Once we receive a file from a peer, add the mapping to the lookup table.

This allows other peers to find out where they can obtain these files if we were to stop hosting them later. Or even if we continue hosting copies, it still informs the network on other locations, for better decentralization.

src/main/java/org/qortal/controller/arbitrary/ArbitraryDataManager.java

@@ -586,13 +586,21 @@ public class ArbitraryDataManager extends Thread {
 			Triple<String, Peer, Long> newEntry = new Triple<>(null, null, request.getC());
 			arbitraryDataFileListRequests.put(message.getId(), newEntry);
 
+			boolean receivedAtLeastOneFile = false;
+
 			// Now fetch actual data from this peer
 			for (byte[] hash : hashes) {
 				if (!arbitraryDataFile.chunkExists(hash)) {
 					// Only request the file if we aren't already requesting it from someone else
 					if (!arbitraryDataFileRequests.containsKey(Base58.encode(hash))) {
 						ArbitraryDataFile receivedArbitraryDataFile = fetchArbitraryDataFile(peer, hash);
-						LOGGER.info("Received data file {} from peer {}", receivedArbitraryDataFile, peer);
+						if (receivedArbitraryDataFile != null) {
+							LOGGER.info("Received data file {} from peer {}", receivedArbitraryDataFile, peer);
+							receivedAtLeastOneFile = true;
+						}
+						else {
+							LOGGER.info("Peer {} didn't respond with data file {}", peer, hash);
+						}
 					}
 					else {
 						LOGGER.info("Already requesting data file {}", arbitraryDataFile);
@@ -600,6 +608,15 @@ public class ArbitraryDataManager extends Thread {
 				}
 			}
 
+			if (receivedAtLeastOneFile) {
+				// Update our lookup table to indicate that this peer holds data for this signature
+				String peerAddress = peer.getPeerData().getAddress().toString();
+				LOGGER.info("Adding arbitrary peer: {} for signature {}", peerAddress, Base58.encode(signature));
+				ArbitraryPeerData arbitraryPeerData = new ArbitraryPeerData(signature, peer);
+				repository.getArbitraryRepository().save(arbitraryPeerData);
+				repository.saveChanges();
+			}
+
 			// Check if we have all the chunks for this transaction
 			if (arbitraryDataFile.exists() || arbitraryDataFile.allChunksExist(arbitraryTransactionData.getChunkHashes())) {