transactions -> objects

+ corresponding changes in comments
This commit is contained in:
UdjinM6 2020-04-08 00:59:19 +03:00 committed by Alexander Block
parent a7b38efb98
commit 775e4ba823

View File

@ -57,10 +57,10 @@
# error "Dash Core cannot be compiled without assertions."
#endif
/** Maximum number of in-flight transactions from a peer */
static constexpr int32_t MAX_PEER_TX_IN_FLIGHT = 100;
/** Maximum number of announced transactions from a peer */
static constexpr int32_t MAX_PEER_TX_ANNOUNCEMENTS = 2 * MAX_INV_SZ;
/** Maximum number of in-flight objects from a peer */
static constexpr int32_t MAX_PEER_OBJECT_IN_FLIGHT = 100;
/** Maximum number of announced objects from a peer */
static constexpr int32_t MAX_PEER_OBJECT_ANNOUNCEMENTS = 2 * MAX_INV_SZ;
/** How many microseconds to delay requesting transactions from inbound peers */
static constexpr std::chrono::microseconds INBOUND_PEER_TX_DELAY{std::chrono::seconds{2}};
/** How long to wait (in microseconds) before downloading a transaction from an additional peer */
@ -272,69 +272,67 @@ struct CNodeState {
int64_t m_last_block_announcement;
/*
* State associated with transaction download.
* State associated with objects download.
*
* Tx download algorithm:
*
* When inv comes in, queue up (process_time, txid) inside the peer's
* CNodeState (m_tx_process_time) as long as m_tx_announced for the peer
* isn't too big (MAX_PEER_TX_ANNOUNCEMENTS).
* When inv comes in, queue up (process_time, inv) inside the peer's
* CNodeState (m_object_process_time) as long as m_object_announced for the peer
* isn't too big (MAX_PEER_OBJECT_ANNOUNCEMENTS).
*
* The process_time for a transaction is set to nNow for outbound peers,
* The process_time for a objects is set to nNow for outbound peers,
* nNow + 2 seconds for inbound peers. This is the time at which we'll
* consider trying to request the transaction from the peer in
* consider trying to request the objects from the peer in
* SendMessages(). The delay for inbound peers is to allow outbound peers
* a chance to announce before we request from inbound peers, to prevent
* an adversary from using inbound connections to blind us to a
* transaction (InvBlock).
* objects (InvBlock).
*
* When we call SendMessages() for a given peer,
* we will loop over the transactions in m_tx_process_time, looking
* at the transactions whose process_time <= nNow. We'll request each
* such transaction that we don't have already and that hasn't been
* we will loop over the objects in m_object_process_time, looking
* at the objects whose process_time <= nNow. We'll request each
* such objects that we don't have already and that hasn't been
* requested from another peer recently, up until we hit the
* MAX_PEER_TX_IN_FLIGHT limit for the peer. Then we'll update
* g_already_asked_for for each requested txid, storing the time of the
* GETDATA request. We use g_already_asked_for to coordinate transaction
* MAX_PEER_OBJECT_IN_FLIGHT limit for the peer. Then we'll update
* g_already_asked_for for each requested inv, storing the time of the
* GETDATA request. We use g_already_asked_for to coordinate objects
* requests amongst our peers.
*
* For transactions that we still need but we have already recently
* requested from some other peer, we'll reinsert (process_time, txid)
* back into the peer's m_tx_process_time at the point in the future at
* For objects that we still need but we have already recently
* requested from some other peer, we'll reinsert (process_time, inv)
* back into the peer's m_object_process_time at the point in the future at
* which the most recent GETDATA request would time out (ie
* GETDATA_TX_INTERVAL + the request time stored in g_already_asked_for).
* GetObjectInterval + the request time stored in g_already_asked_for).
* We add an additional delay for inbound peers, again to prefer
* attempting download from outbound peers first.
* We also add an extra small random delay up to 2 seconds
* to avoid biasing some peers over others. (e.g., due to fixed ordering
* of peer processing in ThreadMessageHandler).
*
* When we receive a transaction from a peer, we remove the txid from the
* peer's m_tx_in_flight set and from their recently announced set
* (m_tx_announced). We also clear g_already_asked_for for that entry, so
* that if somehow the transaction is not accepted but also not added to
* When we receive a objects from a peer, we remove the inv from the
* peer's m_object_in_flight set and from their recently announced set
* (m_object_announced). We also clear g_already_asked_for for that entry, so
* that if somehow the objects is not accepted but also not added to
* the reject filter, then we will eventually redownload from other
* peers.
