From 98e6fb9c5ce125dae6e2f2f1da99d64dabd45119 Mon Sep 17 00:00:00 2001
From: JCW <a1q123456@users.noreply.github.com>
Date: Thu, 8 Jan 2026 16:17:52 +0000
Subject: [PATCH] Move Overlay interface to libxrpl. We can revisit this part
 to decide whether we should move the Overlay implementation to libxrpl

Signed-off-by: JCW <a1q123456@users.noreply.github.com>
---
 cmake/XrplCore.cmake                          |  9 +++++
 cmake/XrplInstall.cmake                       |  1 +
 .../xrpl}/overlay/Compression.h               |  0
 {src/xrpld => include/xrpl}/overlay/Message.h |  3 +-
 {src/xrpld => include/xrpl}/overlay/Overlay.h |  3 +-
 {src/xrpld => include/xrpl}/overlay/Peer.h    |  3 +-
 {src/xrpld => include/xrpl}/overlay/PeerSet.h | 14 ++------
 .../xrpl}/overlay/detail/TrafficCount.h       |  0
 .../detail => libxrpl/overlay}/Message.cpp    |  4 +--
 .../overlay/detail/TrafficCount.cpp           |  4 ++-
 src/test/app/LedgerReplay_test.cpp            |  2 +-
 src/test/overlay/compression_test.cpp         |  4 +--
 src/test/overlay/reduce_relay_test.cpp        |  4 +--
 src/test/overlay/traffic_count_test.cpp       |  5 ++-
 src/test/rpc/Peers_test.cpp                   |  2 +-
 src/xrpld/app/consensus/RCLConsensus.cpp      |  2 +-
 src/xrpld/app/ledger/InboundLedger.h          |  2 +-
 src/xrpld/app/ledger/InboundTransactions.h    |  3 +-
 src/xrpld/app/ledger/detail/InboundLedger.cpp |  1 -
 .../app/ledger/detail/InboundLedgers.cpp      |  3 +-
 .../app/ledger/detail/InboundTransactions.cpp |  6 ++--
 .../app/ledger/detail/LedgerDeltaAcquire.cpp  |  2 +-
 src/xrpld/app/ledger/detail/LedgerMaster.cpp  |  3 +-
 src/xrpld/app/ledger/detail/OpenLedger.cpp    |  2 --
 .../app/ledger/detail/SkipListAcquire.cpp     |  3 +-
 .../app/ledger/detail/TransactionAcquire.h    |  3 +-
 src/xrpld/app/main/Application.cpp            |  9 ++---
 src/xrpld/app/misc/NetworkOPs.cpp             |  2 +-
 src/xrpld/app/misc/NetworkOPs.h               |  1 +
 src/xrpld/app/misc/ValidatorList.h            |  3 +-
 src/xrpld/app/misc/detail/ValidatorList.cpp   |  2 +-
 src/xrpld/overlay/PeerSetImp.h                | 27 ++++++++++++++
 src/xrpld/overlay/Slot.h                      |  2 +-
 src/xrpld/overlay/detail/OverlayImpl.cpp      |  2 +-
 src/xrpld/overlay/detail/OverlayImpl.h        |  6 ++--
 .../detail/{PeerSet.cpp => PeerSetImpl.cpp}   | 36 +++++++++----------
 src/xrpld/overlay/detail/ProtocolMessage.h    |  4 +--
 src/xrpld/overlay/make_Overlay.h              |  2 +-
 src/xrpld/overlay/predicates.h                |  4 +--
 src/xrpld/rpc/detail/ServerHandler.cpp        |  2 +-
 src/xrpld/rpc/handlers/Connect.cpp            |  2 +-
 src/xrpld/rpc/handlers/Peers.cpp              |  2 +-
 src/xrpld/rpc/handlers/TxReduceRelay.cpp      |  2 +-
 43 files changed, 108 insertions(+), 88 deletions(-)
 rename {src/xrpld => include/xrpl}/overlay/Compression.h (100%)
 rename {src/xrpld => include/xrpl}/overlay/Message.h (98%)
 rename {src/xrpld => include/xrpl}/overlay/Overlay.h (99%)
 rename {src/xrpld => include/xrpl}/overlay/Peer.h (98%)
 rename {src/xrpld => include/xrpl}/overlay/PeerSet.h (83%)
 rename {src/xrpld => include/xrpl}/overlay/detail/TrafficCount.h (100%)
 rename src/{xrpld/overlay/detail => libxrpl/overlay}/Message.cpp (98%)
 rename src/{xrpld => libxrpl}/overlay/detail/TrafficCount.cpp (98%)
 create mode 100644 src/xrpld/overlay/PeerSetImp.h
 rename src/xrpld/overlay/detail/{PeerSet.cpp => PeerSetImpl.cpp} (79%)

diff --git a/cmake/XrplCore.cmake b/cmake/XrplCore.cmake
index b3762b37b8..54b649c57c 100644
--- a/cmake/XrplCore.cmake
+++ b/cmake/XrplCore.cmake
@@ -143,12 +143,21 @@ target_link_libraries(xrpl.libxrpl.server PUBLIC
   xrpl.libxrpl.resource
 )
 
