Avoid generating unnecessary strings for comparison.

Author: paulomorgado

src/.cr/personal/FavoritesList/List.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Root Type="DevExpress.CodeRush.Foundation.CodePlaces.Options.FavoritesListContainer">
+  <Options Language="Neutral">
+    <Groups />
+  </Options>
+</Root>

src/SIPSorcery.csproj

@@ -20,14 +20,26 @@
     <PackageReference Include="Concentus" Version="2.2.2" />
     <PackageReference Include="Portable.BouncyCastle" Version="1.9.0" />
     <PackageReference Include="DnsClient" Version="1.8.0" />
+    <PackageReference Include="Roslynator.Analyzers" Version="4.13.1">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Roslynator.CodeFixes" Version="4.13.1">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Roslynator.Refactorings" Version="4.13.1">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
     <PackageReference Include="SIPSorcery.WebSocketSharp" Version="0.0.1" />
     <PackageReference Include="SIPSorceryMedia.Abstractions" Version="8.0.10" />
     <PackageReference Include="System.Net.Security" Version="4.3.2" />
     <PackageReference Include="System.Net.WebSockets.Client" Version="4.3.2" />
   </ItemGroup>
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;netstandard2.1;netcoreapp3.1;net462;net5.0;net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netstandard2.1;netcoreapp3.1;net5.0;net6.0;net8.0</TargetFrameworks>
     <LangVersion>10.0</LangVersion>
     <SuppressTfmSupportBuildWarnings>true</SuppressTfmSupportBuildWarnings>
     <NoWarn>$(NoWarn);SYSLIB0050</NoWarn>

src/core/SIP/SIPConstants.cs

@@ -616,43 +616,69 @@ public static class SIPExtensionHeaders
         /// <returns>A list of extensions that were understood and a boolean indicating whether any unknown extensions were present.</returns>
         public static List<SIPExtensions> ParseSIPExtensions(string extensionList, out string unknownExtensions)
         {
-            List<SIPExtensions> knownExtensions = new List<SIPExtensions>();
-            unknownExtensions = null;
+            List<SIPExtensions> knownExtensions = new();
+            StringBuilder unknownBuilder = null;
 
-            if (String.IsNullOrEmpty(extensionList) == false)
+            if (string.IsNullOrWhiteSpace(extensionList))
             {
-                string[] extensions = extensionList.Trim().Split(',');
+                unknownExtensions = null;
+                return knownExtensions;
+            }
+
+            ReadOnlySpan<char> remaining = extensionList.AsSpan();
+            while (true)
+            {
+                int commaIndex = remaining.IndexOf(',');
+                ReadOnlySpan<char> extension = commaIndex == -1 ? remaining.Trim() : remaining.Slice(0, commaIndex).Trim();
 
-                foreach (string extension in extensions)
+                if (!extension.IsEmpty)
                 {
-                    if (String.IsNullOrEmpty(extension) == false)
+                    SIPExtensions? parsedExtension = null;
+                    if (extension.Equals(PRACK.AsSpan(), StringComparison.OrdinalIgnoreCase))
+                    {
+                        parsedExtension = SIPExtensions.Prack;
+                    }
+                    else if (extension.Equals(NO_REFER_SUB.AsSpan(), StringComparison.OrdinalIgnoreCase))
+                    {
+                        parsedExtension = SIPExtensions.NoReferSub;
+                    }
+                    else if (extension.Equals(REPLACES.AsSpan(), StringComparison.OrdinalIgnoreCase))
+                    {
+                        parsedExtension = SIPExtensions.Replaces;
+                    }
+                    else if (extension.Equals(SIPREC.AsSpan(), StringComparison.OrdinalIgnoreCase))
+                    {
+                        parsedExtension = SIPExtensions.SipRec;
+                    }
+                    else if (extension.Equals(MULTIPLE_REFER.AsSpan(), StringComparison.OrdinalIgnoreCase))
+                    {
+                        parsedExtension = SIPExtensions.MultipleRefer;
+                    }
+
+                    if (parsedExtension.HasValue)
+                    {
+                        knownExtensions.Add(parsedExtension.GetValueOrDefault());
+                    }
+                    else
                     {
-                        string trimmedExtension = extension.Trim().ToLower();
-                        switch (trimmedExtension)
+                        unknownBuilder ??= new StringBuilder();
+                        if (unknownBuilder.Length > 0)
                         {
-                            case PRACK:
-                                knownExtensions.Add(SIPExtensions.Prack);
-                                break;
-                            case NO_REFER_SUB:
-                                knownExtensions.Add(SIPExtensions.NoReferSub);
-                                break;
-                            case REPLACES:
-                                knownExtensions.Add(SIPExtensions.Replaces);
-                                break;
-                            case SIPREC:
-                                knownExtensions.Add(SIPExtensions.SipRec);
-                                break;
-                            case MULTIPLE_REFER:
-                                knownExtensions.Add(SIPExtensions.MultipleRefer);
-                                break;
-                            default:
-                                unknownExtensions += (unknownExtensions != null) ? $",{extension.Trim()}" : extension.Trim();
-                                break;
+                            unknownBuilder.Append(',');
                         }
+                        unknownBuilder.Append(extension);
                     }
                 }
+
+                if (commaIndex == -1)
+                {
+                    break;
+                }
+
+                remaining = remaining.Slice(commaIndex + 1);
             }
 
+            unknownExtensions = unknownBuilder?.ToString();
             return knownExtensions;
         }
     }

src/core/SIP/SIPEndPoint.cs

@@ -137,11 +137,11 @@ public static SIPEndPoint ParseSIPEndPoint(string sipEndPointStr)
                 return null;
             }
 
-            if (sipEndPointStr.ToLower().StartsWith("udp:") ||
-                sipEndPointStr.ToLower().StartsWith("tcp:") ||
-                sipEndPointStr.ToLower().StartsWith("tls:") ||
-                sipEndPointStr.ToLower().StartsWith("ws:") ||
-                sipEndPointStr.ToLower().StartsWith("wss:"))
+            if (sipEndPointStr.StartsWith("udp:", StringComparison.OrdinalIgnoreCase) ||
+                sipEndPointStr.StartsWith("tcp:", StringComparison.OrdinalIgnoreCase) ||
+                sipEndPointStr.StartsWith("tls:", StringComparison.OrdinalIgnoreCase) ||
+                sipEndPointStr.StartsWith("ws:", StringComparison.OrdinalIgnoreCase) ||
+                sipEndPointStr.StartsWith("wss:", StringComparison.OrdinalIgnoreCase))
             {
                 return ParseSerialisedSIPEndPoint(sipEndPointStr);
             }