Generate random thread IDs instead of using an arbitrary Message-ID.

Previously, we used as the thread-id the message-id of the first
message in the thread that we happened to find. In fact, this is a
totally arbitrary identifier, so it might as well be random. And an
advantage of actually using a random identifier is that we now have
fixed-length thead identifiers, (and the way is open to even allow
abbreviated identifiers like git does---though we're less likely to
show these identifiers to actual users).
This commit is contained in:
Carl Worth 2009-10-16 13:33:39 -07:00
parent 5fbdbeb333
commit 387a28281c

View file

@ -128,7 +128,40 @@ find_prefix (const char *name)
return "";
}
int TERM_COMBINED = 0;
/* "128 bits of thread-id ought to be enough for anybody" */
#define NOTMUCH_THREAD_ID_BITS 128
#define NOTMUCH_THREAD_ID_DIGITS (NOTMUCH_THREAD_ID_BITS / 4)
typedef struct _thread_id {
char str[NOTMUCH_THREAD_ID_DIGITS + 1];
} thread_id_t;
static void
thread_id_generate (thread_id_t *thread_id)
{
FILE *urandom;
uint32_t value;
char *s;
int i;
urandom = fopen ("/dev/urandom", "r");
if (urandom == NULL) {
fprintf (stderr, "Error opening /dev/urandom: %s\n",
strerror (errno));
fprintf (stderr, "Perhaps notmuch needs some portability fixes for your platform?\n");
exit (1);
}
s = thread_id->str;
for (i = 0; i < NOTMUCH_THREAD_ID_DIGITS; i += 8) {
fread ((void *) &value, sizeof (value), 1, urandom);
sprintf (s, "%08x", value);
s += 8;
}
fclose (urandom);
printf ("Generated thread id: %s\n", thread_id->str);
}
static void
add_term (Xapian::Document doc,
@ -690,9 +723,13 @@ index_file (Xapian::WritableDatabase db,
g_string_free (thread_id, TRUE);
} else if (message_id) {
/* If not referenced thread, use the message ID */
add_term (doc, "thread", message_id);
doc.add_value (NOTMUCH_VALUE_THREAD, message_id);
/* If not part of any existing thread, generate a new thread_id. */
thread_id_t thread_id;
thread_id_generate (&thread_id);
add_term (doc, "thread", thread_id.str);
doc.add_value (NOTMUCH_VALUE_THREAD, thread_id.str);
}
doc.add_value (NOTMUCH_VALUE_DATE, Xapian::sortable_serialise (time));