+add_module(xrpl overlay)
+target_link_libraries(xrpl.libxrpl.overlay PUBLIC
+  xrpl.libxrpl.basics
+  xrpl.libxrpl.json
+  xrpl.libxrpl.protocol
+  xrpl.libxrpl.rdb
+)
+
 add_module(xrpl ledger)
 target_link_libraries(xrpl.libxrpl.ledger PUBLIC
   xrpl.libxrpl.basics
   xrpl.libxrpl.json
   xrpl.libxrpl.protocol
   xrpl.libxrpl.rdb
+  xrpl.libxrpl.overlay
 )
 
 add_library(xrpl.libxrpl)
diff --git a/cmake/XrplInstall.cmake b/cmake/XrplInstall.cmake
index 9576be8163..83180614f3 100644
--- a/cmake/XrplInstall.cmake
+++ b/cmake/XrplInstall.cmake
@@ -20,6 +20,7 @@ install (
     xrpl.libxrpl.crypto
     xrpl.libxrpl.json
     xrpl.libxrpl.rdb
+    xrpl.libxrpl.overlay
     xrpl.libxrpl.ledger
     xrpl.libxrpl.net
     xrpl.libxrpl.nodestore
diff --git a/src/xrpld/overlay/Compression.h b/include/xrpl/overlay/Compression.h
similarity index 100%
rename from src/xrpld/overlay/Compression.h
rename to include/xrpl/overlay/Compression.h
diff --git a/src/xrpld/overlay/Message.h b/include/xrpl/overlay/Message.h
similarity index 98%
rename from src/xrpld/overlay/Message.h
rename to include/xrpl/overlay/Message.h
index f2b021840d..8d758099ff 100644
--- a/src/xrpld/overlay/Message.h
+++ b/include/xrpl/overlay/Message.h
@@ -1,9 +1,8 @@
 #ifndef XRPL_OVERLAY_MESSAGE_H_INCLUDED
 #define XRPL_OVERLAY_MESSAGE_H_INCLUDED
 
-#include <xrpld/overlay/Compression.h>
-
 #include <xrpl/basics/ByteUtilities.h>
+#include <xrpl/overlay/Compression.h>
 #include <xrpl/protocol/PublicKey.h>
 #include <xrpl/protocol/messages.h>
 
diff --git a/src/xrpld/overlay/Overlay.h b/include/xrpl/overlay/Overlay.h
similarity index 99%
rename from src/xrpld/overlay/Overlay.h
rename to include/xrpl/overlay/Overlay.h
index c30d0f5205..79a9ec14c7 100644
--- a/src/xrpld/overlay/Overlay.h
+++ b/include/xrpl/overlay/Overlay.h
@@ -1,10 +1,9 @@
 #ifndef XRPL_OVERLAY_OVERLAY_H_INCLUDED
 #define XRPL_OVERLAY_OVERLAY_H_INCLUDED
 
-#include <xrpld/overlay/Peer.h>
-
 #include <xrpl/beast/utility/PropertyStream.h>
 #include <xrpl/json/json_value.h>
+#include <xrpl/overlay/Peer.h>
 #include <xrpl/server/Handoff.h>
 
 #include <boost/asio/ip/tcp.hpp>
diff --git a/src/xrpld/overlay/Peer.h b/include/xrpl/overlay/Peer.h
similarity index 98%
rename from src/xrpld/overlay/Peer.h
rename to include/xrpl/overlay/Peer.h
index 35feb05271..018289d772 100644
--- a/src/xrpld/overlay/Peer.h
+++ b/include/xrpl/overlay/Peer.h
@@ -1,11 +1,10 @@
 #ifndef XRPL_OVERLAY_PEER_H_INCLUDED
 #define XRPL_OVERLAY_PEER_H_INCLUDED
 
-#include <xrpld/overlay/Message.h>
-
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/json/json_value.h>
+#include <xrpl/overlay/Message.h>
 #include <xrpl/protocol/PublicKey.h>
 
 namespace xrpl {
diff --git a/src/xrpld/overlay/PeerSet.h b/include/xrpl/overlay/PeerSet.h
similarity index 83%
rename from src/xrpld/overlay/PeerSet.h
rename to include/xrpl/overlay/PeerSet.h
index 850ba21c53..58b4308f3a 100644
--- a/src/xrpld/overlay/PeerSet.h
+++ b/include/xrpl/overlay/PeerSet.h
@@ -2,9 +2,10 @@
 #define XRPL_APP_PEERS_PEERSET_H_INCLUDED
 
 #include <xrpld/app/main/Application.h>
-#include <xrpld/overlay/Peer.h>
 #include <xrpld/overlay/detail/ProtocolMessage.h>
 
+#include <xrpl/overlay/Peer.h>
+
 namespace xrpl {
 
 /** Supports data retrieval by managing a set of peers.
@@ -62,17 +63,6 @@ public:
     build() = 0;
 };
 
-std::unique_ptr<PeerSetBuilder>
-make_PeerSetBuilder(Application& app);
-
-/**
- * Make a dummy PeerSet that does not do anything.
- * @note For the use case of InboundLedger in ApplicationImp::loadOldLedger(),
- *       where a real PeerSet is not needed.
- */
-std::unique_ptr<PeerSet>
-make_DummyPeerSet(Application& app);
-
 }  // namespace xrpl
 
 #endif
diff --git a/src/xrpld/overlay/detail/TrafficCount.h b/include/xrpl/overlay/detail/TrafficCount.h
similarity index 100%
rename from src/xrpld/overlay/detail/TrafficCount.h
rename to include/xrpl/overlay/detail/TrafficCount.h
diff --git a/src/xrpld/overlay/detail/Message.cpp b/src/libxrpl/overlay/Message.cpp
similarity index 98%
rename from src/xrpld/overlay/detail/Message.cpp
rename to src/libxrpl/overlay/Message.cpp
index eb7b88894a..15b191e2a7 100644
--- a/src/xrpld/overlay/detail/Message.cpp
+++ b/src/libxrpl/overlay/Message.cpp
@@ -1,5 +1,5 @@
-#include <xrpld/overlay/Message.h>
-#include <xrpld/overlay/detail/TrafficCount.h>
+#include <xrpl/overlay/Message.h>
+#include <xrpl/overlay/detail/TrafficCount.h>
 