*
* DASH: For Dash, this does not only handles TXs but also all Dash specific objects
*/
struct TxDownloadState {
/* Track when to attempt download of announced transactions (process
* time in micros -> txid)
struct ObjectDownloadState {
/* Track when to attempt download of announced objects (process
* time in micros -> inv)
*/
std::multimap<std::chrono::microseconds, CInv> m_tx_process_time;
std::multimap<std::chrono::microseconds, CInv> m_object_process_time;
//! Store all the transactions a peer has recently announced
std::set<CInv> m_tx_announced;
//! Store all the objects a peer has recently announced
std::set<CInv> m_object_announced;
//! Store transactions which were requested by us, with timestamp
std::map<CInv, std::chrono::microseconds> m_tx_in_flight;
//! Store objects which were requested by us, with timestamp
std::map<CInv, std::chrono::microseconds> m_object_in_flight;
//! Periodically check for stuck getdata requests
std::chrono::microseconds m_check_expiry_timer{0};
};
TxDownloadState m_tx_download;
ObjectDownloadState m_object_download;
CNodeState(CAddress addrIn, std::string addrNameIn) : address(addrIn), name(addrNameIn) {
fCurrentlyConnected = false;
@ -667,8 +665,8 @@ void EraseObjectRequest(CNodeState* nodestate, const CInv& inv) EXCLUSIVE_LOCKS_
g_erased_object_requests.insert(std::make_pair(inv.hash, GetTime<std::chrono::microseconds>()));
if (nodestate) {
nodestate->m_tx_download.m_tx_announced.erase(inv);
nodestate->m_tx_download.m_tx_in_flight.erase(inv);
nodestate->m_object_download.m_object_announced.erase(inv);
nodestate->m_object_download.m_object_in_flight.erase(inv);
}
}
@ -755,21 +753,21 @@ std::chrono::microseconds CalculateObjectGetDataTime(const CInv& inv, std::chron
void RequestObject(CNodeState* state, const CInv& inv, std::chrono::microseconds current_time, bool fForce = false) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
{
AssertLockHeld(cs_main);
CNodeState::TxDownloadState& peer_download_state = state->m_tx_download;
if (peer_download_state.m_tx_announced.size() >= MAX_PEER_TX_ANNOUNCEMENTS ||
peer_download_state.m_tx_process_time.size() >= MAX_PEER_TX_ANNOUNCEMENTS ||
peer_download_state.m_tx_announced.count(inv)) {
CNodeState::ObjectDownloadState& peer_download_state = state->m_object_download;
if (peer_download_state.m_object_announced.size() >= MAX_PEER_OBJECT_ANNOUNCEMENTS ||
peer_download_state.m_object_process_time.size() >= MAX_PEER_OBJECT_ANNOUNCEMENTS ||
peer_download_state.m_object_announced.count(inv)) {
// Too many queued announcements from this peer, or we already have
// this announcement
return;
}
peer_download_state.m_tx_announced.insert(inv);
peer_download_state.m_object_announced.insert(inv);
// Calculate the time to try requesting this transaction. Use
// fPreferredDownload as a proxy for outbound peers.
std::chrono::microseconds process_time = CalculateObjectGetDataTime(inv, current_time, !state->fPreferredDownload);
peer_download_state.m_tx_process_time.emplace(process_time, inv);
peer_download_state.m_object_process_time.emplace(process_time, inv);
if (fForce) {
// make sure this object is actually requested ASAP
@ -797,7 +795,7 @@ size_t GetRequestedObjectCount(NodeId nodeId)
if (!state) {
return 0;
}
return state->m_tx_download.m_tx_process_time.size();
return state->m_object_download.m_object_process_time.size();
}
// This function is used for testing the stale tip eviction logic, see
@ -3430,19 +3428,19 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
CNodeState *state = State(pfrom->GetId());
std::vector<CInv> vInv;
vRecv >> vInv;
if (vInv.size() <= MAX_PEER_TX_IN_FLIGHT + MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
if (vInv.size() <= MAX_PEER_OBJECT_IN_FLIGHT + MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
for (CInv &inv : vInv) {
if (inv.IsKnownType()) {
// If we receive a NOTFOUND message for a txid we requested, erase
// it from our data structures for this peer.
auto in_flight_it = state->m_tx_download.m_tx_in_flight.find(inv);
if (in_flight_it == state->m_tx_download.m_tx_in_flight.end()) {
auto in_flight_it = state->m_object_download.m_object_in_flight.find(inv);
if (in_flight_it == state->m_object_download.m_object_in_flight.end()) {
// Skip any further work if this is a spurious NOTFOUND
// message.
continue;
}
state->m_tx_download.m_tx_in_flight.erase(in_flight_it);
state->m_tx_download.m_tx_announced.erase(inv);
state->m_object_download.m_object_in_flight.erase(in_flight_it);
state->m_object_download.m_object_announced.erase(inv);
}
}
}
@ -4297,40 +4295,40 @@ bool PeerLogicValidation::SendMessages(CNode* pto, std::atomic<bool>& interruptM
//
// For robustness, expire old requests after a long timeout, so that
// we can resume downloading transactions from a peer even if they
// we can resume downloading objects from a peer even if they
// were unresponsive in the past.
