/**
* paxos_ack_retrieve - Acknowledge a retrieve.
*
* This basically just unpacks and wraps a resend.
*/
int paxos_ack_retrieve(struct paxos_header *hdr, msgpack_object *o)
{
paxid_t paxid;
msgpack_object *p;
struct paxos_value val;
struct paxos_request *req;
struct paxos_acceptor *acc;
// Make sure the payload is well-formed.
assert(o->type == MSGPACK_OBJECT_ARRAY);
assert(o->via.array.size == 2);
p = o->via.array.ptr;
// Unpack the retriever's ID and the value being retrieved.
paxos_paxid_unpack(&paxid, p++);
paxos_value_unpack(&val, p++);
// Retrieve the request.
assert(request_needs_cached(val.pv_dkind));
req = request_find(&pax->rcache, val.pv_reqid);
if (req != NULL) {
// If we have the request, look up the recipient and resend.
acc = acceptor_find(&pax->alist, paxid);
return paxos_resend(acc, hdr, req);
} else {
// If we don't have the request either, just return.
return 0;
}
}
int
acceptor_ack_truncate(struct paxos_header *hdr, msgpack_object *o)
{
// Unpack the new ibase.
paxos_paxid_unpack(&pax->ibase, o);
// Do the truncate (< pax->ibase).
ilist_truncate_prefix(&pax->ilist, pax->ibase);
return 0;
}
/**
* proposer_ack_last - Update sync state based on acceptor's reply.
*/
int
proposer_ack_last(struct paxos_header *hdr, msgpack_object *o)
{
paxid_t last;
// Ignore replies to older sync commands.
if (hdr->ph_inum != pax->sync_id) {
return 0;
}
// Update our knowledge of the system's last contiguous learn.
paxos_paxid_unpack(&last, o);
if (last < pax->sync->ps_last || pax->sync->ps_last == 0) {
pax->sync->ps_last = last;
}
// Increment acks and command a truncate if the sync is over.
pax->sync->ps_acks++;
if (pax->sync->ps_acks == pax->sync->ps_total) {
return proposer_truncate(hdr);
}
return 0;
}
