[v5,15/15] bugreport: summarize contents of alternates file

Commit Message

Emily Shaffer Jan. 24, 2020, 3:34 a.m. UTC

From: Emily Shaffer <[e-mail]>

In some cases, it could be that the user is having a problem with an
object which isn't present in their normal object directory. We can get
a hint that that might be the case by examining the list of alternates
where their object may be stored instead. Since paths to alternates may
be sensitive, we'll instead count how many alternates have been
specified and note how many of them exist or are broken.

While object-cache.h describes a function "foreach_alt_odb()", this
function does not provide information on broken alternates, which are
skipped over in "link_alt_odb_entry()". Since the goal is to identify
missing alternates, we can gather the contents of
.git/objects/info/alternates manually.

Signed-off-by: Emily Shaffer <[e-mail]>
---
 bugreport.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

Patch

diff --git a/bugreport.c b/bugreport.c
index 12463ffdc7..2c540182dd 100644
--- a/bugreport.c
+++ b/bugreport.c
@@ -294,6 +294,42 @@  static void get_object_info_summary(struct strbuf *obj_info)
 	strbuf_release(&dirpath);
 }
 
+static void get_alternates_summary(struct strbuf *alternates_info)
+{
+	struct strbuf alternates_path = STRBUF_INIT;
+	struct strbuf alternate = STRBUF_INIT;
+	FILE *file;
+	size_t exists = 0, broken = 0;
+
+	strbuf_addstr(&alternates_path, get_object_directory());
+	strbuf_complete(&alternates_path, '/');
+	strbuf_addstr(&alternates_path, "info/alternates");
+
+	file = fopen(alternates_path.buf, "r");
+	if (!file) {
+		strbuf_addstr(alternates_info, "No alternates file found.\n");
+		strbuf_release(&alternates_path);
+		return;
+	}
+
+	while (strbuf_getline(&alternate, file) != EOF) {
+		if (!access(alternate.buf, F_OK))
+			exists++;
+		else
+			broken++;
+	}
+
+	strbuf_addf(alternates_info,
+		    "%zd alternates found (%zd working, %zd broken)\n",
+		    exists + broken,
+		    exists,
+		    broken);
+
+	fclose(file);
+	strbuf_release(&alternate);
+	strbuf_release(&alternates_path);
+}
+
 static const char * const bugreport_usage[] = {
 	N_("git bugreport [-o|--output <file>]"),
 	NULL
@@ -378,6 +414,9 @@  int cmd_main(int argc, const char **argv)
 	get_header(&buffer, "Object Info Summary");
 	get_object_info_summary(&buffer);
 
+	get_header(&buffer, "Alternates");
+	get_alternates_summary(&buffer);
+
 	report = fopen_for_writing(report_path.buf);
 	strbuf_write(&buffer, report);
 	fclose(report);