I use the Http module to handle my compression. I can’t use the new IIS compression for one of my sites because it is on a shared hosting and they did not enable IIS compression. I also have a custom web.config section in which I can exclude specific file paths, as in:
If you need code for the module, let me know. I can post it too. One class really does the compression, while I use 3 other classes to handle the custom web.config section.
<RiderDesign> <HttpCompressionSettings compressionOn="true"> <includedFileTypes> <add value="text/html"/> <add value="text/xhtml"/> </includedFileTypes> <excludedFilePaths> <add value="~/demos/partialpageupdates.aspx"/> <add value="~/demos/inlinetextedit.aspx"/> </excludedFilePaths> </HttpCompressionSettings </RiderDesign>
Just specify the pages you want to exclude and they are not compressed.
My compression module is below:
Imports System.Web Imports System.IO Imports System.Net Imports System.IO.Compression Namespace RiderDesign.FrameworkV4.HttpModule Public NotInheritable Class HttpCompressionModule Implements IHttpModule Private Shared GZIP As String = "gzip" Private Shared DEFLATE As String = "deflate" Private Shared ENCODING_TYPE As String = "encodingType" Private Shared CONTENT_TYPE As String = "contentType" Private MARK As String = "passedModule" Dim HttpState As HttpCompressionConfigStateModule Sub Dispose() Implements IHttpModule.Dispose End Sub Sub Init(ByVal context As HttpApplication) Implements IHttpModule.Init If HttpCompressionConfigModule.GetConfig().CompressionOn = True Then ' Use for any other then WebResource AddHandler context.PostReleaseRequestState, AddressOf context_PostReleaseRequestState End If If HttpCompressionConfigModule.GetConfig().CompressionOn = True Then ' Use only for WebResource.axd files AddHandler context.BeginRequest, AddressOf context_BeginRequest AddHandler context.EndRequest, AddressOf context_EndRequest End If End Sub 'IHttpModule.Init Sub context_PostReleaseRequestState(ByVal sender As Object, ByVal e As EventArgs) Dim app As HttpApplication = CType(sender, HttpApplication) ' If TypeOf app.Context.CurrentHandler Is System.Web.UI.Page And app.Request("HTTP_X_MICROSOFTAJAX") Is Nothing Then Dim FilePath As String Dim FilePaths As List(Of String) = New List(Of String) For Each Me.HttpState In HttpCompressionConfigModule.GetConfig().ExcludedFilePaths FilePaths.Add(String.Format("{0}", HttpState.Value)) Next HttpState FilePath = String.Join(", ", FilePaths.ToArray()) Dim ContentTypes As String Dim FileTypes As List(Of String) = New List(Of String) Dim state As HttpCompressionConfigStateModule For Each state In HttpCompressionConfigModule.GetConfig().IncludedFileTypes FileTypes.Add(String.Format("{0}", state.Value)) Next state ContentTypes = String.Join(", ", FileTypes.ToArray()) ' Check if the path is not excluded. If FilePath.Contains(app.Request.AppRelativeCurrentExecutionFilePath) Then Return End If ' Check if the mime type is not excluded. (Use to exclude pages that generate specific mime type (such image or Excel...)) If Not ContentTypes.Contains(app.Response.ContentType) Then Return End If ' Check if GZIP is supported by the client If IsGzipEncodingSupported() Then app.Response.Filter = New GZipStream(app.Response.Filter, CompressionMode.Compress) SetEncodingType(GZIP) ' Check if DEFLATE is supported by the client Else If IsDeflateEncodingSupported() Then app.Response.Filter = New DeflateStream(app.Response.Filter, CompressionMode.Compress) SetEncodingType(DEFLATE) End If End If End If End Sub Sub context_BeginRequest(ByVal sender As Object, ByVal e As EventArgs) Dim app As HttpApplication = CType(sender, HttpApplication) ' ' ' Check if the current request is WebResource.axd If app.Request.Path.Contains("WebResource.axd") Then SetCachingHeaders(app) If app.Context.Request.QueryString(MARK) Is Nothing Then app.CompleteRequest() End If End If End Sub 'context_BeginRequest Sub context_EndRequest(ByVal sender As Object, ByVal e As EventArgs) Dim app As HttpApplication = CType(sender, HttpApplication) ' If app.Request.Path.Contains("WebResource.axd") And app.Context.Request.QueryString(MARK) Is Nothing Then Dim cacheKey As String = app.Request.QueryString.ToString() If app.Application(cacheKey) Is Nothing Then CompressedIntoCache(app, cacheKey) End If SetEncodingType(CStr(app.Application((cacheKey + ENCODING_TYPE)))) app.Context.Response.ContentType = CStr(app.Application((cacheKey + CONTENT_TYPE))) app.Context.Response.BinaryWrite(CType(app.Application(cacheKey), Byte())) End If