Use pre-gzipped content files?

[AnderssonPeter]

is there any support for pre-gzipped files if there where we could compress css, html and javascript files with zopfli to make then as small as possible.

the files could be saved as
[filename]_[hash].gzip or some like that.

If there is support how would one go about to enable it?
If there isn't do you have any tips on how to create it?

[neyromant]

I use gulp-gzip package for make .gz files.
And small middleware for handle requests for static files:

public class CompressedStaticFileMiddleware
    {
        private IHostingEnvironment _hostingEnv;
        private StaticFileMiddleware _base;
        public CompressedStaticFileMiddleware(RequestDelegate next, IHostingEnvironment hostingEnv, IOptions<StaticFileOptions> options, ILoggerFactory loggerFactory) 
        {
            _hostingEnv = hostingEnv;
            var contentTypeProvider = options.Value.ContentTypeProvider ?? new FileExtensionContentTypeProvider();
_base = new StaticFileMiddleware(next, hostingEnv, new StaticFileOptions()
            {
                ContentTypeProvider = contentTypeProvider,
                FileProvider = options.Value.FileProvider ?? hostingEnv.WebRootFileProvider,
                OnPrepareResponse = ctx =>
                {
                    const string ext = ".gz";
                    if (ctx.File.Name.EndsWith(ext))
                    {
                        string contentType = null;
                        if(contentTypeProvider.TryGetContentType(ctx.File.PhysicalPath.Remove(ctx.File.PhysicalPath.Length - ext.Length, ext.Length), out contentType))
                            ctx.Context.Response.ContentType = contentType;
                        ctx.Context.Response.Headers.Add("Content-Encoding", new[] { "gzip" });
                    }
                }
            }, loggerFactory);
        }

        public Task Invoke(HttpContext context)
        {
            if(context.Request.Path.HasValue)
            {
                string acceptEncoding = context.Request.Headers["Accept-Encoding"];
                if (
                    !string.IsNullOrEmpty(acceptEncoding) && 
                    (acceptEncoding.Contains("gzip") && 
                    System.IO.File.Exists(_hostingEnv.MapPath(context.Request.Path.Value.StartsWith("/") ? context.Request.Path.Value.Remove(0, 1) : context.Request.Path.Value) + ".gz"))
                )
                {
                    context.Request.Path = new PathString(context.Request.Path.Value + ".gz");
                    return _base.Invoke(context);
                }
            }
            return _base.Invoke(context);
        }
    }

[AnderssonPeter]

the constructor for StaticFileMiddleware takes a IOptions<StaticFileOptions> not a StaticFileOptions so i cant compile this?
And IHostingEnvironment does not seem to contain MapPath?

[neyromant]

@AnderssonPeter, yes, it was code for RC1.
For RC2 , you can try this:

public class CompressedStaticFileMiddleware
    {
        private IHostingEnvironment _hostingEnv;
        private StaticFileMiddleware _base;
        public CompressedStaticFileMiddleware(RequestDelegate next, IHostingEnvironment hostingEnv, IOptions<StaticFileOptions> options, ILoggerFactory loggerFactory)
        {
            _hostingEnv = hostingEnv;
            var contentTypeProvider = options.Value.ContentTypeProvider ?? new FileExtensionContentTypeProvider();
            options.Value.ContentTypeProvider = contentTypeProvider;
            options.Value.FileProvider = options.Value.FileProvider ?? hostingEnv.WebRootFileProvider;
            options.Value.OnPrepareResponse = ctx =>
            {
                const string ext = ".gz";
                if (ctx.File.Name.EndsWith(ext))
                {
                    string contentType = null;
                    if (contentTypeProvider.TryGetContentType(ctx.File.PhysicalPath.Remove(ctx.File.PhysicalPath.Length - ext.Length, ext.Length), out contentType))
                        ctx.Context.Response.ContentType = contentType;
                    ctx.Context.Response.Headers.Add("Content-Encoding", new[] { "gzip" });
                }
            };

            _base = new StaticFileMiddleware(next, hostingEnv, options, loggerFactory);
        }

        public Task Invoke(HttpContext context)
        {
            if (context.Request.Path.HasValue)
            {
                string acceptEncoding = context.Request.Headers["Accept-Encoding"];
                if (
                    !string.IsNullOrEmpty(acceptEncoding) &&
                    (
                        acceptEncoding.Contains("gzip") &&
                        System.IO.File.Exists(
                            System.IO.Path.Combine(
                                _hostingEnv.WebRootPath, context.Request.Path.Value.StartsWith("/") 
                                ? context.Request.Path.Value.Remove(0, 1) 
                                : context.Request.Path.Value
                            ) + ".gz"
                        )
                    )
                )
                {
                    context.Request.Path = new PathString(context.Request.Path.Value + ".gz");
                    return _base.Invoke(context);
                }
            }
            return _base.Invoke(context);
        }
    }

[AnderssonPeter]

Ill try it when i get home, but im using RTM not RC2 ill get back to you if this works in the RTM.

