Add ToBase64() to MemoryProvider

Author: mythz

src/ServiceStack.Memory/NetCoreMemory.cs

@@ -90,6 +90,11 @@ public override byte[] ParseBase64(ReadOnlySpan<char> value)
             }
         }
 
+        public override string ToBase64(ReadOnlyMemory<byte> value)
+        {
+            return Convert.ToBase64String(value.Span);
+        }
+
         public override Task WriteAsync(Stream stream, ReadOnlySpan<char> value, CancellationToken token=default)
         {
             using (var writer = new BinaryWriter(stream, Encoding.UTF8, leaveOpen:true))

src/ServiceStack.Text/DefaultMemory.cs

@@ -2,6 +2,7 @@
 using System.Globalization;
 using System.IO;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -511,6 +512,13 @@ public override byte[] ParseBase64(ReadOnlySpan<char> value)
             return Convert.FromBase64String(value.ToString());
         }
 
+        public override string ToBase64(ReadOnlyMemory<byte> value)
+        {
+            return MemoryMarshal.TryGetArray(value, out var segment)
+                ? Convert.ToBase64String(segment.Array, 0, segment.Count)
+                : Convert.ToBase64String(value.ToArray());
+        }
+
         public override StringBuilder Append(StringBuilder sb, ReadOnlySpan<char> value)
         {
             return sb.Append(value.ToArray());

src/ServiceStack.Text/MemoryProvider.cs

@@ -48,6 +48,8 @@ public abstract class MemoryProvider
 
         public abstract byte[] ParseBase64(ReadOnlySpan<char> value);
 
+        public abstract string ToBase64(ReadOnlyMemory<byte> value);
+
         public abstract Task WriteAsync(Stream stream, ReadOnlySpan<char> value, CancellationToken token = default);
         public abstract Task WriteAsync(Stream stream, ReadOnlyMemory<byte> value, CancellationToken token = default);
 

src/ServiceStack.Text/NetCoreMemory.cs

@@ -90,6 +90,11 @@ public override byte[] ParseBase64(ReadOnlySpan<char> value)
             }
         }
 
+        public override string ToBase64(ReadOnlyMemory<byte> value)
+        {
+            return Convert.ToBase64String(value.Span);
+        }
+
         public override Task WriteAsync(Stream stream, ReadOnlySpan<char> value, CancellationToken token=default)
         {
             using (var writer = new BinaryWriter(stream, Encoding.UTF8, leaveOpen:true))