End Sub 'context_EndRequest Private Sub CompressedIntoCache(ByVal app As HttpApplication, ByVal cacheKey As String) 'Mark the current request by adding QueryString parameter. Dim request As HttpWebRequest = CType(WebRequest.Create((app.Context.Request.Url.OriginalString + "&" + MARK + "=1")), HttpWebRequest) request.Credentials = CredentialCache.DefaultNetworkCredentials Using response As HttpWebResponse = CType(request.GetResponse, HttpWebResponse) If (True) Then ' We getting the response stream, that raise again the 'BeginRequest' event (that why we marked the request) Dim responseStream As Stream = response.GetResponseStream() Dim contentType As String = response.ContentType.ToLower() ' Not a javascript or css content. ' We compress only WebResources that are Javascript or css file. ' The problem is, that we can know the content type only after we got the response. TODO: find a better solution ' for non CSS or JS content If Not IsContentSupported(contentType) Then ' Set the response type app.Context.Response.ContentType = contentType ' Send the file to the client without compression StreamCopy(responseStream, app.Response.OutputStream) responseStream.Dispose() app.Context.Response.End() Return End If ' Copy the response stream into memory stream, so we can convert it into byte[] easly. Dim dataStream As New MemoryStream() StreamCopy(responseStream, dataStream) responseStream.Dispose() ' Convert the response into byte[] Dim data As Byte() = dataStream.ToArray() dataStream.Dispose() Dim encodingType As String = String.Empty Using memstream As MemoryStream = New MemoryStream Dim compress As Stream = Nothing ' Choose the compression type and make the compression If IsGzipEncodingSupported() Then compress = New GZipStream(memstream, CompressionMode.Compress) encodingType = GZIP Else If IsDeflateEncodingSupported() Then compress = New DeflateStream(memstream, CompressionMode.Compress) encodingType = DEFLATE End If End If compress.Write(data, 0, data.Length) compress.Dispose() app.Application.Lock() app.Application.Add(cacheKey, memstream.ToArray()) app.Application.Add(cacheKey + ENCODING_TYPE, encodingType) app.Application.Add(cacheKey + CONTENT_TYPE, response.ContentType) app.Application.UnLock() End Using End If End Using End Sub 'CompressedIntoCache Private Shared Sub StreamCopy(ByVal input As Stream, ByVal output As Stream) Dim buffer(2048) As Byte Dim read As Integer Do read = input.Read(buffer, 0, buffer.Length) output.Write(buffer, 0, read) Loop While read > 0 End Sub 'StreamCopy Private Shared Sub SetCachingHeaders(ByVal app As HttpApplication) Dim etag As String = """" + app.Context.Request.QueryString.ToString().GetHashCode().ToString() + """" Dim incomingEtag As String = app.Request.Headers("If-None-Match") app.Response.Cache.VaryByHeaders("Accept-Encoding") = True app.Response.Cache.SetExpires(DateTime.Now.ToUniversalTime().AddDays(365)) app.Response.Cache.SetCacheability(HttpCacheability.Public) app.Response.Cache.SetLastModified(DateTime.Now.ToUniversalTime().AddDays(-1)) app.Response.Cache.SetETag(etag) If [String].Compare(incomingEtag, etag) = 0 Then app.Response.StatusCode = CInt(HttpStatusCode.NotModified) app.Response.End() End If End Sub 'SetCachingHeaders Private Shared Function IsBrowserSupported() As Boolean ' Because bug in Internet Explorer 6 Return Not (HttpContext.Current.Request.UserAgent Is Nothing Or HttpContext.Current.Request.UserAgent.Contains("MSIE 6")) End Function 'IsBrowserSupported Private Shared Function IsEncodingSupported() As Boolean Return IsGzipEncodingSupported() Or IsDeflateEncodingSupported() End Function 'IsEncodingSupported Private Shared Function IsGzipEncodingSupported() As Boolean Return Not (HttpContext.Current.Request.Headers("Accept-encoding") Is Nothing) And HttpContext.Current.Request.Headers("Accept-encoding").Contains(GZIP) End Function 'IsGzipEncodingSupported Private Shared Function IsDeflateEncodingSupported() As Boolean Return Not (HttpContext.Current.Request.Headers("Accept-encoding") Is Nothing) And HttpContext.Current.Request.Headers("Accept-encoding").Contains(DEFLATE) End Function 'IsDeflateEncodingSupported Private Shared Sub SetEncodingType(ByVal encoding As String) HttpContext.Current.Response.AppendHeader("Content-encoding", encoding) End Sub 'SetEncodingType Private Shared Function IsContentSupported(ByVal contentType As String) As Boolean If contentType.Contains("text/css") Or contentType.Contains("javascript") Then Return True End If Return False End Function End Class End Namespace