Information on Opera's Packed Executable Files

Background:

At least in windows, Opera compresses (packs) the executable (EXE / DLL) code using ASPack to make them smaller on disk. As they are smaller, the hard disk access needed is lower, and on a fast machine decompression in memory is faster than it would have taken to read the extra uncompressed data from disk.

However, when for example a DLL (remember most Opera code is found in Opera.DLL) is unpacked it must all be loaded into memory, whereas uncompressed DLLs can load only the segments that they need. A clear issue therefore is that of modularity. Opera contains mail and other statically linked code that is normally not utilised unless needed; but when packed all code segments will be loaded into memory (though they are unused). Measurements under Opera 8 show a maximum of ~2mb extra memory may be consumed on first load for minimal setups(no mail, no voice etc); though that will drop as Opera code is executed. This is somewhat academic because Windows will swap out that unused memory if it was ever needed, thus the maximum 2mb extra does not mean that space cannot be reclaimed.

Additionally, if you have multiple profiles (OperaProfiles) in Opera that run simultaneously off the same install, packed DLLs cannot be shared among them, and so fresh versions of the DLLs must be loaded for each instance, clearly leading to greater inefficiency.

Benefits of Unpacking:

As is clear, although windows will compensate for some of the extra memory overhead of packed files, unpacking them will bypass these issues in the first place; though whether this results in a "significant" optimisation is currently disputed. Nevertheless for those who use multiple profiles, unpacking will clearly be advantageous.

To unpack, first remember this will certainly break your software licence. I will not link to the program which does unpacking for this reason, but do a search for ASPackDie (or stripper 2.07) in your searchengine of choice for the tool you'll need.

For Opera 9.5 use upx -d opera.dll

Categories:

CategoryOpera
CategoryTechnical

Backlinks:
Comments [Hide comments/form]

Are we sure that ASPackDie? isn't spyware?

eTrust seems to think so. But I don't know if I should trust a company that thinks nForce4 drivers from ASUS are spyware...

Gt500 (2006-03-01 17:29:12)

1. Put eTrust whatever software in your trash.
2. Go to eset.com and enjoy the best AntiVirus? system in whole world/History.

SaBer (2007-05-20 02:29:01)

Or use Linux - no Virus's in sight (well, the *few* theoretically possible ones aren't counted).

But, on a serious note: Shouldn't the title read "Information on Opera's Packed Executable Files in Windows" (Note the 2 last words), since this is specific to windows, whereas opera is also available for Linux etc.

80.218.112.168 (2008-07-08 07:30:42)

zfKZu2 Left on my site a link to this post. I think many people will be interested in it..!!

193.105.210.170 (2012-02-11 13:30:26)

Thanks for taking this poiltbisisy to talk about this, I’m strongly about this and I reap the benefits of garden greenhouse structures this subject. If at all possible, while you gain data, please update this website with new information. I’ve discovered it extremely useful.My blog is about .

216.194.64.155 (2013-02-11 21:54:45)

Add a comment to this page (use wiki formatting if needed, no HTML/BBCode please). Only registered users can submit links, your comment will be deleted otherwise: