CompressionService.cs

        private abstract class CompressionService : ICompressionService
        {
            public abstract string EncodingType { get; }

            protected abstract Stream CreateCompressionStream(Stream output);

            protected abstract Stream CreateDecompressionStream(Stream input);

            public Task Compress(Stream source, Stream destination)
            {
                Stream compressed = CreateCompressionStream(destination);
                return Pump(source, compressed)
                    .ContinueWith(task => compressed.Dispose());
            }

            public Task Decompress(Stream source, Stream destination)
            {
                Stream decompressed = CreateDecompressionStream(source);
                return Pump(decompressed, destination)
                    .ContinueWith(task => decompressed.Dispose());
            }

            private Task Pump(Stream input, Stream output)
            {
                return input.CopyToAsync(output);
            }
        }