From 38d1f4792b0cd98f6ebd7d11f1e06bccbe9dd44f Mon Sep 17 00:00:00 2001
From: chimp1984 <chimp1984@gmx.com>
Date: Mon, 4 Nov 2019 19:59:05 -0500
Subject: [PATCH] Limit max. nr. of PersistableNetworkPayload and
 ProtectedStorageEntry to 5000

To avoid that seed nodes get overloaded with requests for too many
PersistableNetworkPayload and ProtectedStorageEntry data we limit nr. of
entries to max 5000 each.
---
 .../peers/getdata/GetDataRequestHandler.java  | 29 +++++++++++++++----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/p2p/src/main/java/bisq/network/p2p/peers/getdata/GetDataRequestHandler.java b/p2p/src/main/java/bisq/network/p2p/peers/getdata/GetDataRequestHandler.java
index d6e2259b510..920c152d3a3 100644
--- a/p2p/src/main/java/bisq/network/p2p/peers/getdata/GetDataRequestHandler.java
+++ b/p2p/src/main/java/bisq/network/p2p/peers/getdata/GetDataRequestHandler.java
@@ -41,6 +41,7 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 
 import lombok.extern.slf4j.Slf4j;
@@ -50,6 +51,7 @@
 @Slf4j
 public class GetDataRequestHandler {
     private static final long TIMEOUT = 90;
+    private static final int MAX_ENTRIES = 10000;
 
 
     ///////////////////////////////////////////////////////////////////////////////////////////
@@ -138,13 +140,22 @@ private Set<PersistableNetworkPayload> getFilteredPersistableNetworkPayload(GetD
                                                                                 Connection connection) {
         final Set<P2PDataStorage.ByteArray> tempLookupSet = new HashSet<>();
         Set<P2PDataStorage.ByteArray> excludedKeysAsByteArray = P2PDataStorage.ByteArray.convertBytesSetToByteArraySet(getDataRequest.getExcludedKeys());
-
-        return dataStorage.getAppendOnlyDataStoreMap().entrySet().stream()
+        AtomicInteger maxSize = new AtomicInteger(MAX_ENTRIES / 2);
+        Set<PersistableNetworkPayload> result = dataStorage.getAppendOnlyDataStoreMap().entrySet().stream()
                 .filter(e -> !excludedKeysAsByteArray.contains(e.getKey()))
+                .filter(e -> maxSize.decrementAndGet() > 0)
                 .map(Map.Entry::getValue)
-                .filter(payload -> (connection.noCapabilityRequiredOrCapabilityIsSupported(payload)))
-                .filter(payload -> tempLookupSet.add(new P2PDataStorage.ByteArray(payload.getHash())))
+                .filter(connection::noCapabilityRequiredOrCapabilityIsSupported)
+                .filter(payload -> {
+                    boolean notContained = tempLookupSet.add(new P2PDataStorage.ByteArray(payload.getHash()));
+                    return notContained;
+                })
                 .collect(Collectors.toSet());
+        if (maxSize.get() <= 0) {
+            log.warn("The peer request caused too much PersistableNetworkPayload entries to get delivered. We limited the entries for the response to {} entries", MAX_ENTRIES / 2);
+        }
+        log.info("PersistableNetworkPayload set contains {} entries ", result.size());
+        return result;
     }
 
     private Set<ProtectedStorageEntry> getFilteredProtectedStorageEntries(GetDataRequest getDataRequest,
@@ -152,11 +163,17 @@ private Set<ProtectedStorageEntry> getFilteredProtectedStorageEntries(GetDataReq
         final Set<ProtectedStorageEntry> filteredDataSet = new HashSet<>();
         final Set<Integer> lookupSet = new HashSet<>();
 
+        AtomicInteger maxSize = new AtomicInteger(MAX_ENTRIES / 2);
         Set<P2PDataStorage.ByteArray> excludedKeysAsByteArray = P2PDataStorage.ByteArray.convertBytesSetToByteArraySet(getDataRequest.getExcludedKeys());
         Set<ProtectedStorageEntry> filteredSet = dataStorage.getMap().entrySet().stream()
                 .filter(e -> !excludedKeysAsByteArray.contains(e.getKey()))
+                .filter(e -> maxSize.decrementAndGet() > 0)
                 .map(Map.Entry::getValue)
                 .collect(Collectors.toSet());
+        if (maxSize.get() <= 0) {
+            log.warn("The peer request caused too much ProtectedStorageEntry entries to get delivered. We limited the entries for the response to {} entries", MAX_ENTRIES / 2);
+        }
+        log.info("getFilteredProtectedStorageEntries " + filteredSet.size());
 
         for (ProtectedStorageEntry protectedStorageEntry : filteredSet) {
             final ProtectedStoragePayload protectedStoragePayload = protectedStorageEntry.getProtectedStoragePayload();
@@ -171,11 +188,13 @@ private Set<ProtectedStorageEntry> getFilteredProtectedStorageEntries(GetDataReq
                 doAdd = true;
             }
             if (doAdd) {
-                if (lookupSet.add(protectedStoragePayload.hashCode()))
+                boolean notContained = lookupSet.add(protectedStoragePayload.hashCode());
+                if (notContained)
                     filteredDataSet.add(protectedStorageEntry);
             }
         }
 
+        log.info("ProtectedStorageEntry set contains {} entries ", filteredDataSet.size());
         return filteredDataSet;
     }