使用 gzip 压缩组件的 D 级

Question

我使用了 YSlow Firefox 插件，它返回以下结果：

----------------------------------- -------------------------------------------------- ----
使用 gzip 压缩组件的 D 级

有 3 个纯文本组件应压缩发送

* http://localhost:63808/WebSite/BemVindo/
* http://localhost:63808/WebSite/css/Global.css?...
* http://localhost:63808/WebSite/js/Global.js?...

-------------------------------- -------------------------------------------------- --------
所以我开始搜索并得到了这段代码：

Global.asax

Private Sub Application_PreRequestHandlerExecute(ByVal sender As Object, ByVal e As EventArgs)

    Dim Response As HttpResponse = HttpContext.Current.Response
    Dim AcceptEncoding As String = HttpContext.Current.Request.Headers("Accept-Encoding")

    If Not String.IsNullOrEmpty(AcceptEncoding) AndAlso AcceptEncoding.Contains("gzip") OrElse AcceptEncoding.Contains("deflate") Then
        If AcceptEncoding.Contains("deflate") Then
            Response.Filter = New System.IO.Compression.DeflateStream(Response.Filter, System.IO.Compression.CompressionMode.Compress)
            Response.AppendHeader("Content-Encoding", "deflate")
        Else
            Response.Filter = New System.IO.Compression.GZipStream(Response.Filter, System.IO.Compression.CompressionMode.Compress)
            Response.AppendHeader("Content-Encoding", "gzip")
        End If
    End If

    Response.AppendHeader("Vary", "Content-Encoding")

End Sub

现在我有了：

使用 gzip 压缩组件的 A 级

很好，嗯？问题是：Application_PreRequestHandlerExecute 事件是 gzip/deflate 请求的最佳位置吗？

Answer 1

不确定，但您的代码可能会导致使用 Ajax 的页面出现问题。以下页面显示了类似的代码，但如果检测到 Ajax，则取消压缩： 在 ASP.NET 页面中启用 Gzip 和 Deflate HTTP 压缩。我用VB翻译了代码，但没有尝试。

埃里克·

  Private Sub Application_PreRequestHandlerExecute(ByVal sender As Object, ByVal e As EventArgs)
Dim app As HttpApplication = TryCast(sender, HttpApplication)
Dim acceptEncoding As String = app.Request.Headers("Accept-Encoding")
Dim prevUncompressedStream As Stream = app.Response.Filter

If Not (TypeOf app.Context.CurrentHandler Is Page OrElse app.Context.CurrentHandler.[GetType]().Name = "SyncSessionlessHandler") OrElse app.Request("HTTP_X_MICROSOFTAJAX") IsNot Nothing Then
  Return
End If

If acceptEncoding Is Nothing OrElse acceptEncoding.Length = 0 Then
  Return
End If

acceptEncoding = acceptEncoding.ToLower()

If acceptEncoding.Contains("deflate") OrElse acceptEncoding = "*" Then
  ' defalte
  app.Response.Filter = New DeflateStream(prevUncompressedStream, CompressionMode.Compress)
  app.Response.AppendHeader("Content-Encoding", "deflate")
ElseIf acceptEncoding.Contains("gzip") Then
  ' gzip
  app.Response.Filter = New GZipStream(prevUncompressedStream, CompressionMode.Compress)
  app.Response.AppendHeader("Content-Encoding", "gzip")
End If

恩德·替补

Answer 2

是的，Application_PreRequestHandlerExecute 事件是 gzip/deflate 请求的最佳位置。