p2p: enable CAddrMan::GetAddr_() by network, add doxygen

Author: jonatack

src/addrman.cpp

@@ -7,9 +7,11 @@
 
 #include <hash.h>
 #include <logging.h>
+#include <netaddress.h>
 #include <serialize.h>
 
 #include <cmath>
+#include <optional>
 
 int CAddrInfo::GetTriedBucket(const uint256& nKey, const std::vector<bool> &asmap) const
 {
@@ -481,7 +483,7 @@ int CAddrMan::Check_()
 }
 #endif
 
-void CAddrMan::GetAddr_(std::vector<CAddress>& vAddr, size_t max_addresses, size_t max_pct)
+void CAddrMan::GetAddr_(std::vector<CAddress>& vAddr, size_t max_addresses, size_t max_pct, std::optional<Network> network)
 {
     size_t nNodes = vRandom.size();
     if (max_pct != 0) {
@@ -501,8 +503,14 @@ void CAddrMan::GetAddr_(std::vector<CAddress>& vAddr, size_t max_addresses, size
         assert(mapInfo.count(vRandom[n]) == 1);
 
         const CAddrInfo& ai = mapInfo[vRandom[n]];
-        if (!ai.IsTerrible())
-            vAddr.push_back(ai);
+
+        // Filter by network (optional)
+        if (network != std::nullopt && ai.GetNetClass() != network) continue;
+
+        // Filter for quality
+        if (ai.IsTerrible()) continue;
+
+        vAddr.push_back(ai);
     }
 }
 

src/addrman.h

@@ -20,6 +20,7 @@
 #include <hash.h>
 #include <iostream>
 #include <map>
+#include <optional>
 #include <set>
 #include <stdint.h>
 #include <streams.h>
@@ -278,8 +279,15 @@ friend class CAddrManTest;
     int Check_() EXCLUSIVE_LOCKS_REQUIRED(cs);
 #endif
 
-    //! Select several addresses at once.
-    void GetAddr_(std::vector<CAddress> &vAddr, size_t max_addresses, size_t max_pct) EXCLUSIVE_LOCKS_REQUIRED(cs);
+    /**
+     * Return all or many randomly selected addresses, optionally by network.
+     *
+     * @param[out] vAddr         Vector of randomly selected addresses from vRandom.
+     * @param[in] max_addresses  Maximum number of addresses to return (0 = all).
+     * @param[in] max_pct        Maximum percentage of addresses to return (0 = all).
+     * @param[in] network        Select only addresses of this network (nullopt = all).
+     */
+    void GetAddr_(std::vector<CAddress>& vAddr, size_t max_addresses, size_t max_pct, std::optional<Network> network = std::nullopt) EXCLUSIVE_LOCKS_REQUIRED(cs);
 
     /** We have successfully connected to this peer. Calling this function
      *  updates the CAddress's nTime, which is used in our IsTerrible()