ui-blame: add blame UI

Implement a page which provides the blame view of a specified file.

This feature is controlled by a new config variable, "enable-blame",
which is disabled by default.

Signed-off-by: Jeff Smith <whydoubt@gmail.com>
Reviewed-by: John Keeping <john@keeping.me.uk>

1 files changed, 227 insertions, 0 deletions

diff --git a/ui-blame.c b/ui-blame.c
new file mode 100644
index 0000000..62cf431
--- /dev/null
+++ b/ui-blame.c
@@ -0,0 +1,227 @@
+/* ui-blame.c: functions for blame output
+ *
+ * Copyright (C) 2006-2017 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-blame.h"
+#include "html.h"
+#include "ui-shared.h"
+#include "argv-array.h"
+#include "blame.h"
+
+
+static char *emit_suspect_detail(struct blame_origin *suspect)
+{
+	struct commitinfo *info;
+	struct strbuf detail = STRBUF_INIT;
+
+	info = cgit_parse_commit(suspect->commit);
+
+	strbuf_addf(&detail, "author  %s", info->author);
+	if (!ctx.cfg.noplainemail)
+		strbuf_addf(&detail, " %s", info->author_email);
+	strbuf_addf(&detail, "  %s\n",
+		    show_date(info->author_date, info->author_tz,
+				    cgit_date_mode(DATE_ISO8601)));
+
+	strbuf_addf(&detail, "committer  %s", info->committer);
+	if (!ctx.cfg.noplainemail)
+		strbuf_addf(&detail, " %s", info->committer_email);
+	strbuf_addf(&detail, "  %s\n\n",
+		    show_date(info->committer_date, info->committer_tz,
+				    cgit_date_mode(DATE_ISO8601)));
+
+	strbuf_addstr(&detail, info->subject);
+
+	cgit_free_commitinfo(info);
+	return strbuf_detach(&detail, NULL);
+}
+
+static void emit_blame_entry(struct blame_scoreboard *sb,
+			     struct blame_entry *ent)
+{
+	struct blame_origin *suspect = ent->suspect;
+	struct object_id *oid = &suspect->commit->object.oid;
+	const char *numberfmt = "<a id='n%1$d' href='#n%1$d'>%1$d</a>\n";
+	const char *cp, *cpend;
+
+	char *detail = emit_suspect_detail(suspect);
+
+	html("<tr><td class='sha1 lines'>");
+	cgit_commit_link(find_unique_abbrev(oid->hash, DEFAULT_ABBREV), detail,
+			 NULL, ctx.qry.head, oid_to_hex(oid), suspect->path);
+	html("</td>\n");
+
+	free(detail);
+
+	if (ctx.cfg.enable_tree_linenumbers) {
+		unsigned long lineno = ent->lno;
+		html("<td class='linenumbers'><pre>");
+		while (lineno < ent->lno + ent->num_lines)
+			htmlf(numberfmt, ++lineno);
+		html("</pre></td>\n");
+	}
+
+	cp = blame_nth_line(sb, ent->lno);
+	cpend = blame_nth_line(sb, ent->lno + ent->num_lines);
+
+	html("<td class='lines'><pre><code>");
+	html_ntxt(cp, cpend - cp);
+	html("</code></pre></td></tr>\n");
+}
+
+struct walk_tree_context {
+	char *curr_rev;
+	int match_baselen;
+	int state;
+};
+
+static void print_object(const unsigned char *sha1, const char *path,
+			 const char *basename, const char *rev)
+{
+	enum object_type type;
+	unsigned long size;
+	struct argv_array rev_argv = ARGV_ARRAY_INIT;
+	struct rev_info revs;
+	struct blame_scoreboard sb;
+	struct blame_origin *o;
+	struct blame_entry *ent = NULL;
+
+	type = sha1_object_info(sha1, &size);
+	if (type == OBJ_BAD) {
+		cgit_print_error_page(404, "Not found", "Bad object name: %s",
+				      sha1_to_hex(sha1));
+		return;
+	}
+
+	argv_array_push(&rev_argv, "blame");
+	argv_array_push(&rev_argv, rev);
+	init_revisions(&revs, NULL);
+	DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
