DEV: haring: add a new option "-r" to automatically repair broken files
In case a file-backed ring was not properly synced before being dumped,
the output can look bogus due to the head pointer not being perfectly
up to date. In this case, passing "-r" will make haring automatically
skip entries not starting with a zero, and resynchronize with the rest
of the messages.
This should be backported to 2.6.
diff --git a/dev/haring/haring.c b/dev/haring/haring.c
index 27e03ee..53352cb 100644
--- a/dev/haring/haring.c
+++ b/dev/haring/haring.c
@@ -37,6 +37,7 @@
int force = 0; // force access to a different layout
int lfremap = 0; // remap LF in traces
+int repair = 0; // repair file
/* display the message and exit with the code */
@@ -61,6 +62,7 @@
"options :\n"
" -f : force accessing a non-matching layout for 'ring struct'\n"
" -l : replace LF in contents with CR VT\n"
+ " -r : \"repair\" corrupted file (actively search for message boundaries)\n"
"\n"
"", arg0);
}
@@ -146,6 +148,14 @@
* stop before the end.
*/
while (ofs + 1 < b_data(&buf)) {
+ if (unlikely(repair && *b_peek(&buf, ofs))) {
+ /* in repair mode we consider that we could have landed
+ * in the middle of a message so we skip all bytes till
+ * the next zero.
+ */
+ ofs++;
+ continue;
+ }
cnt = 1;
len = b_peek_varint(&buf, ofs + cnt, &msg_len);
if (!len)
@@ -219,6 +229,8 @@
force = 1;
else if (strcmp(argv[0], "-l") == 0)
lfremap = 1;
+ else if (strcmp(argv[0], "-r") == 0)
+ repair = 1;
else if (strcmp(argv[0], "--") == 0)
break;
else