Post a Comment On: xdelta

Thanks for your continuing reports. Release 3.0f fixes a bug in xd3_iopt_flush_instructions:

/* If forcing, pick instructions until the list is empty, otherwise this empties 50% of
* the queue. */
for (flushed = 0; ! xd3_rlist_empty (& stream->iopt.used); )
{
- if ((ret = xd3_iopt_add_encoding (stream,
- xd3_rlist_pop_front (& stream->iopt.used)))) { return ret; }
- // TODO: what about this fraction??
- if (! force && ++flushed > stream->iopt_size / 2) { break; }
+ xd3_rinst *renc = xd3_rlist_pop_front (& stream->iopt.used);
+ if ((ret = xd3_iopt_add_encoding (stream, renc)))
+ {
+ return ret;
+ }
+
+ if (! force)
+ {
+ if (++flushed > stream->iopt_size / 2)
+ {
+ break;
+ }
+
+ /* If there are only two instructions remaining, break, because they were
+ * not optimized. This means there were more than 50% eliminated by the
+ * loop above. */
+ r1 = xd3_rlist_front (& stream->iopt.used);
+ if (xd3_rlist_end(& stream->iopt.used, r1) ||
+ xd3_rlist_end(& stream->iopt.used, r2 = xd3_rlist_next (r1)) ||
+ xd3_rlist_end(& stream->iopt.used, r3 = xd3_rlist_next (r2)))
+ {
+ break;
+ }
+ }
}