// Eventually we should consider disconnecting peers, but this is
// conservative.
if (state.m_tx_download.m_check_expiry_timer <= current_time) {
for (auto it=state.m_tx_download.m_tx_in_flight.begin(); it != state.m_tx_download.m_tx_in_flight.end();) {
if (state.m_object_download.m_check_expiry_timer <= current_time) {
for (auto it=state.m_object_download.m_object_in_flight.begin(); it != state.m_object_download.m_object_in_flight.end();) {
if (it->second <= current_time - GetObjectExpiryInterval(it->first.type)) {
LogPrint(BCLog::NET, "timeout of inflight tx %s from peer=%d\n", it->first.ToString(), pto->GetId());
state.m_tx_download.m_tx_announced.erase(it->first);
state.m_tx_download.m_tx_in_flight.erase(it++);
LogPrint(BCLog::NET, "timeout of inflight object %s from peer=%d\n", it->first.ToString(), pto->GetId());
state.m_object_download.m_object_announced.erase(it->first);
state.m_object_download.m_object_in_flight.erase(it++);
} else {
++it;
}
}
// On average, we do this check every TX_EXPIRY_INTERVAL. Randomize
// On average, we do this check every GetObjectExpiryInterval. Randomize
// so that we're not doing this for all peers at the same time.
state.m_tx_download.m_check_expiry_timer = current_time + GetObjectExpiryInterval(MSG_TX)/2 + GetRandMicros(GetObjectExpiryInterval(MSG_TX));
state.m_object_download.m_check_expiry_timer = current_time + GetObjectExpiryInterval(MSG_TX)/2 + GetRandMicros(GetObjectExpiryInterval(MSG_TX));
}
// DASH this code also handles non-TXs (Dash specific messages)
auto& tx_process_time = state.m_tx_download.m_tx_process_time;
while (!tx_process_time.empty() && tx_process_time.begin()->first <= current_time && state.m_tx_download.m_tx_in_flight.size() < MAX_PEER_TX_IN_FLIGHT) {
const CInv inv = tx_process_time.begin()->second;
// Erase this entry from tx_process_time (it may be added back for
auto& object_process_time = state.m_object_download.m_object_process_time;
while (!object_process_time.empty() && object_process_time.begin()->first <= current_time && state.m_object_download.m_object_in_flight.size() < MAX_PEER_OBJECT_IN_FLIGHT) {
const CInv inv = object_process_time.begin()->second;
// Erase this entry from object_process_time (it may be added back for
// processing at a later time, see below)
tx_process_time.erase(tx_process_time.begin());
object_process_time.erase(object_process_time.begin());
if (g_erased_object_requests.count(inv.hash)) {
LogPrint(BCLog::NET, "%s -- GETDATA skipping inv=(%s), peer=%d\n", __func__, inv.ToString(), pto->GetId());
state.m_tx_download.m_tx_announced.erase(inv);
state.m_tx_download.m_tx_in_flight.erase(inv);
state.m_object_download.m_object_announced.erase(inv);
state.m_object_download.m_object_in_flight.erase(inv);
continue;
}
if (!AlreadyHave(inv)) {
// If this transaction was last requested more than 1 minute ago,
// If this object was last requested more than GetObjectInterval ago,
// then request.
const auto last_request_time = GetObjectRequestTime(inv.hash);
if (last_request_time <= current_time - GetObjectInterval(inv.type)) {
@ -4341,20 +4339,20 @@ bool PeerLogicValidation::SendMessages(CNode* pto, std::atomic<bool>& interruptM
vGetData.clear();
}
UpdateObjectRequestTime(inv.hash, current_time);
state.m_tx_download.m_tx_in_flight.emplace(inv, current_time);
state.m_object_download.m_object_in_flight.emplace(inv, current_time);
} else {
// This transaction is in flight from someone else; queue
// This object is in flight from someone else; queue
// up processing to happen after the download times out
// (with a slight delay for inbound peers, to prefer
// requests to outbound peers).
const auto next_process_time = CalculateObjectGetDataTime(inv, current_time, !state.fPreferredDownload);
tx_process_time.emplace(next_process_time, inv);
object_process_time.emplace(next_process_time, inv);
LogPrint(BCLog::NET, "%s -- GETDATA re-queue inv=(%s), next_process_time=%d, delta=%d, peer=%d\n", __func__, inv.ToString(), next_process_time.count(), (next_process_time - current_time).count(), pto->GetId());
}
} else {
// We have already seen this transaction, no need to download.
state.m_tx_download.m_tx_announced.erase(inv);
state.m_tx_download.m_tx_in_flight.erase(inv);
// We have already seen this object, no need to download.
state.m_object_download.m_object_announced.erase(inv);
state.m_object_download.m_object_in_flight.erase(inv);
LogPrint(BCLog::NET, "%s -- GETDATA already seen inv=(%s), peer=%d\n", __func__, inv.ToString(), pto->GetId());
}
}