 #include <cstdint>
 
diff --git a/src/xrpld/overlay/detail/TrafficCount.cpp b/src/libxrpl/overlay/detail/TrafficCount.cpp
similarity index 98%
rename from src/xrpld/overlay/detail/TrafficCount.cpp
rename to src/libxrpl/overlay/detail/TrafficCount.cpp
index 6fb397ea71..984d813546 100644
--- a/src/xrpld/overlay/detail/TrafficCount.cpp
+++ b/src/libxrpl/overlay/detail/TrafficCount.cpp
@@ -1,4 +1,6 @@
-#include <xrpld/overlay/detail/TrafficCount.h>
+#include <xrpl/overlay/detail/TrafficCount.h>
+
+#include <unordered_map>
 
 namespace xrpl {
 
diff --git a/src/test/app/LedgerReplay_test.cpp b/src/test/app/LedgerReplay_test.cpp
index 6c5c2ce67f..510380928c 100644
--- a/src/test/app/LedgerReplay_test.cpp
+++ b/src/test/app/LedgerReplay_test.cpp
@@ -9,10 +9,10 @@
 #include <xrpld/app/ledger/detail/LedgerDeltaAcquire.h>
 #include <xrpld/app/ledger/detail/LedgerReplayMsgHandler.h>
 #include <xrpld/app/ledger/detail/SkipListAcquire.h>
-#include <xrpld/overlay/PeerSet.h>
 #include <xrpld/overlay/detail/PeerImp.h>
 
 #include <xrpl/basics/Slice.h>
+#include <xrpl/overlay/PeerSet.h>
 
 #include <chrono>
 #include <thread>
diff --git a/src/test/overlay/compression_test.cpp b/src/test/overlay/compression_test.cpp
index 2be69a74c9..706a74c208 100644
--- a/src/test/overlay/compression_test.cpp
+++ b/src/test/overlay/compression_test.cpp
@@ -6,8 +6,6 @@
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/ledger/LedgerMaster.h>
-#include <xrpld/overlay/Compression.h>
-#include <xrpld/overlay/Message.h>
 #include <xrpld/overlay/detail/Handshake.h>
 #include <xrpld/overlay/detail/ProtocolMessage.h>
 #include <xrpld/overlay/detail/ZeroCopyStream.h>
@@ -15,6 +13,8 @@
 #include <xrpl/basics/random.h>
 #include <xrpl/beast/unit_test.h>
 #include <xrpl/beast/utility/Journal.h>
+#include <xrpl/overlay/Compression.h>
+#include <xrpl/overlay/Message.h>
 #include <xrpl/protocol/HashPrefix.h>
 #include <xrpl/protocol/PublicKey.h>
 #include <xrpl/protocol/SecretKey.h>
diff --git a/src/test/overlay/reduce_relay_test.cpp b/src/test/overlay/reduce_relay_test.cpp
index 6af27ea8f1..cf4ada3873 100644
--- a/src/test/overlay/reduce_relay_test.cpp
+++ b/src/test/overlay/reduce_relay_test.cpp
@@ -1,14 +1,14 @@
 #include <test/jtx.h>
 #include <test/jtx/Env.h>
 
-#include <xrpld/overlay/Message.h>
-#include <xrpld/overlay/Peer.h>
 #include <xrpld/overlay/Slot.h>
 #include <xrpld/overlay/Squelch.h>
 #include <xrpld/overlay/detail/Handshake.h>
 
 #include <xrpl/basics/random.h>
 #include <xrpl/beast/unit_test.h>
+#include <xrpl/overlay/Message.h>
+#include <xrpl/overlay/Peer.h>
 #include <xrpl/protocol/SecretKey.h>
 #include <xrpl/protocol/messages.h>
 
diff --git a/src/test/overlay/traffic_count_test.cpp b/src/test/overlay/traffic_count_test.cpp
index a8948879d9..93bc140c34 100644
--- a/src/test/overlay/traffic_count_test.cpp
+++ b/src/test/overlay/traffic_count_test.cpp
@@ -1,7 +1,6 @@
-#include <xrpld/overlay/Message.h>
-#include <xrpld/overlay/detail/TrafficCount.h>
-
 #include <xrpl/beast/unit_test.h>
+#include <xrpl/overlay/Message.h>
+#include <xrpl/overlay/detail/TrafficCount.h>
 #include <xrpl/protocol/messages.h>
 
 namespace xrpl {
diff --git a/src/test/rpc/Peers_test.cpp b/src/test/rpc/Peers_test.cpp
index 639f5e98cb..6d8a7c888b 100644
--- a/src/test/rpc/Peers_test.cpp
+++ b/src/test/rpc/Peers_test.cpp
@@ -2,8 +2,8 @@
 #include <test/jtx/Env.h>
 
 #include <xrpld/overlay/Cluster.h>
-#include <xrpld/overlay/Overlay.h>
 
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/jss.h>
 
 #include <unordered_map>
diff --git a/src/xrpld/app/consensus/RCLConsensus.cpp b/src/xrpld/app/consensus/RCLConsensus.cpp
index eae0962bc6..e4bd496e23 100644
--- a/src/xrpld/app/consensus/RCLConsensus.cpp
+++ b/src/xrpld/app/consensus/RCLConsensus.cpp
@@ -16,12 +16,12 @@
 #include <xrpld/app/misc/ValidatorKeys.h>
 #include <xrpld/app/misc/ValidatorList.h>
 #include <xrpld/consensus/LedgerTiming.h>
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/overlay/predicates.h>
 
