From 8e249b9281c6e330db82da163a1402bd9983b1fb Mon Sep 17 00:00:00 2001
From: Michael Boeckli <michael.boeckli@taal.com>
Date: Tue, 26 Nov 2024 15:40:50 +0100
Subject: [PATCH] refactor(ARCO-212): Send GETDATA message for transaction to
 random connected peer

---
 peer_manager.go | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/peer_manager.go b/peer_manager.go
index a54dfed..cf634eb 100644
--- a/peer_manager.go
+++ b/peer_manager.go
@@ -3,6 +3,7 @@ package p2p
 import (
 	"context"
 	"log/slog"
+	"math/rand"
 	"sort"
 	"sync"
 	"time"
@@ -128,23 +129,17 @@ func (pm *PeerManager) AnnounceTransaction(txHash *chainhash.Hash, peers []PeerI
 }
 
 func (pm *PeerManager) RequestTransaction(txHash *chainhash.Hash) PeerI {
-	// send to the first found peer that is connected
-	var sendToPeer PeerI
-	for _, peer := range pm.GetAnnouncedPeers() {
-		if peer.Connected() {
-			sendToPeer = peer
-			break
-		}
-	}
+	pm.mu.RLock()
+	defer pm.mu.RUnlock()
 
-	// we don't have any connected peers
-	if sendToPeer == nil {
+	peer := pm.GetRandomConnectedPeer()
+	if peer == nil {
 		return nil
 	}
 
-	sendToPeer.RequestTransaction(txHash)
+	peer.RequestTransaction(txHash)
 
-	return sendToPeer
+	return peer
 }
 
 func (pm *PeerManager) AnnounceBlock(blockHash *chainhash.Hash, peers []PeerI) []PeerI {
@@ -179,6 +174,24 @@ func (pm *PeerManager) RequestBlock(blockHash *chainhash.Hash) PeerI {
 	return sendToPeer
 }
 
+func (pm *PeerManager) GetRandomConnectedPeer() PeerI {
+	pm.mu.RLock()
+	defer pm.mu.RUnlock()
+
+	connectedPeers := make([]PeerI, 0, len(pm.peers))
+	for _, peer := range pm.peers {
+		if peer.Connected() {
+			connectedPeers = append(connectedPeers, peer)
+		}
+	}
+
+	if len(connectedPeers) == 0 {
+		return nil
+	}
+
+	return connectedPeers[rand.Intn(len(connectedPeers))]
+}
+
 func (pm *PeerManager) GetAnnouncedPeers() []PeerI {
 	pm.mu.RLock()
 	defer pm.mu.RUnlock()