Thanks @neyromant !!

[neyromant]

You are welcome.
I think that in the RTM will not have problems, because these classes have not changed.

[AnderssonPeter]

Im confused does asp.net core gzip content on the fly?
If i don`t add the "CompressedStaticFileMiddleware" i still get GZipped content, and it does not matter if the .gz files are there or not so i guess they aren't used.

Also it seems like the Invoke method is only called once so it never has a chance to replace the file paths with .gz

[neyromant]

I found small mistake in code:

System.IO.File.Exists(
System.IO.Path.Combine(
_hostingEnv.WebRootPath, context.Request.Path.Value.StartsWith("/")
? context.Request.Path.Value.Remove(0, 1)
: context.Request.Path.Value
) + ".gz"
)

[AnderssonPeter]

Well some of my confusion has been lifted, the default project from visual studio runs IIS Express as a reverse proxy infront of Kestrel and IIS Express does automatic GZip compression on content.

So that was the reason for files being gzipped even when there was no .gz file.

Ill try your updated code when i get home and see if it works better!

Thanks @neyromant

[neyromant]

@AnderssonPeter, You are welcome.

[AnderssonPeter]

I made some improvements to support brotli compression, and if the browser supports both it picks the smallest file.

Now i haven't been able to test brotli for some reason its only used on https (Chrome and FireFox) and im to new to asp.net core and Kestrel to configure local https!

public class CompressedStaticFileMiddleware
{
    private static Dictionary<string, string> compressionTypes = new Dictionary<string, string>()
    {{"gzip", ".gz" },
        {"br", ".br" }};

    private IHostingEnvironment _hostingEnv;
    private StaticFileMiddleware _base;
    public CompressedStaticFileMiddleware(RequestDelegate next, IHostingEnvironment hostingEnv, IOptions<StaticFileOptions> options, ILoggerFactory loggerFactory)
    {
        _hostingEnv = hostingEnv;
        var contentTypeProvider = options.Value.ContentTypeProvider ?? new FileExtensionContentTypeProvider();
        options.Value.ContentTypeProvider = contentTypeProvider;
        options.Value.FileProvider = options.Value.FileProvider ?? hostingEnv.WebRootFileProvider;
        options.Value.OnPrepareResponse = ctx =>
        {
            foreach(var compressionType in compressionTypes.Keys)
            {
                var fileExtension = compressionTypes[compressionType];
                if (ctx.File.Name.EndsWith(fileExtension, StringComparison.OrdinalIgnoreCase))
                {
                    string contentType = null;
                    if (contentTypeProvider.TryGetContentType(ctx.File.PhysicalPath.Remove(ctx.File.PhysicalPath.Length - fileExtension.Length, fileExtension.Length), out contentType))
                        ctx.Context.Response.ContentType = contentType;
                    ctx.Context.Response.Headers.Add("Content-Encoding", new[] { compressionType });
                }
            }
        };

        _base = new StaticFileMiddleware(next, hostingEnv, options, loggerFactory);
    }

    public Task Invoke(HttpContext context)
    {
        if (context.Request.Path.HasValue)
        {
            string acceptEncoding = context.Request.Headers["Accept-Encoding"];
            FileInfo matchedFile = null;
            string[] browserSupportedCompressionTypes = context.Request.Headers["Accept-Encoding"].ToString().Split(new[] {',', ' '}, StringSplitOptions.RemoveEmptyEntries);
            foreach (var compressionType in compressionTypes.Keys)
            {
                if (browserSupportedCompressionTypes.Contains(compressionType, StringComparer.OrdinalIgnoreCase))
                {
                    var fileExtension = compressionTypes[compressionType];
                    var filePath = System.IO.Path.Combine(
                            _hostingEnv.WebRootPath, context.Request.Path.Value.StartsWith("/")
                            ? context.Request.Path.Value.Remove(0, 1)
                            : context.Request.Path.Value
                        ) + fileExtension;
                    var file = new FileInfo(filePath);
                    if (file.Exists)
                    {
                        if (matchedFile == null)
                            matchedFile = file;
                        else if (matchedFile.Length > file.Length)
                            matchedFile = file;
                    }
                }
            }
            if (matchedFile != null)
            {
                context.Request.Path = new PathString(context.Request.Path.Value + matchedFile.Extension);
                return _base.Invoke(context);
            }
        }
        return _base.Invoke(context);
    }
}

gulp-brotli can be used to compress the files with brotli it seems to beat gzip even when gzipped with zopfli.

[AnderssonPeter]

@neyromant is it ok if i create a github page with this code? and if any license you would prefer?
And if i figure out how ill create a nuget package.

[neyromant]

@AnderssonPeter, Of course, you can create a page and nuget package.
I will be happy if you are somewhere in the comments write my nickname :)

[AnderssonPeter]

Github page is up for it: https://github.com/AnderssonPeter/CompressedStaticFiles haven't managed to add nuget yet tho.

[AnderssonPeter]

And its up on nuget https://www.nuget.org/packages/CompressedStaticFiles/