 #include <xrpl/basics/random.h>
 #include <xrpl/beast/core/LexicalCast.h>
 #include <xrpl/beast/utility/instrumentation.h>
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/BuildInfo.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/digest.h>
diff --git a/src/xrpld/app/ledger/InboundLedger.h b/src/xrpld/app/ledger/InboundLedger.h
index cc7bbd8875..806b7729b5 100644
--- a/src/xrpld/app/ledger/InboundLedger.h
+++ b/src/xrpld/app/ledger/InboundLedger.h
@@ -3,9 +3,9 @@
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/ledger/detail/TimeoutCounter.h>
-#include <xrpld/overlay/PeerSet.h>
 
 #include <xrpl/basics/CountedObject.h>
+#include <xrpl/overlay/PeerSet.h>
 
 #include <mutex>
 #include <set>
diff --git a/src/xrpld/app/ledger/InboundTransactions.h b/src/xrpld/app/ledger/InboundTransactions.h
index fec440d64f..71f7ca81ec 100644
--- a/src/xrpld/app/ledger/InboundTransactions.h
+++ b/src/xrpld/app/ledger/InboundTransactions.h
@@ -1,9 +1,8 @@
 #ifndef XRPL_APP_LEDGER_INBOUNDTRANSACTIONS_H_INCLUDED
 #define XRPL_APP_LEDGER_INBOUNDTRANSACTIONS_H_INCLUDED
 
-#include <xrpld/overlay/Peer.h>
-
 #include <xrpl/beast/clock/abstract_clock.h>
+#include <xrpl/overlay/Peer.h>
 #include <xrpl/shamap/SHAMap.h>
 
 #include <memory>
diff --git a/src/xrpld/app/ledger/detail/InboundLedger.cpp b/src/xrpld/app/ledger/detail/InboundLedger.cpp
index 3c5567980d..4b9dd6533b 100644
--- a/src/xrpld/app/ledger/detail/InboundLedger.cpp
+++ b/src/xrpld/app/ledger/detail/InboundLedger.cpp
@@ -3,7 +3,6 @@
 #include <xrpld/app/ledger/InboundLedgers.h>
 #include <xrpld/app/ledger/LedgerMaster.h>
 #include <xrpld/app/ledger/TransactionStateSF.h>
-#include <xrpld/overlay/Overlay.h>
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/core/FeatureSetService.h>
diff --git a/src/xrpld/app/ledger/detail/InboundLedgers.cpp b/src/xrpld/app/ledger/detail/InboundLedgers.cpp
index b0907e2252..6d0e3ad070 100644
--- a/src/xrpld/app/ledger/detail/InboundLedgers.cpp
+++ b/src/xrpld/app/ledger/detail/InboundLedgers.cpp
@@ -1,6 +1,7 @@
 #include <xrpld/app/ledger/InboundLedgers.h>
 #include <xrpld/app/ledger/LedgerMaster.h>
 #include <xrpld/app/misc/NetworkOPs.h>
+#include <xrpld/overlay/PeerSetImp.h>
 
 #include <xrpl/basics/DecayingSample.h>
 #include <xrpl/basics/Log.h>
@@ -454,7 +455,7 @@ make_InboundLedgers(
     beast::insight::Collector::ptr const& collector)
 {
     return std::make_unique<InboundLedgersImp>(
-        registry, clock, collector, make_PeerSetBuilder(registry.app()));
+        registry, clock, collector, make_PeerSetBuilder(registry));
 }
 
 }  // namespace xrpl
diff --git a/src/xrpld/app/ledger/detail/InboundTransactions.cpp b/src/xrpld/app/ledger/detail/InboundTransactions.cpp
index 9fe4bb189a..0138f8b5e8 100644
--- a/src/xrpld/app/ledger/detail/InboundTransactions.cpp
+++ b/src/xrpld/app/ledger/detail/InboundTransactions.cpp
@@ -1,6 +1,7 @@
 #include <xrpld/app/ledger/InboundLedgers.h>
 #include <xrpld/app/ledger/InboundTransactions.h>
 #include <xrpld/app/ledger/detail/TransactionAcquire.h>
+#include <xrpld/overlay/PeerSetImp.h>
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/core/JobQueue.h>
@@ -253,10 +254,7 @@ make_InboundTransactions(
     std::function<void(std::shared_ptr<SHAMap> const&, bool)> gotSet)
 {
     return std::make_unique<InboundTransactionsImp>(
-        registry,
-        collector,
-        std::move(gotSet),
-        make_PeerSetBuilder(registry.app()));
+        registry, collector, std::move(gotSet), make_PeerSetBuilder(registry));
 }
 
 }  // namespace xrpl
diff --git a/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.cpp b/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.cpp
index 0022d819f9..4b07336f7a 100644
--- a/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.cpp
+++ b/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.cpp
@@ -3,10 +3,10 @@
 #include <xrpld/app/ledger/LedgerReplay.h>
 #include <xrpld/app/ledger/LedgerReplayer.h>
 #include <xrpld/app/ledger/detail/LedgerDeltaAcquire.h>
-#include <xrpld/overlay/PeerSet.h>
 
