Add support for Zstd

Author: gleocadie

profiler/test/Datadog.Profiler.IntegrationTests/Datadog.Profiler.IntegrationTests.csproj

@@ -86,6 +86,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
+     <PackageReference Include="ZstdSharp.Port" Version="0.8.6" />
   </ItemGroup>
   <ItemGroup Condition=" $(DD_LOGGER_ENABLED) != 'false' ">
     <PackageReference Include="DatadogTestLogger" Version="0.0.38" ExcludeAssets="compile" />

profiler/test/Datadog.Profiler.IntegrationTests/Helpers/SamplesHelper.cs

@@ -11,12 +11,14 @@
 using K4os.Compression.LZ4.Streams;
 using Perftools.Profiles;
 using Xunit;
+using ZstdSharp;
 
 namespace Datadog.Profiler.IntegrationTests.Helpers
 {
     public static class SamplesHelper
     {
         private static readonly byte[] Lz4MagicNumber = BitConverter.GetBytes(0x184D2204);
+        private static readonly byte[] ZstdMagicNumber = BitConverter.GetBytes(0xFD2FB528);
 
         public static int GetSamplesCount(string directory)
         {
@@ -213,6 +215,10 @@ private static Stream GetStream(string filename)
             {
                 return LZ4Stream.Decode(s);
             }
+            else if (ZstdMagicNumber.SequenceEqual(buffer))
+            {
+                return new DecompressionStream(s);
+            }
             else
             {
                 return s;