--- "Noel J. Bergman" <[EMAIL PROTECTED]> wrote: > > Since we are talking about improving SMTP data > handler > > class I want to draw attention to some performance > > issues I had found earlier while analyzing > > CharTerminatedInputStream class. > > > The point of major concern was the use of read > method > > to read data from Socket InputStream. for example > if > > we consider an average mail size of 40KB, read > method > > will be called 40 x 1024 = 40960 > > This seems to be factually wrong. Consider the > following: > > in = new > BufferedInputStream(socket.getInputStream(), 1024); > inReader = new CRLFTerminatedReader(in, > "ASCII"); > InputStream msgIn = new > CharTerminatedInputStream(in, > SMTPTerminator); > > In all cases, the filtered data is coming through > BufferedInputStream with a > 1K buffer.
The point here is not that the data is coming from BufferedInputStream. The point of concern is that the read() method is called so many times putting a huge amount of function call overhead so i am just trying find a way to avoid that. I would prefer a approach wherein we read a block of data and use a for loop to find out the terminating characters, if terminator falls at the block boundary, read next block and continue to match terminator. In this process any extra bytes in buffer can be easily unread if we use PushBackInputStream. The logic behind the above approach is that the for loop executes much faster on a block of data say 2KB as compared to calling read() method 2048 times over the same block. I have tested the above mentioned approach and the results are quite impressive. It takes 12 seconds to read 110KB mail file 1000 times using CharTerminatedInputStream while on the other hand it takes hardly 5 seconds to read the same mail file 1000 times using the new approach. The hardware configuration was CPU P4/RAM 256MB DDR/HDD 40GB/OS Win 98 I'll submit the source code of my test routine and the new optimized InputStream in my forthcoming mails. Cheers __________________________________ Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
