.difftype : ctx.cfg.difftype;
html_intoption(0, "unified", curr);
html_intoption(1, "ssdiff", curr);
html_intoption(2, "stat only", curr);
html("</select></td></tr>");
html("<tr><td/><td class='ctrl'>");
html("<noscript><input type='submit' value='reload'/></noscript>");
html("</td></tr></table>");
html("</form>");
html("</div>");
}
void cgit_print_diff(const char *new_rev, const char *old_rev,
const char *prefix, int show_ctrls, int raw)
{
struct commit *commit, *commit2;
const unsigned char *old_tree_sha1, *new_tree_sha1;
diff_type difftype;
/*
* If "follow" is set then the diff machinery needs to examine the
* entire commit to detect renames so we must limit the paths in our
* own callbacks and not pass the prefix to the diff machinery.
*/
if (ctx.qry.follow && ctx.cfg.enable_follow_links) {
current_prefix = prefix;
prefix = "";
} else {
current_prefix = NULL;
}
if (!new_rev)
new_rev = ctx.qry.head;
if (get_sha1(new_rev, new_rev_sha1)) {
cgit_print_error("Bad object name: %s", new_rev);
return;
}
commit = lookup_commit_reference(new_rev_sha1);
if (!commit || parse_commit(commit)) {
cgit_print_error("Bad commit: %s", sha1_to_hex(new_rev_sha1));
return;
}
new_tree_sha1 = commit->tree->object.sha1;
if (old_rev) {
if (get_sha1(old_rev, old_rev_sha1)) {
cgit_print_error("Bad object name: %s", old_rev);
return;
}
} else if (commit->parents && commit->parents->item) {
hashcpy(old_rev_sha1, commit->parents->item->object.sha1);
} else {
hashclr(old_rev_sha1);
}
if (!is_null_sha1(old_rev_sha1)) {
commit2 = lookup_commit_reference(old_rev_sha1);
if (!commit2 || parse_commit(commit2)) {
cgit_print_error("Bad commit: %s", sha1_to_hex(old_rev_sha1));
return;
}
old_tree_sha1 = commit2->tree->object.sha1;
} else {
old_tree_sha1 = NULL;
}
if (raw) {
struct diff_options diffopt;
diff_setup(&diffopt);
diffopt.output_format = DIFF_FORMAT_PATCH;
DIFF_OPT_SET(&diffopt, RECURSIVE);
diff_setup_done(&diffopt);
ctx.page.mimetype = "text/plain";
cgit_print_http_headers();
if (old_tree_sha1) {
diff_tree_sha1(old_tree_sha1, new_tree_sha1, "",
&diffopt);
} else {
diff_root_tree_sha1(new_tree_sha1, "", &diffopt);
}
diffcore_std(&diffopt);
diff_flush(&diffopt);
return;
}
difftype = ctx.qry.has_difftype ? ctx.qry.difftype : ctx.cfg.difftype;
use_ssdiff = difftype == DIFF_SSDIFF;
if (show_ctrls)
cgit_print_diff_ctrls();
/*
* Clicking on a link to a file in the diff stat should show a diff
* of the file, showing the diff stat limited to a single file is
* pretty useless. All links from this point on will be to
* individual files, so we simply reset the difftype in the query
* here to avoid propagating DIFF_STATONLY to the individual files.
*/
if (difftype == DIFF_STATONLY)
ctx.qry.difftype = ctx.cfg.difftype;
cgit_print_diffstat(old_rev_sha1, new_rev_sha1, prefix);
if (difftype == DIFF_STATONLY)
return;
if (use_ssdiff) {
html("<table summary='ssdiff' class='ssdiff'>");
} else {
html("<table summary='diff' class='diff'>");
html("<tr><td>");
}
cgit_diff_tree(old_rev_sha1, new_rev_sha1, filepair_cb, prefix,
ctx.qry.ignorews);
if (!use_ssdiff)
html("</td></tr>");
html("</table>");
}