From 143c845a4c0b8a3eef3c75ca2ad17299ccc10ebc Mon Sep 17 00:00:00 2001
From: ian <ianopolous@protonmail.com>
Date: Wed, 13 Dec 2023 17:11:36 +0000
Subject: [PATCH] Fix IPNS publish race condition

---
 .../org/peergos/protocol/dht/Kademlia.java    | 35 ++++++++++---------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/main/java/org/peergos/protocol/dht/Kademlia.java b/src/main/java/org/peergos/protocol/dht/Kademlia.java
index 93c7d591..730f6bf6 100644
--- a/src/main/java/org/peergos/protocol/dht/Kademlia.java
+++ b/src/main/java/org/peergos/protocol/dht/Kademlia.java
@@ -336,7 +336,7 @@ public CompletableFuture<Void> publishValue(Multihash publisher,
 
         byte[] key = IPNS.getKey(publisher);
         Id keyId = Id.create(Hash.sha256(key), 256);
-        SortedSet<RoutingEntry> toQuery = Collections.synchronizedSortedSet(new TreeSet<>((a, b) -> compareKeys(a, b, keyId)));
+        SortedSet<RoutingEntry> toQuery = new TreeSet<>((a, b) -> compareKeys(a, b, keyId));
         List<PeerAddresses> localClosest = engine.getKClosestPeers(key);
         int queryParallelism = 3;
         toQuery.addAll(localClosest.stream()
@@ -349,29 +349,30 @@ public CompletableFuture<Void> publishValue(Multihash publisher,
             List<RoutingEntry> thisRound = toQuery.stream()
                     .limit(queryParallelism)
                     .collect(Collectors.toList());
-            List<? extends Future<?>> futures = thisRound.stream()
+            List<? extends Future<List<RoutingEntry>>> futures = thisRound.stream()
                     .map(r -> {
                         toQuery.remove(r);
                         queried.add(r.addresses.peerId);
                         return ioExec.submit(() -> getCloserPeers(key, r.addresses, us).thenApply(res -> {
-                                    for (PeerAddresses peer : res) {
-                                        if (! queried.contains(peer.peerId)) {
-                                            Id peerKey = Id.create(Hash.sha256(IPNS.getKey(peer.peerId)), 256);
-                                            RoutingEntry e = new RoutingEntry(peerKey, peer);
-                                            toQuery.add(e);
-                                        }
-                                    }
-                                    ioExec.submit(() -> {
-                                        if (putValue(publisher, signedRecord, r.addresses, us))
-                                            publishes.add(r.addresses.peerId);
-                                    });
-                                    return true;
-                                }));
+                            List<RoutingEntry> more = new ArrayList<>();
+                            for (PeerAddresses peer : res) {
+                                if (! queried.contains(peer.peerId)) {
+                                    Id peerKey = Id.create(Hash.sha256(IPNS.getKey(peer.peerId)), 256);
+                                    RoutingEntry e = new RoutingEntry(peerKey, peer);
+                                    more.add(e);
+                                }
+                            }
+                            ioExec.submit(() -> {
+                                if (putValue(publisher, signedRecord, r.addresses, us))
+                                    publishes.add(r.addresses.peerId);
+                            });
+                            return more;
+                        }).join());
                     })
                     .collect(Collectors.toList());
             futures.forEach(f -> {
                 try {
-                    f.get();
+                    toQuery.addAll(f.get());
                 } catch (Exception e) {}
             });
             // exit early if we have enough results
@@ -380,7 +381,7 @@ public CompletableFuture<Void> publishValue(Multihash publisher,
             if (toQuery.size() == remaining) {
                 // publish to closest remaining nodes
                 while (publishes.size() < minPublishes) {
-                    List<RoutingEntry> closest = new TreeSet<>(toQuery).stream()
+                    List<RoutingEntry> closest = toQuery.stream()
                     .limit(minPublishes - publishes.size() + 5)
                     .collect(Collectors.toList());
                     List<? extends Future<?>> lastFutures = closest.stream()