kaspad/server/p2p/on_block_locator.go
Ori Newman 29bcc271b5 [NOD-652] Add selected tip and get selected tip messages (#595)
* [NOD-652] Add selectedTip and getSelectedTip messages

* [NOD-652] Remove peerSyncState.isSelectedTipKnown

* [NOD-652] Do nothing on OnSelectedTip if the peer selected tip hasn't changed

* [NOD-652] Handle selected tip message with block handler

* [NOD-652] Add comments

* [NOD-652] go mod tidy

* [NOD-652] Fix TestVersion

* [NOD-652] Use dag.AdjustedTime instead of dag.timeSource.AdjustedTime

* [NOD-652] Create shouldQueryPeerSelectedTips and queueMsgGetSelectedTip functions

* [NOD-652] Change selectedTip to selectedTipHash where needed

* [NOD-652] add minDAGTimeDelay constant

* [NOD-652] add comments

* [NOD-652] Fix names and comments

* [NOD-652] Put msg.reply push in the right place

* [NOD-652] Fix comments and names
2020-01-22 16:34:21 +02:00

50 lines
1.7 KiB
Go

package p2p
import (
"github.com/kaspanet/kaspad/peer"
"github.com/kaspanet/kaspad/wire"
)
// OnBlockLocator is invoked when a peer receives a locator kaspa
// message.
func (sp *Peer) OnBlockLocator(_ *peer.Peer, msg *wire.MsgBlockLocator) {
// Find the highest known shared block between the peers, and asks
// the block and its future from the peer. If the block is not
// found, create a lower resolution block locator and send it to
// the peer in order to find it in the next iteration.
dag := sp.server.DAG
if len(msg.BlockLocatorHashes) == 0 {
peerLog.Warnf("Got empty block locator from peer %s",
sp)
return
}
// If the first hash of the block locator is known, it means we found
// the highest shared block.
highHash := msg.BlockLocatorHashes[0]
if dag.BlockExists(highHash) {
if dag.IsKnownFinalizedBlock(highHash) {
peerLog.Debugf("Cannot sync with peer %s because the highest"+
" shared chain block (%s) is below the finality point", sp, highHash)
sp.server.SyncManager.RemoveFromSyncCandidates(sp.Peer)
return
}
// We send the highHash as the GetBlockInvsMsg's lowHash here.
// This is not a mistake. The invs we desire start from the highest
// hash that we know of and end at the highest hash that the peer
// knows of.
err := sp.Peer.PushGetBlockInvsMsg(highHash, sp.Peer.SelectedTipHash())
if err != nil {
peerLog.Errorf("Failed pushing get blocks message for peer %s: %s",
sp, err)
return
}
return
}
highHash, lowHash := dag.FindNextLocatorBoundaries(msg.BlockLocatorHashes)
if highHash == nil {
panic("Couldn't find any unknown hashes in the block locator.")
}
sp.PushGetBlockLocatorMsg(highHash, lowHash)
}