Added an ImapToken cache to try and reduce ImapToken allocations

Author: jstedfast

MailKit/ByteArrayBuilder.cs

@@ -48,6 +48,15 @@ public int Length {
 			get { return length; }
 		}
 
+		public byte this[int index] {
+			get { return buffer[index]; }
+		}
+
+		public byte[] GetBuffer ()
+		{
+			return buffer;
+		}
+
 		[MethodImpl (MethodImplOptions.AggressiveInlining)]
 		void EnsureCapacity (int capacity)
 		{

MailKit/MailKit.csproj

@@ -73,6 +73,7 @@
 
   <ItemGroup>
     <Compile Include="Net\Imap\AsyncImapClient.cs" />
+    <Compile Include="Net\Imap\HashCode.cs" Condition=" $(TargetFramework.StartsWith('net4')) Or '$(TargetFramework)' == 'netstandard2.0' " />
     <Compile Include="Net\Imap\IImapClient.cs" />
     <Compile Include="Net\Imap\IImapFolder.cs" />
     <Compile Include="Net\Imap\ImapAuthenticationSecretDetector.cs" />
@@ -100,6 +101,7 @@
     <Compile Include="Net\Imap\ImapSearchQueryOptimizer.cs" />
     <Compile Include="Net\Imap\ImapStream.cs" />
     <Compile Include="Net\Imap\ImapToken.cs" />
+    <Compile Include="Net\Imap\ImapTokenCache.cs" />
     <Compile Include="Net\Imap\ImapUtils.cs" />
     <Compile Include="Net\Pop3\AsyncPop3Client.cs" />
     <Compile Include="Net\Pop3\IPop3Client.cs" />

MailKit/MailKitLite.csproj

@@ -74,6 +74,7 @@
 
   <ItemGroup>
     <Compile Include="Net\Imap\AsyncImapClient.cs" />
+    <Compile Include="Net\Imap\HashCode.cs" Condition=" $(TargetFramework.StartsWith('net4')) Or '$(TargetFramework)' == 'netstandard2.0' " />
     <Compile Include="Net\Imap\IImapClient.cs" />
     <Compile Include="Net\Imap\IImapFolder.cs" />
     <Compile Include="Net\Imap\ImapAuthenticationSecretDetector.cs" />
@@ -101,6 +102,7 @@
     <Compile Include="Net\Imap\ImapSearchQueryOptimizer.cs" />
     <Compile Include="Net\Imap\ImapStream.cs" />
     <Compile Include="Net\Imap\ImapToken.cs" />
+    <Compile Include="Net\Imap\ImapTokenCache.cs" />
     <Compile Include="Net\Imap\ImapUtils.cs" />
     <Compile Include="Net\Pop3\AsyncPop3Client.cs" />
     <Compile Include="Net\Pop3\IPop3Client.cs" />