 #include <xrpl/core/JobQueue.h>
 #include <xrpl/ledger/LedgerConfigService.h>
+#include <xrpl/overlay/PeerSet.h>
 
 namespace xrpl {
 
diff --git a/src/xrpld/app/ledger/detail/LedgerMaster.cpp b/src/xrpld/app/ledger/detail/LedgerMaster.cpp
index 2a76d6caee..adf5a6e865 100644
--- a/src/xrpld/app/ledger/detail/LedgerMaster.cpp
+++ b/src/xrpld/app/ledger/detail/LedgerMaster.cpp
@@ -13,8 +13,6 @@
 #include <xrpld/app/misc/TxQ.h>
 #include <xrpld/app/misc/ValidatorList.h>
 #include <xrpld/app/paths/PathRequests.h>
-#include <xrpld/overlay/Overlay.h>
-#include <xrpld/overlay/Peer.h>
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/MathUtilities.h>
@@ -25,6 +23,7 @@
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/core/ServiceRegistry.h>
 #include <xrpl/core/TimeKeeper.h>
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/BuildInfo.h>
 #include <xrpl/protocol/HashPrefix.h>
 #include <xrpl/protocol/digest.h>
diff --git a/src/xrpld/app/ledger/detail/OpenLedger.cpp b/src/xrpld/app/ledger/detail/OpenLedger.cpp
index 873eb1713a..0d982c5ac6 100644
--- a/src/xrpld/app/ledger/detail/OpenLedger.cpp
+++ b/src/xrpld/app/ledger/detail/OpenLedger.cpp
@@ -2,8 +2,6 @@
 #include <xrpld/app/misc/HashRouter.h>
 #include <xrpld/app/misc/TxQ.h>
 #include <xrpld/app/tx/apply.h>
-#include <xrpld/overlay/Message.h>
-#include <xrpld/overlay/Overlay.h>
 
 #include <xrpl/ledger/CachedView.h>
 #include <xrpl/protocol/TxFlags.h>
diff --git a/src/xrpld/app/ledger/detail/SkipListAcquire.cpp b/src/xrpld/app/ledger/detail/SkipListAcquire.cpp
index 2d4ca5a628..488b54ddda 100644
--- a/src/xrpld/app/ledger/detail/SkipListAcquire.cpp
+++ b/src/xrpld/app/ledger/detail/SkipListAcquire.cpp
@@ -1,7 +1,8 @@
 #include <xrpld/app/ledger/InboundLedger.h>
 #include <xrpld/app/ledger/LedgerReplayer.h>
 #include <xrpld/app/ledger/detail/SkipListAcquire.h>
-#include <xrpld/overlay/PeerSet.h>
+
+#include <xrpl/overlay/PeerSet.h>
 
 namespace xrpl {
 
diff --git a/src/xrpld/app/ledger/detail/TransactionAcquire.h b/src/xrpld/app/ledger/detail/TransactionAcquire.h
index 2b9b86cbd8..229372c6ff 100644
--- a/src/xrpld/app/ledger/detail/TransactionAcquire.h
+++ b/src/xrpld/app/ledger/detail/TransactionAcquire.h
@@ -1,9 +1,8 @@
 #ifndef XRPL_APP_LEDGER_TRANSACTIONACQUIRE_H_INCLUDED
 #define XRPL_APP_LEDGER_TRANSACTIONACQUIRE_H_INCLUDED
 
-#include <xrpld/overlay/PeerSet.h>
-
 #include <xrpl/core/ServiceRegistry.h>
+#include <xrpl/overlay/PeerSet.h>
 #include <xrpl/shamap/SHAMap.h>
 
 namespace xrpl {
diff --git a/src/xrpld/app/main/Application.cpp b/src/xrpld/app/main/Application.cpp
index 3eef26de93..957cb6130e 100644
--- a/src/xrpld/app/main/Application.cpp
+++ b/src/xrpld/app/main/Application.cpp
@@ -30,7 +30,7 @@
 #include <xrpld/ledger/FeatureSetServiceImpl.h>
 #include <xrpld/ledger/LedgerConfigServiceImpl.h>
 #include <xrpld/overlay/Cluster.h>
-#include <xrpld/overlay/PeerSet.h>
+#include <xrpld/overlay/PeerSetImp.h>
 #include <xrpld/overlay/make_Overlay.h>
 #include <xrpld/shamap/NodeFamily.h>
 
@@ -44,6 +44,7 @@
 #include <xrpl/crypto/csprng.h>
 #include <xrpl/json/json_reader.h>
 #include <xrpl/nodestore/DummyScheduler.h>
+#include <xrpl/overlay/PeerSet.h>
 #include <xrpl/protocol/ApiVersion.h>
 #include <xrpl/protocol/BuildInfo.h>
 #include <xrpl/protocol/Feature.h>
@@ -397,7 +398,7 @@ public:
         , m_ledgerReplayer(std::make_unique<LedgerReplayer>(
               *serviceRegistry_,
               *m_inboundLedgers,
-              make_PeerSetBuilder(*this)))
+              make_PeerSetBuilder(getServiceRegistry())))
 
         , m_acceptedLedgerCache(
               "AcceptedLedger",
@@ -1984,7 +1985,7 @@ ApplicationImp::loadOldLedger(
                         0,
                         InboundLedger::Reason::GENERIC,
                         stopwatch(),
-                        make_DummyPeerSet(*this));
+                        make_DummyPeerSet(getServiceRegistry()));
                     if (il->checkLocal())
                         loadLedger = il->getLedger();
                 }
@@ -2029,7 +2030,7 @@ ApplicationImp::loadOldLedger(
                     0,
                     InboundLedger::Reason::GENERIC,
                     stopwatch(),
-                    make_DummyPeerSet(*this));
+                    make_DummyPeerSet(getServiceRegistry()));
 
                 if (il->checkLocal())
                     loadLedger = il->getLedger();
diff --git a/src/xrpld/app/misc/NetworkOPs.cpp b/src/xrpld/app/misc/NetworkOPs.cpp
index 3d9ed587f4..bbc5a4bf55 100644
--- a/src/xrpld/app/misc/NetworkOPs.cpp
+++ b/src/xrpld/app/misc/NetworkOPs.cpp
@@ -25,7 +25,6 @@
 #include <xrpld/consensus/Consensus.h>
 #include <xrpld/consensus/ConsensusParms.h>
 #include <xrpld/overlay/Cluster.h>
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/overlay/predicates.h>
 #include <xrpld/rpc/BookChanges.h>
 #include <xrpld/rpc/CTID.h>
@@ -41,6 +40,7 @@
 #include <xrpl/core/PerfLog.h>
 #include <xrpl/crypto/RFC1751.h>
 #include <xrpl/crypto/csprng.h>
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/BuildInfo.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/MultiApiJson.h>
diff --git a/src/xrpld/app/misc/NetworkOPs.h b/src/xrpld/app/misc/NetworkOPs.h
index 148d5418db..131fd376b5 100644
--- a/src/xrpld/app/misc/NetworkOPs.h
+++ b/src/xrpld/app/misc/NetworkOPs.h
@@ -3,6 +3,7 @@
 
