p2p: Add DumpAnchors()

src/addrdb.cpp

@@ -10,6 +10,7 @@
 #include <clientversion.h>
 #include <cstdint>
 #include <hash.h>
+#include <logging/timer.h>
 #include <random.h>
 #include <streams.h>
 #include <tinyformat.h>
@@ -156,3 +157,9 @@ bool CAddrDB::Read(CAddrMan& addr, CDataStream& ssPeers)
     }
     return ret;
 }
+
+void DumpAnchors(const fs::path& anchors_db_path, const std::vector<CAddress>& anchors)
+{
+    LOG_TIME_SECONDS(strprintf("Flush %d outbound block-relay-only peer addresses to anchors.dat", anchors.size()));
+    SerializeFileDB("anchors", anchors_db_path, anchors);
+}

src/addrdb.h

@@ -11,9 +11,9 @@
 #include <serialize.h>
 
 #include <string>
-#include <map>
+#include <vector>
 
-class CSubNet;
+class CAddress;
 class CAddrMan;
 class CDataStream;
 
@@ -73,4 +73,12 @@ public:
     bool Read(banmap_t& banSet);
 };
 
+/**
+ * Dump the anchor IP address database (anchors.dat)
+ *
+ * Anchors are last known outgoing block-relay-only peers that are
+ * tried to re-connect to on startup.
+ */
+void DumpAnchors(const fs::path& anchors_db_path, const std::vector<CAddress>& anchors);
+
 #endif // BITCOIN_ADDRDB_H