asp.net-mvc - asp.net mvc 压缩流并删除空格

Question

所以我通过 Action 过滤器压缩我的输出流:

var response = filterContext.HttpContext.Response;
response.Filter = new DeflateStream(response.Filter), CompressionMode.Compress);

效果很好。现在，我还想删除存在的多余空格。我找到了 Mads Kristensen 的 http 模块 http://madskristensen.net/post/A-whitespace-removal-HTTP-module-for-ASPNET-20.aspx .

public class WhitespaceFilter : Stream {

    // using Mads Kristensen httpModule
    // http://madskristensen.net/post/A-whitespace-removal-HTTP-module-for-ASPNET-20.aspx

    private Stream os;
    private static Regex reg = new Regex(@"^\s+", RegexOptions.Multiline | RegexOptions.Compiled); 

    public WhitespaceFilter(Stream os) {
        this.os = os;
    }

    //methods that need to be overridden from stream
    public override bool CanRead {
        get { return true; }
    }

    public override bool CanSeek {
        get { return true; }
    }

    public override bool CanWrite {
        get { return true; }
    }

    public override void Flush() {
        os.Flush();
    }

    public override long Length {
        get { return 0; }
    }

    private long _position;
    public override long Position {
        get { return _position; }
        set { _position = value; }
    }

    public override int Read(byte[] buffer, int offset, int count) {
        return os.Read(buffer, offset, count);
    }

    public override long Seek(long offset, SeekOrigin origin) {
        return os.Seek(offset, origin);
    }

    public override void SetLength(long value) {
        os.SetLength(value);
    }

    public override void Close() {
        os.Close();
    }

    public override void Write(byte[] buffer, int offset, int count) {
        string html = System.Text.Encoding.Default.GetString(buffer);

        //remove whitespace
        html = reg.Replace(html, string.Empty);

        byte[] outdata = System.Text.Encoding.Default.GetBytes(html);

        //write bytes to stream
        os.Write(outdata, 0, outdata.GetLength(0));
    } 

我添加了 WhitespaceFilter 类并添加了一个新的过滤器，如压缩:

var response = filterContext.HttpContext.Response;
response.Filter = new WhitepaperFilter(response.Filter);

这也很好用。但是，我似乎在将两者结合起来时遇到了问题!

我试过:

var response = filterContext.HttpContext.Response;
response.Filter = new DeflateStream(new WhitespaceFilter(response.Filter), CompressionMode.Compress);

然而，这会导致一些重大问题。 html 完全搞砸了，有时我会收到 330 错误。

似乎 Whitespace 过滤器写入方法被多次调用。第一次 html 字符串很好，但在随后的调用中它只是随机字符。

我认为这可能是因为流已被放气，但空白过滤器不是使用未触及的流然后将结果流传递给 DeflateStream 调用吗？

有任何想法吗？

Answer 1

对于那些走到这一步的人......你可以做到......只需交换流链接的顺序:

   public override void OnActionExecuting(ActionExecutingContext filterContext)
   {
        var response = filterContext.HttpContext.Response;

        // - COMPRESS
        HttpRequestBase request = filterContext.HttpContext.Request;
        string acceptEncoding = request.Headers["Accept-Encoding"];
        if (!String.IsNullOrEmpty(acceptEncoding))
        {
            acceptEncoding = acceptEncoding.ToUpperInvariant();

            if (acceptEncoding.Contains("GZIP"))
            {
                response.AppendHeader("Content-encoding", "gzip");
                response.Filter = new GZipStream(response.Filter, CompressionMode.Compress);
            }
            else if (acceptEncoding.Contains("DEFLATE"))
            {
                response.AppendHeader("Content-encoding", "deflate");
                response.Filter = new DeflateStream(response.Filter, CompressionMode.Compress);
            }
        }

        // - REMOVE WHITE SPACE
        response.Filter = new WhitespaceFilter(response.Filter);
    }