 #include <xrpld/app/consensus/RCLCxPeerPos.h>
 #include <xrpld/app/ledger/Ledger.h>
+#include <xrpld/app/main/Application.h>
 
 #include <xrpl/core/JobQueue.h>
 #include <xrpl/ledger/ReadView.h>
diff --git a/src/xrpld/app/misc/ValidatorList.h b/src/xrpld/app/misc/ValidatorList.h
index 2a541a3099..b2564517fe 100644
--- a/src/xrpld/app/misc/ValidatorList.h
+++ b/src/xrpld/app/misc/ValidatorList.h
@@ -1,13 +1,12 @@
 #ifndef XRPL_APP_MISC_VALIDATORLIST_H_INCLUDED
 #define XRPL_APP_MISC_VALIDATORLIST_H_INCLUDED
 
-#include <xrpld/overlay/Message.h>
-
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/UnorderedContainers.h>
 #include <xrpl/core/TimeKeeper.h>
 #include <xrpl/crypto/csprng.h>
 #include <xrpl/json/json_value.h>
+#include <xrpl/overlay/Message.h>
 #include <xrpl/protocol/PublicKey.h>
 #include <xrpl/server/Manifest.h>
 
diff --git a/src/xrpld/app/misc/detail/ValidatorList.cpp b/src/xrpld/app/misc/detail/ValidatorList.cpp
index db2ee980b8..4436da313c 100644
--- a/src/xrpld/app/misc/detail/ValidatorList.cpp
+++ b/src/xrpld/app/misc/detail/ValidatorList.cpp
@@ -1,13 +1,13 @@
 #include <xrpld/app/misc/HashRouter.h>
 #include <xrpld/app/misc/NetworkOPs.h>
 #include <xrpld/app/misc/ValidatorList.h>
-#include <xrpld/overlay/Overlay.h>
 
 #include <xrpl/basics/FileUtilities.h>
 #include <xrpl/basics/Slice.h>
 #include <xrpl/basics/StringUtilities.h>
 #include <xrpl/basics/base64.h>
 #include <xrpl/json/json_reader.h>
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/PublicKey.h>
 #include <xrpl/protocol/STValidation.h>
 #include <xrpl/protocol/digest.h>
diff --git a/src/xrpld/overlay/PeerSetImp.h b/src/xrpld/overlay/PeerSetImp.h
new file mode 100644
index 0000000000..c7ab360267
--- /dev/null
+++ b/src/xrpld/overlay/PeerSetImp.h
@@ -0,0 +1,27 @@
+#ifndef XRPL_OVERLAY_MAKE_PEERSET_H_INCLUDED
+#define XRPL_OVERLAY_MAKE_PEERSET_H_INCLUDED
+
+#include <xrpl/overlay/PeerSet.h>
+
+#include <memory>
+
+namespace xrpl {
+
+class ServiceRegistry;
+class PeerSet;
+class PeerSetBuilder;
+
+std::unique_ptr<PeerSetBuilder>
+make_PeerSetBuilder(ServiceRegistry& registry);
+
+/**
+ * Make a dummy PeerSet that does not do anything.
+ * @note For the use case of InboundLedger in ApplicationImp::loadOldLedger(),
+ *       where a real PeerSet is not needed.
+ */
+std::unique_ptr<PeerSet>
+make_DummyPeerSet(ServiceRegistry& registry);
+
+}  // namespace xrpl
+
+#endif
diff --git a/src/xrpld/overlay/Slot.h b/src/xrpld/overlay/Slot.h
index 9e717fef9c..0075861d11 100644
--- a/src/xrpld/overlay/Slot.h
+++ b/src/xrpld/overlay/Slot.h
@@ -2,7 +2,6 @@
 #define XRPL_OVERLAY_SLOT_H_INCLUDED
 
 #include <xrpld/core/Config.h>
-#include <xrpld/overlay/Peer.h>
 #include <xrpld/overlay/ReduceRelayCommon.h>
 
 #include <xrpl/basics/Log.h>
@@ -10,6 +9,7 @@
 #include <xrpl/basics/random.h>
 #include <xrpl/beast/container/aged_unordered_map.h>
 #include <xrpl/beast/utility/Journal.h>
+#include <xrpl/overlay/Peer.h>
 #include <xrpl/protocol/PublicKey.h>
 #include <xrpl/protocol/messages.h>
 
