Title	Optimize FileUtil.copyContents()
Date	23-Feb-2006 19:49:19 EET
Version	2.3.72
Submitter	mchristensen
Bug criticality	MediumBug
Browser version	IE 6.0
Bug status	ClosedBug
PageProvider used
Servlet Container	Tomcat5
Operating System	Linux
URL
Java version	1.4.2

Uploading a 30MB attachment takes 10-20 minutes. Researching the problem I traced the slowness to BasicAttachmentProvider.putAttachementData()'s call to com.ecyrd.jspwiki.FileUtil.copyContents().

This method copies the attachments byte-by-byte, which results in 90+% of the delay. Please make this a buffered operation.

Instead of,

    public static void copyContents( InputStream in, OutputStream out )
        throws IOException
    {
        int c;
        
        while( (c = in.read()) != -1  )
        {
            out.write( c );
        }

        out.flush();
    }

How about something like the following (compiled but not tested. I have used this approach before with MASSIVE speed improvement over the byte-by-byte method)

	public static void copyContents(InputStream in, OutputStream out)
			throws IOException {
		byte[] buf = new byte[4096];
		int bytesRead = 0;

		while ((bytesRead = in.read(buf)) > 0) {
			out.write(buf, 0, bytesRead);
		}

		out.flush();
	}

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Oops... I thought I already had. Thanks, will be fixed.

-- JanneJalkanen

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Be careful with the fix! I had also changed that code because it performs horrible but there whas a problem with the javaclass TranslatorReader (I measured a 5-7x improvement). I had to revert my change! see BugClickingOnmoreInfoOnHttpwww.jspwiki.orgwikiMainTakesAVeryLongTime at 'Oef, A major setback'

-- KeesKuip

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Since 2.3 no longer uses the TranslatorReader, we can safely go and take this patch in. It's in 2.3.100. Thanks!

-- JanneJalkanen, 13-Apr-2006