[Opera-Linux] How to reload faster?

[Larry Alkoff]

Thanks very much for your informative response Daniel.

My machine uses a 950 mhz Athlon so that would account for some of my 
slowness.  I'll be getting a much faster machine pretty soon and will 
check the speeds of a reload.

With \tcpdump -v  I get the following for the reload:

16:00:08.353743 IP (tos 0x0, ttl  64, id 16772, offset 0, flags [DF], proto:
TCP (6), length: 52) kinda.56633 > farnsworth.tigertech.net.www: F, cksum
0xde9a (correct), 513:513(0) ack 501 win 216 <nop,nop,timestamp 405712733
830627882>

16:00:09.037755 IP (tos 0x0, ttl  64, id 22699, offset 0, flags [DF], proto:
TCP (6), length: 52) kinda.56634 > farnsworth.tigertech.net.www: F, cksum
0xb7a9 (correct), 518:518(0) ack 12356 win 997 <nop,nop,timestamp 405712904
830627986>

Does this seem right to you?  About the same as you got?  It seems to 
indicate about a 2 second lag plus cpu time getting the cache information.

There is so much other stuff coming in it's difficult to focus what's 
coming back from the reload.

I agree it would be nice if option 4 (cache in memory) would be implemented.

Larry


Daniel Eckl wrote:
> I now tried this. Going back to digg.com takes about 2 seconds for me.
> I'm running on a Dual Core 1,8 Ghz. If your CPU is slower, it might take
> longer to render the content, so 5 to 10 seconds sounds possible.
> 
> I traced my network traffic with wireshark and I I found out that one
> thing is being transfered when going back: A hit counter image from
> another server of digg.com. This image is being transfered with these
> HTTP Response Headers:
> Date: Sat, 09 Jun 2007 09:43:01 GMT
> Cache-Control: no-cache, private, must-revalidate
> Pragma: no-cache
> Expires: Sat, 09 Jun 2007 09:43:02 GMT
> (as you can see, the expiration date is on second after the response)
> 
> So it's wanted that a browser fetches this image every time.
> Now I think that a history back action is thought to fetch EVERYTHING
> from the cache to be able to show the exact state you saw when you
> visited it. But now there's a dilemma: Opera is not allowed to cache
> this image when it first gets it. But when you go back in history, opera
> is supposed to show it to you...
> 
> So this would give three options:
> 1: Fetch it again from the source URL
> 2: Not show this image at all when going back in history
> 3: Always cache everything opera loads, even when the server does not
> allow to.
> 4: Cache these kind of content just in memory.
> 
> At the moment opera seems to use option 1.
> Option 2 could lead to lots of angry support queries if visible content
> it missing because of that. Not wanted.
> For privacy and security reasons, option 3 is not a real option. If
> server sais "don't cache", then opera is supposed to exactly do so. The
> content marked this way might contain private information that no
> attacker should be able to read from your harddisk.
> 
> But I think option 4 doesn't sound that bad. Caching this content in
> memory only should be rather safe. Well you can be attacked with a
> rootkit which is able to read from your RAM (well I'm not a security
> expert but this sounds plausible to me) but if you have such a problem,
> then all your traffic and all your keystrokes are compromised as well
> anyway.
> 
> I think this would be a good option to handle this kind of content.
> Is there any opera dev who can comment on this? Is there any drawback I
> didn't think of? Is this doable or even planned already?
> 
> Best,
> Daniel
> 
> Larry Alkoff schrieb:
>> Daniel Eckl wrote:
>>   
>>> Hmmmmm okay, this way we excluded wrong version as well as wrong settings...
>>>
>>> I ran out of ideas now, but perhaps not the opera devs. Could you give
>>> us some easily accessable example URLs, where the devs can try to
>>> reproduce that?
>>>
>>> Best,
>>> Daniel
>>>     
>> Open http://digg.com/ in Opera.
>> Click on an article, then use the back button or z to return to the digg 
>> first page.  It takes me 5-10 seconds and seems like it's reloading from 
>> the internet, not from cache.
>>
>> Larry
>>
>>   



-- 
Larry Alkoff N2LA - Austin TX
Using Thunderbird on Linux