add content gzip compression for cloudconnection

Author: NRHelmi

README.md

@@ -2,7 +2,7 @@
 
 This is a Client SDK for RelationalAI
 
-- API version: 1.2.1
+- API version: 1.2.2
 
 ## Frameworks supported
 

RelationalAI/KGMSClient.cs

@@ -22,7 +22,7 @@ public partial class GeneratedRelationalAIClient
 
         public const string JSON_CONTENT_TYPE = "application/json";
         public const string CSV_CONTENT_TYPE = "text/csv";
-        public const string USER_AGENT_HEADER = "KGMSClient/1.2.1/csharp";
+        public const string USER_AGENT_HEADER = "KGMSClient/1.2.2/csharp";
 
         public int DebugLevel = Connection.DEFAULT_DEBUG_LEVEL;
 
@@ -53,14 +53,25 @@ partial void PrepareRequest(Transaction body, HttpClient client, HttpRequestMess
             }
             if(conn is CloudConnection) {
                 query["compute_name"] = conn.ComputeName;
+                // Note:
+                // We need to send the gzip content encoding header and a gzip compressed body only in case of a CloudConnection.
+                // Local rai-server cannot handle gzip encoding, only infra server support does.
+        
+                // Compress the contents (request body) as gzipped byte array. C# httpclient does not implicitly compress the content over the wire 
+                // if content encoding is gzip; we need to manually compress the body.
+                // Note: If the client sends content-encoding as gzip but does not encode the content to gzip, then the server will return 400 Bad Request. 
+                request.Content = CompressionUtils.CompressRequestContentAsGzip(request.Content);
+                //Set the content encoding type header as gzip. It will tell the server that the content is gzip encoded.
+                request.Content.Headers.Add("content-encoding", "gzip");
             }
             uriBuilder.Query = query.ToString();
             request.RequestUri = uriBuilder.Uri;
 
             // populate headers
             request.Headers.Host = request.RequestUri.Host;
+            //Set the content type header
             request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json; charset=utf-8");
-
+            
             // sign request here
             var raiRequest = new RAIRequest(request, conn);
             raiRequest.Sign(debugLevel: DebugLevel);

RelationalAI/RAIRequest.cs

@@ -61,7 +61,8 @@ public void Sign(string[] includeHeaders = null, int debugLevel=1) {
 
         public void Sign(DateTime t, string[] includeHeaders = null, int debugLevel=1) {
             if(includeHeaders == null) {
-                includeHeaders = new string[]{"host", "content-type", "x-rai-date"};
+                //Adding a new header content-encoding for signature purposes.
+                includeHeaders = new string[]{"host", "content-type", "x-rai-date", "content-encoding"};
             }
             if(this.Creds == null) return;
 

RelationalAI/RelationalAI.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <Version>1.2.1</Version>
+    <Version>1.2.2</Version>
     <TargetFramework>netcoreapp3.1</TargetFramework>
     <PackageId>RelationalAI</PackageId>
     <Authors>RelationalAI</Authors>

RelationalAI/Util.cs

@@ -5,6 +5,9 @@
 using System.Linq;
 using System.Reflection;
 using System.Text;
+using System.IO;
+using System.IO.Compression;
+using System.Net.Http;
 
 namespace Com.RelationalAI
 {
@@ -170,4 +173,36 @@ public static string FlattenException(Exception exception)
             return stringBuilder.ToString();
         }
     }
+
+    public static class CompressionUtils{
+        /**
+            This function will take HttpContent object and then perform the following
+            - Initialize a memory stream and copy the contents as bytes into it; called the Content Stream.
+            - Initialize a gzip stream with a compressed stream.
+            - Compress the content stream as bytes using gzip and copy it to the Compressed Stream.
+            - Return the HttpContent with compressed stream as bytes 
+        */ 
+        public static HttpContent CompressRequestContentAsGzip(HttpContent content)
+        {
+            //Initialize a memory stream to hold the compressed contents.
+            var compressedStream = new MemoryStream();
+
+            //Read bytes from HttpContent into byte array
+            byte[] byteArray = content.ReadAsByteArrayAsync().Result;
+            //Initialize a memory stream with byte array content to compress it.
+            using (var contentStream = new MemoryStream(byteArray))
+            {
+                //Initialize the gzip stream and feed compressed stream to copy the compressed contents.
+                using (var gzipStream = new GZipStream(compressedStream, System.IO.Compression.CompressionMode.Compress))
+                {
+                    //Copy the contents to gzip stream. Gzip stream will compress and copy them to the compressed stream that we fed earlier. 
+                    contentStream.CopyTo(gzipStream);
+                }
+            }
+            //Make the HttpContent as byte array content
+            var httpContent = new ByteArrayContent(compressedStream.ToArray());
+            //Return the byte array content.
+            return httpContent;
+        }
+    }
 }

default.nix

@@ -9,7 +9,7 @@ let
 in
 stdenv.mkDerivation rec {
   name = "rai-server-csharp-client-sdk-${version}";
-  version = "1.2.1";
+  version = "1.2.2";
   buildInputs = [
     raiserverBinary
     dotnet-sdk_3