Wireshark · Wireshark-dev: Re: [Wireshark-dev] proto_filter_names hash collision

[Jaap Keuter <jaap.keuter@xxxxxxxxx>]

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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