+	setup_revisions(rev_argv.argc, rev_argv.argv, &revs, NULL);
+	init_scoreboard(&sb);
+	sb.revs = &revs;
+	setup_scoreboard(&sb, path, &o);
+	o->suspects = blame_entry_prepend(NULL, 0, sb.num_lines, o);
+	prio_queue_put(&sb.commits, o->commit);
+	blame_origin_decref(o);
+	sb.ent = NULL;
+	sb.path = path;
+	assign_blame(&sb, 0);
+	blame_sort_final(&sb);
+	blame_coalesce(&sb);
+
+	cgit_set_title_from_path(path);
+
+	cgit_print_layout_start();
+	htmlf("blob: %s (", sha1_to_hex(sha1));
+	cgit_plain_link("plain", NULL, NULL, ctx.qry.head, rev, path);
+	html(") (");
+	cgit_tree_link("tree", NULL, NULL, ctx.qry.head, rev, path);
+	html(")\n");
+
+	if (ctx.cfg.max_blob_size && size / 1024 > ctx.cfg.max_blob_size) {
+		htmlf("<div class='error'>blob size (%ldKB)"
+		      " exceeds display size limit (%dKB).</div>",
+		      size / 1024, ctx.cfg.max_blob_size);
+		return;
+	}
+
+	html("<table class='blame blob'>");
+	for (ent = sb.ent; ent; ) {
+		struct blame_entry *e = ent->next;
+		emit_blame_entry(&sb, ent);
+		free(ent);
+		ent = e;
+	}
+	html("</table>\n");
+	free((void *)sb.final_buf);
+
+	cgit_print_layout_end();
+}
+
+static int walk_tree(const unsigned char *sha1, struct strbuf *base,
+		     const char *pathname, unsigned mode, int stage,
+		     void *cbdata)
+{
+	struct walk_tree_context *walk_tree_ctx = cbdata;
+
+	if (base->len == walk_tree_ctx->match_baselen) {
+		if (S_ISREG(mode)) {
+			struct strbuf buffer = STRBUF_INIT;
+			strbuf_addbuf(&buffer, base);
+			strbuf_addstr(&buffer, pathname);
+			print_object(sha1, buffer.buf, pathname,
+				     walk_tree_ctx->curr_rev);
+			strbuf_release(&buffer);
+			walk_tree_ctx->state = 1;
+		} else if (S_ISDIR(mode)) {
+			walk_tree_ctx->state = 2;
+		}
+	} else if (base->len < INT_MAX
+			&& (int)base->len > walk_tree_ctx->match_baselen) {
+		walk_tree_ctx->state = 2;
+	} else if (S_ISDIR(mode)) {
+		return READ_TREE_RECURSIVE;
+	}
+	return 0;
+}
+
+static int basedir_len(const char *path)
+{
+	char *p = strrchr(path, '/');
+	if (p)
+		return p - path + 1;
+	return 0;
+}
+
+void cgit_print_blame(void)
+{
+	const char *rev = ctx.qry.sha1;
+	struct object_id oid;
+	struct commit *commit;
+	struct pathspec_item path_items = {
+		.match = ctx.qry.path,
+		.len = ctx.qry.path ? strlen(ctx.qry.path) : 0
+	};
+	struct pathspec paths = {
+		.nr = 1,
+		.items = &path_items
+	};
+	struct walk_tree_context walk_tree_ctx = {
+		.state = 0
+	};
+
+	if (!rev)
+		rev = ctx.qry.head;
+
+	if (get_oid(rev, &oid)) {
+		cgit_print_error_page(404, "Not found",
+			"Invalid revision name: %s", rev);
+		return;
+	}
+	commit = lookup_commit_reference(&oid);
+	if (!commit || parse_commit(commit)) {
+		cgit_print_error_page(404, "Not found",
+			"Invalid commit reference: %s", rev);
+		return;
+	}
+
+	walk_tree_ctx.curr_rev = xstrdup(rev);
+	walk_tree_ctx.match_baselen = (path_items.match) ?
+				       basedir_len(path_items.match) : -1;
+
+	read_tree_recursive(commit->tree, "", 0, 0, &paths, walk_tree,
+		&walk_tree_ctx);
+	if (!walk_tree_ctx.state)
+		cgit_print_error_page(404, "Not found", "Not found");
+	else if (walk_tree_ctx.state == 2)
+		cgit_print_error_page(404, "No blame for folders",
+			"Blame is not available for folders.");
+
+	free(walk_tree_ctx.curr_rev);
+}