feat: random walk to discover peers

IpfsServer/IpfsServer.csproj

@@ -13,7 +13,7 @@
 
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Ipfs.Core" Version="0.50.0" />
+    <PackageReference Include="Ipfs.Core" Version="0.50.1" />
     <PackageReference Include="Microsoft.AspNetCore.App" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="4.0.1" />
   </ItemGroup>

src/DiscoveryOptions.cs

@@ -32,5 +32,11 @@ public class DiscoveryOptions
         ///   and advertising of this peer.
         /// </summary>
         public bool DisableMdns;
+
+        /// <summary>
+        ///   Disables discovery of other peers by walking the
+        ///   DHT.
+        /// </summary>
+        public bool DisableRandomWalk;
     }
 }

src/IpfsEngine.cs

@@ -480,6 +480,14 @@ public async Task StartAsync()
                     stopTasks.Add(async () => await mdns.StopAsync().ConfigureAwait(false));
                     await mdns.StartAsync().ConfigureAwait(false);
                 },
+                async () => 
+                {
+                    if (Options.Discovery.DisableRandomWalk)
+                        return;
+                    var randomWalk = new RandomWalk { Dht = Dht };
+                    stopTasks.Add(async () => await randomWalk.StopAsync().ConfigureAwait(false));
+                    await randomWalk.StartAsync().ConfigureAwait(false);
+                }
             };
             log.Debug("waiting for discovery services to start");
             await Task.WhenAll(tasks.Select(t => t())).ConfigureAwait(false);

src/IpfsEngine.csproj

@@ -36,11 +36,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Ipfs.Core" Version="0.50.0" />
+    <PackageReference Include="Ipfs.Core" Version="0.50.1" />
     <PackageReference Include="Makaretu.Dns.Unicast" Version="0.8.0" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.1" />
     <PackageReference Include="Nito.AsyncEx.Coordination" Version="5.0.0" />
-    <PackageReference Include="PeerTalk" Version="0.11.2" />
+    <PackageReference Include="PeerTalk" Version="0.11.3" />
     <PackageReference Include="PeterO.Cbor" Version="3.1.0" />
     <PackageReference Include="Portable.BouncyCastle" Version="1.8.5" />
     <PackageReference Include="protobuf-net" Version="2.4.0" />

src/RandomWalk.cs

@@ -16,7 +16,7 @@ namespace Ipfs.Engine
     /// <remarks>
     ///   This is a background task that runs every <see cref="Period"/>.
     /// </remarks>
-    class RandomWalk : IService
+    public class RandomWalk : IService
     {
         static ILog log = LogManager.GetLogger(typeof(RandomWalk));
         Random rng = new Random();
@@ -49,7 +49,7 @@ class RandomWalk : IService
         /// </summary>
         public Task StartAsync()
         {
-            if (this != null)
+            if (thread != null)
             {
                 throw new Exception("Already started.");
             }
@@ -59,6 +59,7 @@ public Task StartAsync()
                 IsBackground = true
             };
             thread.Start();
+            log.Debug("started");
 
             return Task.CompletedTask;
         }
@@ -71,6 +72,8 @@ public Task StopAsync()
             thread?.Abort();
             thread = null;
 
+            log.Debug("stopped");
+
             return Task.CompletedTask;
         }
 
@@ -95,6 +98,8 @@ void Runner()
 
         void RunQuery()
         {
+            log.Debug("Running a query");
+
             // Get a random peer id.
             byte[] x = new byte[32];
             rng.NextBytes(x);

test/CoreApi/DhtApiTest.cs

@@ -65,35 +65,6 @@ public async Task FindProvider()
             }
         }
 
-        [TestMethod]
-        public async Task RandomWalk()
-        {
-            //var id = "QmSoLMeWqB7YGVLJN3pxxQpmmEk35v6wYtsMGLzSr5QBU3"; // TODO
-            byte[] x = new byte[32];
-            (new Random()).NextBytes(x);
-            var id = MultiHash.ComputeHash(x);
-
-            var ipfs = TestFixture.Ipfs;
-            await ipfs.StartAsync();
-            try
-            {
-                var prevPeers = (await ipfs.Swarm.AddressesAsync()).ToArray();
-                var cts = new CancellationTokenSource(TimeSpan.FromSeconds(1 * 60));
-                await ipfs.Dht.FindPeerAsync(id, cts.Token);
-                var peers = (await ipfs.Swarm.AddressesAsync()).ToArray();
-                foreach (var peer in peers)
-                {
-                    if (!prevPeers.Contains(peer))
-                    {
-                        Console.WriteLine($"found {peer} conn={peer.ConnectedAddress}");
-                    }
-                }
-            }
-            finally
-            {
-                await ipfs.StopAsync();
-            }
-        }
     }
 }
 

test/RandomWalkTest.cs

@@ -0,0 +1,49 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System.IO;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Newtonsoft.Json;
+
+namespace Ipfs.Engine
+{
+    [TestClass]
+    public class RandomWalkTest
+    {
+        [TestMethod]
+        public async Task CanStartAndStop()
+        {
+            var walk = new RandomWalk();
+            await walk.StartAsync();
+            await walk.StopAsync();
+
+            await walk.StartAsync();
+            await walk.StopAsync();
+        }
+
+        [TestMethod]
+        public void CannotStartTwice()
+        {
+            var walk = new RandomWalk();
+            walk.StartAsync().Wait();
+            ExceptionAssert.Throws<Exception>(() =>
+            {
+                walk.StartAsync().Wait();
+            });
+        }
+
+        [TestMethod]
+        public async Task CanStopMultipletimes()
+        {
+            var walk = new RandomWalk();
+            await walk.StartAsync();
+            await walk.StopAsync();
+            await walk.StopAsync();
+            await walk.StartAsync();
+            await walk.StopAsync();
+        }
+    }
+}