Miscellaneous improvements to "jar".
Ulf.Zibis at gmx.de
Fri Jun 26 16:35:27 UTC 2009
Oops, I'm not as fast as you two, writing in english. :-(
Am 26.06.2009 18:04, Martin Buchholz schrieb:
> Removing one layer of BufferedInputStream
> in my change saves one bulk copy per file.
> And reusing the same buffer saves on cache misses
> and GC. But bulk copy is actually very fast,
> (especially as memory is becoming more like disk),
> so the win is relatively small.
> I would be surprised if you could get more than
> the 10-20% that I've gotten with this change,
> by using direct buffers.
> On Fri, Jun 26, 2009 at 08:47, Xueming Shen <Xueming.Shen at sun.com
> <mailto:Xueming.Shen at sun.com>> wrote:
> I do have a "prototype implementation" that uses buffer based
> read/write on Jar/ZipFile, it
> is not that "much" faster as you would have expected (basically
> the gain of using direct buffer
> comes from saving one or two memory copy of the content, which is
> very faster, compared to
> the "real hard" work of moving bits from harddisk to memory).
> While it's still something
> worth doing, but definitely not a high priority for now, yes,
> it's on the list.
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