eth: utilize sync bloom for getNodeData (ethereum#21445)

* eth/downloader, eth/handler: utilize sync bloom for getNodeData

* trie: handle if bloom is nil

* trie, downloader: check bloom nilness externally

eth/downloader/downloader.go

@@ -283,6 +283,15 @@ func (d *Downloader) Synchronising() bool {
 	return atomic.LoadInt32(&d.synchronising) > 0
 }
 
+// SyncBloomContains tests if the syncbloom filter contains the given hash:
+//   - false: the bloom definitely does not contain hash
+//   - true:  the bloom maybe contains hash
+//
+// While the bloom is being initialized (or is closed), all queries will return true.
+func (d *Downloader) SyncBloomContains(hash []byte) bool {
+	return d.stateBloom == nil || d.stateBloom.Contains(hash)
+}
+
 // RegisterPeer injects a new download peer into the set of block source to be
 // used for fetching hashes and blocks from.
 func (d *Downloader) RegisterPeer(id string, version int, peer Peer) error {

eth/handler.go

@@ -610,6 +610,10 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 			// Retrieve the requested state entry, stopping if enough was found
 			// todo now the code and trienode is mixed in the protocol level,
 			// separate these two types.
+			if !pm.downloader.SyncBloomContains(hash[:]) {
+				// Only lookup the trie node if there's chance that we actually have it
+				continue
+			}
 			entry, err := pm.blockchain.TrieNode(hash)
 			if len(entry) == 0 || err != nil {
 				// Read the contract code with prefix only to save unnecessary lookups.