Compressing web api response using GZip

In this post we are going to see how to create a compressed web api response to user,  because of compressing the result content-length will be less and it is more faster in get response. First let we create a new Web Api project.

    public class Student

    {

        public int Id { get; set; }

        public string Name { get; set; }

        public string Department { get; set; }

        public int Marks { get; set; }

    }

   public IEnumerable<Student> Get()

   {

            List<Student> studs = new List<Student>();

            studs.Add(new Student() { Id = 1, Name = "rajesh",

Department ="CSE", Marks=83});

            studs.Add(new Student() { Id = 2, Name = "suresh",

Department = "ECE", Marks=92  });

            studs.Add(new Student() { Id = 2, Name = "ramesh",

Department = "CSE", Marks = 76 });

            studs.Add(new Student() { Id = 2, Name = "ramu",

Department = "ECE", Marks = 94 });

            return studs;

    }

From the above code we can see the student list is returning, now we test this in post man rest client.

from the above , you can see the result is content-length is 219, now we will enable the GZip compression. For this we have to create actionFilterAttribute there we have to set the content-encoding as gzip. we have to add a package DotnetZip from nuget package manager

public class GZipCompression

    {

        public static byte[] GzipByte(byte[] input)

        {

            if (input == null)

                return null;

            using (var result= new MemoryStream())

            {

                using(var compress = new Ionic.Zlib.GZipStream(result,

Ionic.Zlib.CompressionMode.Compress))

                {

                    compress.Write(input, 0, input.Length);

                }

                return result.ToArray();

            }

        }

    }

public class ZipCompressionAttribute:ActionFilterAttribute

    {

        public override void OnActionExecuted(HttpActionExecutedContext                                                actionExecutedContext)

        {

            var content = actionExecutedContext.Response.Content;

            var bytes = content == null ? null : content.ReadAsByteArrayAsync().Result;

            var compressedContent = bytes == null ? new byte[0] :                                                                            GZipCompression.GzipByte(bytes);

            actionExecutedContext.Response.Content = new ByteArrayContent(compressedContent);

            actionExecutedContext.Response.Content.Headers.Remove("Content-Type");

            actionExecutedContext.Response.Content.Headers.Add("Content-encoding", "gzip");

            actionExecutedContext.Response.Content.Headers.Add("Content-Type",                                                                             "application/json");

            base.OnActionExecuted(actionExecutedContext);

        }

    }

Finally we have to add this action filter above the api method

[ZipCompression]

public IEnumerable<Student> Get()

{

            List<Student> studs = new List<Student>();

            studs.Add(new Student() { Id = 1, Name = "rajesh",

Department ="CSE", Marks=83});

            studs.Add(new Student() { Id = 2, Name = "suresh",

Department = "ECE", Marks=92  });

            studs.Add(new Student() { Id = 2, Name = "ramesh",

Department = "CSE", Marks = 76 });

            studs.Add(new Student() { Id = 2, Name = "ramu",

Department = "ECE", Marks = 94 });

            return studs;

}

Now we see the response in post man client, content-length will be reduced.

From this post you can learn how to create a compressing web api response using Gzip.