/**
* Helper function for rerouting
*
* @param link
*/
void reroute_bundles(final Link link) {
assert !link.isdeleted() : "TableBasedRouter : reroute_bundles, link is deleted";
// "if the reroute timer fires, the link should be down and there
// should be at least one bundle queued on it." [DTN2]
if (link.state() != Link.state_t.UNAVAILABLE) {
Log.w(
TAG,
String.format(
"reroute timer fired but link %s state is %s, not UNAVAILABLE",
link, link.state().toString()));
return;
}
Log.d(
TAG,
String.format(
"reroute timer fired -- cancelling %s bundles on link %s",
link.queue().size(), link.toString()));
link.queue().get_lock().lock();
try {
while (!link.queue().empty()) {
Bundle bundle = link.queue().front();
actions_.cancel_bundle(bundle, link);
assert !bundle.is_queued_on(link.queue())
: "TableBasedRouter : reroute_bundles, bundle is not queued on link";
}
// "there should never have been any in flight since the link is
// unavailable" [DTN2]
assert link.inflight().empty()
: "TableBasedRouter : reroute_bundles, link on flight list is not empty";
} finally {
link.queue().get_lock().unlock();
}
}
/** "Try to forward a bundle to a next hop route." [DTN2] */
protected boolean fwd_to_nexthop(Bundle bundle, RouteEntry route) {
Link link = route.link();
// "if the link is available and not open, open it" [DTN2]
if (link.isNotUnavailable() && (!link.isopen()) && (!link.isopening())) {
Log.d(TAG, String.format("opening %s because a message is intended for it", link.name()));
actions_.open_link(link);
}
// "if the link is open and has space in the queue, then queue the
// bundle for transmission there" [DTN2]
if (link.isopen() && !link.queue_is_full()) {
Log.d(TAG, String.format("queuing %d on %s", bundle.bundleid(), link.name()));
actions_.queue_bundle(bundle, link, route.action(), route.custody_spec());
return true;
}
// "otherwise we can't send the bundle now, so put it on the link's
// deferred list and log reason why we can't forward it" [DTN2]
DeferredList deferred = deferred_list(link);
if (!bundle.is_queued_on(deferred.list())) {
ForwardingInfo info =
new ForwardingInfo(
ForwardingInfo.state_t.NONE,
route.action(),
link.name_str(),
0xffffffff,
link.remote_eid(),
route.custody_spec());
deferred.add(bundle, info);
} else {
Log.w(
TAG,
String.format(
"bundle %d already exists on deferred list of link %s",
bundle.bundleid(), link.name()));
}
if (!link.isNotUnavailable()) {
Log.d(
TAG,
String.format(
"can't forward bundle %d to %s because link not available",
bundle.bundleid(), link.name()));
} else if (!link.isopen()) {
Log.d(
TAG,
String.format(
TAG,
"can't forward bundle %d to %s because link not open",
bundle.bundleid(),
link.name()));
} else if (link.queue_is_full()) {
Log.d(
TAG,
String.format(
TAG,
"can't forward bundle %d to %s because link queue is full",
bundle.bundleid(),
link.name()));
} else {
Log.d(TAG, String.format(TAG, "can't forward %d to %s", bundle.bundleid(), link.name()));
}
return false;
}