diff --git a/src/xrpld/overlay/detail/OverlayImpl.cpp b/src/xrpld/overlay/detail/OverlayImpl.cpp
index aeabb76a46..b1ab45da0d 100644
--- a/src/xrpld/overlay/detail/OverlayImpl.cpp
+++ b/src/xrpld/overlay/detail/OverlayImpl.cpp
@@ -5,7 +5,6 @@
 #include <xrpld/overlay/Cluster.h>
 #include <xrpld/overlay/detail/ConnectAttempt.h>
 #include <xrpld/overlay/detail/PeerImp.h>
-#include <xrpld/overlay/detail/TrafficCount.h>
 #include <xrpld/overlay/detail/Tuning.h>
 #include <xrpld/overlay/predicates.h>
 #include <xrpld/peerfinder/make_Manager.h>
@@ -16,6 +15,7 @@
 #include <xrpl/basics/make_SSLContext.h>
 #include <xrpl/basics/random.h>
 #include <xrpl/beast/core/LexicalCast.h>
+#include <xrpl/overlay/detail/TrafficCount.h>
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/rdb/RelationalDatabase.h>
 #include <xrpl/server/SimpleWriter.h>
diff --git a/src/xrpld/overlay/detail/OverlayImpl.h b/src/xrpld/overlay/detail/OverlayImpl.h
index dc7e4975a3..4b062519c8 100644
--- a/src/xrpld/overlay/detail/OverlayImpl.h
+++ b/src/xrpld/overlay/detail/OverlayImpl.h
@@ -2,11 +2,8 @@
 #define XRPL_OVERLAY_OVERLAYIMPL_H_INCLUDED
 
 #include <xrpld/app/main/Application.h>
-#include <xrpld/overlay/Message.h>
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/overlay/Slot.h>
 #include <xrpld/overlay/detail/Handshake.h>
-#include <xrpld/overlay/detail/TrafficCount.h>
 #include <xrpld/overlay/detail/TxMetrics.h>
 #include <xrpld/peerfinder/PeerfinderManager.h>
 #include <xrpld/rpc/ServerHandler.h>
@@ -16,6 +13,9 @@
 #include <xrpl/basics/chrono.h>
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/core/Job.h>
+#include <xrpl/overlay/Message.h>
+#include <xrpl/overlay/Overlay.h>
+#include <xrpl/overlay/detail/TrafficCount.h>
 #include <xrpl/resource/ResourceManager.h>
 #include <xrpl/server/Handoff.h>
 
diff --git a/src/xrpld/overlay/detail/PeerSet.cpp b/src/xrpld/overlay/detail/PeerSetImpl.cpp
similarity index 79%
rename from src/xrpld/overlay/detail/PeerSet.cpp
rename to src/xrpld/overlay/detail/PeerSetImpl.cpp
index f11a07f7a3..13413c7693 100644
--- a/src/xrpld/overlay/detail/PeerSet.cpp
+++ b/src/xrpld/overlay/detail/PeerSetImpl.cpp
@@ -1,15 +1,14 @@
-#include <xrpld/app/main/Application.h>
-#include <xrpld/overlay/Overlay.h>
-#include <xrpld/overlay/PeerSet.h>
-
 #include <xrpl/core/JobQueue.h>
+#include <xrpl/core/ServiceRegistry.h>
+#include <xrpl/overlay/Overlay.h>
+#include <xrpl/overlay/PeerSet.h>
 
 namespace xrpl {
 
 class PeerSetImpl : public PeerSet
 {
 public:
-    PeerSetImpl(Application& app);
+    PeerSetImpl(ServiceRegistry& registry);
 
     void
     addPeers(
@@ -30,15 +29,15 @@ public:
 private:
     // Used in this class for access to boost::asio::io_context and
     // xrpl::Overlay.
-    Application& app_;
+    ServiceRegistry& registry_;
     beast::Journal journal_;
 
     /** The identifiers of the peers we are tracking. */
     std::set<Peer::id_t> peers_;
 };
 
-PeerSetImpl::PeerSetImpl(Application& app)
-    : app_(app), journal_(app.journal("PeerSet"))
+PeerSetImpl::PeerSetImpl(ServiceRegistry& registry)
+    : registry_(registry), journal_(registry.journal("PeerSet"))
 {
 }
 
@@ -50,7 +49,7 @@ PeerSetImpl::addPeers(
 {
     using ScoredPeer = std::pair<int, std::shared_ptr<Peer>>;
 
-    auto const& overlay = app_.overlay();
+    auto const& overlay = registry_.overlay();
 
     std::vector<ScoredPeer> pairs;
     pairs.reserve(overlay.size());
@@ -94,7 +93,7 @@ PeerSetImpl::sendRequest(
 
     for (auto id : peers_)
     {
-        if (auto p = app_.overlay().findPeerByShortID(id))
+        if (auto p = registry_.overlay().findPeerByShortID(id))
             p->send(packet);
     }
 }
@@ -108,30 +107,31 @@ PeerSetImpl::getPeerIds() const
 class PeerSetBuilderImpl : public PeerSetBuilder
 {
 public:
-    PeerSetBuilderImpl(Application& app) : app_(app)
+    PeerSetBuilderImpl(ServiceRegistry& registry) : registry_(registry)
     {
     }
 
     virtual std::unique_ptr<PeerSet>
     build() override
     {
-        return std::make_unique<PeerSetImpl>(app_);
+        return std::make_unique<PeerSetImpl>(registry_);
     }
 
 private:
-    Application& app_;
+    ServiceRegistry& registry_;
 };
 
 std::unique_ptr<PeerSetBuilder>
-make_PeerSetBuilder(Application& app)
+make_PeerSetBuilder(ServiceRegistry& registry)
 {
-    return std::make_unique<PeerSetBuilderImpl>(app);
+    return std::make_unique<PeerSetBuilderImpl>(registry);
 }
 
 class DummyPeerSet : public PeerSet
 {
 public:
-    DummyPeerSet(Application& app) : j_(app.journal("DummyPeerSet"))
+    DummyPeerSet(ServiceRegistry& registry)
+        : j_(registry.journal("DummyPeerSet"))
     {
     }
 
@@ -166,9 +166,9 @@ private:
 };
 
 std::unique_ptr<PeerSet>
-make_DummyPeerSet(Application& app)
+make_DummyPeerSet(ServiceRegistry& registry)
 {
-    return std::make_unique<DummyPeerSet>(app);
+    return std::make_unique<DummyPeerSet>(registry);
 }
 
