From e2df39e9f6c8b2ce4dddbfb0b815e192b21849c6 Mon Sep 17 00:00:00 2001
From: Sedat Kapanoglu <sedat@kapanoglu.com>
Date: Fri, 18 Oct 2024 20:11:29 -0700
Subject: [PATCH 1/2] avoid double dictionary lookups

---
 FluentFTP/Helpers/Hashing/HashAlgorithms.cs | 16 ++++++----------
 FluentFTP/Streams/FtpSocketStream.cs        | 19 +++----------------
 2 files changed, 9 insertions(+), 26 deletions(-)

diff --git a/FluentFTP/Helpers/Hashing/HashAlgorithms.cs b/FluentFTP/Helpers/Hashing/HashAlgorithms.cs
index f2f5e48b5..07282daa0 100644
--- a/FluentFTP/Helpers/Hashing/HashAlgorithms.cs
+++ b/FluentFTP/Helpers/Hashing/HashAlgorithms.cs
@@ -29,11 +29,9 @@ internal static class HashAlgorithms {
 		/// <param name="name">Name of the hash algorithm</param>
 		/// <returns>The FtpHashAlgorithm</returns>
 		public static FtpHashAlgorithm FromString(string name) {
-			if (!NameToEnum.ContainsKey(name.ToUpper())) {
-				throw new NotImplementedException("Unknown hash algorithm: " + name);
-			}
-
-			return NameToEnum[name];
+			return NameToEnum.TryGetValue(name, out var value)
+				? value
+				: throw new NotImplementedException("Unknown hash algorithm: " + name);
 		}
 
 		/// <summary>
@@ -42,11 +40,9 @@ public static FtpHashAlgorithm FromString(string name) {
 		/// <param name="name">FtpHashAlgorithm to be converted into string</param>
 		/// <returns>Name of the hash algorithm</returns>
 		public static string PrintToString(this FtpHashAlgorithm name) {
-			if (!EnumToName.ContainsKey(name)) {
-				return name.ToString();
-			}
-
-			return EnumToName[name];
+			return EnumToName.TryGetValue(name, out var value)
+				? value
+				: name.ToString();
 		}
 
 		private static readonly List<FtpHashAlgorithm> AlgoPreference = new List<FtpHashAlgorithm> {
diff --git a/FluentFTP/Streams/FtpSocketStream.cs b/FluentFTP/Streams/FtpSocketStream.cs
index 43540e9de..53eebc106 100644
--- a/FluentFTP/Streams/FtpSocketStream.cs
+++ b/FluentFTP/Streams/FtpSocketStream.cs
@@ -862,12 +862,8 @@ private static bool IsIpVersionAllowed(IPAddress ipad, FtpIpVersion ipVersions,
 		/// </summary>
 		/// <param name="host">The host to query</param>
 		private IPAddress[] GetCachedHostAddresses(string host) {
-			IPAddress[] ipads;
 
-			if (Client.Status.CachedHostIpads.ContainsKey(host)) {
-				ipads = Client.Status.CachedHostIpads[host];
-			}
-			else {
+			if (!Client.Status.CachedHostIpads.TryGetValue(host, out IPAddress[] ipads)) {
 #if NETSTANDARD || NET5_0_OR_GREATER
 				ipads = Dns.GetHostAddressesAsync(host).Result;
 #else
@@ -885,12 +881,7 @@ private IPAddress[] GetCachedHostAddresses(string host) {
 		/// <param name="host">The host to query</param>
 		/// <param name="ipad">The IP address to store in the cache</param>
 		private void SetCachedHostAddresses(string host, IPAddress ipad) {
-			if (Client.Status.CachedHostIpads.ContainsKey(host)) {
-				Client.Status.CachedHostIpads[host] = new IPAddress[1] { ipad };
-			}
-			else {
-				Client.Status.CachedHostIpads.Add(host, new IPAddress[1] { ipad });
-			}
+			Client.Status.CachedHostIpads[host] = new IPAddress[1] { ipad };
 		}
 
 		/// <summary>
@@ -1021,12 +1012,8 @@ private bool ConnectHelper(IPAddress ipad, int port) {
 		/// <param name="host">The host to query</param>
 		/// <param name="token">The token that can be used to cancel the entire process</param>
 		private async Task<IPAddress[]> GetCachedHostAddressesAsync(string host, CancellationToken token) {
-			IPAddress[] ipads;
 
-			if (Client.Status.CachedHostIpads.ContainsKey(host)) {
-				ipads = Client.Status.CachedHostIpads[host];
-			}
-			else {
+			if (!Client.Status.CachedHostIpads.TryGetValue(host, out IPAddress[] ipads)) {
 #if NET6_0_OR_GREATER
 				ipads = await Dns.GetHostAddressesAsync(host, token);
 #else

From 6a0312825c638c0bdf40640f9d76252bde69440b Mon Sep 17 00:00:00 2001
From: Sedat Kapanoglu <sedat@kapanoglu.com>
Date: Fri, 18 Oct 2024 20:19:26 -0700
Subject: [PATCH 2/2] avoid ArgumentException in multi-thread scenarios

---
 FluentFTP/Streams/FtpSocketStream.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/FluentFTP/Streams/FtpSocketStream.cs b/FluentFTP/Streams/FtpSocketStream.cs
index 53eebc106..a5fc71abe 100644
--- a/FluentFTP/Streams/FtpSocketStream.cs
+++ b/FluentFTP/Streams/FtpSocketStream.cs
@@ -869,7 +869,7 @@ private IPAddress[] GetCachedHostAddresses(string host) {
 #else
 				ipads = Dns.GetHostAddresses(host);
 #endif
-				Client.Status.CachedHostIpads.Add(host, ipads);
+				Client.Status.CachedHostIpads[host] = ipads;
 			}
 
 			return ipads;
@@ -1019,7 +1019,7 @@ private async Task<IPAddress[]> GetCachedHostAddressesAsync(string host, Cancell
 #else
 				ipads = await Dns.GetHostAddressesAsync(host);
 #endif
-				Client.Status.CachedHostIpads.Add(host, ipads);
+				Client.Status.CachedHostIpads[host] = ipads;
 			}
 
 			return ipads;