private void CompressContent(object sender, EventArgs e)
{
HttpApplication app = (HttpApplication)sender;
if ((app == null) || (app.Context == null) || (app.Context.Items == null))
{
return;
}
else
{
CommonLibrary.Framework.CDefault page = app.Context.Handler as CommonLibrary.Framework.CDefault;
if ((page == null))
{
return;
}
}
if (app.Response == null || app.Response.ContentType == null || app.Response.ContentType.ToLower() != "text/html")
{
return;
}
if (!app.Context.Items.Contains(INSTALLED_KEY))
{
app.Context.Items.Add(INSTALLED_KEY, INSTALLED_TAG);
string realPath = app.Request.Url.PathAndQuery;
CommonLibrary.HttpModules.Compression.Config.Settings _Settings = CommonLibrary.HttpModules.Compression.Config.Settings.GetSettings();
if (_Settings == null)
{
return;
}
bool compress = true;
if (_Settings.PreferredAlgorithm == CommonLibrary.HttpModules.Compression.Config.Algorithms.None)
{
compress = false;
if (!_Settings.Whitespace)
{
return;
}
}
string acceptedTypes = app.Request.Headers["Accept-Encoding"];
if (_Settings.IsExcludedPath(realPath) || acceptedTypes == null)
{
return;
}
app.Response.Cache.VaryByHeaders["Accept-Encoding"] = true;
CompressingFilter filter = null;
if (compress)
{
string[] types = acceptedTypes.Split(',');
filter = GetFilterForScheme(types, app.Response.Filter, _Settings);
}
if (filter == null)
{
if (_Settings.Whitespace)
{
app.Response.Filter = new WhitespaceFilter(app.Response.Filter, _Settings.Reg);
}
else
{
return;
}
}
else
{
if (_Settings.Whitespace)
{
app.Response.Filter = new WhitespaceFilter(filter, _Settings.Reg);
}
else
{
app.Response.Filter = filter;
}
}
}
}
public static CompressingFilter GetFilterForScheme(string[] schemes, Stream output, CommonLibrary.HttpModules.Compression.Config.Settings prefs)
{
bool foundDeflate = false;
bool foundGZip = false;
bool foundStar = false;
float deflateQuality = 0;
float gZipQuality = 0;
float starQuality = 0;
bool isAcceptableDeflate;
bool isAcceptableGZip;
bool isAcceptableStar;
for (int i = 0; i <= schemes.Length - 1; i++)
{
string acceptEncodingValue = schemes[i].Trim().ToLower();
if (acceptEncodingValue.StartsWith("deflate"))
{
foundDeflate = true;
float newDeflateQuality = GetQuality(acceptEncodingValue);
if (deflateQuality < newDeflateQuality)
{
deflateQuality = newDeflateQuality;
}
}
else if ((acceptEncodingValue.StartsWith("gzip") || acceptEncodingValue.StartsWith("x-gzip")))
{
foundGZip = true;
float newGZipQuality = GetQuality(acceptEncodingValue);
if ((gZipQuality < newGZipQuality))
{
gZipQuality = newGZipQuality;
}
}
else if ((acceptEncodingValue.StartsWith("*")))
{
foundStar = true;
float newStarQuality = GetQuality(acceptEncodingValue);
if ((starQuality < newStarQuality))
{
starQuality = newStarQuality;
}
}
}
isAcceptableStar = foundStar && (starQuality > 0);
isAcceptableDeflate = (foundDeflate && (deflateQuality > 0)) || (!foundDeflate && isAcceptableStar);
isAcceptableGZip = (foundGZip && (gZipQuality > 0)) || (!foundGZip && isAcceptableStar);
if (isAcceptableDeflate && !foundDeflate)
{
deflateQuality = starQuality;
}
if (isAcceptableGZip && !foundGZip)
{
gZipQuality = starQuality;
}
if ((!(isAcceptableDeflate || isAcceptableGZip || isAcceptableStar)))
{
return(null);
}
if ((isAcceptableDeflate && (!isAcceptableGZip || (deflateQuality > gZipQuality))))
{
return(new DeflateFilter(output));
}
if ((isAcceptableGZip && (!isAcceptableDeflate || (deflateQuality < gZipQuality))))
{
return(new GZipFilter(output));
}
if ((isAcceptableDeflate && (prefs.PreferredAlgorithm == Algorithms.Deflate || prefs.PreferredAlgorithm == Algorithms.Default)))
{
return(new DeflateFilter(output));
}
if ((isAcceptableGZip && prefs.PreferredAlgorithm == Algorithms.GZip))
{
return(new GZipFilter(output));
}
if ((isAcceptableDeflate || isAcceptableStar))
{
return(new DeflateFilter(output));
}
if ((isAcceptableGZip))
{
return(new GZipFilter(output));
}
return(null);
}