 }  // namespace xrpl
diff --git a/src/xrpld/overlay/detail/ProtocolMessage.h b/src/xrpld/overlay/detail/ProtocolMessage.h
index 1a35deb6f0..d94264a8c4 100644
--- a/src/xrpld/overlay/detail/ProtocolMessage.h
+++ b/src/xrpld/overlay/detail/ProtocolMessage.h
@@ -1,11 +1,11 @@
 #ifndef XRPL_OVERLAY_PROTOCOLMESSAGE_H_INCLUDED
 #define XRPL_OVERLAY_PROTOCOLMESSAGE_H_INCLUDED
 
-#include <xrpld/overlay/Compression.h>
-#include <xrpld/overlay/Message.h>
 #include <xrpld/overlay/detail/ZeroCopyStream.h>
 
 #include <xrpl/beast/utility/instrumentation.h>
+#include <xrpl/overlay/Compression.h>
+#include <xrpl/overlay/Message.h>
 #include <xrpl/protocol/messages.h>
 
 #include <boost/asio/buffer.hpp>
diff --git a/src/xrpld/overlay/make_Overlay.h b/src/xrpld/overlay/make_Overlay.h
index 6c37c1c825..4858cbe6f9 100644
--- a/src/xrpld/overlay/make_Overlay.h
+++ b/src/xrpld/overlay/make_Overlay.h
@@ -1,10 +1,10 @@
 #ifndef XRPL_OVERLAY_MAKE_OVERLAY_H_INCLUDED
 #define XRPL_OVERLAY_MAKE_OVERLAY_H_INCLUDED
 
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/rpc/ServerHandler.h>
 
 #include <xrpl/basics/Resolver.h>
+#include <xrpl/overlay/Overlay.h>
 
 #include <boost/asio/io_context.hpp>
 
diff --git a/src/xrpld/overlay/predicates.h b/src/xrpld/overlay/predicates.h
index 6683d8007f..08a2310455 100644
--- a/src/xrpld/overlay/predicates.h
+++ b/src/xrpld/overlay/predicates.h
@@ -1,8 +1,8 @@
 #ifndef XRPL_OVERLAY_PREDICATES_H_INCLUDED
 #define XRPL_OVERLAY_PREDICATES_H_INCLUDED
 
-#include <xrpld/overlay/Message.h>
-#include <xrpld/overlay/Peer.h>
+#include <xrpl/overlay/Message.h>
+#include <xrpl/overlay/Peer.h>
 
 #include <set>
 
diff --git a/src/xrpld/rpc/detail/ServerHandler.cpp b/src/xrpld/rpc/detail/ServerHandler.cpp
index 91b709bc06..041b742fe3 100644
--- a/src/xrpld/rpc/detail/ServerHandler.cpp
+++ b/src/xrpld/rpc/detail/ServerHandler.cpp
@@ -1,7 +1,6 @@
 #include <xrpld/app/main/Application.h>
 #include <xrpld/app/misc/NetworkOPs.h>
 #include <xrpld/core/ConfigSections.h>
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/rpc/RPCHandler.h>
 #include <xrpld/rpc/Role.h>
 #include <xrpld/rpc/ServerHandler.h>
@@ -18,6 +17,7 @@
 #include <xrpl/core/JobQueue.h>
 #include <xrpl/json/json_reader.h>
 #include <xrpl/json/to_string.h>
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/ApiVersion.h>
 #include <xrpl/protocol/ErrorCodes.h>
 #include <xrpl/protocol/RPCErr.h>
diff --git a/src/xrpld/rpc/handlers/Connect.cpp b/src/xrpld/rpc/handlers/Connect.cpp
index 2cd3b70149..88ed4549d1 100644
--- a/src/xrpld/rpc/handlers/Connect.cpp
+++ b/src/xrpld/rpc/handlers/Connect.cpp
@@ -1,9 +1,9 @@
 #include <xrpld/app/main/Application.h>
 #include <xrpld/core/Config.h>
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/rpc/Context.h>
 #include <xrpld/rpc/detail/Handler.h>
 
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/ErrorCodes.h>
 #include <xrpl/protocol/RPCErr.h>
 #include <xrpl/protocol/SystemParameters.h>
diff --git a/src/xrpld/rpc/handlers/Peers.cpp b/src/xrpld/rpc/handlers/Peers.cpp
index 1cb4a198dd..5ceb71e6dd 100644
--- a/src/xrpld/rpc/handlers/Peers.cpp
+++ b/src/xrpld/rpc/handlers/Peers.cpp
@@ -1,10 +1,10 @@
 #include <xrpld/app/main/Application.h>
 #include <xrpld/app/misc/LoadFeeTrack.h>
 #include <xrpld/overlay/Cluster.h>
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/rpc/Context.h>
 
 #include <xrpl/core/TimeKeeper.h>
+#include <xrpl/overlay/Overlay.h>
 #include <xrpl/protocol/ErrorCodes.h>
 #include <xrpl/protocol/jss.h>
 
diff --git a/src/xrpld/rpc/handlers/TxReduceRelay.cpp b/src/xrpld/rpc/handlers/TxReduceRelay.cpp
index d269ef448e..93699f1d47 100644
--- a/src/xrpld/rpc/handlers/TxReduceRelay.cpp
+++ b/src/xrpld/rpc/handlers/TxReduceRelay.cpp
@@ -1,8 +1,8 @@
 #include <xrpld/app/main/Application.h>
-#include <xrpld/overlay/Overlay.h>
 #include <xrpld/rpc/Context.h>
 
 #include <xrpl/json/json_value.h>
+#include <xrpl/overlay/Overlay.h>
 
 namespace xrpl {