Wireshark-dev: Re: [Wireshark-dev] proto_filter_names hash collision
From: Jaap Keuter <[email protected]>
Date: Wed, 21 Nov 2007 19:13:30 +0100
Hi,

Sounds good to me.

Thanx,
Jaap

Kukosa, Tomas wrote:
Does it make sense to do all those sanity checks only if a special command-line flag is supplied to TShark, so that the checks
are done as
part of the build process, rather than being done every
time you run
Wireshark or TShark?
Yes, because you ever know what cocktail of plugins the user has added to its installation.
I think we can leave this sanity check for short and filter names.

The whole proto_register_protocol() function (including hash
computation) takes about 5% of startup time now.
More than 60% of proto_register_protocol() time takes g_str_hash()
computation. I guess most of that time are hashes for long protocol
names.

My proposal is following:
 - leave sanity check of short and filter names but do not hash them as
2-4 string comparision is not much slower than integer comparision and
g_str_hash() is not very god for short strings and it is easy to have
collision
 - remove sanity check for long protocol names as it is not critical to
have this name unique (or perform this check only with some new
command-line option "strict sanity check")

Any comments?
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