- Initial commit

Runtime/HTTP/Response/Decompression/DecompressorFactory.cs

@@ -0,0 +1,72 @@
+using Best.HTTP.Shared;
+using Best.HTTP.Shared.Logger;
+using Best.HTTP.Shared.PlatformSupport.Text;
+
+namespace Best.HTTP.Response.Decompression
+{
+    public static class DecompressorFactory
+    {
+        public const int MinLengthToDecompress = 256;
+
+        // cached header value
+        private static string AcceptEncoding = null;
+
+        public static void SetupHeaders(HTTPRequest request)
+        {
+            if (!request.HasHeader("Accept-Encoding"))
+            {
+                if (AcceptEncoding == null)
+                {
+                    var sb = StringBuilderPool.Get(4);
+
+                    if (BrotliDecompressor.IsSupported())
+                        sb.Append("br, ");
+
+                    if (GZipDecompressor.IsSupported)
+                        sb.Append("gzip, ");
+
+                    if (DeflateDecompressor.IsSupported)
+                        sb.Append("deflate, ");
+
+                    sb.Append("identity");
+
+                    AcceptEncoding = StringBuilderPool.ReleaseAndGrab(sb);
+                }
+
+                request.AddHeader("Accept-Encoding", AcceptEncoding);
+            }
+        }
+
+        public static IDecompressor GetDecompressor(string encoding, LoggingContext context)
+        {
+            if (encoding == null)
+                return null;
+
+            switch (encoding.ToLowerInvariant())
+            {
+                // https://github.com/Benedicht/BestHTTP-Issues/issues/183
+                case "none":
+
+                case "identity":
+                case "utf-8":
+                    break;
+
+                case "gzip": return new GZipDecompressor(MinLengthToDecompress);
+
+                case "deflate": return new DeflateDecompressor(MinLengthToDecompress);
+
+                case "br":
+                    if (BrotliDecompressor.IsSupported())
+                        return new BrotliDecompressor(MinLengthToDecompress);
+                    else
+                        goto default;
+
+                default:
+                    HTTPManager.Logger.Warning(nameof(DecompressorFactory), $"GetDecompressor - unsupported encoding '{encoding}'!", context);
+                    break;
+            }
+
+            return null;
+        }
+    }
+}