同時(shí)我們還可以刪除一些空白
段,空行,注釋等以使得HTML文檔的尺寸變得更小. 讓我們先來(lái)實(shí)現(xiàn)壓縮與刪除空白類, 繼承自Stream類:
復(fù)制代碼 代碼如下:
/// summary>
/// CompressWhitespaceFilter
/// /summary>
public class CompressWhitespaceFilter : Stream
{
private GZipStream _contentGZipStream;
private DeflateStream _content_DeflateStream;
private Stream _contentStream;
private CompressOptions _compressOptions;
/// summary>
/// Initializes a new instance of the see cref="CompressWhitespaceFilter"/> class.
/// /summary>
/// param name="contentStream">The content stream./param>
/// param name="compressOptions">The compress options./param>
public CompressWhitespaceFilter(Stream contentStream, CompressOptions compressOptions)
{
if (compressOptions == CompressOptions.GZip)
{
this._contentGZipStream = new GZipStream(contentStream, CompressionMode.Compress);
this._contentStream = this._contentGZipStream;
}
else if (compressOptions == CompressOptions.Deflate)
{
this._content_DeflateStream = new DeflateStream(contentStream,CompressionMode.Compress);
this._contentStream = this._content_DeflateStream;
}
else
{
this._contentStream = contentStream;
}
this._compressOptions = compressOptions;
}
public override bool CanRead
{
get { return this._contentStream.CanRead; }
}
public override bool CanSeek
{
get { return this._contentStream.CanSeek; }
}
public override bool CanWrite
{
get { return this._contentStream.CanWrite; }
}
public override void Flush()
{
this._contentStream.Flush();
}
public override long Length
{
get { return this._contentStream.Length; }
}
public override long Position
{
get
{
return this._contentStream.Position;
}
set
{
this._contentStream.Position = value;
}
}
public override int Read(byte[] buffer, int offset, int count)
{
return this._contentStream.Read(buffer, offset, count);
}
public override long Seek(long offset, SeekOrigin origin)
{
return this._contentStream.Seek(offset, origin);
}
public override void SetLength(long value)
{
this._contentStream.SetLength(value);
}
public override void Write(byte[] buffer, int offset, int count)
{
byte[] data = new byte[count + 1];
Buffer.BlockCopy(buffer, offset, data, 0, count);
string strtext = System.Text.Encoding.UTF8.GetString(data);
strtext = Regex.Replace(strtext, "^\\s*", string.Empty, RegexOptions.Compiled | RegexOptions.Multiline);
strtext = Regex.Replace(strtext, "\\r\\n", string.Empty, RegexOptions.Compiled | RegexOptions.Multiline);
strtext = Regex.Replace(strtext, "!--*.*?-->", string.Empty, RegexOptions.Compiled | RegexOptions.Multiline);
byte[] outdata = System.Text.Encoding.UTF8.GetBytes(strtext);
this._contentStream.Write(outdata, 0, outdata.GetLength(0));
}
}
/// summary>
/// CompressOptions
/// /summary>
/// seealso cref="http://en.wikipedia.org/wiki/Zcat#gunzip_and_zcat"/>
/// seealso cref="http://en.wikipedia.org/wiki/DEFLATE"/>
public enum CompressOptions
{
GZip,
Deflate,
None
}
上面的代碼使用正則表達(dá)式替換字符串,你可以修改那些正則表達(dá)式來(lái)滿足你的需求. 我們同時(shí)使用了GZipStream與DeflateStream實(shí)現(xiàn)了壓縮. 好的,接下來(lái)與
HttpModule結(jié)合:
復(fù)制代碼 代碼如下:
/// summary>
/// CompressWhitespaceModule
/// /summary>
public class CompressWhitespaceModule : IHttpModule
{
#region IHttpModule Members
/// summary>
/// Disposes of the resources (other than memory) used by the module that implements see cref="T:System.Web.IHttpModule"/>.
/// /summary>
public void Dispose()
{
// Nothing to dispose;
}
/// summary>
/// Initializes a module and prepares it to handle requests.
/// /summary>
/// param name="context">An see cref="T:System.Web.HttpApplication"/> that provides access to the methods, properties, and events common to all application objects within an ASP.NET application/param>
public void Init(HttpApplication context)
{
context.BeginRequest += new EventHandler(context_BeginRequest);
}
/// summary>
/// Handles the BeginRequest event of the context control.
/// /summary>
/// param name="sender">The source of the event./param>
/// param name="e">The see cref="System.EventArgs"/> instance containing the event data./param>
void context_BeginRequest(object sender, EventArgs e)
{
HttpApplication app = sender as HttpApplication;
if (app.Request.RawUrl.Contains(".aspx"))
{
HttpContext context = app.Context;
HttpRequest request = context.Request;
string acceptEncoding = request.Headers["Accept-Encoding"];
HttpResponse response = context.Response;
if (!string.IsNullOrEmpty(acceptEncoding))
{
acceptEncoding = acceptEncoding.ToUpperInvariant();
if (acceptEncoding.Contains("GZIP"))
{
response.Filter = new CompressWhitespaceFilter(context.Response.Filter, CompressOptions.GZip);
response.AppendHeader("Content-encoding", "gzip");
}
else if (acceptEncoding.Contains("DEFLATE"))
{
response.Filter = new CompressWhitespaceFilter(context.Response.Filter, CompressOptions.Deflate);
response.AppendHeader("Content-encoding", "deflate");
}
}
response.Cache.VaryByHeaders["Accept-Encoding"] = true;
}
}
#endregion
}
HttpApplication.BeginRequest 事件是 在 ASP.NET 響應(yīng)請(qǐng)求時(shí)作為 HTTP 執(zhí)行管線鏈中的第一個(gè)事件發(fā)生。
在WEB.CONFIG中你還需要配置:
復(fù)制代碼 代碼如下:
httpModules>
add name="CompressWhitespaceModule" type="MyWeb.CompressWhitespaceModule" />
/httpModules>
我們來(lái)看一下效果,下面沒(méi)有使用時(shí), 4.8KB
接著看,處理過(guò)后的效果,Cotent-Encoding: gzip, filezie: 1.6KB
很簡(jiǎn)單,你可以按需求來(lái)增加更多的功能. 希望對(duì)您開(kāi)發(fā)有幫助.
作者：Petter Liu
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